Grass-birdsfoot trefoil mixtures to improve the economic and environmental sustainability of pasture-based organic dairies in the western U.S.

Final report for SW17-046

Project Type: Research and Education
Funds awarded in 2017: $214,123.00
Projected End Date: 03/31/2021
Grant Recipient: USDA-Agricultural Research Service
Region: Western
State: Utah
Principal Investigator:
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Project Information

Abstract:

With over 3.5 million milk cows in the western U.S., dairy is a dominant sector of western agriculture, and pasture-based organic dairies are becoming more prevalent in the region. Organic milk is marketed for the health and environmental benefits of pasture-raised milk; however, organic dairies using the most pasture forage (75-100%) have the lowest net returns due to a 32% decrease in milk production. Reduced dry matter intake (DMI) by grazing dairy cows is one of the major factors limiting milk production. Moreover, dairy cattle breeds are finicky-grazers, resulting in even lower DMI of traditional pasture species like tall fescue. Dairy herd fertility is critical to dairy sustainability, but nutrient-rich pastures may reduce pregnancy rates further complicating pasture-based dairy.

Previous Western SARE research (SW10-088) demonstrated that mixtures of tall fescue and the condensed-tannin containing legume, birdsfoot trefoil (BFT) improved beef steer performance. Critical questions, particularly for pasture-based dairy include, are there grass-BFT mixtures that increase both tannins and energy, and what will be their synergistic effect on dairy cattle performance? This research proposes to use university and on-farm trials to assess dairy heifer DMI, health, reproductive performance, economics, and impact on nitrogen cycling in response to grazing grass-BFT mixtures containing various protein, energy, preference, and tannin levels. An innovative outreach plan will reach a diverse audience of producers, educators, and the public, and include traditional field tours and web-based outlets such as eOrganic. These objectives are in direct response to stakeholder feedback, and it is anticipated that pasture mixtures will be identified that improve the sustainability of organic pasture-based dairy.

Project Objectives:

Objective 1. Determine the relationship between forage mass, total metabolizable energy, water-soluble carbohydrates, and condensed tannins on dairy heifer forage intake and weight gain in response to grazing grass monocultures and grass-legume mixtures.

Sub-objective 1.1. Determine the effect of forage metabolizable energy on dairy heifer performance and forage intake. Determine dairy heifer dry-matter intake (DMI) and performance (weight gain), forage mass, and forage nutritive value when rotationally grazing replicated grass-legume pastures characterized by various levels of forage mass, metabolizable energy (ME) [both as water-soluble carbohydrates (WSC) and fiber-based carbohydrates (cellulose and hemi-cellulose)], protein, fiber, digestibility, tannins, and livestock preference. Analyses will determine which forage characteristics primarily contribute to differences in dairy heifer DMI and performance. Our investigation will determine if different forms of metabolizable energy affect heifer weight gain and DMI. In particular, we will examine both the WSC and fiber components of ME to determine how ratios of WSC (immediately available energy) to cellulose and hemi-cellulose (slowly available energy) differ in their effect on DMI and weight gain. One would hypothesize that increased available energy would improve heifer performance, but it is also possible that greater ratios of WSC could lower rumen pH and decrease overall performance. Our mixtures with BFT will allow us to test if the tannins in BFT overcome negative effects of greater WSC.

Sub-objective 1.2. Determine the effects of different planting methods on BFT establishment, persistence, and dairy heifer utilization. Determine relative BFT establishment, persistence, and utilization when grass-BFT mixtures are drilled together in same row, drilled in alternating rows, or BFT drilled into existing stand of grass.

Sub-objective 1.3. On-farm validation of forage mass, nutritive value, and dairy cattle utilization.  Grass and BFT treatments will be planted on existing pasture-based dairies (producer participants), and producers will estimate forage mass and cattle utilization. Data will be analyzed, compared to USU pastures, and presented at field days. Producers will be trained how to use Rising Plate Meters (RPM) and clipped samples to estimate forage mass and cattle utilization, increasing their ability to quickly estimate available forage and potential stocking rate. We will also complete pre- and post-grazing forage nutritive analyses of the on-farm samples, helping them make better management decisions in choice of plant materials and grazing duration.

Objective 2. Determine the effect of grass-legume mixtures containing various levels of metabolizable energy, tannins, and other nutritive components on dairy heifer health, growth, and reproductive performance.

Sub-objective 2.1. Describe the effect of grazing treatments on body condition, rumen pH, and systemic markers of growth. Determine effect of total metabolizable energy, water soluble carbohydrates, and excess dietary protein from nutrient-rich pastures on body condition, rumen pH, Blood Urea Nitrogen and other systemic markers of growth. Results will be compared to predict which plant species best meet nutritional requirements for dairy heifer growth and reproductive fertility. We propose to determine the effect of different forms of metabolizable energy on rumen pH. This will be done in-vivo using pH monitoring boluses. We hypothesize that increased water-soluble carbohydrates in some forage mixtures will lower rumen pH, and perhaps decrease performance.

Sub-objective 2.2. Evaluate the effect of tannins and varying levels of metabolizable energy on parasite load. The parasite load (fecal egg count) within the gastrointestinal tracts of the growing heifers will be determined for individual animals within each treatment and compared to systemic growth markers. The effect of excess protein, metabolizable energy, and tannins on parasite load will be determined.

Sub-objective 2.3. Effect of excess dietary protein and varying levels of forage metabolizable energy on conception and early embryo development. Embryos will be flushed from heifers and evaluated for number and quality. Conception rates will be determined. Data will be analyzed to determine the effect of pasture total metabolizable energy, water soluble carbohydrates, and excess dietary protein on superovulation response, embryo recovery.

Objective 3. Determine pasture-based dairy impact on nitrogen and phosphorous cycling in response to grazing grass-legume mixtures containing various protein, total metabolizable energy, water-soluble carbohydrates, and tannin levels.

Sub-objective 3.1. Impact of BFT tannins on nitrogen and phosphorous cycling. A mass balance approach will compare nitrogen and phosphorous outputs (plant material, soil, leachate) against nitrogen inputs. Both nitrogen and phosphorous loss from farm fields is a common environmental concern in the U.S. We propose to add phosphorous cycling to the analyses and to look at nitrogen outputs at six, instead of three, soil depths.

Sub-objective 3.2. Impact of increased forage metabolizable energy and water-soluble carbohydrates on nitrogen and phosphorous cycling. Same approach as sub-objective 3.1 to compare high- and low-sugar grasses.

Sub-objective 3.3. Impact of pasture root structure on nitrogen and phosphorous capture. Evaluate the impact of different grass species and their root structure on nitrogen and phosphorus capture.

Objective 4. Assess the economic sustainability of the proposed pasture grazing-based heifer development programs.

Sub-objective 4.1. Determine the cost differences from each of the heifer development programs. Costs associated with developing each of the different pasture based program treatments will be determined and compared to the cost of dry-lot heifers on TMR.

Sub-objective 4.2. Quantify the impact of the animal performance on the economic value of the dairy heifers and determine the most profitable method of raising the dairy heifers. Actual costs differences and revenue differences from the alternative heifer development programs will be combined to determine the program that offers the greatest economic return.

Objective 5: Execute an innovative and impactful outreach program on the successful implementation of grass/legume grazing for organic dairy production systems.

Outreach plan: Enhance communication among producers, processors, marketers, researchers, and Extension personnel by building an interactive communications network facilitated by e-Organic and Utah State University and University of Idaho Extension.

Miller, R. L., J. Long, B. Waldron, S. C. Isom, K. Rood, J. E. Creech, M. Peel, J. Briscoe, M. Rose, J. Hadfield.  2020.  Impacts of grass-legume mixtures versus monocultures on nitrogen cycling in an organic dairy grazing system.  Pacific and Mountain West Nutrient Cycling, Soil Health and Food Safety Virtual Conference.  Oct. 27-28, 2020.  Pullman, WA:  Washington State University.  Available at:  https://www.youtube.com/watch?v=CT93ojQfQe8&feature=youtu.be

Miller, R. L., J. Long, B. Waldron, S. C. Isom, K. Rood, J. E. Creech, M. Peel, J. Briscoe, M. Rose, J. Hadfield.  2020.  Improving organic grazing systems.  Pacific and Mountain West Nutrient Cycling, Soil Health and Food Safety Virtual Conference.  Oct. 27-28, 2020.  Pullman, WA:  Washington State University.  Available at:  https://www.youtube.com/watch?v=vYp4ucfNzxs&feature=youtu.be

Cooperators

Click linked name(s) to expand/collapse or show everyone's info
  • Dr. Clay Isom (Researcher)
  • Dr. Earl Creech (Educator)
  • Dr. Michael Peel (Researcher)
  • Dr. Kara Thornton-Kurth (Researcher)
  • Dr. Kerry Rood (Educator)
  • Dr. Allen Young (Educator)
  • Dr. Dillon Feuz (Researcher)
  • Bracken Henderson (Educator)
  • Jacob Hadfield (Educator)
  • Alice Formiga (Educator)
  • Greg Bingham - Producer (Researcher)
  • Frank Turnbow - Producer (Researcher)
  • Mike Wangsgard - Producer

Research

Hypothesis:

Hypothesis (Objective 1): We hypothesize that greater inherent grass metabolizable energy will act synergistically with low levels of condensed tannins in birdsfoot trefoil to improve dairy heifer dry matter intake and performance when grazing grass-birdsfoot trefoil mixtures.

Hypotheses (Objective 2): We hypothesize that animal growth and reproductive performance and overall animal health will be slightly reduced in organic, pasture-raised heifers compared to TMR-fed control animals. However, we hypothesize that heifers grazing grass/legume mixtures will grow faster and be more reproductively competent than heifers grazing grass-only pastures.

Hypothesis (Objective 3): We hypothesize that the addition of tannin-containing legumes will reduce nitrogen and phosphorous loss compared to grass monoculture treatments of varying protein, total metabolizable energy, and water soluble carbohydrate levels.

Hypothesis (Objective 4): We hypothesize that the grass/birdsfoot trefoil mixtures with the greatest forage mass and metabolizable energy will be more economically sustainable than monoculture grass or TMR-based heifer development.

Materials and methods:

USU Pastures and Grazing Details.

With the assistance of a Utah Agricultural Experiment Station seed grant, pastures were established and preliminary grazing data collected in 2016. Pastures were established at the Intermountain Irrigated Pasture Project facilities in Lewiston, UT in June 2015, arranged in a RCB design to accommodate three replications of each of eight experimental pasture ‘treatments’ (1 acres each). The eight pasture treatments consist of tall fescue, meadow bromegrass, high-sugar orchardgrass, and high-sugar perennial ryegrass in monocultures and binary mixtures with birdsfoot trefoil (BFT). Pastures will be irrigated weekly and grass monocultures will annually receive 50 to 100 lb/acre N fertilizer from an approved organic source. Grass-BFT mixtures will not receive N fertilizer. For each of the two full grazing seasons that will make up this study, 54 post-pubertal Jersey dairy heifers will be allocated to each of the eight pasture treatments, or fed a total mixed ration (TMR) in confinement as a control group. Pasture stocking rates will be two heifers per pasture (2 heifers acre-1). Each pasture will be subdivided into five 0.2-acre paddocks with a grazing period of 7 days per paddock, resulting in a 35-day rotation cycle. Paddocks will be mowed to uniform height and harrowed following grazing. Grazing will begin May of each year (2017 and 2018), and continue for 105 days (three 35-day rotation cycles), ending in August. Various observations, collections, and/or analyses will be made from animal, plant, soil, and water sources throughout the course of the year, as described below for each individual sub-objective.

Objective 1. Determine the relationship between forage mass, total metabolizable energy, water-soluble carbohydrates, and condensed tannins on dairy heifer forage intake and weight gain in response to grazing grass monocultures and grass-legume mixtures.

Sub-objective 1.1. Determine the effect of forage metabolizable energy on dairy heifer performance and forage intake. Determine dairy heifer dry-matter intake (DMI) and performance (weight gain), forage mass, and forage nutritive value when rotationally grazing replicated grass-legume pastures characterized by various levels of forage mass and nutritive value, including metabolizable energy. Six samples (2.7-ft2) per paddock will be clipped before grazing and at the end of the 7-day grazing period, and will be used to determine forage mass and nutritive value. In addition, Rising Plate Meter (RPM) readings will be taken before and after grazing and calibrated using the clipped samples. Percent birdsfoot trefoil (BFT) in mixtures will be determined by NIRS and hand separation. Nutritive values will be estimated using wet chemistry and NIRS, and will consist of total metabolizable energy (ME), water-soluble carbohydrates (WSC), cellulose, hemicellulose, crude protein (CP), fiber (NDF, dNDF, ADF), digestibility (IVTD), ash, and tannin concentrations. Ratios of WSC to cellulose and hemicellulose will be determined. NIRSystem software will be used to calibrate existing NIRS grass monoculture and grass/legume mixture equations. Random samples will undergo laboratory analysis and be used for calibration and validation data sets.

Forage intake (DMI) will be estimated by comparing the forage mass and RPM readings before grazing with the 7-day-grazing forage mass and RPM readings. Heifer body weight (ADG), and hip and wither height (estimates of dietary balance) will be recorded at beginning of each grazing season and the end of each 35-day rotation. Statistical analysis will be performed and differences in heifer performance among pasture treatments will be reported. Multivariate analyses will determine which forage nutritive components, in particular the amount and form of metabolizable energy, primarily contribute to heifer DMI and performance.

Sub-objective 1.2. Determine the effects of different planting methods on BFT establishment, persistence, and dairy heifer utilization. Determine relative BFT establishment, persistence, and utilization when grass-BFT mixtures are drilled together in same row, drilled in alternating rows, or BFT drilled into existing stand of grass.

The potential to direct-seed forage legumes into established grass will be investigated. Birdsfoot trefoil, cicer milkvetch, and alfalfa will be interseeded into existing stands of tall fescue following four treatments to reduce the vigor of the grass stand. The treatments will include close grazing/mowing, light tillage, light rate of glyphosate (25% of recommended label rate), and no-treatment (control). Establishment will be determined using with a grid system described by Vogel and Masters [7], and by replicated sampling to determine the percent of legume in the forage mass.

One-half of each grass-BFT paddock at the Lewiston Pasture Research location will be established with the BFT drilled in the same row with grass, and one-half with BFT drilled in alternating rows with grass, and heifers will be allowed to graze the entire area. All grass-BFT treatments will have the same design so the treatments will not be confounded. Birdsfoot trefoil establishment and persistence will be evaluated by determining initial and end of grazing season plant frequency as measured with a grid system described by Vogel and Masters [7]. Differential utilization of BFT will be estimated from the DMI data described above in sub-objective 1.1, by clipping 50% of samples in each of the alternating-row or same-row planted areas. Utilization will also be estimated by scan sampling of grazing behavior. In brief, observers on raised platforms will visually score, and/or flying UAV will digitally record, each heifer’s location in the paddock (alternating row or same-row area) and behavior (grazing, standing, laying) in five minute intervals during grazing bouts on day 1 and 7 of each grazing period. Statistical analyses will be performed and differences in heifer utilization and BFT persistence between planting methods will be reported.

Sub-objective 1.3. On-farm validation of forage mass, nutritive value, and dairy cattle utilization. Replicated strips (12 × 250 ft) of the eight pasture treatments will be established on three existing organic pasture-based dairies in Idaho and Utah (see project team). Strips will be grazed by lactating cows and/or replacement heifers as practiced by the producer. Producers will collect forage samples prior to and following (six 2.7-ft2 samples per treatment) grazing and they will be analyzed as in objective 1.1 to determine forage mass and nutritive value, including the metabolizable energy in the forage pre- and post-grazing. Rising plate meters will also be used to estimate forage mass before and after grazing. Clipped samples will be used to calibrate RPM and equations determined specific to pasture mixture. Producers will also visually score utilization after grazing. Data will be statistically analyzed, reported as to how the on-farm trials compare to the controlled USU pastures, and presented at pasture-walks/field days.

Objective 2. Determine the effect of grass-legume mixtures containing various levels of metabolizable energy, tannins, and other nutritive components on dairy heifer health, growth, and reproductive performance.

Sub-objective 2.1. Describe the effect of grazing treatments on body condition, rumen pH, and systemic markers of growth. All heifers will be weighed and measured (hip height, and pelvis width) as described in sub-objective 1.1. Blood samples will be drawn from the heifers before grazing begins and every 35 days thereafter for hormone and metabolite analyses. Blood work will include assays for Blood Urea Nitrogen (BUN; marker of bypass protein), Beta-Hydroxybutyric Acid (BHBA; marker of fat mobilization and negative energy balance), Growth Hormone (GH; drives body mass accumulation and mammary gland function), Leptin (adipose-derived hormone that reflects body condition and nutritional status), and Progesterone (P4; key reproductive hormone). Blood will be collected from the coccygeal vein into heparinized vacutainer tubes and stored on ice until processed. These assays will be performed using colorimetric plate-based assays, with the exception of P4, which will be performed at the Utah Veterinary Diagnostics Laboratory, and leptin, which will be performed at the University of Missouri. One heifer in each pasture treatment will receive an electronic pH measuring bolus. The bolus will be inserted via the esophagus into the rumen, and rumen pH will be monitored real time using the associated software. Statistical analysis will be performed and pasture treatments will be compared to predict the effect of metabolizable energy and WSC on rumen pH, and which plant species best meet nutritional requirements for dairy heifer growth and reproductive fertility.

Sub-objective 2.2. Evaluate the effect of tannins and varying levels of metabolizable energy on parasite load. Determination of the parasite load (nematode eggs) within the gastrointestinal tracts of the growing heifers will be performed before grazing begins and every 35 days thereafter (four different timepoints). Fecal samples will be collected per rectum, stored at 4°C, and analyzed within 1-7 days following collection. The number of nematode eggs per 5 g of feces will be determined for individual animals using a modified Wisconsin sugar float technique [8]. Parasite load will be compared to plasma IGF-I levels (sub-obj 2.1), inasmuch as plasma IGF-I levels have been shown to be negatively correlated with fecal egg count.

Sub-objective 2.3. Effect of excess dietary protein and varying levels of forage metabolizable energy on conception and early embryo development. Heifers will undergo a single hormonal superovulation to coax large numbers of eggs to develop. At the appropriate stage, heifers will be artificially inseminated to fertilize the developing eggs. Seven days later, embryos will be flushed from the heifers according to standard dairy husbandry techniques. Briefly, after a 2% lidocaine epidural, an ET catheter will be guided per rectum through the cervix. Uteri of bred heifers will be flushed with standard embryo flush medium; the flush medium will then be drained/expelled from the uterus and collected and filtered to find the embryos, which will immediately be evaluated for number and quality, according to International Embryo Transfer Society guidelines [9]. Data will be analyzed by multivariate ANOVA to determine the effect of pasture on superovulation response, embryo recovery, and embryo quality, and to describe the correlation (or lack there-of) of BUN, BHBA, GH, Leptin, P4, and/or IGF-I with these reproductive endpoints. Significant effects would provide evidence for disruption of reproductive capacity by dietary components. As a final endpoint, all heifers will be artificial inseminated and conception rates determined.

Objective 3. Determine pasture-based dairy impact on nitrogen and phosphorous cycling in response to grazing grass-legume mixtures containing various protein, total metabolizable energy, water-soluble carbohydrates, and tannin levels.

Sub-objective 3.1. Impact of BFT tannins on nitrogen and phosphorous cycling. A mass balance approach will compare nitrogen and phosphorous outputs (plant material, soil, leachate) against nitrogen and phosphorous inputs. Plant samples will be collected before and after each grazing event. Herbage analyses (as outlined in sub-object. 1.1) will be utilized to determine the nutrients removed in the forage. Soil samples will be collected prior to grazing, and in the fall after the growing season each year using a Giddings® soil extraction instrument to a depth of 1.5 m (4.8 ft). Soil samples will also be collected in the spring of the third year to monitor nutrient movement. Four soil cores will be taken in each plot and divided into three subsamples; 0-15 cm, 15-30 cm, and 30-45 cm (As part of a separate study, data will also be taken at depths of 45-60 cm, 60-106 cm, and 106-152 cm). Subsamples will be combined at each depth to make a composite and then analyzed for available nitrogen (NO3-N) using potassium chloride [10] on the Lachat Auto-analyzer, QuickChem Method 10-107-04-1-C [11], and for total N by combustion using an Elementar varioMAX CN elemental analyzer. Soil water (leachate) nitrogen will be monitored by means of zero-tension lysimeters that were previously installed at this location. Leachate will be collected every two weeks during the growing season, and as close as possible to every two weeks during the winter months. Samples will be analyzed for nitrate-nitrite using QuickChem Method 10-107-04-1-C [11] on the Lachat auto-analyzer. Data will be statistically analyzed with a repeated measures model and grass monocultures will be compared to grass-BFT mixtures and differences reported.

Sub-objective 3.2. Impact of increased forage metabolizable energy and water-soluble carbohydrates on nitrogen and phosphorous cycling. Same approach as sub-objective 3.1 to compare high- and low-sugar grasses.

Sub-objective 3.3. Impact of pasture root structure on nitrogen and phosphorous capture. Roots will be sampled from each treatment to determine the importance of root structure on nitrogen capture and nutrient cycling using the methodology of Leonard et al. [12]. Briefly, 25 root cores will be collected from each treatment, washed, dried, and digitally scanned using WinRhizo Pro software. Scans will be scored for root length, root diameter, root volume, and root hair characteristics. Associations between root structure and nitrogen uptake/leaching will be reported.

Objective 4. Assess the economic sustainability of the proposed forage-based heifer development programs.

Sub-objective 4.1. Determine the cost differences from each of the heifer development programs. Partial budgeting techniques will be used to determine costs associated with developing each of the different pasture based program treatments and compared to costs of dry-lotting heifers on TMR program. The cost of the TMR feeds will be based on the last 5-years average feed costs so as to minimize bias by arbitrarily choosing one year for feed prices.

Sub-objective 4.2. Quantify the impact of the animal performance on the economic value of the dairy heifers and determine the most profitable method of raising the dairy heifers. Actual costs differences and revenue differences from the alternative heifer development programs will be combined to determine the program that offers the greatest economic return. A price sensitivity analysis will be conducted, by adjusting both heifer prices and feed costs, will determine how sensitive the most economical program is to costs or revenue differences.

Objective 5: Execute an innovative and impactful outreach program on the successful implementation of grass/legume grazing for organic dairy production systems.

Outreach plan: Enhance communication among producers, processors, marketers, researchers, and Extension personnel by building an interactive multi-state communications network facilitated by e-Organic. Outreach efforts, guided by input from our project team, will target producers, Cooperative Extension personnel, and agricultural professionals who advise producers on organic practices through in-person events (on-farm trials, field tours, winter meetings), printed materials (Extension publications and analysis tools), and digital resources (webinars, webpages, and web-based videos). Details are listed in the “Producer & Agricultural Professional Educational Activities” and “Scholarly Publications and Educational Materials”.

Research results and discussion:

2020 Annual Report

Objective 1

  • Completed analyses of all data from Objective 1 and published (in press) results in peer-reviewed journal. Reprint attached and results outlined in Research Conclusions section.  
  • ABSTRACT. Low dietary energy and decreased intake of herbage have been attributed to the reduced performance of grazing dairy cattle. We hypothesized that grasses with inherently greater energy would interact in a complementary way with condensed tannins (CT) in birdsfoot trefoil to increase herbage intake by grazing dairy heifers. Eight pasture treatments comprised of high-sugar perennial ryegrass (Lolium perenne L.; PR), orchardgrass (Dactylis glomerata L.; OG), meadow bromegrass (Bromus riparius Rehmann; MB), and tall fescue (Schendonorus arundinaceus [Schreb.] Dumort; TF) were established in Lewiston, Utah, USA as monocultures and binary mixtures with birdsfoot trefoil (Lotus corniculatus L; BFT). Pasture treatments were rotationally stocked by Jersey heifers for 105 days in 2017 and 2018, and herbage samples were collected pre- and post-grazing each 7-day grazing period and analyzed for herbage mass, nutritive value, and apparent herbage intake. We observed differences among pasture treatments in herbage quantity and nutritive value, as well as differences in herbage intake by grazing Jersey heifers. On average, grass-BFT mixtures had greater herbage intake than grass monocultures, and individually every grass-BFT treatment had greater herbage intake than their respective grass monocultures. Using multivariate analyses, we determined that approximately 50% of the variation in herbage intake was due to nutritive and physical herbage characteristics, with the most explanatory being characteristics related to fiber and energy, followed by those related to the percent of BFT in the herbage. Grass monocultures exhibited a range of inherent dietary energy, but there was indication that an energy to crude protein imbalance (e.g., protein deficient) reduced intake of grass monocultures. Moreover, there was some evidence of a complementary effect between increased dietary energy and CT, however, low CT levels made it impossible to determine the effect of CT on herbage intake per se. This study confirmed that chemical and physical characteristics inherent to different pasture species have a large effect on herbage intake by grazing cattle. Pastures planted to binary mixtures of nutritious grasses and birdsfoot trefoil increase herbage intake of temperate pastures by grazing Jersey heifers.

Objective 2

  • Completed all analyses of data from Objective 2 and published (in review following revision) results in peer-reviewed journal. Heifer gains and economic tables attached, and results outlined in Research Conclusions section.  
  • ABSTRACT. Dairy heifers developed in certified organic programs, especially those utilizing pasture-based management schemes, have lower rates of gain than heifers raised in non-organic confinement production systems in temperate climates, such as in the Intermountain West region of the US. This study investigates the effects that different forages in a rotational grazing system have on development of organically raised Jersey heifers. Over three years, 210 yearling Jersey heifers were randomly assigned to one of nine treatments, including a conventional confinement control where animals were fed a total mixed ration or one of eight pasture treatments: Cache Meadow bromegrass (Brumus riparius Rehmann), QuickDraw orchard grass (Dactylis glomerata L.), Amazon perennial ryegrass (Lolium perenne L.), or Fawn tall fescue (Schendonorus arundinaceus [Schreb.] Dumort) and each individual grass interseeded with birdsfoot trefoil (Lotus corniculatus L., BFT). Each treatment had three blocks per year over the three year period with each block having a 0.4 ha pasture of each treatment. Every 35 d, over a 105 d period, heifers were weighed, measured for hip height, and blood samples were collected to determine serum insulin-like growth factor-1 and blood urea nitrogen concentrations. Fecal egg counts were also assessed. Heifer body weights (BW), blood urea nitrogen, and insulin-like growth factor-1 concentrations were affected by treatment when analyzed over time. Heifers on grass-BFT pastures had increased BW compared to heifers on monoculture grass pastures. Heifers receiving a total mixed ration or perennial ryegrass+BFT had increased BW gain over the 105 d period compared to heifers grazing tall fescue+BFT, orchard grass, perennial ryegrass, meadow bromegrass, or tall fescue. Whereas, individually for all grass species, heifers grazing +BFT pastures had greater ending BW and weight gain than heifers grazing the respective grass monocultures. Furthermore, weight gain for heifers on perennial ryegrass+BFT, meadow bromegrass+BFT, and orchard grass+BFT were not different from those on a total mixed ration. Heifers grazing grass-BFT pastures had increased blood urea nitrogen compared to heifers grazing monoculture grass pastures. Heifer hip-height and fecal egg counts were not affected by treatment. These results show that the addition of BFT to organic pasture improves growth of grazing replacement heifers. Economic analyses also demonstrate that interseeding grass pastures with BFT results in an increased economic return compared to grazing monoculture grass pastures. Grass pastures interseeded with BFT may be a sustainable option to achieve adequate growth of Jersey heifers raised in an organic pasture scenario in a temperate climate.

Objective 3

  • All soil sample, leachate, urine, and fecal samples have been analyzed for nitrate, urea, ammonia, and/or total nitrogen. Statistical analyses and manuscript preparation are ongoing.

 

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2019 Annual Report

Objective 1

  • Grazing and herbage measurement portions of study at the USU pasture research facility were previously completed in 2018. The forage treatments included Amazon perennial ryegrass (PR), Quickdraw orchardgrass (OG), Cache meadow bromegrass (MB), and Fawn tall fescue (TF), in monoculture and mixed with birdsfoot trefoil (BFT). In 2019, the herbage data was analyzed and reported as part of the requirements for a USU M.S. thesis (Marcus Rose).  The main results of the thesis are summarized as follows:
    • Herbage intake was measured by sampling herbage before and after each seven-day grazing period. Overall, grass-BFT mixtures had greater herbage intake than grass monoculture pastures (Table 1), and greatest to least intake for pasture treatments was as follows: MB+BFT, OG+BFT, OG, MB, PR+BFT, TF+BFT, PR, TF (Table 1).
    • Multivariate analyses indicated that physical characteristics of pasture bulk density, herbage height, herbage allowance, leaf pubescence, leaf softness, and birdsfoot trefoil content as well as nutritive value properties of fat, non-fibrous carbohydrates, fiber, and energy resulted in nearly 100% discrimination (identification) among the pasture treatments; and were moderately associated with the differences in herbage intake.
    • While PR+BFT did not have the greatest overall herbage intake by heifers, it was the only treatment that consistently had greater intake than its respective grass monoculture (PR). Since it had more energy and tannins than all other grasses, a complimentary effect between energy and tannins to increase herbage intake was likely.
    • The fact that both physical and chemical herbage characteristics were associated with intake shows the importance of planting the right species in pasture as well as making proper management decisions to maximize nutritive value and herbage intake.
    • Annual Report 2019_Table 1
  • On-farm trials – Completed two years of evaluation on the Bingham dairy in Weston, ID. Objective was to determine which grass and/or grass-birdsfoot trefoil mixture had the greatest nutritive value, predicted intake and predicted milk production in a rotationally grazed dairy operation. Pasture treatments were as described above.  Animals in the study consisted of lactating, crossbred Holstein, Montbeliard, Swedish red dairy cows in an organic dairy operation in Weston, Idaho. Rotational stocking was used with a typical stocking period of 24 hours, followed by a rest period ranging from 21 to 45 days depending on herbage growth and climatic conditions. Herbage from strips of the treatments inside two randomly placed 0.25 m2 hoops was clipped before grazing in 2017 and 2018 at a height of 7.6 cm. Samples were dried, weighed, and ground and analyzed with NIRS to determine herbage nutritive value of the feed on offer. Milk production was predicted from nutritive value via MILK equation and serves as a relative comparison among treatments. In 2019, the herbage data was analyzed and reported as part of the requirements for a USU M.S. thesis (Marcus Rose).  The main results are summarized as follows:
    • The perennial ryegrass treatments generally had the most favorable nutritive characteristics in many respects (Table 3), but they did not persist well and were largely overtaken by weeds by the end of 2018.
    • The tall fescue treatments were considered the benchmark in this study based on previous research. While they were not as readily consumed as the other treatments, likely due to course leaves, it consistently produced large amounts of herbage and had more predicted milk/acre than any other treatment (Table 3).
    • The meadow brome and orchardgrass were comparable in many respects. They often had intermediate nutritive values, with meadow brome treatments being slightly greater than the orchardgrass treatments (Table 3). However, since the orchardgrass treatments had the second highest herbage production, they were usually like the meadow brome treatments in milk production per acre (Table 3).
    • Annual Report 2019_Table 3
  • On-farm trials – Completed one year of evaluation on the Wangsgard dairy in Young Ward, UT. Objective was to determine if herbage mass and nutritive value be increased by applying Chilean nitrate, elemental sulfur, and/or high sulfur gypsum to organic dairy grazing pastures. Soil amendments were applied in April 2018. Treatments consisted of high sulfur gypsum (G), elemental sulfur (S), high sulfur gypsum+sulfur (Gyp+Sulf), nitrate (Nit), nitrate+high sulfur gypsum (Nit+Gyp), and no amendment. Gypsum was applied at a rate of 300 lb./acre, sulfur was applied at a rate of 125 lb./ acre, and nitrate was applied at a rate of 100 lb./ acre, resulting in a nitrogen rate of 15 lb./acre. Mixed amendment treatments were applied separately at the same rates as single amendment applications. Grazing and sampling took place on existing mixed pastures of meadow bromegrass, garrison creeping foxtail, and clover. Livestock consisted of lactating Holstein dairy cows in an organic dairy operation. Rotational stocking was used with a typical stocking period of approximately 24 hours, followed by a rest period ranging from 21 to 45 days depending on herbage growth and climatic conditions. Cows were on pasture for at least 120 days per growing season which consisted of three rotations. Herbage within four randomly placed 0.25 m2 hoops was clipped to a height of 3.8 cm before grazing and harvesting. Samples were dried, weighed, and ground and analyzed with NIRS to determine herbage nutritive value of the feed on offer. Milk production was predicted from nutritive value via MILK equation and serves as a relative comparison among treatments. In 2019, the herbage data was analyzed and reported as part of the requirements for a USU M.S. thesis (Marcus Rose).  The main results are summarized as follows:
    • Although only 15 lb N/acre was applied to the nitrate treatments, a slight nitrogen response was evident, showing the importance of nitrogen in pasture grass production (Table 4).
    • The Nit+Gyp treatment herbage production was significantly greater than the untreated pasture and the sulfur treatments and not significant from the others (Table 4). The nitrate treatment was only greater than the sulfur treatment (Table 4). The nitrate treatments also had the greatest predicted milk production/acre (Table 4).
    • While the pasture treated with sulfur had low herbage mass, it seemed to play a role in many of the nutritive value parameters and was usually among those treatments with the greatest nutritive value and milk production/day (Table 4). Many of the other treatments were not significant from one another and more replication would be necessary to effectively distinguish one from the other.
    • Annual Report 2019_Table 4

 Objective 2

  • Data relative to growth, health and reproductive capacity of the heifers when grazing grass-BFT versus grass monoculture pastures was collected in 2017 and 2018. These measurements include, weight, hip height, serum concentrations of blood urea nitrogen (BUN) and insulin-like growth factor-1 (IGF-1), conception rates, and fecal parasite load (FEC). In 2019, the heifer data was analyzed and reported as part of the requirements for a USU M.S. thesis (Jacob Hadfield).  The main results from the thesis are summarized as follows:
    • Heifer weight, overall weight gain and BUN concentrations were affected by pasture treatment (Table 2), whereas heifer hip-height, IGF-1, conception rate, and FEC were not affected by treatment.
    • Heifers receiving grass-BFT mixture pastures had increases in weight and BUN compared to heifers receiving grass monoculture pastures (Table 2).
    • Heifers receiving total mixed ration (TMR) or PR+BFT had higher weight gains over the 105-d period than heifers grazing TF+BFT, OG, PR, MB, or TF.
    • These results show that the addition of BFT to pasture increases growth and development of replacement heifers. Mixed pastures with BFT may be a sustainable alternative to feeding a TMR in a confined setting in order to achieve adequate growth of dairy heifers.
    • Annual Report 2019_Table 2

Objective 3

  • All field data have been collected and sample analyses are ongoing. Field data collected included the following: 1) plant samples were collected before and after each grazing event and dried for later analysis; 2) soil samples were collected in the fall at the beginning of the study for a baseline reading, and in the spring, prior to grazing, and in the fall after the growing season using a Giddings® soil extraction instrument to a depth of 1.524 meters. Soil samples were also collected in the spring of the third year to monitor nutrient movement; 3) soil water (leachate) nitrogen was monitored by lysimeters and leachate collected every two weeks during the growing seasons, and as close as possible to every two weeks during the winter months; and 4) urine and feces were collected from heifers at weigh-ins.
  • The 2016 soil samples have been analyzed for nitrate, but still need to be analyzed from 2017 and 2018. Nearly completed all three years of soil samples for ammonia, but still need to run all three years of soil samples for phosphorus.
  • All leachate samples have been analyzed from 2016, 2017 and 2018 for nitrate.
  • Urine samples have been analyzed for urea for all three years. Fecal samples have been run for total nitrogen and total carbon for all three years, but still need to be analyzed for ammonia.

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2018 Annual Report

Objective 1

  • The grazing portion of study completed for 2016, 2017, and 2018. The forage treatments included Amazon perennial ryegrass (PR), Quickdraw orchardgrass (OG), Cache meadow bromegrass (MB), and Fawn tall fescue (TF), in monoculture and mixed with birdsfoot trefoil (BFT). Data analysis is ongoing and preliminarily summarized as follows:
  • Grass-Birdsfoot trefoil mixtures had greater herbage mass, crude protein (CP), digestibility (IVTD48), and energy (NEgain) than their respective grass monocultures (Table 1 and 2).
  • All grass-BFT mixtures had greater apparent dry-matter intake (disappearance) than their respective monocultures, except for OG+BFT (Table 3).
  • Alternating versus mixed rows (Figure 3-2, 3-3): The grazing preference of heifers in mixed pastures of birdsfoot trefoil with tall fescue, perennial ryegrass, orchardgrass and meadow bromegrass was tested. When compared to tall fescue, birdsfoot trefoil was always utilized more, with an average of 23 percentage points difference. In most observations, birdsfoot trefoil utilization was higher than orchardgrass utilization, with an average difference of 14 percentage points. In contrast, there was no difference in utilization in all comparisons with meadow bromegrass. During early growth, perennial ryegrass utilization was higher than birdsfoot trefoil utilization, but no difference in utilization was detected in later observations, though, perennial ryegrass averaged 9 percentage points higher utilization than birdsfoot trefoil.
  • In depth data analysis is being undertaken to look at and explain differences and trends.
  • Annual-Report-2018_Tables-from-M.Rose-thesis
  • Annual-Report-2018_Figures-from-J.Briscoe-thesis

Objective 2

  • Data relative to growth, health and reproductive capacity of the heifers was collected in 2017 and 2018. These measurements include, weight, hip height, serum concentrations of blood urea nitrogen (BUN) and insulin-like growth factor-1 (IGF-1), conception rates, and fecal parasite load. Data analysis is ongoing and preliminarily summarized as follows:
  • At d-105 heifers receiving TMR, PR+BFT, OG+BFT, or MB+BFT had higher (P<0.05) weights than heifers receiving TF (Table 4). Heifer hip-height (P = 0.13), conception rate (P = 0.67), and FEC (2017: P = 0.26; 2018: P = 0.62) were not affected by treatment when analyzed over time.
  • Heifers receiving MIX pastures had increases in weight (P < 0.01) (Figure 1) and BUN (P < 0.01) compared to heifers receiving MONO pastures. Heifer IGF-1, FEC, and conception rates were not influenced (P = 0.63, P > 0.05, P = 0.56, respectively) by pasture type when analyzed over time. Heifers on MIX pasture had a tendency (P = 0.06) to have increased hip-heights.
  • These results show that the addition of BFT to pasture increases growth and development of replacement heifers. Mixed pastures with BFT may be a sustainable alternative to feeding a TMR in a confined setting in order to achieve adequate growth of dairy heifers.
  • In depth data analysis is being undertaken to look at and explain differences and trends.
  • Annual-Report-2018_Figures-and-table-from-J.Hadfield-thesis

Objective 3

  • Plant samples were collected before and after each grazing event and dried for later analysis. Soil samples were collected in the fall at the beginning of the study for a baseline reading. Soil samples were collected in the spring, prior to grazing, and in the fall after the growing season using a Giddings® soil extraction instrument to a depth of 1.524 meters. Soil samples will also be collected in the spring of the third year to monitor nutrient movement. Four soil cores are taken in each plot and divided into three subsamples; 0-30.48 cm, 30.48-60.96 cm, 60.96-152.40 cm. Composite soil subsamples are analyzed for available nitrogen (ammonia and nitrate) and for total N.
  • Soil water (leachate) nitrogen is monitored by means of zero-tension lysimeters that were previously installed at this location. Leachate is collected every two weeks during the growing season, and as close as possible to every two weeks during the winter months from zero-tension lysimeters. Suction cup lysimeters (60 cm deep) were installed in each plot, with samples being collected weekly by suction cup lysimeters. All leachate samples will be analyzed for nitrate-nitrite. 
  • Data analysis is ongoing.

 

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2017 Annual Report

Objective 1

  • The grazing portion of study completed for 2016 and 2017. The forage treatments included Amazon perennial ryegrass (PR), Quickdraw orchardgrass (OG), Cache meadow bromegrass (MB), and Fawn tall fescue (TF), in monoculture and mixed with birdsfoot trefoil(BFT). Data from 2016 has been analyzed and is summarized as follows:
  • All grass-BFT mixtures had higher protein content than their respective monocultures. Protein content ranged from 9.3% (TF, PR) to 18.4% (MB+BFT, PR+BFT). OG, MB, and PR mixes and monocultures all had higher TDN (56.7-57.5%) than TF+BFT mixes and monocultures (53.2-54.8%). The TF+BFT had a statistically higher TDN percentage than the TF monoculture.
  • OG and OG+BFT had the highest predicted dry matter intake (2.5%, 2.4% BW) while TF and MB+BFT had the lowest (2.2%, 2.15%). The other treatments fell between those two margins.The overall average rate of gain for all of the heifers was around 1.47 lb/day. The BFT mixtures and OG and PR monocultures resulted in the highest rates of gain (1.44-1.62 lb/day). The TF and MB monocultures had the lowest rate of gain(1.08, 1.34 lb/day), but the TF+BFT and MB+BFT rates of gain were statistically equivalent to many of the higher energy grasses.
  • Alternating versus mixed rows: Birdsfoot trefoil is preferred over tall fescue, and alternating rows may accelerate dominance of tall fescue. In late spring and early summer perennial ryegrass is preferred over birdsfoot trefoil, resulting in possible dominance of birdsfoot trefoil. Birdsfoot trefoil is preferred in mixtures with orchardgrass. The meadow bromegrass-birdsfoot trefoil mixtures show the least preferential grazing.
  • The mixed row utilization was generally in between the alternating rows. This suggests a more stable mixture over time.

Objective 2

  • Data relative to growth, health and reproductive capacity of the heifers was collected in 2017. These measurements include, weight, hip height, serum concentrations of blood urea nitrogen (BUN) and insulin-like growth factor-1 (IGF-1), conception rates, gene expression in oocytes and embryos, fecal parasite load.
  • Preliminary statistics indicate that pasture had a significant effect (P < 0.01) on growth over time, indicating that different pastures have the capability to impact growth rates of developing heifers. There were no significant difference between pastures relative to change in hip height over time in preliminary analyses. However, additional years of data are needed in order to validate the effects of specific pastures on growth.
  • Significant differences (P < 0.01) in BUN were noted between the different treatments over time. Specifically, heifers that consumed pasture that included birdsfoot trefoil (BFT) had a higher (P < 0.07) BUN at all time points, indicating an increased intake of protein/nitrogen in those animals.
  • No differences in fecal parasite loads were detected between the different pasture treatments. Additionally, when comparing grass monocultures and pastures with BFT, there was no significant difference in fecal egg count, although the data at some time points was tending towards showing a difference. We anticipate that we might be able to further elucidate this difference with additional years of animals added to our data set.
  • Furthermore, no differences in conception rates were noted in the heifers between the different pasture treatments. Currently, we are still completing analyses relative to serum IGF-1 concentrations and gene expression in oocytes and embryos.

Objective 3

  • Plant samples were collected before and after each grazing event and dried for later analysis. Soil samples were collected in the fall at the beginning of the study for a baseline reading. Soil samples were collected in the spring, prior to grazing, and in the fall after the growing season using a Giddings® soil extraction instrument to a depth of 1.524 meters. Soil samples will also be collected in the spring of the third year to monitor nutrient movement. Four soil cores are taken in each plot and divided into three subsamples; 0-30.48 cm, 30.48-60.96 cm, 60.96-152.40 cm. Composite soil subsamples are analyzed for available nitrogen (ammonia and nitrate) and for total N.

  • Soil water (leachate) nitrogen is monitored by means of zero-tension lysimeters that were previously installed at this location. Leachate is collected every two weeks during the growing season, and as close as possible to every two weeks during the winter months from zero-tension lysimeters. Suction cup lysimeters (60 cm deep) were installed in each plot, with samples being collected weekly by suction cup lysimeters. All leachate samples will be analyzed for nitrate-nitrite. 

 

Research conclusions:
  • The number of grazing dairies is increasing, but decreased herbage intake by grazing livestock reduces the performance of dairy cattle. Therefore, it is important to identify herbage characteristics inherent to various pasture species that affect intake. We confirmed that grass-birdsfoot trefoil mixtures have greater herbage intake by grazing Jersey heifers than grass monocultures (Table 1 from Rose et al. Journal of Dairy Science paper). Furthermore, 50% of the intake differences were due to characteristics of the herbage; with fiber, energy, and percent birdsfoot trefoil most predictive. These findings indicate that mixtures of high-energy grasses and as little as 14% birdsfoot trefoil increase intake of temperate pastures by grazing Jersey heifers.
  • Jersey heifers developed on organic pasture in the Intermountain West region of the US have decreased performance compared to those in conventional confinement. As the number of organic dairies increases, new strategies are needed to improve performance. This research indicates Jersey heifers developed on organic grass pastures interseeded with the legume birdsfoot trefoil have similar performance to heifers raised in a conventional confinement setting (non-organic) and improved performance compared to heifers on organic grass monoculture pastures (Table 2 from Hadfield et al. Journal of Dairy Science manuscript). These findings provide a potential solution for producers to improve performance of heifers in an organic pasture-based setting.
  • This study also evaluated economic impacts of grazing organic replacement dairy heifers on four cool-season pasture grasses both as monocultures and as mixtures with the tannin-containing non-bloating legume birdsfoot trefoil (BFT). Results were benchmarked against a conventional system feeding a mixed ration in confinement. All pasture treatments, but perennial ryegrass monoculture, were expected to be economically viable; however, the BFT mixed pastures were determined to be better investments as compared to the monoculture pastures (Table 7 from Hadfield et al. Journal of Dairy Science manuscript). This research demonstrates possible economic benefits of organic heifer programs as compared to conventional, which may alleviate some producer concerns when considering an organic operation.
Participation Summary
3 Farmers participating in research

Education

Educational approach:

A centerpiece of this project will be a multi-faceted Extension program on the production and environmental benefits of grazing mixtures of high-energy grasses and tannin-containing birdsfoot trefoil, and how such mixtures can improve sustainability of organic, pasture-based dairy. This program will integrate traditional outreach efforts with electronic media (by e-Organic), and will be guided throughout by input from our farmer/rancher team members and similar stakeholders. The primary targeted audiences will be current and potential (transitional) organic producers, Extension educators, NRCS personnel, and other professionals who advise farmers/ranchers on livestock and agronomic practices. Emphasis will be placed on providing opportunities and resources to train these individuals in the local area, statewide, and across the western region – with particular emphasis on partnering with University of Idaho Extension.

Local Area: The on-farm research/demonstration component of this project will be hosted by three progressive organic dairy producers in northern Utah and southern Idaho. Each of these farms will showcase to local producers and agricultural professionals the establishment and maintenance, forage production, nutritive value, and livestock grazing preference and performance benefits of incorporating grass-birdsfoot trefoil mixtures into grazing dairy operations. Pasture walks will be conducted annually at each of these farms to highlight the work and provide an opportunity for producer cooperators to share their experience and perspective on implementing the new production strategies on their farm or ranch. Local educational outreach will also occur through annual presentations at the major winter Extension meetings in the area, the Cache County Crop School in Logan, UT, and the Southeast Idaho Forage School in Preston, ID. Presentations will be made at producer organization meetings (i.e., Soil Conservation Districts, county Farm Bureau, etc.) and updates on project progress will be disseminated through local newspapers (Herald Journal and Preston Citizen) and Extension newsletters for Cache (UT) and Franklin (ID) counties.

Statewide: Each year of the project we will hold major field days at the Utah State University (USU) Lewiston Pasture Research Facility to engage growers and other clientele in the latest developments of our project. Participants will have the opportunity to view and discuss issues important to grazing-based dairies, including proper grass and legume species selection and establishment, fertilizer and irrigation requirements, relative forage production and nutritive value, preferential grazing and dry matter intake issues, and dairy heifer growth and fertility. These field days are advertised widely and will attract producers and agricultural professionals from across Utah, Idaho and surrounding states.  Educational outreach across Utah and Idaho will also occur through presentations at major forage meetings (Utah Hay and Forage Conference and the Idaho Alfalfa and Forage Conference), summer tours for the Idaho and Utah Associations of County Extension Ag Agents, USDA-NRCS, and Idaho and Utah Association of Conservation Districts, and presentations at the Extension Annual Conferences of USU and Univ. of Idaho. Additionally, articles will be developed for publication in the USU Dairy Newsletter, which has distribution across the Intermountain West.

Western Region: e-Organic will facilitate the development of digital resources to deliver our research findings to a broader regional audience using the internet and social media techniques described in Scholarly Publications and Educational Materials. The Utah Association of County Extension Ag Agents will host the National Association of County Agricultural Agents annual meeting in summer 2017. This project will be included as part of one of the preconference tour offerings. Project results will be presented to agricultural professionals (e.g., NRCS, Extension), EPA regulatory personnel, and producers at the Waste-to-Worth Conference and the Western Alfalfa and Forage Conference, and to agricultural researchers at the ASA-CSSA-SSSA annual meetings. Results will also be made available through articles written for producer-oriented regional trade journals such as Western Farmer Stockman and Progressive Forage Grower.

 

SCHOLARLY PUBLICATIONS AND EDUCATIONAL MATERIALS:

Researchers will ensure that all publications properly cite Western SARE grant funding and all educational materials include the associated Western SARE logos.

Scholarly Publications: The breadth and depth of the research will result in a wide array of scholarly publications ranging from bovine reproduction to nutrient cycling. The project will utilize three graduate student research projects which will also result in multiple theses, symposium proceedings, and conference abstracts.

Educational Products: As part of our comprehensive outreach plans, eOrganic will provide our project with a workspace at eOrganic.info as well as a public website to post research results, publications, and other resources. eOrganic will provide support for delivery of a webinar series. They will also provide related broadcasts of presentations at winter Extension trainings and conferences. USU Extension Marketing will produce multiple 1-3 minute videos on various aspects of the project that will be published on the USU Extension YouTube channel and embedded in the eOrganic website. These videos will focus not only on the work of researchers and Extension personnel in this project, but will also provide a platform for cooperating producers to share their thoughts and observations to a broader statewide, regional, and national audience. We will create a project Facebook page on which to post updates, video, photographs, and publications in a timely manner. A refereed USU Extension fact sheet series on grass-legume mixtures for pasture-based dairies will be produced and will include the following: (1) Pasture species selection and establishment; (2) Grazing preference and dry-matter intake; (3) Fertilizer use and nutrient cycling; and (4) Growth and reproductive fertility of dairy heifers. Fact sheets will be printed for distribution at pasture walks, field days, field tours, and winter workshops and will be available electronically on the internet.

PRODUCER ADOPTION:

Given that the questions addressed in this research were primarily driven by discussions with producers, the rapid growth of organic pasture-based dairy in the region, and the producer-oriented format of education materials; it is anticipated that there will be a high level of producer adoption. Assessment of program impact will occur through a combination of surveys of attendees at all outreach events and one-on-one discussions with producer cooperators. Changes expected to result from producer and agricultural professional participation in this program include: (1) change in attitude or opinion regarding the potential of grass/legume pastures (particularly high energy grasses with tannin-containing birdsfoot trefoil) to improve the productiveness and sustainability of organic, pasture-based dairy; (2) increased knowledge and awareness of the production skills and techniques associated with this project; and (3) implementation of the new practices and production systems on organic and grazing dairies.

Surveys will be administered to every participant at each educational event. The survey will be paper-based for all events except for those in a classroom setting, where survey responses will be recorded using electronic ‘iclickers’, which have been shown to improve survey participation. The “Western Region Sustainable Agriculture Research & Education Program Outreach Survey” (available at wsaregrants.usu.edu) will serve as the foundation of the survey and additional questions will be added to assess the specific learning objectives of the particular event. Evaluation of each field day, field tour, and workshop will occur by means of a self-assessment survey to measure knowledge of participants before and after each educational event. Changes in knowledge will be determined statistically by comparing pre- and post-event responses using t-tests. One-on-one discussions with producers will be another important strategy to assess producer adoption. During pasture walks and field days, direct verbal feedback will be solicited from participants to determine level of interest, how the information might assist them in making farm management decisions, barriers to adoption, and new opportunities for research and Extension. ‘eOrganic’ will evaluate the quality and utility of the digital content. Webinars will be evaluated immediately following the webinar, and the impact of the webinar on participant practices and understanding in the winter following webinar delivery. ‘eOrganic’ will also evaluate the quality and utility of all project content in the last year of the project.

Educational & Outreach Activities

27 Consultations
4 Curricula, factsheets or educational tools
2 Journal articles
1 Published press articles, newsletters
4 Tours
25 Webinars / talks / presentations
2 Workshop field days
1 Other educational activities: A web site for the project was established through eOrganic and can be found at https://eorganic.info/node/33809 (verified 1/3/20).

Participation Summary:

1062 Farmers
2711 Ag professionals participated
Education/outreach description:

Education and Outreach Description for 2020 Annual Report

Consultations for 2020 annual report:

  • Responded to 14 questions (phone calls and emails) about grass-legume mixtures for pasture, including how to establish and manage grazing.

 Curricula, factsheets or educational tools for 2020 annual report:

 Journal articles for 2020 annual report:

  • Rose, Marcus F., Blair L. Waldron, S. Clay Isom, Michael D. Peel, Kara J. Thornton, Rhonda L. Miller, Kerry A. Rood, Jacob A. Hadfield, Jennifer Long, Bracken Henderson, and J. Earl Creech. The effects of organic grass and grass-birdsfoot trefoil pastures on Jersey heifer development: Herbage characteristics affecting intake. Journal of Dairy Science. https://doi.org/10.3168/jds.2020-19563. In Press. (submitted 08/05/2020; Accepted 03/22/2021; published online 4/30/2021)
  • Hadfield, Jacob A., Blair L. Waldron, S. Clay Isom, Ryan Fuez, Ryan Larsen, J. Earl Creech, Marcus F. Rose, Jennifer Long, Rhonda L. Miller, Kerry A. Rood, Allen Young, Rusty Stott, Alexis Sweat, and Kara J. Thornton. The effects of organic grass and grass-birdsfoot trefoil pastures on Jersey heifer development: Heifer growth, performance, and economic impact. Journal of Dairy Science. In Review. (JDS.2020-19524.R2; Submitted 8/25/2020 and revised as of 04/09/2021).

 Webinars, talks and presentations for 2020 annual report:

  • Waldron, Blair. Pasture Mixtures to Improve Sustainability of Organic Pasture-Based Dairy: Nutritive Quality and Dry Matter Intake. eOrganic webinar, January 9, 2020. Four eOrganic webinars had a combined 285 live viewers, and 973 additional YouTube views, resulting in both a regional and national impact. https://eorganic.info/node/33813
  • Hadfield, Jacob. Effects of Different Pasture Mixes on Heifer Growth and Development. eOrganic webinar, February 20, 2020. Four eOrganic webinars had a combined 285 live viewers, and 973 additional YouTube views, resulting in both a regional and national impact. https://eorganic.info/node/33813
  • Peel, Michael. Forage Legumes in Pasture and Successful Inter-seeding. eOrganic webinar, March 19, 2020. Four eOrganic webinars had a combined 285 live viewers, and 973 additional YouTube views, resulting in both a regional and national impact. https://eorganic.info/node/33813
  • Feuz, Ryan and Ryan Larsen. Economics of Organic Replacement Dairy Heifers. eOrganic webinar, April 22, 2020. Four eOrganic webinars had a combined 285 live viewers, and 973 additional YouTube views, resulting in both a regional and national impact. https://eorganic.info/node/33813
  • Waldron, Blair. The Value of Improved Pasture and Rangeland. Invited presentation to the American Society of Farm Managers and Rural Appraisers, Logan, UT. January 2020. Participants: 100 agricultural real estate professionals, and bankers.

 

Workshops/Field days for 2020 annual report:

  • Waldron, Blair. Pasture Mixtures to Improve Sustainability of Pasture-Based Dairy. First Utah Virtual Field Day hosted by Utah State University. July 2020. Participants: 260 people of which 87% gave high ratings and 50% indicated high knowledge gain from viewing the field day.

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Education and Outreach Description for 2019 Annual Report

Consultations for 2019 annual report:

  • Responded to 10 questions (phone calls and emails) about grass-legume mixtures for pasture, including how to establish and manage grazing.

 Curricula, factsheets or educational tools for 2019 annual report:

  • Briscoe, J., E. Creech, M. Peel, B. Waldron, G. Cardon, and K. Heaton. 2018. Successfully inter-seeding legumes into existing cool-season pastures. Utah State University Extension Publication. AG/Crops/2018-01pr.

Published press articles, newsletters for 2019 annual report:

Tours for 2019 annual report:

  • Dairy heifer grazing research tour for Barenbrug USA. USU Pasture Research Facility in Lewiston, Utah, and Turnbow on-farm research site in Weston, Idaho. June 18, 2019. Tour included discussing grass-legume mixtures and pasture production, heifer development under grazing, and establishing grass-legume mixtures on organic dairy farm. Participants: 2 farmers/ranchers, 5 agricultural professionals, 4 academia.

Webinars, talks and presentations for 2019 annual report:

  • Long, J., Miller, R. Pasture‐based Dairy Impact on Nitrogen and Phosphorus Cycling in Response to Grazing Grass‐Legume Mixtures over Monocultures. Symposium conducted at Waste to Worth Conference 2019, Minneapolis, MN. April, 2019. Participants: 50 farmers/ranchers, 200 agricultural professionals, 100 academia.
  • Hadfield, Jacob. The effects of different organic pastures on dairy heifer growth and development. M.S. thesis defense presentation. Utah State University, Logan. April 25, 2019. Participants: 4 farmers/ranchers, 3 agricultural professionals, 40 academia.
  • Rose, Marcus. Herbage characteristics affecting intake by dairy heifers grazing grass-monoculture and grass-birdsfoot trefoil pastures. M.S. thesis defense presentation. Utah State University, Logan. August 5, 2019. Participants: 3 farmers/ranchers, 2 agricultural professionals, 35 academia.

Other Educational and Outreach Activities for 2019 annual report

  • A web site for the project was established through eOrganic and can be found at https://eorganic.info/node/33809 (verified 1/3/20). Grass-Birdsfoot Trefoil Mixtures to Improve the Sustainability of Pasture-based Organic Dairies in the Western U.S. This website describes two research projects on the effects of legume grass mixtures on dairy cattle performance and heifer development. As publications, presentations and trial results from the projects become available, we will make them available here.

Publications for 2019 annual report

 

 

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Presentation summary for 2018 annual report

Hadfield, Jacob. Effects of Different Organic Pastures on Dairy Heifer Growth in the Intermountain West. Utah State University's Animal, Dairy and Veterinarian Sciences Student Research Symposium. August 2018. 80 Academia served, 20 Ag professionals served.

Long, J. and R. Miller. Pasture-based Dairy Impact on Nitrogen and Phosphorus Cycling in Response to Grazing Grass-Legume Mixtures over Monocultures. Poster presented at: Our Farms, Our Future Conference: Envisioning the Next 30 Years of Sustainable Agriculture; 2018 Apr 3-5; St. Louis, MO. 970 total participants, 200 Ag producers served, estimated at least 200 Ag. Professionals.

Miller, R. L., J. Long, and M. Jensen. 2017. Using tannins to alter nitrogen cycling in a grazing system. In 2017 Agronomy Abstracts. Madison, WI: American Society of Agronomy. 500 Academia served, 100 Ag professionals served.

Rose, Marcus. Grass-Birdsfoot Trefoil Mixtures to Increase Dairy Heifer Performance, University of Idaho extension Forage School, Blackfoot Idaho. March 14, 2018. 9 Ag professionals served, 6 Ag producers served.

Rose, Marcus. Grass-Birdsfoot Trefoil Mixtures to Increase Dairy Heifer Performance, University of Idaho extension Forage School, Preston, Idaho. March 15, 2018. 11 Ag professionals served, 25 Ag producers served.

Rose, Marcus. Grass-Birdfoot Trefoil Mixtures to Improve Organic Dairy Heifer Performance, Utah State University Student showcase, Logan, Utah. March 19, 2018. 60 Academia served, 20 Ag professionals served.

Rose, Marcus., B. Waldron, M. Peel, C. Isom, E. Creech. Grass-Birdsfoot Trefoil Mixtures to Increase Organic Dairy Heifer Performance. North American Alfalfa Improvement, Trifolium, and Grass Breeders Conference. Poster 22. Logan, Utah. June 5-6, 2018. 75 Academia served, 75 Ag professionals served.

Field Days/Tours for 2018 annual report

2018 Joint Conference NAAIC, Trifolium, and Grass Breeders Field Tour. Lewiston, Utah. June 6, 2018. Conference tour had the following presentations. A. Forage legume breeding, Mike Peel. B. Grass-legume mixtures and pasture production, Marcus Rose and Blair Waldron. C. Heifer development under grazing, Jacob Hadfield, Kara Thornton, and Clay Isom. D. Nutrient cycling, Jenny Long, and Rhonda Miller. 75 Academia served, 75 Ag professionals served.

Field Day. Showing alternating strips of birdsfoot trefoil and orchardgrass prior to grazing

USU Pasture Field Day: Heifer development and pasture management. Lewiston, Utah. June 7, 2018. Field day had the following presentations. A. Forage species identification, Earl Creech and Mike Peel. B. Grass-legume pasture production, Marcus Rose and Blair Waldron. C. Grazing heifers, Jacob Hadfield, Kara Thornton, and Clay Isom. D. Nutrient cycling, Jenny Long, and Rhonda Miller. 25 Academia served, 25 Ag professionals served, 25 Ag producers served.

Field day: Dr. Mike Peel discussing the benefit of grass-legume mixtures.
Field day. Graduate student showing producers how to use a Rising Plate Meter to estimate available forage.

 

Presentations (2017)

  • Briscoe, Jacob. Preference of Cattle Grazing Birdsfoot Trefoil in Binary Mixtures with Meadow Bromegrass, Orchardgrass, Perennial Ryegrass, and Tall Fescue. Western Society of Crop Science annual meeting, June 7, 2017, Parma, ID. There were approximately 20 ag professionals at my presentation.
  • Briscoe, Jacob. Preference of Cattle Grazing Birdsfoot Trefoil in Binary Mixtures with Meadow Bromegrass, Orchardgrass, Perennial Ryegrass, and Tall Fescue. Lewiston pasture grazing project meeting, September 22, 2017, Lunch Presentation, Utah State University campus. There was one farmer present and approximately a dozen ag professionals.
  • Briscoe, Jacob. Preference of Cattle Grazing Birdsfoot Trefoil in Binary Mixtures with Meadow Bromegrass, Orchardgrass, Perennial Ryegrass, and Tall Fescue. ASA, CSSA and SSSA International Annual Meeting, Robert F. Barnes M.S. Poster Session, October 23, 2017, Tampa, Florida. Approximately 100 ag professionals saw the poster, many more were in attendance of the meeting.
  • Briscoe, Jacob. Preference of Cattle Grazing Birdsfoot Trefoil in Binary Mixtures with Meadow Bromegrass, Orchardgrass, Perennial Ryegrass, and Tall Fescue. Plants, soils and climate graduate student seminar, December 11, 2017, Utah State University campus. There were approximatley 30 ag professionals present at this seminar.
  • Marcus Rose, Grass-Birdsfoot Trefoil Mixtures to Increase Dairy Heifer Performance, Western Society for Crop Science, Parma, Idaho. June 6, 2017. 20 Ag professionals served.
  • Marcus Rose, Grass-Birdsfoot Trefoil Mixtures to Increase Dairy Heifer Performance, Brown-bag Grazing Research discussion group, Logan, Utah. July 21, 2017. 10 Ag professionals served.
  • Marcus Rose, Grass-Birdsfoot Trefoil Mixtures to Increase Dairy Heifer Performance, USU Lewiston Grazing Research Facility, Extension agent tour, Lewiston, Utah, August 2017. 10 Ag professionals served.
  • Marcus Rose, Grass-Birdsfoot Trefoil Mixtures to Increase Dairy Heifer Performance, Utah State University Plant Soils and Climate department seminar, Logan, Utah, October 2, 2017. 25 Ag professionals served.
  • Marcus Rose, Grass-Birdsfoot Trefoil Mixtures to Increase Dairy Heifer Performance-Condensed results, Brown bag discussion group, Logan, Utah, November 27, 2017. 10 Ag professionals served, 2 Ag producers served.
  • Long, Jenny. 2017. Impact of tannins on nitrogen cycling and the potential to reduce ammonia and greenhouse gas emissions. ASABE Presentation No. 1701035. St. Joseph, MI: American Society of Agricultural and Biological Engineers.
  • Long, Jenny, and M. Jensen. 2017. Impacts of tannins on nitrogen cycling and the potential to reduce greenhouse gas emissions. 2017. In 2017 Agronomy Abstracts. Madison, WI: American Society of Agronomy.

Learning Outcomes

955 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation
Key areas taught:
  • • Grass-legume mixtures improve dairy heifer forage intake, health, and growth performance compared to grass monocultures.
  • • Birdsfoot trefoil is an option for western U.S. irrigated pastures, is non-bloating, and fixes nitrogen reducing the need for commercial fertilizer.
  • • Grazing high energy grasses in mixtures with birdsfoot trefoil results in heifer performance similar to those fed a total mixed ration in drylot and high positive economic impact.

Project Outcomes

53 Farmers changed or adopted a practice
478 Farmers intend/plan to change their practice(s)
2 Grants received that built upon this project
5 New working collaborations
Project outcomes:
  • The number of grazing dairies is increasing, but decreased herbage intake by grazing livestock reduces the performance of dairy cattle. These findings indicate that mixtures of high-energy grasses and as little as 14% birdsfoot trefoil increase intake of temperate pastures by grazing Jersey heifers. Furthermore, the heifers grazing grass-birdsfoot trefoil pastures had similar performance to heifers raised in a conventional confinement setting (non-organic). We showed that the payback period for converting to grass-birdsfoot trefoil pastures was less than 1 month and annual financial impact was nearly 3 times greater than the grass monoculture pastures. Overall, these findings provide a potential solution for producers to improve performance of dairy heifers on pasture and alleviate some producer concerns when considering transitioning to an organic operation.

 

  • Furthermore, because of the positive results from this research, producers on our research team asked about the influence of dairy breed on performance within their pasture-based systems. Thus, in direct response to this stakeholder feedback, we proposed and were awarded a new Western SARE grant to investigate the effects of dairy breed, pasture type, and breed-by-pasture type interactions on DMI, feed efficiency, and environmental and economic sustainability of heifers raised in pasture-based systems. When this additional phase of research is completed, we expect to provide producers with solid scientific AND economic data on pasture-based dairy heifer development for a variety of pasture-types and dairy breeds.
Success stories:

A dairy farmer in southeast Idaho became an active supporter of the research part way through the project and is now an integral part of continuing Western SARE research looking at dairy breed by pasture-type interactions. When the SW17-046 project began, this dairy was a family farm transitioning from conventional to organic dairy production. As a result of the research, the dairy has planted over 100 acres of high-energy grass and birdsfoot trefoil mixtures for grazing. The dairy producer stated, “The no bloat-risk is a definite bonus, but more importantly is the production bump we get every time we graze those grass-birdsfoot trefoil pastures. This research has changed how and what we plant for every new pasture.”

Another dairy farmer in southeast Idaho was one of the original Producer Participants of this project. At the onset of the research, their dairy was already successfully using grazing as part of their organic milk production operation. However, their previous experience with birdsfoot trefoil was not favorable. Western SARE research plots on the farm showed how grass-birdsfoot trefoil mixtures could be both more productive and persistent than their previous grass pastures. In the end they were highly impressed by the results of the research, and as such, this producer is now also an integral part of the new team looking at dairy breed by pasture-type interactions, including providing cross-bred heifers. As the Mountain Region Representative on the Dairy Executive Committee for Organic Valley Coop, this producer has become an influential leader who helped obtain industry support for our continued pasture research.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.