Final report for LNE13-323
We learned through focus group interviews and surveys that profitable strategies to maximize forage production are challenging to northeastern dairy farmers particularly those feeding high forage diets to their milking cows. Our project increased farmers’ knowledge about the benefits of using annual forage crops (AFC) such as warm and cool season grasses, legumes, and brassicas for pasture and silage feeding. We have now scientific information to guide dairy farmers on how to select best AFC species that provide supplemental forage during periods of limited biomass production (e.g., early spring, the “summer slump”, and late fall). Agronomic plots were established at the University of New Hampshire (UNH) Kingman Research Farm with studies conducted over 2 growing seasons. The spring-available monocultures and mixtures include 5 species: wheat, triticale, barley, cereal rye, and hairy vetch. The summer-available forage species and associated mixtures consisted of warm-season annual grasses and forbs including BMR sorghum, teff, millet, oats, buckwheat, and chickling vetch. The fall-available monocultures and mixtures include 6 species: forage radish, oats, canola, wheat, triticale, and sunn hemp. Overall, forage yield and nutritive value varied by year. Wheat, triticale, and cereal rye resulted in the best combination of forage biomass yield at grazing height and forage nutritive value during the spring. The summer annual buckwheat consistently produced the highest forage biomass yield followed by triticale, with chickling vetch resulting in the poorest yield at grazing height. Most summer AFC resulted in good nutritive value with the exception of buckwheat. In the fall, canola and forage radish consistently ranked first or second in biomass production followed by wheat and oats at grazing height. All fall-available AFC resulted in forage with good nutritive value for grazing.
Feeding trials were conducted at the UNH Organic Dairy Research Farm and Pennsylvania State University (PSU) Dairy Teaching and Research Center Farm. At UNH, 2 studies were done where organic-certified Jersey cows grazed spring-available AFC and summer-available AFC strip tilled into traditional cool season legume-grass pasture mixture. Overall, our results showed that strip tilling AFC into established traditional legume-grass pasture mixture did not change animal production (e.g., dry matter intake, milk production), rumen fermentation profile, and methane emissions or consistently increased forage dry matter yield. At PSU, 2 feeding trials using Holstein cows in confinement were conducted. In trial 1, corn silage was partially replaced with silages harvested from 2 AFC forages (wheat or triticale). Results showed that at milk production around 42 kg/day, wheat and triticale silages can partially replace corn silage with no effect on dry matter intake, but slightly decrease in milk production. For dairy farms in need of more forage, triticale or wheat double cropped with corn silage may be an appropriate cropping strategy. In trial 2, corn silage was partially replaced with 2 AFC, BMR brachytic dwarf forage sorghum or fall-grown oat silage in the diet of lactating dairy cows. Results showed that that oat silage can partially replace corn silage with no negative effect on milk production. BMR sorghum silage harvested at the milk stage with <1% starch may decrease dry matter intake and milk production in dairy cows.
In addition to UNH and PSU studies, our team developed several educational activities including field days, videos, workshops, and AFC demonstration plots engaging over 1,000 dairy farmers across the Northeast.
PROBLEM DESCRIPTION: A survey of 987 dairy farms across the Northeast revealed that 13% of dairy farmers use rotational grazing, 7% use large, modern confinement systems (no grazing) with >300 cows, and 80% use a combination of low intensity grazing and traditional confinement with a herd size <300 cows. We learned through focus group interviews (n = 35 farmers) and surveys (n = 143 respondents) that profitable strategies to maximize forage production are challenging to 75% northeastern dairy farmers using rotational grazing. Traditional and grazing dairy farms feed higher forage diets than modern confinement dairies, and as a result they share similar concerns about how to maximize forage production year-round. Therefore, opportunities exist to develop resilient annual forage crops (AFC) systems (e.g., warm and cool season grasses, summer annuals, brassicas) that provide supplemental forage for grazing and/or silage feeding during periods of limited biomass production (e.g., early spring, the “summer slump”, and late fall). However, despite the rapidly growing interest and adoption of AFC across the Northeast, research data are lacking to help farmers make informed decisions regarding which AFC and rotations maximize animal production, farm profitability, and ecosystem services (e.g., carbon and nitrogen sequestration, soil health, weed control, etc.) in their enterprises.
While agricultural soils account for 69% of the total U.S. nitrous oxide emissions, ruminants are responsible for 21% of the total enteric methane emissions, raising concerns about the impacts of these greenhouse gases (GHG) on global warming. In addition to detrimental environmental impact, enteric methane production represents energy losses to ruminants, thus impairing milk production and farm profitability. Continued GHG emissions are expected to exacerbate the frequency and severity of extreme weather threatening the economic sustainability of agriculture in the region. Skyrocketing feed costs are also threatening the viability of northeastern dairy farming. Annual forage crops offer a unique opportunity to provide supplemental forage year-round potentially mitigating both grain costs by producing more forage dry matter per unit of land and enteric methane emissions by enhanced forage digestibility. Managing AFC (e.g., oats, triticale, winter rye, winter barley) as cover crops holds strong potential to mitigate soil GHG emissions by minimizing soil erosion and nutrient runoff while providing supplemental forage for grazing and/or silage use. With this project, farmers in NH and PA will learn how to successfully utilize AFC in ways that maximize farm profitability and ecosystem services by reducing feed costs and carbon and nitrogen emissions.
SOLUTION AND BENEFITS: This project engaged NH and PA dairy farmers in a research and educational program focused on the use of AFC for yielding supplemental forage for grazing season extension and silage production with the overarching goal of enhancing forage intake and reducing grain costs while maintaining milk production. We also addressed agronomical constraints to implementing AFC in grazing and silage-based rotations by measuring establishment success, growth, yield, and weed pressure. We coupled AFC field experiments at University of New Hampshire (UNH) and Penn State University (PSU) with educational field days and farmer managed AFC demonstration plots.
Management strategies to increase forage production and intake are our major focus because escalating grain costs are threatening the economic sustainability of northeastern dairy farms. We estimate that some AFC species can increase dry matter production by 2 to 3.5 tons/acre with net returns of up to $175/acre. At times of limited forage biomass production (i.e., early spring, the “summer slump”, and late fall), opportunities exist to fill these production gaps with AFC, thus reducing: 1) feed costs by replacing expensive supplemental grain with forage, and 2) whole-farm GHG emissions per unit of land and milk output through enhanced soil carbon:nitrogen ratio and forage digestibility. Compared to corn, new brown-midrib (BMR) forage sorghums can be planted later in the season, allowing for double cropping, greater crop diversity, and good yields on droughty soils with lower establishment costs. Cover cropping strategies using oats and triticale also show promise. While oats can provide cover and forage for silage in the fall, triticale can fill this niche in the spring with higher forage quality than winter rye. Although northeastern dairy farmers have been trying these AFC, lack of scientifically-based information regarding economics, yields, forage and silage quality, season extension, and animal performance limit the large scale utilization of AFC in the region. This project filled these knowledge gaps by engaging researchers and farmers through a multidisciplinary approach to deliver best forage practices to NH and PA dairy farmers.
Compared to the previous year, 60 farmers milking 5,000 cows enhance income over feed costs by $0.50/cow/day after replacing expensive grain with annual forage crops, generating cumulative profit of approximately $5,000 per farm as a result of 120-days’ worth of forage surplus.
We hypothesize that AFC can improve the economic and environmental sustainability of NH and PA dairy farms through two primary mechanisms (see below). To test this overarching hypothesis, we will establish region specific (i.e., NH or PA) field experiments aimed at grazing- or silage-based dairy systems. These experiments will provide the information necessary to provide science-based recommendations for incorporating AFC in forage rotations and lactating cow diets in northeastern dairy farms.
UNH site (Agronomic Research):
A field study was established in May 2014 at the UNH Kingman Research Farm. The study includes 13 AFC species and 3 annual forage crop mixtures. The summer-available AFC and associated mixtures consisted of warm-season annual grasses and forbs such as BMR sorghum-sudangrass, teff, millet, oats, buckwheat, and chickling vetch. These summer-available treatments were seeded in late spring in a randomized block with 4 replications. Prior to forage crop seeding, the field was moldboard plowed and the seedbed was prepared using a Perfecta II field cultivator. Each forage monoculture was seeded using an ALMACO light-duty plot grain drill at the rate recommended for that species. The forage crop mixture was constructed using a substitutive approach (i.e., proportional replacement design) such that seeding rates for each species in the mixture were proportional to their monoculture rate. Therefore, the seeding rates for individual species in the summer-available mixture were determined by dividing each recommended seeding rate by the total number of species in the mixture (i.e., 6). This approach minimizes potentially confounding effects of a higher overall seeding rate in the mixture and preserves the ability to use well established intercropping indices such as the land equivalent ratio. Individual plot size was 1.8 x 6.1 m. No fertilizers or pesticides were applied to any of the experimental plots during the duration of the experiment; however, compost was applied to the entire site in spring 2014 prior to the establishment of the experiment. The fall- and spring-available monocultures and mixtures were established in the summer and fall of 2014, respectively, using the same approach described above. The fall-available monocultures and mixture included 6 species: forage radish, oats, canola, wheat, triticale, and sunn hemp. The spring-available monocultures and mixture included 5 species: wheat, triticale, barley, cereal rye, and hairy vetch. The study was conducted over 2 growing seasons.
Forage composition and productivity and weed abundance were measured in all AFC treatments at 3 time points, with the first time point aimed at maximizing forage quality (just prior to heading out) at grazing height, while the second and third time points were used to assess the tradeoffs between forage quality and forage yield. Data collection occurred in July/August for the summer-available treatments, late October for the fall-available treatments, and early May for the spring-available treatments. To determine how the forage crop treatments affect water and light availability to weeds, we also measured soil moisture and photosynthetically active radiation (PAR) at several points during the growing season using a Field Scout TDR 300 soil moisture Meter and an AccuPAR 200 ceptometer, respectively. At all sampling points, forage crop and weed community biomass were harvested to ground level using 3, 0.25-m2 quadrats placed randomly within each plot. Plant biomass were sorted to species, dried to constant weight at 60°C and weighed to the nearest 0.01 g.
UNH site (Animal Research):
Both experiments were carried out at the University of New Hampshire Burley-Demeritt Organic Dairy Research Farm (43°10’N, 70°99’W) from May 13 to June 3, 2015 (Experiment 1) and from July 14 to August 2, 2015 (Experiment 2). Unfortunately, we were not able to establish the third grazing experiment (fall-available AFC) due to consecutive droughts in 2015 and 2016.
Planting and pasture measurements: The spring available AFC (spAFC) were strip tilled using a Unverferth 4-row Ripper-Stripper and planted with a Great Plains no-till drill into a traditional perennial legume-grass pasture mixture in October 1, 2014. The following spAFC species were used: oats, barley, winter wheat, cereal rye, and hairy vetch. Pasture was clipped weekly for quality analysis and botanical composition and biweekly for allowance and disappearance (pre- and post-grazing) measurements. Measurements for pasture allowance, disappearance, and quality were conducted by randomly throwing a quarter-meter quadrat in the traditional perennial legume-grass pasture mixture control and spAFC paddocks for 10 separate times. All herbage biomass within the quadrat was clipped to approximately 7 cm off the ground, weighed, and placed in forced air ovens set at 55°C for 48 h.
Animal measurements: Sixteen organically-certified lactating Jersey cows (14 multiparous and 2 primiparous) were randomly assigned to 1 out of 2 treatments in a completely randomized design: 1) traditional legume-grass pasture mixture (control; n = 8 cows) or 2) spAFC strip tilled into traditional legume-grass pasture (n = 8 cows). Within each treatment, cows were balanced for milk yield, parity, and days in milk. Cows used averaged (mean ± standard deviation) 433 ± 48 kg of body weight and 83 ± 50 days in milk for the control treatment, and 416 ± 46 kg of body weight and 86 ± 43 days in milk for the spAFC treatment before the beginning of the study. Diets were formulated to provide 50% of total dry matter intake from a total mixed ration and the remaining 50% from the control or spAFC pasture mixtures. Cows had access to their respective pasture treatments once daily after the afternoon milking from 1800 to 0500 h in a strip grazing management system. A new strip of fresh pasture was provided daily. Cows in each treatment were allotted the same amount of pasture dry matter (~12 kg dry matter per cow daily). Cows were housed in a bedded pack barn with access to an open concrete lot and a covered feeding area where the total mixed ration was provided using the Calan doors system to individualize intake. Cows were milked twice daily at 5:30 am and 4:30 pm in a 4-stall step-up parlor with headlocks.
Milk samples were collected over 4 consecutive milkings during the last week of the study. Blood samples were taken by venipuncture of the coccygeal vein or artery after the morning and afternoon milkings over 2 consecutive days. Rumen samples were collected after the morning milking for 2 consecutive days using an esophageal tube. Cows were fed 1 kg/day of a pelleted concentrate containing chromium oxide for 10 consecutive days during the morning and afternoon feeding concurrently with the total mixed ration. Chromium oxide was used as an external marker to estimate fecal output of dry matter, nutrient digestibility, and pasture intake. Cows received 6.23 g of chromium per day. Fecal samples were collected and pooled daily after the morning and afternoon milkings for 5 consecutive days. Fecal output of dry matter was calculated by using fecal chromium concentration via the following equation: fecal output = (grams per day of chromium) ÷ (grams of chromium/grams of fecal dry matter) (Kolver and Muller 1998). Pasture dry matter intake was then calculated by the following equation: pasture dry matter intake = [(grams of chromium/day) ÷ (grams of chromium/grams of fecal dry matter) – concentrate dry matter intake × (1 – in vitro dry matter digestibility of concentrate) – total mixed ration dry matter intake × (1 – in vitro dry matter digestibility of total mixed ration)] ÷ (1 – in vitro dry matter digestibility of pasture) (Bargo et al. 2002). Data were analyzed using the MIXED procedure of SAS (SAS version 9.4; SAS Inst. Inc., Cary, NC) according to a completely randomized design. All reported values are least squares means and standard error of the mean. Significance was declared at P ≤ 0.05 and trends at 0.05 < P ≤ 0.10.
Bargo, F., Muller, L.D., Delahoy, J.E., and T.W. Cassidy. 2002. Performance of high producing dairy cows with three different feeding systems combining pasture and total mixed rations. J. Dairy Sci. 85:2948–2963.
Kolver, E.S., and L.D. Muller. 1998. Performance and nutrient intake of high producing Holstein cows consuming pasture or a total mixed ration. J. Dairy Sci. 81:1403–1411.
Planting and pasture measurements: A methodology similar to that used for the Experiment 1 was adopted during the summer experiment for pasture sampling, processing, and analyses. The summer available AFC (suAFC) were strip tilled and planted into a traditional perennial legume-grass pasture mixture in June 18, 2015. The following suAFC species were used: millet, teff, buckwheat, oats, and chickling vetch.
Animal measurements: Twenty organically-certified lactating Jersey cows (16 multiparous and 4 primiparous) were randomly assigned to 1 out of 2 treatments in a completely randomized design: 1) traditional legume-grass pasture mixture (control; n = 10 cows) or suAFC strip tilled into traditional legume-grass pasture mixture (n = 10 cows). Cows used averaged (mean ± standard deviation) 434 ± 46 of body weight and 146 ± 61 days in milk for the control treatment, and 449 ± 53 kg of body weight and 140 ± 57 days in milk for the suAFC treatment. Diets were formulated to provide 60% of total dry matter intake from a total mixed ration and the remaining 40% from the control or suAFC pasture mixtures. Data and sample collection and analyses were done as reported for Experiment 1.
USDA-ARS Pasture Lab (University Park, PA) and UNH Collaboration on an In Vitro Study using AFC
A 4-unit, dual-flow continuous culture fermentor system was used to assess nutrient digestibility, volatile fatty acids (VFA) production, bacterial protein synthesis, and methane (CH4) output of warm-season annual grasses. Treatments were randomly assigned to fermentors in a 4 × 4 Latin square design using 7 d for adaptation to treatment and 3 d for sample collection. Treatments were (1) 100% orchardgrass (Dactylis glomerata L.; ORD); (2) 50% orchardgrass + 50% Japanese millet [Echinochloa esculenta (A. Braun) H. Scholz; MIL]; (3) 50% orchardgrass + 50% brown midrib sorghum × sudangrass (Sorghum bicolor L. Moench × S. bicolor var. sudanense; SSG]; or (4) 50% orchardgrass + 25% millet + 25% sorghum × sudangrass (MIX). Fermentors were fed 60 g of dry matter (DM)/d in equal portions of herbage 4 times daily (0730, 1030, 1400, and 1900 h). To replicate a typical 12-h pasture rotation, fermentors were fed the orchardgrass at 0730 and 1030 h and the individual treatment herbage (orchardgrass, Japanese millet, sorghum × sudangrass, or 50:50 Japanese millet and sorghum × sudangrass) at 1400 and 1900 h. Gas samples for CH4 analysis were collected 6 times daily at 0725, 0900, 1000, 1355, 1530, and 1630 h. Fermentor pH was determined at the time of feeding, and fermentor effluent samples for ammonia-N (NH3-N) and VFA analyses were taken daily at 1030 h on d 8, 9, and 10. Samples were also analyzed for DM, organic matter (OM), crude protein, and fiber fractions to determine nutrient digestibilities. Bacterial efficiency was estimated by dividing bacterial N by truly digested OM. True DM and OM digestibilities and pH were not different among treatments. Apparent OM digestibility was greater in ORD than in MIL and SSG. The concentration of propionate was greater in ORD than in SSG and MIX, and that of butyrate was greatest in ORD and MIL. Methane output was greatest in MIL, intermediate in ORD, and lowest in SSG and MIX. Nitrogen intake did not differ across treatments, whereas bacterial N efficiency per kilogram of truly digestible OM was greatest in MIL, intermediate in SSG and MIX, and lowest in ORD. True crude protein digestibility was greater in ORD versus MIL, and ORD had lower total N, non-NH3-N, bacterial N, and dietary N in effluent flows than MIL. Overall, we detected little difference in true nutrient digestibility; however, SSG and MIX provided the lowest acetate to propionate ratio and lower CH4 output than MIL and ORD. Thus, improved warm-season annual pastures (i.e., brown midrib sorghum × sudangrass) could provide a reasonable alternative to orchardgrass pastures during the summer months when such perennial cool-season grass species have greatly reduced productivity.
For further information see Dillard et al, 2017.
UNH site (Soil Health Research):
We assessed the effects of AFC in monocultures and mixes on soil health by measuring bulk density, aggregates, microbial biomass, nitrogen pool, carbon dioxide respiration, and dissolved nitrogen in plots established at UNH Kingman Research Farm (UNH Agronomic Research). Core soil samples (n = 3 per plot) were collected from the spring available AFC plots on May 14, 2015 (after snow melt) and composited by plot. For the summer available AFC plots, the soil sampling strategy was modified so the soil cores were collected at 3 time points starting in the beginning of the season on June 13, the middle of the season on July 16, and on July 31 where the growth stage of the AFC species were at heights recommended for grazing. For the fall available AFC plots, a sampling strategy similar to that described for the summer available AFC plots was adopted with soil cores taken in the beginning (August 22), middle (September 25), and at recommended grazing heights (October 23). All soil cores were sealed in airtight bags, placed in a cooler, and transported immediately to the laboratory for later analyses. Samples were sieved to pass through an 8 mm screen and analyzed for soil bunk density using the dimension of the sampler (soil bulk density = dry weight/pr2) and soil aggregates using a rotary sieve shaker with 7 sieves to obtain 7 aggregate size fractions: > 4 mm, 2 to 4 mm, 1 to 2 mm, 0.500 to 1 mm, 0.250 to 0.5 mm, 0.125 to 0.25 mm, and < 0.125 mm. Subsamples of soils were sieved through a 2 mm screen, refrigerated at 4°C, and analyzed for microbial biomass within 5 days of removal from the field. One set of soil samples was designated fumigated samples and the second set was designated as non-fumigated. Subsamples of air dried soils were grounded to a fine powder and then used for determination of total soil carbon and N on an elemental analyzer. Subsamples of soil were sieved to 2 mm, air dried, placed into jars with water, and followed by measurements of carbon dioxide respiration for 3 weeks. Total organic carbon, total organic N, and N pool fractions (ammonia and nitrates) were analyzed.
PSU site (Agronomic Research):
A field experiment was established in the fall of 2013 to examine the impact of fall cover crops on forage yield, forage quality, and soil health. Fall treatments included no cover, spring oats, spring oats/triticale, rye, 2 triticale treatments, and winter barley. Oats were harvested in the fall, rye and 1 triticale treatment were harvested at the flag leaf stage, and the second triticale and barley treatment were harvested at the soft dough stage. Corn was planted following the no cover, oats, triticale, and rye treatments. Forage sorghums were planted following the later soft dough harvest treatments. In the fall of 2014, the small grain alternative forage treatments were planted again. These data were used to provide background for outreach activities in the winter and spring. In addition, we established a small forage sorghum study to evaluate 2 varieties, seeding rates, and N levels.
PSU site (Animal Research):
Crops and silages: Brown midrib-6 brachytic dwarf forage sorghum and oats were grown in Centre County, PA during the summer and fall of 2014. Both crops were planted with a no-till drill into fields fertilized with 44.8 t/ha of dairy manure before planting, contributing 42 kg/ha of ammonium N. Sorghum was planted with 38-cm row spacing, and oats were planted with 19-cm row spacing. A John Deere 946 mower with a roll conditioner was used to mow both crops and, after wilting to around 30% dry matter, the forages were gathered and chopped using a John Deere 6750 harvester. Both crops were ensiled without inoculant in 3-m-diameter plastic silage bags. Sorghum was planted on June 30, 2014, after barley and triticale harvested for forage, at a seeding rate of 7.3 kg/ha and fertilized with 67 kg of N/ha from a 30% urea and ammonium nitrate liquid fertilizer on August 18, 2014. It was mowed on November 10, 2014, at the milk stage of grain development after being partially frost-killed and harvested on November 11, 2014, with a 16-mm theoretical chop length. Oats were planted at a seeding rate of 108 kg/ha on August 16, 2014, after wheat harvested for grain. The oats were mowed in the boot stage on November 8, 2014, and harvested on November14, 2014, with a 12-mm theoretical chop length. The corn silage, which was the control in this experiment, was a mixture of the following hybrids: Mycogen TMF2R737 (112-d relative maturity), Dekalb DKC 52-61 (102-d relative maturity), and NK N60F-3111 (107-d relative maturity). Corn silage was grown in Centre County, PA, and planted between May 1 and May 10, 2014, at a rate of 79,000 seeds/ha. It was planted with a no-till drill into fields fertilized with 44.8 t/ha of dairy manure before planting, contributing 42 kg/ha of ammonium N. An additional 43 kg/ha of N was applied as 30% urea and ammonium nitrate liquid before planting and 100 kg/ha of N in the same form as a sidedress application. Corn silage harvest was conducted between September 15 and September 30 at a target dry matter of 38% with a 19-mm chop length and ensiled in an upright concrete silo.
Animals and diets: Twelve midlactation Holstein dairy cows, 6 primiparous (milk production 37 ± 2.6 kg; days in milk 100 ± 6 d; body weight 592 ± 51 kg) and 6 multiparous (milk production 47 ± 5.8 kg; 2.3 ± 0.5 lactations; days in milk 61 ± 16 d; body weight 639 ± 39 kg at the beginning of the experiment with two 28-d periods) were used in a replicated 3 × 3 Latin square design balanced for residual effects. Each 28-d period consisted of 18 d of adaptation and 10 d of data and sample collection. All cows were housed in the tie stall barn of The Pennsylvania State University’s Dairy Research and Teaching Center. Cows were fed once daily around 8 am and milked twice daily at 7 am and 6 pm. Three different diets were fed to the cows during the experiment as follows: a control diet, based on corn silage and alfalfa haylage; an oat silage diet, oat silage included at 10% of dietary dry matter, replacing 22.7% of the control diet corn silage dry matter; and a sorghum silage diet, sorghum silage included at 10% of dietary dry matter, replacing 22.7% of the control diet corn silage dry matter.
Sampling and analyses: Milk samples for components and fatty acids analysis were collected on 2 consecutive days (4 consecutive milkings) during wk 4 of each period from the p.m. and a.m. milkings. Milk component samples were analyzed individually by Dairy One Laboratory for fat, true protein, milk urea N (MUN), and lactose content using infrared spectroscopy. Milk samples for fatty acids analysis from the 4 milkings for each period and cow were collected without preservative and frozen at −20°C until composited based on milk production so that a single composited sample was analyzed per cow. Body weight was recorded daily upon exiting the milking parlor using an AfiFarm 3.04E scale system. During wk 4 of each period, urine and fecal samples were collected for digestibility and N utilization estimates. Enteric methane and carbon dioxide emissions were measured during wk 4 of each period with the GreenFeed system. Measurements were collected 8 times over 3 days to obtain a representative sample of a 24-h period.
Income Over Feed Costs: Income over feed costs (IOFC) for the 3 diets was calculated using the Pennsylvania State Extension Dairy Team IOFC Tool. The cash flow spreadsheet from the Pennsylvania State Extension Dairy Team was used to calculate forage monetary values for the IOFC tool. The model dairy included 34.4 ha cropland, 65 lactating cows, 10 dry cows, 52 heifers, and 12 calves. It was assumed that only the forages were grown on the farm, whereas concentrates were purchased. The lactating cow ration was changed in the scenarios to reflect the treatment diet, whereas diets for other cow groups (e.g., dry cows, heifers, and calves) were kept the same among scenarios. First, the total amount of the different forages required for each scenario was calculated. Next, the hectares needed to produce that amount was found by dividing the total amount of each crop needed by the per hectare crop yields obtained for the forages used in the trial. The corn silage yield when double cropped with oats was decreased by 4.9 t of dry matter/ha to account for the lower yield of short season corn, which would have to be planted before oats. An additional scenario was run in which a sorghum yield of 13.4 t of dry matter/ha was used to show a more typical yield based on timely planting. Then, the variable costs of seed, fertilizer, and herbicide per acre for each crop during 2014 was entered into the spreadsheet. Along with the input costs and the yield information for each crop, the fixed costs were allocated among the forages based on the labor used to produce them to determine price per ton. Milk and components yield from the current study was used with the average milk pricing in Pennsylvania for 2015 to generate the income side of the IOFC equation.
Statistical Analysis: Statistical analyses for all but the in situ data were run using the MIXED procedure of SAS v9.4. Cow was the experimental unit.
Crops and silages: Wheat and triticale were grown in Centre County, PA during the fall of 2014. Both crops were planted with a no-till drill into fields fertilized with 44.8 t/ha of dairy manure before planting, contributing 42 kg/ha of ammonium N. Forages were planted next to each other in the same field with 19-cm row spacing on October 10, 2014, after wheat harvested for grain. Seeding rate was 151 kg/ha for triticale and wheat. On April 4, 2015, both wheat and triticale were fertilized with 67 kg of N/ha from a 30% urea and ammonium nitrate liquid fertilizer. A John Deere 946 mower with a roll conditioner was used to mow both crops and, after wilting to target 30% dry matter, the forages were gathered and chopped using a John Deere 6750 harvester. Mowing was conducted on May 13 and 19, 2015, at the boot stage for triticale and wheat, respectively, and chopping occurred on May 15 and 20, respectively. Chop length was set to 12 mm. Both crops were ensiled without inoculant in 3-m diameter plastic silage bags. Corn silage hybrids used and planting methods were done as reported in Experiment 1.
Animals and diets: Twelve mid-lactation Holstein dairy cows (milk production = 42 ± 10.1 kg; 2.5 ± 1.38 lactations; days in milk = 38 ± 5.7; body weight = 632 ± 101.6 kg at the beginning of the experiment) were used in a replicated 3 × 3 Latin square design balanced for residual effects. The experiment had 3 periods and each period was 28 d, with 18 d for adaptation to the diet and 10 d for data and sample collection. All cows were housed in the tie stall barn of The Pennsylvania State University’s Dairy Research and Teaching Center. Cows were fed once daily around 8 am and milked twice daily at 7 am and 6 pm. Three different diets were fed to the cows during the experiment: a control diet, based on corn silage and alfalfa haylage; a triticale silage diet, triticale silage included at 10% of dietary dry matter, replacing 22.7% of the control diet corn silage dry matter; and a wheat silage diet, wheat silage included at 10% of dietary dry matter, replacing 22.7% of the control diet corn silage dry matter.
Samples collection and analyses (animal production, methane emissions, etc.), IOFC, and statistical comparison of treatments were done as reported in Experiment 1.
UNH site (Agronomic Research)
Overall, forage yield and nutritive value were affected by year. Wheat, triticale, and cereal rye resulted in the best combination of forage biomass yield at grazing height and forage nutritive value during the spring. The summer annual buckwheat consistently produced the highest forage biomass yield followed by triticale, with chickling vetch resulting in the poorest yield at grazing height. Most summer AFC resulted in good nutritive value with the exception of buckwheat. In the fall, canola and forage radish consistently ranked first or second in biomass production followed by wheat and oats. All fall-available AFC resulted in forage with good nutritive value for grazing. Forage production and nutritive value are presented in UNH AFC Agronomic Plots Data (UNH-AFC-Agronomic-Plots-Data1).
The regrowth study indicates that the individual summer-available AFC treatments differ in their ability to supply additional forage after an initial harvest and that regrowth potential was dependent on the timing of initial harvest. While buckwheat produced high levels of dry matter at initial harvest, it did not regrow and therefore has little subsequent summer forage value. In contrast, millet, which also produced relatively high levels of dry matter at initial harvest, had relatively high subsequent regrowth (as much as 225 g dry matter/m2 in 3 weeks following the initial harvest on July 16). In addition to millet, regrowth in the oats and sorghum monocultures and summer mixture treatments was also dependent on the timing of initial harvest, with regrowth potential being as much as twice as high following an early compared with later initial harvest. Regrowth in other treatments, including the chickling vetch and teff monocultures and “super mixture” (all AFC together), did not appear to be affected by the timing of initial harvest. Overall, forage biomass production increased and nutritional quality decreased with delaying of harvesting for all AFC crops.
Weed suppression also varied among the summer-available treatments and was highest (lowest weed biomass) in the buckwheat, oats, and millet monocultures and the summer and “super mixture” treatments, where weed biomass ranged from near zero to less than 20 g/m2 across the three harvest periods. In contrast, treatments such as the chickling vetch, sorghum, and teff monocultures had weed biomass levels that ranged from 10 to as much as 120 g/m2 over the 3 harvest periods. Weed biomass in the fallow treatment ranged from 30 to 140 g/m2 over the 3 harvest periods. We are still analyzing weed pressure data for AFC.
UNH site (Animal Research)
The botanical composition (dry matter basis) for the control treatment averaged 70% grasses, 17% legumes, and 13% other (broadleaf, weeds, and dead), while that for spAFC treatments averaged 60% grasses, 14% legumes, 13% AFC grasses, 4% AFC legumes, and 9% other (broadleaf, weeds, and dead). Perennial species primarily consisted of timothy grass, Kentucky bluegrass, orchardgrass, white clover, and alfalfa. Pasture biomass averaged 3,038 ± 303 and 4,052 ± 353 kg of dry matter/ha for the control and spAFC treatments, respectively. Pasture nutrient composition during the sampling period (i.e., last week of the experiment) averaged 16.0% and 15.1% crude protein, 53.3% and 56% neutral detergent fiber, and 34.6% and 32.1% acid detergent fiber for the control and spAFC treatments, respectively (UNH-Grazing-Experiments).
Animal production, plasma metabolites, and ruminal fermentation profile data can be found in the UNH Grazing Experiments attachment (UNH-Grazing-Experiments). No difference was observed for intake of pasture (8.10 versus 7.49 kg/day) or total mixed ration (10.9 versus 10.7 kg/day) when comparing control versus spAFC treatments, respectively. However, a trend (P = 0.08) was observed for greater total dry matter intake (18.9 vs. 18.1 kg/day) in cows fed control versus spAFC, respectively. Milk yield (25.2 versus 23.1 kg/day), along with contents and yields of milk fat (4.15 versus 3.89 %; 1.02 versus 0.92 kg/day) and milk true protein (3.53 versus 3.63 %; 0.86 versus 0.85 kg/day) did not differ between treatments. Similarly, no difference was observed for average daily weight gain (0.56 versus 0.77 kg/day). A trend (P = 0.06) for greater MUN (13.1 versus 14.7 mg/dL) was observed with feeding spAFC rather than the control treatment. No significant differences were observed for the plasma concentrations of urea-N (11.9 versus 12.2 mg/dL) and non-esterified fatty acids (176 versus 174 mEq/L), or for the ruminal concentration of total volatile fatty acids (73.1 vs. 75.1 mM). Ruminal molar proportions of acetate (70.0 versus 69.8 mol/100 mol), propionate (16.2 versus 16.5 mol/100 mol), and butyrate (113. versus 11.1 mol/100 mol) also did not differ significantly between treatments. The lack of treatments effects on animal production and ruminal metabolism may have been caused by the relatively similar nutrient composition of both pasture sources used in the spring experiment.
Botanical composition (dry matter basis) for the control treatment averaged 69% grasses, 11% legumes, and 20% other (broadleaf, weeds, and dead), while that for suAFC treatment averaged 61% grasses, 13% legumes, 1% AFC grasses, 2% AFC legumes, 12% AFC broadleaf, and 11% other (non-AFC broadleaf, weeds, and dead). Pasture biomass averaged 2,774± 275 and 2,588 ± 272 kg of dry matter/ha for the control and suAFC treatments, respectively. Pasture nutrient composition during the sampling period averaged 12.9% and 14.8% crude protein, 53.1% and 50.1% neutral detergent fiber, and 35.0% and 38.8% acid detergent fiber for the control and suAFC, respectively (UNH-Grazing-Experiments).
Animal production, plasma metabolites, and ruminal fermentation profile data can be found in the UNH Grazing Experiments attachment (UNH-Grazing-Experiments). There were no significant differences for the intake of pasture (8.26 versus 8.75 kg/day), total mixed ration (11.2 versus 11.6 kg/day), and total dry matter (19.6 versus 20.3 kg/day), average daily weigh gain (0.65 versus 0.57 kg/day), or milk yield (17.1 versus 17.0 kg/day) between control and suAFC treatments, respectively. However, concentrations and yields of milk fat (4.42 versus 5.02 %; 0.78 versus 0.93 kg/day) and milk true protein (3.49 versus 3.73%; 0.61 versus 0.69 kg/day) were significantly greater in cows offered suAFC than control. These responses were independent of intake and milk yield, thus suggesting improved nutrient utilization. A trend (P = 0.09) for lower MUN (11.8 versus 10.8 mg/dL) in cows fed suAFC vs. control was observed. Cows offered suAFC also had significantly less concentration of plasma urea-N than those offered control (10.6 versus 8.92 mg/dL). Decreased milk urea-N and plasma urea-N in cows offered suAFC suggests improved N use efficiency. Ruminal concentrations of total volatile fatty acids (74.6 versus 75.0 mM) and plasma non-esterified fatty acids (174 versus 168 mEq/L) did not differ significantly between treatments. Ruminal acetate (71.8 versus 71.8 mol/100 mol), propionate (15.5 versus 15.6 mol/100 mol), and butyrate (10.6 versus 10.5 mol/100 mol) also did not differ between control and suAFC.
UNH site (Soil Health Research)
Overall, soil density, aggregates, and sand concentration were not affected AFC monocultures or mixtures. Likewise, N and carbon concentrations, as well as the carbon:N ratio of the microbial biomass were not affected by AFC monocultures or mixtures in the present study. The lack of treatment differences in soil attributes may have been caused by the short period of AFC establishment (2 years) relative to time needed for changing soil properties and microbial communities.
PSU site (Agronomic Research)
Yield results from the alternative crop trials are shown in PSU AFC Field Trials (PSU-AFC-Field-Trials) . These results showed that some of the double cropping alternatives have resulted in higher annual yields, while providing winter soil cover at the same time.
PSU site (Animal Research)
See Harper et al. (2017a) attachment for further details (Harper-et-al.-2017a).
Double cropping and increasing crop diversity could improve dairy farm economic and environmental sustainability. In this experiment, corn silage was partially replaced with 2 alternative forages, brown midrib-6 brachytic dwarf forage sorghum or fall-grown oat silage, in the diet of lactating dairy cows. We investigated the effect on dry matter intake, milk production, milk components and fatty acid profile, apparent total-tract nutrient digestibility, N utilization, enteric methane emissions, and income over feed cost. We analyzed the in situ dry matter and neutral detergent fiber disappearance of the alternative forages versus corn silage and alfalfa haylage. Sorghum was grown in the summer and harvested in the milk stage. Oats were grown in the fall and harvested in the boot stage. Compared with corn silage, neutral detergent fiber and acid detergent fiber concentrations were higher in the alternative forages. Lignin content was highest for sorghum silage and similar for corn silage and oat silage. The alternative forages had less than 1% starch compared with the approximately 35% starch in the corn silage. Ruminal in situ dry matter effective degradability was similar, although statistically different, for corn silage and oat silage, but lower for sorghum silage. Sorghum silage inclusion decreased dry matter intake, milk production, and milk protein content but increased milk fat and maintained energy-corrected milk production similar to the control. Oat silage had no effect on dry matter intake, milk production, or milk components compared to the control. The oat silage diet increased apparent total-tract digestibility of dietary nutrients, except starch, whereas the sorghum diet slightly decreased dry matter, organic matter, crude protein, and starch digestibility. Cows consuming the oat silage diet had higher MUN and urinary urea N concentrations. Milk N efficiency was decreased by the sorghum diet. Diets did not affect enteric methane or carbon dioxide emissions. This study shows that oat silage can partially replace corn silage at 10% of the diet dry matter with no effect on milk production. Brown midrib sorghum silage harvested at the milk stage with <1% starch may decrease dry matter intake and milk production in dairy cows.
The economic outcome of the use of alternative forages is critical for their adoption. The IOFC of corn silage and oat silage were comparable at $9.49 and $9.43/cow per day, respectively. The sorghum silage diet resulted in slightly lower IOFC, $9.32/cow/d. A disadvantage in double cropping fall oats in central PA is that they must be planted in mid-August to yield well. To plant at that time, a short-season corn (<85 d relative maturity) must be used. Short-season corn usually has a decreased yield compared with longer season varieties, and its use raises corn crop production costs. The sorghum silage diet had the lowest IOFC due to a lower production and a lower BMR sorghum crop yield, even though input costs were lower. When we ran the IOFC analysis with a 65 milking cow dairy, we had to account for rental costs of additional arable land to produce the necessary forage because of the low yield from a late planting date. Sorghum would have an advantage of using less irrigation water, but irrigation is not very common in the northeastern United States, and therefore it was not included in the IOFC analysis. Sorghum can perform better than corn silage on soils with low water-holding capacity, which would positively affect the IOFC of sorghum silage. Using a scenario of a higher yield of 13.4 t/ha that would be more typical with a proper planting, we found the IOFC of sorghum silage to increase to $9.43/cow per day. This outcome is equal to that of the oat silage scenario and only $0.06/cow per day lower than the corn silage scenario. The reported results are only a model and individual farm results would vary, but they do demonstrate that, financially, these forages deserve consideration in dairy farm crop rotations and lactating cow feeding programs.
See Harper et al. (2017b) attachment for further details (Harper-et-al-2017b).
The objective of this experiment was to partially replace corn silage with 2 alternative forages, wheat or triticale silages at 10% of the diet dry matter, and investigate the effects on dairy cow productivity, nutrient utilization, enteric methane emissions, and farm IOFC. Wheat and triticale were planted in the fall as cover crops and harvested in the spring at the boot stage. Neutral- and acid-detergent fiber and lignin concentrations were higher in the wheat and triticale silages compared with corn silage. The forages had similar ruminal in situ effective degradability of dry matter. Both alternative forages had 1% starch or less compared with the approximately 35% starch in corn silage. Dry matter intake was not affected by diet, but both wheat and triticale silage decreased yield of milk (41.4 and 41.2 vs. 42.7 ± 5.18 kg/d) and milk components, compared with corn silage. Milk fat from cows fed the alternative forage diets contained higher concentrations of 4:0, 6:0, and 18:0 and tended to have lower concentrations of total trans fatty acids. Apparent total-tract digestibility of dry matter and organic matter was decreased in the wheat silage diet, and digestibility of neutral-and acid-detergent fiber was increased in the triticale silage diet. The wheat and triticale silage diets resulted in higher excretion of urinary urea, higher MUN, and lower milk N efficiency compared with the corn silage diet. Enteric methane emission per kilogram of energy-corrected milk was highest in the triticale silage diet, whereas carbon dioxide emission was decreased by both wheat and triticale silage. This study showed that, at milk production of around 42 kg/d, wheat silage and triticale silage can partially replace corn silage dry matter and not affect dry matter intake, but milk yield may decrease slightly. For dairy farms in need of more forage, triticale or wheat double cropped with corn silage may be an appropriate cropping strategy.
The IOFC of corn silage was $11.05 and decreased to $10.39 and $10.26 for wheat silage and triticale silage, respectively. Decreased per hectare corn silage yield due to later corn planting and decreased milk yield caused the decrease in IOFC for wheat silage and triticale silage. The higher IOFC for wheat silage over triticale silage was due to the numerically higher milk and milk fat yield resulting in higher calculated income. The wheat silage and triticale silage diets were not least cost formulations and did not fully use the protein value of the alternative forages, as indicated by the higher MUN and urinary urea N losses. Likely, the supplemental protein content of wheat silage and triticale silage could be decreased to lower costs of on-farm rations.
Strip-tillage of spring available AFC into perennial legume-grass pasture mixture increased herbage biomass production and did not negatively affect milk production and milk components when grazed by lactating organic Jersey cows. Strip-tillage of summer available AFC into perennial legume-grass pasture mixture did not increase herbage biomass production or negatively impacted milk production. However, yields of milk fat and true protein were increased in cows that grazed summer-available AFC versus traditional legume-grass pasture mixture. Overall, it was difficult to establish AFC using strip tillage because of the competition with the established stand of perennial, cool season legumes-grass mixture. Thus, strip-tillage of AFC into established pasture does not seem to be justified based on the marginal increase in forage productivity and similar animal production when compared with traditional pastures. Farmers considering the use of AFC should establish these alternative forage sources using traditional tillage approaches to avoid competition with established pasture.
We demonstrated that fall-grown oat and BMR-6 dwarf sorghum silages could support milk production above 38 kg/d when included at 10% of the diet dry matter replacing corn silage. The oat silage diet gave similar dry matter intake, milk production, and milk component yields as the control corn silage diet. The higher MUN and urinary urea N excretion with oat silage reveals a potential for reducing dietary protein from other feed sources when replacing corn silage for oat silage. The sorghum silage diet decreased dry matter intake, milk production, and milk protein yield, which indicates a need for additional rumen digestible energy sources when feeding low-starch sorghum silage in place of corn silage. The alternative forages tested in this study have potential in an integrated cropping strategy and nutritional program for high-producing dairy cows.
We demonstrated that triticale and wheat cover crops harvested as silage at the boot stage can support milk production above 41 kg/d when included at 10% of the diet dry matter replacing corn silage. Triticale and wheat silage inclusion did not affect dry matter intake, but decreased milk production compared with corn silage, likely due to replacing starch with fiber. Higher crude protein content in the alternative forages along with lower starch resulted in higher urinary urea excretion, higher MUN concentration, and lower milk N efficiency. Enteric methane emissions per kilogram of energy-corrected milk was increased by triticale silage. Triticale silage had higher in situ effective degradability of fiber and a slightly higher crop yield than wheat silage, although IOFC was slightly more favorable for wheat silage due to higher milk production and milk protein content. Both alternative forages provide a highly digestible source of fiber that can successfully replace corn silage at low inclusion rates. For dairy farms in need of more forage, triticale or wheat double-cropped with corn silage may be an appropriate cropping strategy.
This project combine comprehensive AFC education and research that explored forage-based approaches for improving profitability of NH and PA dairy farms. We conduct focus group interviews with over 60 dairy farmers (conventional and organic) across the Northeast (NH, ME, VT, NY, and PA) to better understand current AFC practices and constraints to larger-scale adoption. We also collected information about research and extension needs related to AFC. The educational program proceeded through a multi-pronged approach that included field days, direct farmer-to-farmer learning, web-driven technology transfer, and development of IOFC budgets.
Field days were conducted at the UNH-Organic Dairy Research Farm (Lee, NH), UNH Fairchild Dairy Teaching and Research Center (Durham, NH) and PSU-Russell Larson Research Farm (Rock Springs, PA) to demonstrate how agronomic constraints to AFC production can be overcome to help farmers make informed decisions about establishing AFC in their enterprises. Based on knowledge acquired at the University field days, engaged farmers, with the assistance from our project team, selected specific AFC to try on their farms. To facilitate farmer-to-farmer learning, we collaborated with 4 dairy farmers in NH and PA to set up demonstration trials. These trials helped farmers educate peers about the use of AFC. Participants had the opportunity to evaluate AFC within actual specific production systems. Short videos were produced by our team and posted on University extension websites to bring participants to a common level of knowledge about AFC and a common understanding of the project goals and learning opportunities. Information gained through University experiments and on-farm demonstration trials, including costs of AFC per unit of dry matter and IOFC budgets were used to educate dairy farmers, extension educators, and the scientific community through videos, presentations, field days, and articles.
Throughout the project we conducted a total of 5 focus groups interviews with funding from this project in combination with funding from an OREI-NIFA planning grant. Focus groups were conducted in NH, VT, ME, PA, and NY. Overall, we able to better understand knowledge gaps related to AFC production, high-forage diets, and no-grain rations. During these focus groups we also had opportunities to share preliminary project results
We collaborated with the Northeast Pasture Consortium and Northeast Organic Dairy Producers Alliance (NODPA) Field Days and Annual Meeting in 2 surveys to gain knowledge about limitations in pasture management, forage production (including AFC), and no-grain rations in the Northeast. Our decision to partnership with the Northeast Pasture Consortium and NODPA was to leverage farmers participation without over-surveying this community in the region.
In addition to the survey, 3 workshops about pasture management, forage production (annuals and perennials), and no-grain rations were conducted in collaboration with Granite State Graziers Association, Northeast Pasture Consortium, and Kings Agriseeds with a total of 60 participants. We were also able to partnership with 4 dairy farmers (2 in NH and 2 in PA) who agreed to grow AFC in their farms. Overall, we identified the following knowledge gaps: (1) strategies that improve the stability of the legume component within mixed-species forage swards (i.e., legume persistence); (2) strategies that improve nutritive value and optimal energy:protein balance of forages including perennials and AFC; and (3) research that elucidates the linkages between soil health parameters, pasture sward composition and nutritive value, and grazing practices that promote pasture sward resilience, and grazing season extension.
We conducted 3 workshops (see above) about pasture management, forage production (annuals and perennials), and no-grain rations in collaboration with Granite State Graziers Association, Northeast Pasture Consortium, and Kings Agriseeds with a total of 60 participants. We decided not to host at UNH and PSU so we could engage more dairy famers in events that they may be more willing to attend. We provide a background about project, an overview of AFC production and management, and profitability of replacing corn silage with AFC sources. Simulations with the Integrated Farm Systems Model (IFSM) were presented and farmers were able to see how to use the IFSM to estimate profitability and greenhouse gas emissions in dairy farms using corn silage, and high-forage and no-grain rations.
Field days at UNH, PSU, and collaborator farmers took place throughout the project. Both UNH and PSU host annual field days in collaboration with University Cooperative Extension and Agricultural Experiment Stations. Approximately 60 participants (farmers, students, extension educators, general public) attended our events where preliminary data (AFC yields, milk production, methane emissions) were shared and attendees had the opportunity to actually see agronomic plots and grazing swards used in the feeding trials. Videos were posted at: https://www.youtube.com/watch?v=HiPjrL4vVcw&feature=youtu.be
As stated above, field days at UNH, PSU, and collaborator farmers took place throughout the project. Both UNH and PSU host annual field days in collaboration with University Cooperative Extension and Agricultural Experiment Stations. Approximately 60 participants (farmers, students, extension educators, general public) attended our events annually where preliminary data (AFC yields, milk production, methane emissions) were shared and attendees had the opportunity to actually see agronomic plots and grazing swards used in the feeding trials. Both NH and PA farmers who collaborated with our team planted AFC in their farms. Benedikt-Dairy-2016-Summer-annual-planting-report1
Videos were posted at:
Our YouTube Video has reached 23,000 views to date.
We kept contact with our 4 close collaborators by visiting their farms, providing seeds, and supporting technical information related to AFC production. On each farm, forage production was tracked along with production practices to develop case studies of effective management tactics. These results were summarized and the data used as part of our educational meetings and field days.
As stated above, field days at UNH, PSU, and collaborator farmers took place throughout the project. Both UNH and PSU host annual field days in collaboration with University Cooperative Extension and Agricultural Experiment Stations. Approximately 60 participants (farmers, students, extension educators, general public) attended our events annually where preliminary data (AFC yields, milk production, methane emissions) were shared and attendees had the opportunity to actually see agronomic plots and grazing swards used in the feeding trials. Forage production was tracked along with production practices to develop case studies of effective management tactics in our 4 collaborating farms.
As stated above, field days at UNH, PSU, and collaborator farmers took place throughout the project. Both UNH and PSU host annual field days in collaboration with University Cooperative Extension and Agricultural Experiment Stations. Approximately 60 participants (farmers, students, extension educators, general public) attended our events annually where preliminary data (AFC yields, milk production, methane emissions) were shared and attendees had the opportunity to actually see agronomic plots and grazing swards used in the feeding trials. Our greenhouse gas data based on feeding trials conducted at UNH and PSU showed no substantial changes in methane and carbon dioxide emission in dairy cows fed AFC.
The current SARE project was conducted in collaboration with a regional OREI project led bi PI Brito. In both projects we collaborated with dairy farmers (conventional and organic) across NH, VT, ME, PA, and NY. Our estimations are that more than 200 northeastern organic dairies have adopted or fine-tuned the use of annual forage crops to extend the grazing season and more than 6,000 acres of organic summer annuals have been planted in NH, VT, ME, PA, and NY). We will continue to strengthen this network and keep communicating with farmers and extension educators to disseminate project results and exchange experiences about AFC production and adoption in the region.
Milestone Activities and Participation Summary
Pasture mangement, corn silage production, AFC production and management.
Performance Target Outcomes
Adopt AFC for grazing or silage production.
120-days of forage surplus.
Farmers in PA and NH tried several AFC in mixture or monocultures and different rotation systems.
AFC used as grazed forage or silage maintain milk production.
Income over feed costs were by using AFC were comparable to corn silage or traditional perennial grass-legume pasture mix.
We estimate that at least 30 dairy farmers made changes in AFC practices based on this project verified by exchanges with farmers during project events such field days, workshops, and conferences. We directly verified that 4 dairy farmers with whom we worked closely tested different AFC mixtures and made adjustment in practices in consultation with project team. We also estimated that more than 200 northeastern organic dairies have adopted or fine-tuned the use of annual forage crops to extend the grazing season and increase forage production from the combined education program of this project and the OREI.
Additional Project Outcomes
This grant was very important to gain knowledge about AFC in the Northeast. This proposal leverage previous OREI funding led by PI Brito that also had an AFC component. So, both projects share activities and audience in several opportunities. Specifically, agronomic work done at UVM with spring, summer, and fall AFC by Heather Darby (co-PI in the OREI project) complemented research done at UNH led by co-PD Smith and at PSU by co-PD Roth.
Below are farmer’s testimonials collected after participation in project events:
“Very informative project, information on high forage programs and soil fertility helped me increase milk production by 5 lb per cow”.
“Working closely with this program helped me reduce grain purchases by 25% and helped put more money back in my pocket”.
"2016 had 4 consecutive months of severe drought making establishment of summer crops difficult. The results we saw were none the less promising. I am particularly fond of millet as a forage crop for the dry summer as it needs minimal water to grow, grows rapidly, appears to be very palatable and re-grows for a second grazing. Oats, wheat and triticale did not do well in dry conditions. Our legumes in the mix, vetch and sunn hemp failed completely in the drought. Radish and Canola grew well and appeared to be palatable."
The collaboration with extension educators and 4 dairy farmers was key to implement research/demonstration plots that were used for grazing and forage production. I think we successfully leveraged this project by collaborating with folks from the OREI project (Heather Darby-UVM, Fay Benson-Cornell, and Rick Kersbergen-University of Maine) who were conducted research on AFC. We had challenges to establish fall AFC in NH for grazing due to droughts. We also think that strip tillage did not produce enough AFC forage. So, it seems that AFC should be established after full tillage in the field.
- Using brown midrib 6 dwarf forage sorghum silage and fall-grown oat silage in lactating dairy cow rations (Peer-reviewed Journal Article)
- Inclusion of wheat and triticale silage in the diet of lactating dairy cows (Peer-reviewed Journal Article)