Objective 1. To determine if warm-season grasses will increase forage availability during summer months when compared to a traditional cool-season system.
Objective 2. To determine the most productive and economically advantageous method of establishment (monoculture or interseeded) for the two warm-season test forages in horse pastures.
Objective 3. To determine if sequential grazing in integrated cool- and warm-season pastures provides adequate nutrition to maintain optimal horse body condition.
Objective 4. To determine if any advantage in production cost exists when integrating either a warm-season annual or perennial into a traditional cool-season horse grazing system.
The purpose of this project is to investigate the potential for increasing pasture productivity, thereby extending the number of grazing days and decreasing producer feed costs through implementation of an integrated cool- and warm-season grass grazing system in horse pastures. Traditional pasture forages in temperate regions of the United States are mainly cool-season perennial grasses. Cool-season grasses are well adapted for survival of cold winters and growth in periods of cooler temperatures in spring, early summer and fall. However, these species are less tolerant of heat and drought, which leads to a period of low forage productivity often called the “summer slump”. Conversely, warm-season grasses produce their greatest yields during the hot summer months while cool-season grasses are semi-dormant. Warm-season grasses, therefore, present an intriguing option for bridging the “summer slump” forage gap.
The “summer slump” presents management challenges to horse producers, with both economic and environmental implications. Supplemental feed is often needed to meet the nutritional needs of horses during the “summer slump,” which increases feed costs during this period. Often, producers will provide supplemental feed to horses in existing pastures. Leaving horses on low productivity pastures can result in overgrazing, leading to negative consequences for the environment. If forage is overgrazed, over time vegetative cover will be reduced. Decreases in vegetative cover increase the potential for soil erosion and nutrient runoff. Furthermore, overgrazing may result in decreased forage stand persistence and weed invasion. This may necessitate more frequent pasture renovation, conferring additional cost to producers. Alternatively, producers may choose to confine horses to dry lots, allowing the pasture forage time to rest and regrow. However, dry lots often have a high stocking density and lack vegetative filtration, increasing the risk for nutrient runoff and erosion. Thus, the “summer slump” negatively impacts economic and environmental sustainability in horse operations.
Developing a grazing system comprised of complementary cool- and warm-season forage varieties would potentially provide more uniform productivity over the grazing season, increasing overall yield and reducing costs associated with supplemental feeding during periods of summer drought. This management strategy is recommended to producers in various industry and extension programs and publications, but little research has been conducted to support the utility of integrated grazing systems for horse producers. Most recommendations are based upon cattle grazing studies. Extrapolating data from studies in other livestock species is often of limited value in management decisions for horse operations. Forage preference, grazing behaviors, nutritional requirements, digestive physiology, animal management goals, and drivers of enterprise profitability are vastly different. While studies in cattle have not shown an economic benefit associated with implementation of integrated cool- and warm- season rotational grazing systems, integrating warm-season grasses into a cool-season pasture system may be better suited to feeding and nutritional goals of horse producers as horses are fed to maintain weight and sustain athletic performance rather than for maximal growth. In fact, over-consumption of cool-season grasses high in non-structural carbohydrates has been linked to many negative health outcomes in horses related to equine metabolic syndrome including obesity, insulin resistance and pasture-associated laminitis.
The goal of this project is to determine if two warm-season forage grasses, Quick-N-Big crabgrass and Wrangler bermudagrass, possess utility and economic advantage as alternative summer forages in temperate equine grazing systems. The results of this project will provide much-needed data on forage yield, persistence (vegetative cover), nutritional value, and production costs associated with integration of warm-season grasses into cool-season temperate pastures in the upper transition zone. Discoveries in this area could have real-world impact on horse producers, informing management decisions and shaping best management practices in equine grazing designed to improve economic and environmental sustainability of equine operations. In addition, these results will provide key information for other livestock producers interested in alternative forages.
General Grazing System: This project is being conducted at the Rutgers’ Ryders Lane Best Management Practices Demonstration Horse Farm. Three separate rotational grazing systems, each consisting of 6 sections, were established. System 1 will serve as a control, and all sections was planted with a cool-season grass mix (CON-CSG). Inavale Orchardgrass (OG), Tower Tall Fescue (endophyte-free) (TF), and Argyle Kentucky Bluegrass (KB) (DLF Pickseed, Halsey, OR) were planted in a 24-16-16 mix for a total seeding rate of 56 kg/ha. System 2 and System 3 were integrated systems (IRS-BER; IRS-CRB) utilizing Wrangler bermudagrass (BER) or Quick-N-Big crabgrass (CRB) as test forages. Sections in each integrated system were planted as follows: three as a cool-season grass mix in and three in a test forage monoculture section. The BER was planted at a seeding rate of 34 kg/ha as a monoculture. A seeding rate of 13 kg/ha was used for the monoculture CRB sections. In the fall 2017, vegetation in all sections of each system was killed with glyphosate (Roundup®) and all sections were re-planted with the cool-season mix. After close grazing of two sections in the spring, the warm-season grass (WSG) test forages were planted in Systems 2 and 3. In the monoculture sections, glyphosate was applied after close grazing to eliminate existing forage and the test forage was no-till planted into the existing sod. Due to weather-related delays in 2018, planting of the WSG did not occur until late June. As the target for planting was in late May or early June after soil temperatures reached 18°C, this significant delay necessitated postponing full data collection until the 2019 grazing season and only preliminary data were collected in 2018. In 2019, seeding of monoculture CRB was completed on June 3. Re-growth of BER (perennial) was poor, and therefore BER sections were once again sprayed with glyphosate and re-planted at the above rate in mid-June.
In 2019, horses began spring grazing of CSG when the forage in CSGS sections reached a height of approximately 15.2 cm. Horses were allowed to graze a given section until forage was reduced to approximately 7.6 cm sward height, at which time horses wer moved to a new section to begin grazing. Previously grazed sections were then allowed to regrow to a 15.2 cm sward height. Sequential grazing of WSG sections began once the planted forage reached at least 15.2 cm. All sections were then managed with the take-half, leave-half rule as described above (Crider 1955). After horses were removed from a grazed section, any remaining tall weeds were mowed to a height of 7.6 cm, and the pasture was dragged to evenly spread out manure from defecation areas. Horses were allowed 24-hour ad libitum access to pasture forage. If adequate pasture forage was not available (no sections at 15.2 cm) when horses were to be rotated, horses were confined to a sacrifice (or stress) lot and supplemental grass hay was provided at 2% of body weight(BW) on a dry-matter (DM) basis.
Horses: Nine adult Standardbred mares with a body condition score (BCS) of 5-7 out of 9 were used for the study. Prior to grazing horses was weighed and assigned a BCS. Horses was grouped by body weight so that each group represents a similar carrying capacity on a per-kilogram basis. Groups of three horses were randomly assigned to each of the three grazing systems.
Weather: Weather data was tracked using the Rutgers Office of the State Climatologist for the New Brunswick station and will include daily temperature, daily precipitation, and relative humidity for each of the sampling days and monthly averages.
Forage Measurements: To determine if WSG would increase forage availability during summer months, grazing days, yield, and persistence were compared between traditional and integrated systems. The number of grazing days in each section of each system was tracked and recorded. Prior to grazing of each section, herbage mass (HM) and sward height (SH) were determined as measures of yield. Vegetative cover and species composition were assessed as measures of forage species persistence. The HM was determined by hand-clipping random sub-quadrants of pasture forage to estimate yield. A 0.5 m wooden square was placed randomly at 4 sites in each 0.4 ha section of pasture, and forage in each square was clipped to 7.6 cm to represent minimum allowed grazing height. Forage clipped was placed in a paper bag and dried at 60°C in a Thelco oven to remove moisture content and obtain a dry matter weight. The HM was then estimated using the following equation: kg/ac = ¼ ([g/m2 [collected sample] x [4,047/1,000] x 2.47) (Kenny 2016). The SH was determined by dropping a styrofoam plate down a meter stick and recording the height where the plate rests on the forage (Burk et al., 2011). Twenty-five measurements were taken per section of pasture. Species composition and vegetative cover were evaluated using the Step Point method, performed by transecting each pasture approximately 8 times, stopping every 20 steps to pass a pin over the toe of the observer’s boot at a 30-40° angle into the forage canopy (Evans and Love, 1956). The first species touched by the pin (or potentially bare ground) was identified. A total of 25 observations per section was recorded.
Animal Measures: To determine if sequential grazing in integrated cool- and warm-season pastures provides adequate nutrition to maintain optimal horse body condition, the amount of forage consumed was estimated, forage nutritive value was analyzed, and horse body condition was assessed. The amount of forage consumed was determined by taking additional HM measurements at the conclusion of grazing in each section using the method described for Objective 1 and subtracting those measurements from the measurements taken in Objective 1. Forage nutrient composition was analyzed by collecting samples hand-clipped to a 7.6 cm height. Samples were weighed before and after drying at 60º C for at least 36 hours in a Thermocore oven to calculate dry matter (DM). After drying, samples were ground to 1 mm using a Wiley Mill and submitted to Equi-Analytical Laboratories (Ithaca, NY) for wet chemistry analysis. Digestible energy (DE), crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), water soluble carbohydrate (WSC), ethanol soluble carbohydrates (ESC), starch, calcium and phosphorus content were determined. Horse body condition was assessed by body weight (BW), percent body fat (FAT), and body condition score (BSC). Horse BW was measured by using an electronic scale, and FAT was determined using the Westervelt method (1976) which uses a regression equation to convert ultrasonographic measurement of subcutaneous rump fat to an overall body fat percentage. BCS was evaluated using the Henneke Body Condition Score scale (Henneke 1983). In this method, fat cover over 5 different areas of the body (crest of neck, topline, over the ribs, behind the shoulder, and over the tailhead) is assessed on a scale of 1-9, with 1 being emaciated and 9 morbidly obese.
Production Cost: To determine if any advantage in production cost exists in integrating either a WSG annual or perennial into traditional cool-season grazing system, total production costs was calculated and compared for each system. Relevant costs include cost of establishment (herbicide, fertilizer, seed, equipment and labor costs), pasture maintenance (mowing and dragging), and supplemental feeding (if any). As described above, in the event that pasture forage is inadequate for grazing, horses were confined to a stress lot and fed supplemental hay at 2% BW DM. Any hay provided was weighed, and the cost of that feed was calculated.
Plot Design and Forage Establishment: Differences between monoculture establishment and interseeding of WSG test forages was evaluated in small plots using a randomized complete block design (Grev et al., 2018). Two main plots each containing four replicates of three treatments (CSG, MON (either CRB or BER in monoculture), and INT (either CRB or BER interseeded) for a total of 12 sub-plots per main plot were established. The CSG had been planted in the fall of 2017. The WSG test forages were planted in early- to mid-June 2019. The MON plots were planted at the above specified rate used for the full-pasture study. The INT plots were planted at a rate of 24 kg/ha for BER and 7 kg/ha for CRB.
Grazing Events: Horses in each integrated system grazed each main plot for one 8-hr grazing event (2 days of grazing, one in each main plot). Horses had access to all replicates within the main plot during the grazing event. Grazing events were repeated 3 times across the grazing season.
Pasture Measures: Prior to each grazing event, yield and persistence parameters were evaluated similar to the above description for the full pasture study. For HM, a 0.25 m square was used to collect three samples per sub-plot. For SH and species composition, ten measures were collected for each sub-plot. Hand-clipped forage samples were collected for each of the sub-plots and then pooled by treatment within each main plot.
2018: Preliminary Data
Due to weather-related delays in establishment of pasture fields, full data collection for this project was postponed to the 2019 grazing season. Warm-season test forages planted in monoculture were utilized for collection of preliminary data and results are presented below.
Sample/data collection will not commence until the beginning of the 2018 grazing season (April-May 2018). Mean herbage mass prior to the first grazing rotation did not differ by forage type (CRAB 2,174.7 ± 189.4 kg/ha; BERM 2254.7 ± 268.3 kg/ha). Furthermore, yield recorded in CRAB and BERM was similar to herbage mass of cool-season pasture sections at their peak production prior to first grazing in late spring (2244 ± 140.6 kg/ha). However, due to late establishment, data was only collected on one rotation through all sections of each warm-season forage, and a full season of data collection will be necessary to fully evaluate pasture production in the integrated systems compared to the traditional cool-season control.
The mean nutrient content of pasture samples collected over 48-hr diurnal sampling periods is shown in Table 1. Both warm-season test forages were below the NSC risk threshold (10% NSC) for exacerbation of conditions associated with Equine Metabolic Syndrome such as pasture-associated laminitis (CRAB 8.15 ± 0.42%; BERM 4.89 ± 0.21%). Starch content was greater in CRAB (4.04 ± 0.42%) than BERM (0.86 ± 0.61%; p<0.0001). Crude protein was high in both test forages (CRAB 20.59 ± 0.33%; BERM 22.27 ± 0.43%). Digestible energy was also similar in CRAB (2.07 ± 0.02 Mcal/kg) and BERM (2.02 ± 0.02 Mcal/kg).
Diurnal variation in NSC was evident in both CRAB and BERM (Figure 1). Similar diurnal variation occurred in the water-soluble carbohydrate (WSC) fraction in BERM (Figure 1a). However, in CRAB, diurnal variation appeared to be driven by the starch fraction rather than WSC (Figure 1b).
Horses lost weight over the initial week of grazing BERM (-19.96 ± 3.12 %BW) while the horses on CRAB maintained BW (-0.79 ± 2.26 %BW). However, over a 2-3 weeks of adaptation to their respective warm-season test forage, horses on both forages exhibited little change in body weight. (BERM 2.68 ± 0.640 %BW; 0.47 ± 1.43 %BW). This indicates that nutrients supplied by the warm-season test varieties may be adequate to maintain body weight in the grazing horse while potentially limiting weight gain. More data is necessary to determine if results are similar in horses grazing in integrated systems over a full grazing season and weight and body condition differ from horses grazing traditional cool-season pasture.
In all, a full grazing season is necessary to evaluate the production benefits of integrated grazing seasons and the utility of the “Wrangler” bermudagrass and “Quick N Big” crabgrass varieties as potential alternative forage sources in equine grazing systems. However, preliminary results suggests that these test forages may offer adequate production and nutritional value to maintain horses on pasture over the “summer slump”.
2019: Full-Pasture and Small-Plot Studies
Full Pasture Study
Summer re-growth of previously established BER (in 2018) in the full pasture sections was poor. Re-seeding of BER sections (2019) also resulted in inadequate establishment, even following repeated application of Nitrogen fertilizer and weed management with 2,4 D and mowing. Of the three sections planted with BER, one section had so little BER established that it was not possible to graze. The remaining two sections were evaluated and grazed, but prevalence of the planted BER was ≤ 60%. Only one rotation of each BER section was possible, as the delay in establishment resulted in inadequate re-growth for subsequent rotations prior to the onset of cooler temperatures at the end of the BER growing season window. The establishment was similarly poor in the BER small plots. Thus, it was not possible to complete a full evaluation of the IRS-BER system. The results communicated below are, therefore, for the IRS-CRB and CON-CSG systems only, in addition to the CRB small plot study.
In the full pasture study, grazing began on May 17, 2019, and horses in both the IRS-CRB and CON-CSG had access to CSG forage beginning at that date. For IRS-CRB, horses were removed from pasture for the final time on October 25, 2019. Horses in CON-CSG were removed from pasture on November 9, 2019. Of the full grazing season duration (May 17 to Nov 9), horses in IRS-CRB had pasture access for 123 days. Horses in CON-CSG had pasture access for 104 days. Therefore, the IRS system supported horses on pasture for 69% of the grazing season, while the CON-CSG allowed grazing for 59% of the season. For IRS-CRB, there were a total of 18 rotations, and for CON-CSG, there were 16 rotations.
Horses for both systems had access to CSG pasture sections from mid-May to mid-July. Pasture yield was high during these months, and only three rotations were required in each of the systems. The three sections of CON-CSG that were not grazed during this period had to be mowed, as they were becoming over-mature. Regrowth in these sections was subsequently grazed upon reaching an adequate height in July.
The CRB was planted in IRS-CRB on June 3, 2019, and the initial growth was sufficient for grazing beginning on July 15. This also coincided with a decline in forage production in the CSG sections entering the summer slump. The CRB sections were grazed during the “summer slump” period from mid-July to mid-September, when cooler temperatures began to slow the growth of CRB and allow for the CSG to once again be more productive. During this period, CRB production was high, and two of the sections had to be mowed prior to grazing rotation (horses then grazed re-growth) for weed control purposes. In late September through early October, unseasonably warm temperatures returned, however, allowing for additional rotations to graze the forage remaining in the CRB sections in mid-October. Because the objectives of our study were to evaluate forage production during the “summer slump” and to determine if integrating warm-season grasses could bridge the “summer slump” forage gap, the analysis of pasture production reported below focuses primarily on this period (mid-July through mid-September).
Mean SH during the “summer slump” period was greater in CRB sections (35.63 ± 5.81 cm) of IRS-CRB than in the CSG sections within that grazing system (15.92 ± 5.81 cm; p <0.05; Figure 1). Mean SH of CRB sections was also greater than that of CSG sections in the CON-CSG system (13.12 ± 5.81 cm; p < 0.05). Total HM on-offer (available to be grazed) produced in each section during the “summer slump” was greater in CRB (3,482 ± 459 kg/ha) than CSG sections within IRS-CRB (1086 ± 459 kg/ha) or in CON-CSG (970 ± 459 kg/ha; p < 0.05; Figure 2). Total grazing days per section was greater for CRB (16.0 ± 2.38 d) than for CSG sections within IRS-CRB (3.33 16.0 ± 2.38 d) or in CON-CSG (5.0 16.0 ± 2.38 d; p < 0.05; Figure 3).
The nutrient composition of CRB vs. CSG during the summer slump is shown in Table 1. There was a trend for greater water-soluble carbohydrate (WSC) content in CRB (6.91 ± 0.95%) compared to CSG (4.46 ± 0.67%; p < 0.07) during the summer slump (mid-July to mid-September). However, no other nutrients differed between forage types within the summer slump. Over the full grazing season, there was a trend for greater NSC and WSC in CSG (NSC: 8.70 ± 0.80; 7.76 ± 0.52 %) vs CRB (6.99 ± 0.48; 5.20 ± 0.27 %; p < 0.08), but the levels of all other nutrients did not differ. It is important to note that the magnitude of these differences in WSC or NSC is small. Furthermore, with the exception of one CSG rotational section, the NSC levels measured in both forage types during the summer slump months fell below the 10% NSC threshold established for obese horses and those with metabolic dysfunction (Frank, 2010). NSC levels were elevated above 10% for several CSG rotations occurring earlier in the growing season (mid-May to mid-July) and in November, but NSC levels never exceeded 15%.
Horse BW, BCS, and FAT did not vary by grazing system (INT-CRB: 541.7 ± 24.0 kg, 5.73 ± 0.46, 15.9 ± 0.78 %; CON-CSG: 549.19 ± 24.0 kg, 6.05 ± 0.46, 17.2 ± 0.78 %). Horse BW and FAT did differ by month, however, while there was only a trend for a monthly difference in BCS (p < 0.10). Monthly data are shown in Figure 24(A-C). While these results did not support the original hypothesis, they are not surprising. Horses in each system were maintained on CSG pasture sections for the same number of grazing days from the initial grazing beginning in mid-May to the start of the summer slump (and first availability of CRB) in mid-July. Thus, it is logical that an increase in these measures of animal condition would be similar between systems during these months. However, horses in IRS-CRB had unlimited pasture access throughout the summer slump (mid-Jul to mid Sep), with grazing split between CRB (48 days) and CSG (14 days), while adequate pasture forage was only available for 27 days in CON-CSG during this period. Horses in CON-CSG were thus confined to a stress lot for over half of the summer slump period. When confined to the stress lot, horses were fed supplemental hay at the maintenance requirement of 2% BW DM. In CON-CSG, horse BW decreased in September (p < 0.05), and horses had been confined to a stress lot without ad libitum pasture access for more than a month at the time the September horse condition measures were collected. Similarly, horse BW in IRS-CRB decreased in November (p < 0.05), when grazing had already ceased in this system and horses were confined to a stress lot and fed the hay diet. Conversely, fall re-growth of CSG pasture forage in CON-CSG allowed for continued grazing through mid-November, and there was a numeric increase in horse BW.
Small Plot Study (Establishment Method)
In the small plot study, the prevalence of CRB was as follows: MON – 63.3%; INT – 33.3%; and CSG – 12.5%. Establishment in the MON did not match levels seen in the full pasture sections (>85%), which was attributable to emergence of weeds (primarily foxtail) and instances of dead forage in the later grazing events. The prevalence of planted grasses (CRB in MON; CRB, KB, OG, TF in INT; KB, OG, TF in CSG) was greatest for INT (82.5; p < 0.05; Figure 5). As noted above, CRB was observed at low levels in some of the CSG plots. This was not evident at the first grazing, and the later emergence of the CRB in the CSG plots could be attributable to wind drift of seeds from mature CRB plants in the MON or INT plots.
With the exception of crude protein (CP), nutrient levels did not differ by treatment (shown in Table 2). The CP was greater in INT (25.83 ± 0.79 %) and CSG (25.73 ± 0.79 %) than in the MON small plots (21.78 ± 0.79 %; p < 0.05). For the small plots, no differences or trends for differences were found for soluble carbohydrate content, which differs from the results in the full pasture study. However, this may be explained by the differences in establishment level (and weed infiltration) of the CRB in the MON sub-plots vs the MON sections of the full pastures. Additionally, while the emergence of CRB in the CSG subplots was minimal, this transfer of CRB to CSG did not occur in the full pasture study.
The SH was greatest in MON plots (29.16 ± 0.59 cm), intermediate for INT plots (23.85 ± 0.59 cm) and lowest in plots established with CSG (20.11 ± 0.59 cm; p < 0.05; Figure 6). In addition, HM also differed by treatment (p < 0.05; Figure 7). The HM of MON plots (2714 ± 122 kg/ha) was greater than that of either INT (2139 ± 122 kg/ha; p < 0.05), but HM did not differ between INT and CSG (1988 ± 122 kg/ha). These differences were primarily attributable to the first grazing event in late July, as the yield in MON plots declined in August and September (p < 0.05; Figure 8). Conversely, INT yield was lowest at the first grazing event in July, but had increased at the time of the second grazing event in August and remained at a similar level in September (p < 0.05). These results suggest that the integrated approach utilized in the full pastures for this study may have merit over interseeding the CRB into an existing CSG stand, as the yield in the INT plots did not exceed that of the CSG. When comparing MON vs. INT, however, it is important to note that measurements were only collected on the plots over the “summer slump” period. Over a full grazing season, an interseeded stand would offer the advantage of forage availability in the spring/early summer and later in the fall, whereas under monoculture establishment, such areas would be non-productive during these times. Furthermore, this study only evaluated one year of growth under grazing pressure. The INT plots had the greatest prevalence of planted grasses, while weeds, dead matter, and bare ground were more common in CSG and MON, which indicates that the INT establishment approach may have advantages for stand persistence.
Data analysis and interpretation is on-going for this project. Conclusions will be updated with submission of final project report in March 2020.
Education & Outreach Activities and Participation Summary
Several tours conducted at the Ryders Lane Best Management Practices Demonstration Horse Farm at Rutgers University in the fall of 2017 previewed the upcoming research funded through SARE. Tour groups included equine science students from Rowan College as well as international delegations from China. In addition, the research to be conducted over the 2018 grazing season was introduced during the NE-1441 Annual Meeting (webinar, 8-31-2017). The upcoming research was also highlighted in the Rutgers Equine Science Center Annual Report, which is available on the ESC website (http://esc.rutgers.edu/) and was distributed in print to stakeholders in the New Jersey equine industry.
This research project was previewed at the annual Rutgers Horse Management Seminar on February 11, 2018. Preliminary results were shared during the NE-1441 Annual Meeting on August 21, 2018, as well as at the Rutgers Equine Science Center Evening of Science and Celebration on November 9, 2018. Additional tours for university and public groups were also conducted at the Ryders Lane Farm throughout 2018.
The Rutgers Equine Science Center (ESC) provides an established vehicle for widespread dissemination of equine research conducted at Rutgers University. The ESC hosts several educational seminars each year and maintains a world-class website (http://esc.rutgers.edu/) and Facebook page with almost 2,000 followers (as of April 2017). As the project progresses, results will be presented and discussed at regular ESC-sponsored events including our annual Horse Management Seminar for horse and farm owners, which attracts over 100 participants each year; the Equine Science Update, which summarizes the Center’s recent research for the general public; Stakeholder Meetings, and monthly industry meetings. We will also schedule special “Pasture Walk” workshops at the Ryders Lane Best Management Practices Horse Farm to present the results of this project to horse owners and producers interested in implementing integrated grazing systems on their own farms. New Rutgers fact sheets will be published and posted on the NJAES publications page (http://njaes.rutgers.edu/pubs/) and the ESC website and Facebook page.
Scientific publications and presentations at scientific society meetings will also be planned. This material is appropriate for general academics in animal and plant science as well as veterinarians and would be appropriate in journals like The Journal of Animal Science, Journal of Equine Veterinary Science or The Veterinary Journal. The Equine Science Society Symposium, American Society of Animal Science, and Soil Health Conference are a few conferences where this material could be presented. There are also numerous university and regional student competitions including the Mid-Atlantic Nutrition Conference and the New Jersey Agriculture Experiment Station graduate student competition where this material will be presented.
The PI of this project is involved with a regional USDA project called NE-1441: Horses and the Environment. In its eighth year as a multi-state project, NE-1441 incorporates the best regionally available data about animal use, feed, manure storage and disposal, pasture/cropping management, soil and environmental quality, erosion control, and site characteristics to meet the goal of minimizing negative environmental impacts of equine operations on soil, water, and air quality. Participating states include NJ, VA, MA, SD, MD, MN, NC, FL and PA. NE-1441 provides a national format for disseminating the results of this study.
Data analysis and interpretation is on-going.
However, we anticipate that the results of this project will provide much-needed data on forage yield, persistence (vegetative cover), nutritional value, and production costs associated with integration of warm-season grasses into cool-season temperate pastures in the upper transition zone. Discoveries in this area could have real-world impact on horse producers, informing management decisions and shaping best management practices in equine grazing designed to improve economic and environmental sustainability of equine operations. In addition, these results will provide key information for other livestock producers interested in alternative forages.
In New Jersey alone, there are 42,500 equine animals and 7,200 equine operations covering 176,000 acres of land (Rutgers Equine Science Center 2007). Results of this project have the potential to influence the pasture management decisions of many of these operators. From an environmental standpoint, continued development and promotion of best management practices in horse grazing serves to protect valuable resources, such as soil and water. From an economic perspective, teaching farm owners how to reduce costs through pasture best management practices can positively impact the financial sustainability of individual businesses, protecting the stability and viability of the entire industry.
Data analysis and interpretation is on-going for this project. As this work progresses, more details will be added to this section.
In addition to the production-centered research focused on in this project, additional grant funding has been secured to expand on the impact of integrating warm season grasses in to cool-season rotational grazing system on equine health. We are specifically interested in assessing if these alternative forages affect intake and if any alterations in intake are sufficient to elicit a physiological response in the horse in glucose/insulin dynamics. We will also evaluate the gut microbiome of grazing horses and determine if there are any differences in microbial community composition or diversity attributable to grazing warm season grasses. The final segment of this project will evaluate a crabgrass based grazing approach in obese horses.