Progress 09/01/16 to 08/31/21
Outputs
Target Audience:We directly served organic and conventional dairy farmers across the Northeast region, as well as extension educators, industry stakeholders (e.g., organic milk processors, nutritionists, veterinarians), and the scientific and academic communities (e.g., graduate and undergraduate students, post-docs, and fellow scientists). Our team disseminated project results through workshops, webinars, pasture walks, farmer-oriented conferences, and national and international scientific conferences. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The project outreach and research components are advancing as planned. Workshops and outreach activities such as presentations, dairy farm meetings, field days, farm tours, and webinars featuring project results have been delivered. Specifically, PI Brito and co-PI Smith presented project materials at the University of New Hampshire Cooperative Extension Fall Forage Webinar Series, New England Dairy Nutrition Conference, University of New Hampshire Cooperative Extension Dairy and Livestock Crops Virtual Field Day, Northeast Organic Dairy Producers Alliance (NODPA) Field Days and Conference, University of Vermont 2021 Online Dairy Education Series, and 2021 American Dairy Science Association Annual Meeting. Allen Wilder (co-PI Bosworth graduate student) presented project data during University of New Hampshire Cooperative Extension Fall Forage Webinar Series. Altogether, these presentations were delivered to over 300 participants, thus engaging organic dairy farmers, industry stakeholders, and the scientific community. How have the results been disseminated to communities of interest?Project results have been disseminated to dairy farmers, dairy nutritionists, extension educators, dairy industry personnel, students, and the scientific community through field days, professional meetings, farmer conferences, webinars, and workshops. Over the lifespan of the project, our team delivered 9 webinars during extension and conference events. We also delivered 3 field days/pasture walks in collaboration with the Wolfe's Neck Center Agriculture & the Environment (Freeport, ME), University of Vermont-Extension, and Choiniere Family Farm, (Highgate, VT.). Several in-person presentations were delivered during conferences in the region such as Northeast Pasture Consortium Annual Meeting, Northeast Organic Dairy Farmers Association New York (NOFA-NY), Vermont Organic Dairy Producers Conference, Granite State Graziers Association, New England Ag Service Providers In-Service Annual Meeting, and American Dairy Science Association Annual Meeting amounting to a total of 10 presentations. We published project results in conference proceeding papers (total = 7), dissertation theses (total = 3), popular-press articles (NODPA News; total = 3), and a booklet (2021 University of New Hampshire Agricultural Experimental Station Dairy Report). Our team is currently working to submit several peer-reviewed manuscripts to publication, and we anticipated that 10 articles will be published between 2022 and 2024. Throughout the duration of the project, 3 Ph.D. students and 1 MS student directly used data generated in the project as part of their theses. We also trained 3 post-doctorate students whe actively participated in data collection and analyses, multiple undergraduate students (n = 10), and 2 international research scholars. We will continue to deliver data regionally and nationally beyond the lifespan of the project to keep organic dairy farmers and allied industry engaged and informed. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Agronomic Small-Plot Study at the University of New Hampshire: As described in previous progress reports, we reestablished the experimental plots in August 2018 due to poor establishment of the previous iteration of the experiment. Each plot was seeded to 1 of 4 forage legumes (alfalfa, white clover, red clover, and birdsfoot trefoil) and orchardgrass at a 70:30 (legume:grass) ratio. In addition, we also included 2 legume mixture treatments (all 4 legumes sown together with orchardgrass in either a 70:30 or 30:70 ratio). The intermediate intensity cutting (3X) frequency treatment was aimed at a relatively long interval and recovery time between each harvest and involved harvesting each plot a total of 3 times over the growing season, beginning in early June and ending in October each year. In contrast, the high intensity cutting (5X) frequency treatment involved harvesting each plot a total of 5 times over the season, creating a shorter interval and recovery period (30 d) between cuts. Plots were also assigned to a cutting height treatment of either 5 or 10 cm residual forage height. Despite the severity and duration of the 2020 drought, all 4 legume species persisted over the subsequent winter and were present (<5% to ~10% of total forage, depending on species) in harvest samples collected at the beginning of the 2021 growing season. White clover total abundance and proportion of total forage mass remained relatively low by the second harvest of 2021 (<5% of total forage mass); however, abundance of red clover increased in the second harvest, especially in the 5X harvest intensity treatments (~30% of total forage mass). We also compared the nutritive value of 4 binary legume-grass (LG) mixtures, and 2 complex LG mixtures under different seeding strategies over 2 years following a 3-cutting schedule. A randomized complete block design with a 6 × 3 factorial arrangement of treatments and 4 replicates for each treatment was used. Legumes selected were alfalfa (ALF), red clover (RC), birdsfoot trefoil (BFT), and white clover (WC) in binary mixtures with orchardgrass at 70:30 LG seeding rate, a high legume mixture (HI) with 70% of all 4 legumes and 30% orchardgrass, and 30:70 LG seeding rate, a low legume mixture (LO) with 30% of all 4 legumes and 70% orchardgrass. Crude protein increased in HI compared with ALF and BFT, with HI and LO showing reduced NDF concentration relative to ALF and BFT. Starch was greater in LO vs. WC but it did not differ compared with the other treatments. RC, HI, and LO resulted in greatest sugar content and ALF the lowest. In vitro fiber digestibility was lower for HI and LO than the binary LG mixtures. In general, second and third cuttings improved nutritive value. Feeding Trial at the University of New Hampshire: Red clover (Trifolium pratense L.) is one of the most used legumes in the Northeast United States, with the advantage to produce milk with lower milk urea-N than alfalfa (Medicago sativa L.) due the presence of the enzyme polyphenol oxidase in red clover tissues that acts to reduce protein degradation during ensiling. Previous research demonstrated that red clover silage was comparable to alfalfa silage in terms of dry matter intake, milk production, and percentage of milk fat. However, some studies conducted in the United States showed that cows fed alfalfa silage produced more milk than those fed red clover silage. White clover (Trifolium repens L.) silage has been shown to produce more milk than red clover silage at the same dry matter intake, thus resulting in better feed efficiency. Therefore, partially replacing red clover silage with alfalfa-white clover mixture in the diet dry matter may maintain the positive effect of red clover on dietary N utilization while improving milk production. It is important to emphasize that there is limited data comparing the effects of red clover-grass mixture harvested as baleage on dry matter intake, milk production and composition, nutrient digestibility, and energy utilization in dairy cows. Two fields were planted as reported abov with forages were harvested as baleage. Diets were fed as total mixed ration and contained (dry matter basis): (1) 60% second and third cut red clover-grass baleage (30% of each cut) and 40% concentrate (high red clover-grass mixture diet = HRC-M), and (2) 30% second and third cut red clover-grass baleage (15% of each cut), 30% second cut alfalfa/white clover-grass baleage, and 40% concentrate (low red clover-grass mixture diet = LRC-M). The experiment was done as a crossover design with 24-d periods.Cows fed the HRC-M diet had greater intake than those receiving the LRC-M diet, but milk production did not differ between diets. Milk fat percentage increased, and milk protein tended to increase in cows fed the LRC-M diet. Milk fat and protein yield, and milk urea-N were not affected by diets. Conversely, plasma urea-N concentration was lower with feeding HRC-M than LRC-M. Total-tract digestibility of dry matter, organic matter, and neutral detergent increased, and that of crude protein tended to increase in cows fed HRC-M versus LRC-M. Modeling and Economic Analyis: We compared the economic and environmental performance of traditional (ORG-T) vs. grass-fed (ORG-GF) organic dairy farms using the Integrated Farm System Model. The ORG-T diet was characterized by pasture, grass-legume and corn silage, and grain during the grazing season, and conserved feed and grain during the winter season. The ORG-GF was characterized by an all pasture diet during the grazing season, and all conserved feed diet except corn silage during the winter season. Milk price and annual milk production used in the simulations averaged 71.50 vs. $81.70/100L and 6,590 vs. 4,879 kg/cow for ORG-T vs. ORG-GF, respectively. Net return/cow was 35% greater in the ORG-GF ($2,766) than ORG-T ($2,051) due to additional premiums paid by milk processors to ORG-GF. Average greenhouse gas (GHG) emission was 87% greater in ORG-GF (0.56 kg of CO2 eq/kg of energy-corrected milk production) than ORG-T (0.30 kg of CO2 eq/kg of energy-corrected milk production).
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Sacramento, J. P., L. H. P. Silva, D. C. Reyes, Y. Geng, and A. F. Brito. 2021. Feeding legume-based forages: Effects on milk yield, nutrient digestibility, and methane emissions in dairy cows. J. Dairy Sci. (Suppl. 1) 104:307.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Sacramento, J. P., L. H. P. Silva, D. C. Reyes, Y. Geng, and A. F. Brito. 2021. Feeding legume-based forages: Effects on N utilization in dairy cows. J. Dairy Sci. (Suppl. 1) 104:306307.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Almeida, K. V., L. H. P. Silva, J. P. Sacramento, D. C. Reyes, R. G. Smith, N. Warren, and A. F. Brito. 2021. Effects of seeding intensity and cutting on the nutritional quality of grass-legume mixtures. J. Dairy Sci. (Suppl. 1) 104:249.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Lange, M. J., L. H. P. Silva, M. Ghelichkhan, M. A. Zambom, and A. F. Brito. 2021. Feeding alfalfa- or red clover-grass mixtures: Effects on methane emissions and plasma amino acids in dairy cows. J. Dairy Sci. (Suppl. 1) 104:101.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Lange, M. J., L. H. P. Silva, M. Ghelichkhan, M. A. Zambom, and A. F. Brito. 2021. Feeding alfalfa- or red clover-grass mixtures: Effects on production and milk fatty acids in dairy cows. J. Dairy Sci. (Suppl. 1) 104:101.
- Type:
Other
Status:
Published
Year Published:
2021
Citation:
Brito, A.F., M. J. Lange, J. P. Sacramento, L. H. P. Silva, M. Ghelichkhan, Y. Geng, D. C. Reyes, and M. A. Zambom. 2021. Alfalfa-grass or red clover-grass: Effects on milk production, composition, nitrogen and energy utilization. 2021 Dairy Research Report (Joint publication by NH Agricultural Experiment Station and UNH Cooperative Extension). https://colsa.unh.edu/nhaes/dairyreport2021
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2021
Citation:
Sacramento, J. P. 2021. Energy nutritional requirements and dietary strategies for lactating dairy cows under different production and climatic conditions. Federal University of S�o Jo�o del-Rei, S�o Jo�o del-Rei, Minas Gerais, Brazil (Ph.D. Dissertation).
|
Progress 09/01/19 to 08/31/20
Outputs
Target Audience:We directly served organic and conventional dairy farmers across the Northeast region, as well as extension educators, industry stakeholders (e.g., organic milk processors, nutritionists, veterinarians), and the scientific and academic community (e.g., graduateand undergraduate students, post-docs, and fellow scientists). Our team disseminated project results through workshops,webinars, pasture walks, farmer oriented conferences, and national and international scientific conferences. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Project results have been disseminated to dairy farmers, dairy nutritionists, extension educators, dairy industry personnel, students, and the scientific community through field days, professional meetings, farmer conferences, webinars, and workshops. Specifically, we delivered project results during farm tours and local and regional producer conferences. How have the results been disseminated to communities of interest?Project results have been disseminated to dairy farmers, dairy nutritionists, extension educators, dairy industry personnel,students, and the scientific community through field days, professional meetings, farmer conferences, webinars, and workshops. What do you plan to do during the next reporting period to accomplish the goals?We planned to report data from a second feeding trial done at the University of New Hampshire Organic Dairy Research Farm, modeling and ecomomic analyses, and results of the ongoing legume-grass mixtures agronomic plots.
Impacts
What was accomplished under these goals?
Agronomic Small-Plot Study at the University of New Hampshire: As described in previous progress reports, we reestablished the experimental plots in August 2018 due to poor establishment of the previous iteration of the experiment. Each plot was seeded to 1 of 4 forage legumes (alfalfa, white clover, red clover, and birdsfoot trefoil) and orchardgrass at a 70:30 (legume:grass) ratio. In addition, we also included 2 legume mixture treatments (all 4 legumes sown together with orchardgrass in either a 70:30 or 30:70 ratio). We observed good germination and overwinter survival in 2018/19 despite region-wide issues with winterkill. We initiated the cutting frequency and height treatments in the spring of 2019 using a plot-scale forage harvester. The intermediate intensity cutting (3X) frequency treatment was aimed at a relatively long interval and recovery time between each harvest and involved harvesting each plot a total of 3 times over the growing season, beginning in early June and ending in October each year. In contrast, the high intensity cutting (5X) frequency treatment involved harvesting each plot a total of 5 times over the season, creating a shorter interval and recovery period (30 d) between cuts. Plots were also assigned to a cutting height treatment of either 5 or 10 cm residual forage height. These treatments have been maintained in the same plots for the duration of the study. At the time of each harvest, we sort herbage to species and dry and weigh the biomass. Similar to the 2019 growing season, total forage (legume + orchardgrass) production over the 2020 growing season was greatest in the red clover treatments compared to the other three legume treatments. Unlike 2019, however, total production in the white clover plots was higher compared to the alfalfa and birdsfoot trefoil plots, which both had similar production. The differences in total production among the four legumes treatments were due primarily to differences in the productivity of the legumes rather than orchardgrass, the abundance of which was relatively similar across legume treatments. Total forage production across all treatments was strongly influenced by the forage available at the first cut, which was much greater than in subsequent harvests due to the severe drought conditions that set in soon after the first harvest. Second harvests in both the 5X and 3X treatments produced on average 75% lower total forage dry matter than the first harvest. Total forage production continued to decline over the growing season in all treatments due to lack of rainfall. Among legume species, white clover appeared to be most negatively affected by the drought. Cutting height and intensity treatments appeared to have little influence over how each legume species responded to the drought conditions. Agronomic Small-Plot Study at the University of Vermont: Field work at the University of Vermont was completed. Feeding Trail at the University of New Hampshire: Twenty mid-lactation organic certified Jersey cows were assigned to 1 of 2 diets in a crossover design with 2 periods. Each experimental period lasted 24 days, with14 days for diet adaptation and 10 days for sample collection. Two fields were planted with alfalfa- or red clover-grass mixture with a 79:14:7 legume:meadow fescue:timothy seeding rate (% total). Second- and third-cut legume-grass mixture used in this study were harvested as baleage in 2019. The botanical composition (dry matter basis) of fields from which the second and third cut red clover-grass averaged: 75 vs. 62% red clover, 4 vs. 11% grasses, and 21 vs. 10% weeds, respectively. Note that 17% (dry matter basis) of white clover was present in the red clover-grass field from the third cut. The botanical composition of the second cut alfalfa-grass field harvested as baleage averaged (dry matter basis): 40% alfalfa, 2% red clover, 26% white clover, 9% grass, and 23% weeds. Compared with 2018, the botanical composition of the alfalfa-grass field changed, with some alfalfa being replaced by white clover due to alfalfa winter kill. Diets were fed as total mixed ration and contained (DM basis): (1) 60% second and third cut red clover-grass baleage (30% of each cut) and 40% of a ground corn-soybean meal-based mash concentrate (high red clover-grass mixture diet = HRC-M), and (2) 30% second and third cut red clover-grass baleage (15% of each cut), 30% second cut alfalfa/white clover-grass baleage, and 40% of a ground corn-soybean meal-based mash concentrate (low red clover-grass mixture diet = LRC-M) Diets averaged 17.8 vs. 17.2% crude protein and 31.7 vs. 31.3% neutral detergent fiber (NDF) for HRC-M vs. LRC-M, respectively. Cows were fed and milked twice daily, with feed offered and refused weighed daily to compute dry matter intake throughout the study. Milk volume was recorded daily, and milk samples were collected for 4 consecutive milkings during the first 3 days of each experimental period. Milk was analyzed for fat, protein, and milk urea-N (Dairy One; Ithaca, NY). Blood samples were collected approximately 4 h after the morning feeding once in the last day both experimental periods and analyzed for urea N. Fecal samples were collected and analyzed for indigestible NDF to determine apparent total-tract digestibility of nutrients. Enteric methane emissions were measured using the GreenFeed system (C-Lock Inc., Rapid City, SD). The GreenFeed operates by automatically releasing a bait pellet every 30 seconds for up to 5-min measurements several times throughout the day triggered by a RFID ear tag wear by each cow. Built-in sensors are used to measure methane fluxes near real-time. Data are currenlty being analyzed statistically.
Publications
|
Progress 09/01/18 to 08/31/19
Outputs
Target Audience:We directly served organic and conventional dairy farmers across the Northeast region, as well as extension educators, industry stakeholders (e.g., organic milk processors, nutritionists, veterinarians), and the scientific and academic communities (e.g., graduate and undergraduate students, post-docs, and fellow scientists). Our team disseminated project results through workshops, webinars, pasture walks, farmer-oriented conferences, and national and international scientific conferences. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Project results have been disseminated to dairy farmers, dairy nutritionists, extension educators, dairy industry personnel, students, and the scientific community through field days, professional meetings, farmer conferences, webinars, and workshops. Specifically, we delivered project results during the American Dairy Science Association Annual Meeting, farm tours, and local and regional producer conferences. How have the results been disseminated to communities of interest?Project results have been disseminated to dairy farmers, dairy nutritionists, extension educators, dairy industry personnel,students, and the scientific community through field days, professional meetings, farmer conferences, webinars, and workshops. What do you plan to do during the next reporting period to accomplish the goals?We planned to report data from a second feeding trial done at the University of New Hampshire Organic Dairy Research Farm, modeling and ecomomic analyses, and results of the ongoing legume-grass mixtures agronomic plots.
Impacts
What was accomplished under these goals?
Agronomic Small-Plot Study at the University of New Hampshire: As described in previous progress reports, we reestablished the experimental plots in August 2018 due to poor establishment of the previous iteration of the experiment. Each plot was seeded to 1 of 4 forage legumes (alfalfa, white clover, red clover, and birdsfoot trefoil) and orchardgrass at a 70:30 (legume:grass) ratio. In addition, we also included 2 legume mixture treatments (all 4 legumes sown together with orchardgrass in either a 70:30 or 30:70 ratio). We observed good germination and overwinter survival in 2018/19 despite region-wide issues with winterkill. We initiated the cutting frequency and height treatments in the spring of 2019 using a plot-scale forage harvester. The intermediate intensity cutting (3X) frequency treatment was aimed at a relatively long interval and recovery time between each harvest and involved harvesting each plot a total of 3 times over the growing season, beginning in early June and ending in October each year. In contrast, the high intensity cutting (5X) frequency treatment involved harvesting each plot a total of 5 times over the season, creating a shorter interval and recovery period (30 d) between cuts. Plots were also assigned to a cutting height treatment of either 5 or 10 cm residual forage height. These treatments have been maintained in the same plots for the duration of the study. At the time of each harvest, we sort herbage to species and dry and weigh the biomass. Similar to the 2019 growing season, total forage (legume + orchardgrass) production over the 2020 growing season was greatest in the red clover treatments compared to the other three legume treatments. Unlike 2019, however, total production in the white clover plots was higher compared to the alfalfa and birdsfoot trefoil plots, which both had similar production. The differences in total production among the four legumes treatments were due primarily to differences in the productivity of the legumes rather than orchardgrass, the abundance of which was relatively similar across legume treatments. Total forage production across all treatments was strongly influenced by the forage available at the first cut, which was much greater than in subsequent harvests due to the severe drought conditions that set in soon after the first harvest. Second harvests in both the 5X and 3X treatments produced on average 75% lower total forage dry matter than the first harvest. Total forage production continued to decline over the growing season in all treatments due to lack of rainfall. Among legume species, white clover appeared to be most negatively affected by the drought. Cutting height and intensity treatments appeared to have little influence over how each legume species responded to the drought conditions. Feeding Trial at the University of New Hampshire: Alfalfa (Medicago sativa L.) has become the "gold standard" for production of silage, baleage, and hay in the United States, but a large proportion of alfalfa protein is broken down to non-protein N (i.e., ammonia, amino acids, and peptides) during ensiling, thus reducing the efficiency of protein utilization when cows are fed alfalfa silage. In contrast, protein from red clover (Trifolium pratense L.) is protected against degradation in the silo due to the presence of the enzyme polyphenol oxidase in red clover tissues. Previous research demonstrated that red clover silage was comparable to alfalfa silage in terms of dry matter intake, milk production, and percentage of milk fat (Johansen et al., 2018). However, cows fed red clover silage had lower concentration of milk urea N and excreted less N to the environment than those fed alfalfa silage (Broderick et al., 2007), thus showing improved use of dietary protein with red clover. However, there have been limited research comparing the effects of alfalfa- vs. red clover-grass mixtures on feed intake, milk production and composition, and dietary utilization of N and energy in dairy cows. Feed intake, milk production and composition, and N utilization were reported previously. Two fields were planted with alfalfa- or red clover-grass mixture with a 79:14:7 legume:meadow fescue:timothy seeding rate (% total), with forages harvested as baleage. Twenty mid-lactation organic certified Jersey cows were assigned to 1 of 2 diets in a randomized complete block design: alfalfa-grass (ALF-GR) or red clover-grass (RC-GR). A diet by week interaction was observed for the concentration of ammonia-N in the rumen fluid. Specifically, rumen ammonia-N concentration decreased with feeding RC-GR during week 4 (3.99 vs. 8.73 mg/dL) but no change during week 7. Rumen concentration of total volatile fatty acids was not affected by diets. In contrast, the molar proportion of rumen acetate was greater in cows fed RC-GR than ALF-GR. Diet by week interactions were found for the rumen molar proportions of propionate, butyrate, valerate, and isobutyrate. While the molar proportion of propionate decreased in RC-GR during week 4 (12.7 vs. 13.6 mol/100 mol), diets did not affect propionate in week 7. The rumen molar proportion of butyrate did not change in week 4, but it was reduced in cows fed RC-GR during week 7 (9.67 vs. 10.6 mol/100 mol). Rumen valerate (0.98 vs. 1.32 mol/100 mol) and isobutyrate (0.61 vs. 0.92 mol/100 mol) were lower in week 4 for cows offered RC-GR versus ALF-GR, with isobutyrate also been lower in the RC-GR diet in week 7. Rumen isovalerate was reduced with feeding RC-GR than ALF-GR. Cows fed RC-GR had increased total-tract digestibilities of dry matter, organic matter, and neutral detergent fiber compared with those fed ALF-GR. Diets did not affect intake of gross energy, digestible energy, metabolizable energy, and net energy of lactation. In contrast, diet by week interactions were observed for urinary energy and methane energy outputs, with these 2 variables decreasing in cows offered RC-GR during week 4, but no changes detected between diets during week 7. An interaction was also observed for the efficiency of converting metabolizable energy into milk energy. Specifically, cows fed RC-GR was less efficiency in converting metabolizable energy into milk energy during week 4 with no change detected in week 7.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
Wilder, A., and S. Bosworth. 2020. Fermentation and protein evaluation of 12 binary legume-grass mixtures ensiled during multiple small plot harvests using vacuum-bag mini-silos. J. Dairy Sci. 103 (Suppl. 1):229-230.
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Progress 09/01/17 to 08/31/18
Outputs
Target Audience:We directly served organic and conventional dairy farmers across the Northeast region, as well as extension educators, industry stakeholders (e.g., organic milk processors, nutritionists, veterinarians), and the scientific and academic community (e.g., graduate and undergraduate students, post-docs, and fellow scientists). Our team disseminated project results through workshops, webinars, pasture walks, farmer-oriented conferences, and national and international scientific conferences. Changes/Problems:At the University of Vermont, we were able to accomplish our goal in 2018 having 4 harvests of the intensive cutting management strategy and 3 harvests of the delayed strategy. However, due to spotty winter kill and injury in the winter of 2019, which eliminated about half our plots, we were limited to only 1 cutting strategy in 2019. Therefore, we only evaluated the 12 legume-grass mixtures plus legume monocultures within the intensive cutting strategy because that is the approach used by most dairy farms in the region. What opportunities for training and professional development has the project provided?The project outreach and research components are advancing as planned. Workshops and outreach activities such as presentations, dairy farm meetings, field days, farm tours, and webinars featuring project results have been delivered. Specifically, presentations to extension educators done by our team during the New England Ag Service Providers In-Service Annual Meeting (Portsmouth, NH; January 29, 2020; 55 participants) and the University of New Hampshire Cooperative Extension Twilight Meeting (online presentation; June 24, 2020; 15 participants) were delivered and highlighted the importance of incorporating legumes in forage mixtures to improve milk production and feed efficiency in organic dairy farmers. Our team also presented at the 10th Vermont Organic Dairy Producers (Randolph, VT; March 11, 2020) and educate approximately 100 organic dairy farmers, extension educators, and industry personnel about forage-legume mixtures for silage production. Two webinars about forage quality and best forage-grass mixtures to boost milk production in cows fed high-forage diets were delivered during the Penn State Dairy Grazing Management Series (February 12, 2020 and March 11, 2020). Our team also presented project results in local, regional, national, and international conferences. How have the results been disseminated to communities of interest?Project results have been disseminated to dairy farmers, dairy nutritionists, extension educators, dairy industry personnel,students, and the scientific community through field days, professional meetings, farmer conferences, webinars, and workshops. What do you plan to do during the next reporting period to accomplish the goals?For the next report (final report), our team will present results of 2 feeding trials and the third growing season (UNH site). We will also plan to deliver e-organic webinars and continue to present project results in local, regional, national, and international conferences. Greenhouse gas modeling and economic analyses will be finalized as well.
Impacts
What was accomplished under these goals?
Agronomic Small-Plot Study at the University of Vermont: The small plot legume-grass study established in 2017 was continued and completed in 2019. The goal was to evaluate the effect of intensive and delayed management strategies on the yield and quality of 12 legume-grass mixtures created by combining alfalfa, red clover, or birdsfoot trefoil with timothy, tall fescue, meadow fescue, or perennial ryegrass. We also included monocultures of the 3 legumes for a total of 15 treatments. Field measurements were taken for yield and botanical composition and samples were analyzed by near infrared spectroscopy (NIRS) to determine crude protein (CP), non-fiber carbohydrates (NFC), non-structural carbohydrates (NSC), neutral detergent fiber (NDF), 30-h and 240-h NDF digestibility, relative forage quality (RFQ), and estimated milk/ha. The results of an analysis of covariance (ANCOVA) test showed that using a delayed cutting strategy increased NDF% and decreased CP, NFC, NSC, 30-h and 240-h NDF digestibility, and RFQ. Reductions in quality combined with lower average dry matter (DM) yields resulted in losses of 3,310 kg of milk/ha. Mixtures containing alfalfa significantly outperformed red clover-grass mixtures and birdsfoot trefoil-grass mixtures in plot yield and milk/ha during 2018. Birdsfoot trefoil-grass mixtures showed exceptional quality but failed to produce significantly higher milk/ha than alfalfa-grass mixtures, even when alfalfa and red clover suffered from severe winter injury in the second year. Red clover-grass mixtures were consistently lower in quality than mixtures containing the other legumes and showed the highest yield reduction when delayed cutting management was used. Binary mixtures that included perennial ryegrass were high in quality but were significantly lower in yield in most cases. Thus, yield differences were not offset by higher quality in terms of milk/ha. The opposite was true for legume-timothy mixtures. One hypothesis from our study was that different legume-grass mixtures would influence silage fermentation and the degree of proteolysis of these mixtures. To test this, binary mixtures of legumes (alfalfa, red clover, and birdsfoot trefoil) and grasses (timothy, tall fescue, meadow fescue, and perennial ryegrass) were artificially wilted to 45% DM and ensiled across 6 cuttings over 2 years. Measurements were taken on vacuum-bag mini-silos to determine volumetric fermentation expansion and silage pH. NIRS was used to determine CP, soluble protein, insoluble degradable protein, and degradable protein. An analysis of covariance was conducted, and results indicated that legume-grass mixtures containing birdsfoot trefoil or red clover had more CP as insoluble degradable protein and less CP as rapidly degradable soluble protein compared to alfalfa mixtures. While grass species generally had little effect on silage protein fractions, tall fescue inclusion resulted in higher soluble protein and lower insoluble degradable protein in some cuttings. The fermentation of alfalfa and alfalfa-grass mixtures generated more gas expansion in the vacuum bag minisilos than red clover and birdsfoot trefoil mixtures along with reduced silage pH in non-inoculated birdsfoot trefoil mixtures and occasionally in red clover mixtures (delayed cuttings) compared to alfalfa mixtures. Agronomic Small-Plot Study at the University of New Hampshire: As described in the previous progress report, we reestablished the experimental plots in August 2018 due to poor establishment of the previous iteration of the experiment. Each plot was seeded to 1 of 4 forage legumes (alfalfa, white clover, red clover, and birdsfoot trefoil) and orchardgrass at a 70:30 (legume:grass) ratio. In addition, we also included 2 legume mixture treatments (all 4 legumes sown together with orchardgrass in either a 70:30 or 30:70 ratio). We observed good germination and overwinter survival in 2018/19 despite region-wide issues with winterkill. We initiated the cutting frequency and height treatments in the spring of 2019 using a plot-scale forage harvester. The haying (3X) frequency treatment was aimed at a relatively long interval and recovery time between each harvest and involved harvesting each plot a total of 3 times over the growing season, beginning June 3 and ending October 15, 2019. In contrast, the grazing (5X) frequency treatment involved harvesting each plot a total of 5 times over the season creating a shorter interval and recovery period (30 d) between cuts. Plots were also assigned to a cutting height treatment of either or 10 cm. For each harvest we sorted herbage to species and dried and weighed the biomass. Red clover was much more productive compared to the other 3 legumes. The second emerging trend is that harvest frequency has a greater impact on total forage production (total amount of forage DM produced over the season) than does cutting height. We observed greater total forage yield in the 5X compared to the 3X treatment and this was apparent regardless of which legume was included in the mixture. Importantly, most of this difference in total DM production was due to the abundance of the orchardgrass component of the mixture, which was on average 40% greater in the 5X treatment. In other words, the orchardgrass was much more responsive to the cutting frequency than were any of the four legume species. Finally, we observed that the proportion of legumes in each mixture varied over the course of the season and the trends were species-specific. This was particularly apparent in the 5X cutting treatment. For example, the proportion of red clover was nearly 70% of the total DM at the first harvest, just over 40% at the fourth harvest, and a little higher than that at the fifth and final harvest of the season. In contrast, both alfalfa and birdsfoot trefoil made up just over 35% of the total DM at the first harvest but not more than 5% by the final harvest. White clover exhibited a different trend; it made up just 20% of the total DM at the first harvest, but by the final harvest it had increased to over 30%. Feeding Trial at the University of New Hampshire: Twenty mid-lactation organic Jersey cows were used to investigate the effects of different legume-grass mixtures on production, milk fatty acids (FA) profile, CH4 emissions and plasma amino acids (AA) concentration. Two fields were planted with alfalfa (ALF)- or red clover (RC)-grass mixture with a 79:14:7 legume:meadow fescue:timothy seeding rate (% total). Forages were harvested as baleage, with second- and third-cut legume-grass mixtures used in the study. Diets were formulated to contain 65% second- and third-cut ALF or RC-grass (32.5% of each cut) and 35% concentrate. The study lasted 9 wk (2-wk covariate) with sample collection done at wk 4 and 7. Production and milk composition were reported previously. Significant diet by wk interactions were found for the milk proportions of total ?-3 FA and 16-carbon FA, with ?-3 FA and 16-carbon FA increasing more noticeably in cows fed RC- or ALF-grass in wk 7 than wk 4, respectively. No differences were detected for total <16-carbon FA in milk fat but feeding RC-grass increased total ?-6 FA and 18-carbon FA. A significant diet by wk interaction was observed for CH4 production, with cows fed RC-grass showing lower CH4 in wk 4 but no change in wk 7. Diets did not affect the plasma concentrations of Lys and Met. However, plasma Leu increased with feeding RC-grass. Significant diet by wk interactions were found for the plasma concentrations of Arg, His, Phe, Trp, Val, and total EAA. Feeding RC-grass increased plasma Arg, Phe, Val, and total EAA in wk 7 but not in wk 4. Further, RC-grass enhanced plasma His more noticeably in wk 7 than wk 4. Compared with ALF-grass, plasma Trp decreased in cows fed RC-grass in wk 4 and increased in wk 7.
Publications
- Type:
Other
Status:
Published
Year Published:
2020
Citation:
Brito, A. F., M. J. Lange, and L. H. P. Silva. 2020. The key role of forage legumes in organic dairy diets: Effects on your bottom line. Northeast Organic Dairy Producers Alliance Online Newsletter. https://nodpa.com/n/945/The-Key-Role-of-Forage-Legumes-in-Organic-Dairy-Diets-Effects-on-Your-Bottom-Line
- Type:
Other
Status:
Awaiting Publication
Year Published:
2020
Citation:
Smith, R. G., and N. D. Warren. 2020. Managing forage legumes for improved productivity and persistence. Northeast Organic Dairy Producers Alliance Online Newsletter. (In Press).
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
Wilder, A. and S. Bosworth. 2020. Artificial wilting in a forced-air oven has minimal effects on silage fermentation and quality in both inoculated and untreated vacuum-bag mini-silos. J. Dairy Sci. 103 (Suppl. 1):64.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2020
Citation:
Wilder, A M. 2020. The agronomics of organically managed legume-grass mixtures for ensiled forage production. MS Thesis. Department of Plant and Soil Science, University of Vermont, Burlington.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
Wilder, A. and S. Bosworth. 2020. Fermentation and protein evaluation of 12 binary legume-grass mixtures ensiled during multiple small-plot harvests using vacuum-bag mini-silos. J. Dairy Sci. 103 (Suppl. 1):229.
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Progress 09/01/16 to 08/31/17
Outputs
Target Audience:We directly served organic and conventional dairy farmers across the Northeast region, as well as extension educators, industry stakeholders (e.g., organic milk processors, nutritionists), and the scientific and academic community (e.g., graduate and undergraduate students, post-docs, and fellow scientists). Our team presented project results in workshops, farmer- and extension-based conferences, and pasture walks. We also set up on-farm demonstration sites in NH and VT featuring the use of forage-crops mixtures as souces of conserved feeds (i.e., hay, haylage, silage, baleage) to organic dairy cows. Changes/Problems:We had to deal with poor establishment of our forage crop treatments in the agronomic small-plot study done at the UNH Kingman Farm back in 2017. Therefore, we decided to reset the study changing treatments by using only 1 grass species (i.e., orchardgrass) and the same 3 companion legumes (i.e., alfalfa, red clover, and birdsfoot trefoil). What opportunities for training and professional development has the project provided?The project outreach and research components are advancing as planned. Workshops and outreach activities such as presentations, dairy farm meetings, field days, farm tours, and webinars featuring project results have been delivered. Specifically, a presentation to extension educators as part of the 21st Annual Mid-Atlantic Regional Dairy and Beef Extension In-service Training Program was delivered and highlighted the importance of incorporating legumes in forage mixtures to improve milk production and feed efficiency in organic dairy farmers. Approximately 45 extension educators attended the two-day meeting in Wilkes-Barre, PA on May 29-30. Our team also presented at the 9th Vermont Organic Dairy Producers (Randolph, VT; March 14, 2019) and educate approximately 80 organic dairy farmers about forage-legume mixtures for silage production. A similar presentation was done during the Granite State Graziers Conference (Concord, NH) this past February where 30+ dairy and beef producers learned about forage quality and best forage-grass mixtures to boost production in high-forage diets. How have the results been disseminated to communities of interest?Project results have been disseminated to dairy farmers, dairy nutritionists, extension educators, dairy industry personnel,students, and the scientific community through field days, professional meetings, farmer conferences, webinars, and workshops. What do you plan to do during the next reporting period to accomplish the goals?Our team will continue moving forward with the research and extension components of the project. The UVM will conduct the third year of agronomic data collection including forage biomass production, botanical composition, mini-silo production, silage fermentation profiles, and forage nutritive value. It can be anticipated that some plots at UVM were affected by winterkill after evaluation of the field preceding the first cut.At the UNH Kingman Farm, we will conduct the second year of agronomic data collection (similar to the UVM except for silage production and evaluation). At the UNH Organic Dairy Research Farm, we will conduct a second feeding trial to evaluate the impact of grass-legume mixtures harvested as baleage on milk production, methane emissions, and N excretion to the environment. We also observed winterkill of both legume and grasses in the fields planted to produce the forage mixtures that will be used to harvest baleage for the feeding trial. However, fields may recover as the 2019 growing season progress. Regarding the extension/outreach component of the project, we will partnership with UVM extension to deliver field days focused on grass-legume mixtures to improve forage quality. Our team will also delivery presentations at professional meetings, producer conferences, and produce 3 webinars.
Impacts
What was accomplished under these goals?
Agronomic Small-Plot Study at the University of Vermont: On August 8th, 2017, an agronomic small-plot study was established at the University of Vermont (UVM) Horticultural Research Center in South Burlington, VT. The 5 x 20 ft. plots were established with a Carter small plot seeder and firmed with a roller following seeding. The study was seeded with 4 replications in a split plot design. Treatments include 1 of 3 legume species (alfalfa, birdsfoot trefoil, or red clover) in a pure stand, or combined in a binary mixture with a forage grass species (meadow fescue, tall fescue, timothy, or perennial ryegrass). The plots were exposed to 2 different cutting management treatments: low-intensive (3 cuts/year) and intensive (4 cuts/year). The plots were split by legume species and cutting management, clipped for weed management on October 4th, 2017, and cut to remove excess residue on November 8th, 2017. Small plot management for the 2018 season began with the first cut of the intensive treatment plots. This occurred May 24th, 2018. Quadrats were used to assess yield and samples were taken for forage quality analysis and sward botanical composition. Samples for forage quality analysis were microwaved to reach 70°C to minimize the loss of carbohydrates due to enzymatic activity. Botanical composition samples were hand separated into legume, grass, and weed material. For the low-intensive cutting management plots, the first cut took place on June 6th, 2018 and measurements were taken similarly to the first cut intensive treatment plots. The second cutting for the intensive and low-intensive cutting managements was taken on June 26th and July 16th, 2018, respectively. For this cutting, 1200 g of material were ensiled from each plot for 3 of the 4 replications. This was done by wilting the forage material to 45% dry matter (DM) in a forced air oven and sealing the samples in vacuum bag mini-silos. Additional measurements were taken similarly to the first cutting. However, a Carter small-plot forage harvester was used to measure whole plot yield instead of quadrat samples. The third cut was taken on July 30th for the intensive cutting management and August 23rd for the low-intensive cutting management. Due to hot and dry weather during this period, some plots suffered from significant drought stress and yields were reduced. Silage was also made from these 2 cuttings in a similar manner to the second cut. A fourth cutting was taken for the intensive cutting management plots on September 6th, but only DM yield was measured. Mini-silos were opened after 90 days of ensiling and subsampled for quality and pH analysis. It was noted that some of the mini-silos had expanded with fermentation gasses and this expansion was quantified through measurements of volume. Analysis of silage pH revealed that all mini-silos were well fermented. The companion grass species did not affect pH, but legume species did. Silos containing birdsfoot trefoil had a significantly lower pH than silos containing alfalfa or red clover. This difference does not appear to be solely explained by botanical composition variation between legume species. Legume species had a significant effect on total plot DM yield for the season, with alfalfa and red clover generally yielding more than birdsfoot trefoil. Alfalfa yields were also higher than red clover yields in the low-intensive cutting management. Companion grass species also influenced total DM yield. Timothy and meadow fescue mixtures tended to have higher yields than legume pure stands, while tall fescue and perennial ryegrass tended to yield similarly to or lower than the pure legume stand. Agronomic Small-Plot Study at the University of New Hampshire: In September of 2017, an agronomic small-plot study with treatments like those used at UVM was planted at the University of New Hampshire (UNH) Kingman Farm (Madbury, NH). However, we faced poor establishment of treatments in our plots possibly in response to less than average rain for the period and a harsh winter. Therefore, we decided to change our treatments by using only 1 grass species (i.e., orchardgrass) while keeping the same 3 companion legumes (i.e., alfalfa, red clover, and birdsfoot trefoil). The following treatments were established in August 2018: (1) Bi-culture treatments = 70% legume and 30% orchard grass, adjusted to pure live seed per area; (2) Legume Mixture Treatments "High" = the "high" legume mixture is 30% orchardgrass and 70% legumes (divided evenly at 17.5% of each constituent legume species); and (3) Legume Mixture Treatments "Low" = The "low" legume mixture is 70% orchardgrass and 30% legumes (divided at 7.5% per legume species). These treatments will be submitted to 2 cutting management approaches: "Hay schedule" with approximately 3 cuttings per year and "Grazing schedule" with calendar-based cuttings approximately every 4 weeks. In addition, 2 cutting heights will be established: 5 or 10 cm from the ground. Forage biomass, forage nutritive value, and plot botanical composition will be measured. The expriment was designed as a split plot arrangement with 5 blocks. Feeding Trial at the University of New Hampshire Organic Dairy Research Farm: A feeding trial was conducted at the UNH Organic Dairy research Farm (Lee, NH) using 20 organic-certified Jersey cows in mid-lactation in a randomized complete block design. The forage sources produced to be used in the study was established in 3 adjacent fields and contained: (1) alfalfa, meadow fescue, and timothy grass; (2) red clover, meadow fescue, and timothy grass; and (3) birdsfoot trefoil, meadow fescue, and timothy grass. Over 2 growing seasons, the establishment of birdsfoot trefoil was less than desirable so that treatment 3 was not harvested as baleage to be fed to cows assigned to the study. Therefore, cows were fed baleage harvested from treatments 1 or 2. Our preliminary results showed no differences in DMI, milk yield, and concentrations and yields milk components (i.e., fat, true protein, lactose, solids non-fat, and total solids. However, MUN concentration decreased significantly in cows fed red clover-grass mixture baleage than the alfalfa-grass mixture counterpart, thus suggesting improved N utilization likely in response to the enzyme polyphenol oxidase present in red clover, which prevents proteolysis during baleage and ruminal fermentation. Gaseous measurements (CH4 and CO2) were measured using the GreenFeed System and data are being currently analyzed. Additional samples were taken including blood (plasma urea N and amino acids), ruminal fluid (ammonia-N and volatile fatty acids), urine (total N, creatinine, purine derivatives), and feces (nutrient digestibility) for later analyses.
Publications
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