Forage Nutritive Value Research Articles

78 Winter Hardy Small Cereal Cover Crops for Grazing and Silage in Nebraska

Abstract Cereal rye, winter wheat, and winter triticale are commonly planted cover crops in corn and soybean systems and have the potential to provide early spring grazing. The three cover crops differ in growth pattern. Therefore, a study was conducted to investigate the grazing potential of the three species, including the timing of the start of grazing and nutritive value of forage as measured by growing calf gain. A 7.3 hectare field was divided into 9, 0.81-hectare paddocks. Three paddocks (n = 3 replicates per treatment) were randomly assigned to each treatment: variety not stated cereal rye, Pronghorn winter wheat, or NT11406 triticale. Pastures were seeded in Mid-September following early maturity soybean harvest and received no fertilizer. Fifty-four steers (305 kg SD ± 5 kg) were stratified by weight and assigned to one of nine groups which were then assigned to a paddock. The paddocks were split in half. Steers were turned out when forage reached a 12.7 cm height and rotated to the other half once the occupied half reached 5 cm. Grazing began April 3 for rye pastures and April 9 for triticale and wheat pastures. Two groups of cattle grazing rye were pulled April 29 due to limited forage. All remaining cattle were pulled May 8 to allow for soybean planting. Throughout the grazing period pre and post-graze biomass did not differ (P ≥ 0.36) among treatments. Average daily gain did not differ among treatments (P = 0.88) averaging 1.79, 1.86, 1.84 kg/day for rye, wheat and triticale, respectively. Likewise, gain per hectare did not differ (P = 0.80) among treatments with 378, 399, 394 kg/ha for rye, wheat, and triticale, respectively. Rye offered grazing a full week before triticale and wheat, but all three small grain cereal species resulted in desirable animal performance.

Evaluating Soybean Cultivars for Forage Yield and Nutritive Values

Abstract Alfalfa (Medicago sativa) and perennial peanut (Arachis glabrata) are frequently utilized by equine producers in the Southeast. However, challenges related to their production have producers searching for alternative legume options. In 2019 and 2020, five soybean cultivars, “Tower of Leaves,” “Stonewall,” “Laredo,” “AG79X9,” and “AG64X8,” were evaluated for yield and nutritive value. Soybeans were grown at two row spacings (36 and 71 cm), two locations (Central and South Alabama), and harvested at three heights (10, 15, and 20 cm; HH). Forages were harvested using a plot harvester, dried at 55°C, and ground to 1 mm. Forage quality was determined using a NIRS, with verification by wet chemistry analyses. The study was a randomized, complete block design (n = 4) and statistical analysis was carried out using PROC Glimmix of SAS version 9.4 (SAS Inst., - Cary, NC). Forage yields were greatest in “Stonewall” and “Tower of Leaves,” and lowest in “Laredo” (2,074, 1,978, and 1,348 kg/ha, respectively). Across years, HH and forage cultivar had a significant effect on yield (P < 0.0001). As expected, yield increased as HH decreased (P < 0.0001). In 2019, crude protein (CP) was affected by HH (P < 0.0001), with 10 cm having lower CP than 15 and 20 cm (14 vs 16%, respectively; P < 0.0001). Neutral detergent fiber (NDF), acid detergent fiber (ADF), and total digestible nutrients (TDN) were affected (P < 0.01) by HH and variety. “Stonewall” had the lowest NDF (30.84%) and ADF (29.27%; P < 0.01). “Stonewall” and “AG79X9” had the greatest TDN (74 and 73%, respectively; P < 0.01). The cultivar “Stonewall” shows promise as a forage, with greater yields and moderate forage nutritive value compared with the other cultivars tested. Further research is needed to evaluate “Stonewall” in mixtures with other warm-season annual forages.

Plant Growth-Promoting Rhizobacteria: Effects on Yield and Nutritive Value of ‘Russell’ Bermudagrass and ‘KY 31’ Tall Fescue

Abstract Commercial N fertilizer are labor intensive and expensive for many forage producers. Alternative N fertility options are necessary for the long-term sustainability of forage systems. A 2-yr experiment evaluating plant growth-promoting rhizobacteria (PGPR) as an alternative N source for ‘Russell’ bermudagrass (C. dactylon) and ‘KY 31’ tall fescue (L. arundinaceum) was conducted in Alabama. Fourteen, 3-m2 plots were treated with full N (56 kg/ha) and ½ N (28 kg/ha), Accomplish LM (AMS), AMS + ½ N, DH44, Blend 20, and a control. DH44 is a single strain of Paenibacillus sonchi, while Blend 20 contains 2 strains of Bacillus pumilus and 1 strain of B. spaericus. Forage samples were taken every 4 weeks with a 0.1-m2 quadrat then analyzed for NDF, ADF, CP, and yield using NIRS. Data were analyzed using Proc GLIMMIX of SAS 9.4 (SAS Inst., Cary, NC) as a completely randomized design (n = 2). For both forages, full N had greater (P < 0.0139) yield when compared to the control (tall fescue: 8,295 vs. 7,353 kg/ha; bermudagrass: 9,329 vs. 8,109 kg/ha). There were no differences (P ≥ 0.05) in NDF concentration for either forage. Full and ½ N had greater CP than AMS in bermudagrass (11.5, 11.4%; P ≤ 0.0490). Blend 20 treated bermudagrass had greater ADF than full and ½ N (32.7, 30.7, and 30.9%, respectively; P < 0.0313). Blend 20 treated tall fescue had greater ADF compared to AMS + N and DH44 (35.8, 12.1, and 33.9%, respectively; P < 0.0227). Full N tall fescue had greater CP) compared to AMS (12.1, AMS CP %, respectively; P < 0.0082). DH44 had greater CP compared to AMS and Blend 20 (11.9, 11.0, and 11.0%, respectively; P < 0.0423). For both forages, PGPR treated plots produced yields and maintained forage nutritive value not different than the commercial fertilizer.

85 Utilizing cover crops in an equine grazing system

Cover crops are commonly used to provide soil cover and can extend the grazing season, but have not been explored in horse pastures. The objectives of this research were to evaluate yield, forage nutritive value, and horse preference of annual ryegrass ( Lolium multiflorum L.), winter rye ( Secale cereale L.), berseem clover ( Trifolium alexandrinum L.), purple top turnip ( Brassica rapa ssp. rapa L.), and daikon radish ( Raphanus sativus ssp. longipinnatus L.) under horse grazing in the fall. We hypothesized that grasses and clover would be more suitable cover crops for horse pastures compared with turnip and radish. Cover crops were seeded in monoculture and mixtures in August 2018 and 2019 as a randomized complete block with 4 replicates and grazed by 4 adult horses. Horses grazed 2 replicates per day for 4 h. Grazing occurred in October 2018 and in both September and October 2019. Before grazing, forages were sampled and weighed to determine herbage and root yield and nutritive value was evaluated using wet chemistry. After grazing, forages were visually assessed for preference based on percentage of removal on a scale of 0 to 100%. Data were analyzed using an ANOVA and linear regression; significance was set at P < 0.05. Berseem clover was the lowest yielding forage ( P < 0.0001). Yield of annual ryegrass, winter rye, berseem clover, turnip and radish averaged 2,293, 2,287, 763, 4,252, and 4,095 kg ha −1 , respectively. All forages met digestible energy (>2.17 Mcal kg −1 ) and crude protein (>19%) requirements for adult horses at maintenance. Berseem clover was most preferred (>73% removal) while turnip and radish were the least preferred (<19% removal; P < 0.0001). No adverse health effects were observed while grazing cover crops during this short grazing period. Placing a priority on preference, berseem clover, annual ryegrass, and winter rye appear to be suitable cover crops to extend the grazing season in horse pastures.

Interseeding annual warm‐season grasses into pastures: Forage nutritive value and yields

AbstractInterseeding annual warm‐season grasses into pastures often increases forage accumulation. Yet, impacts on nutritive value and yields remain unreported. We analyzed forage collected from five Nebraska and Kansas experiments in 2015–2016 (eight environments) for crude protein (CP), neutral detergent fiber (NDF), and in vitro organic matter digestibility (IVOMD) concentrations and yields. Each experiment subjected perennial cool‐season grasses to two harvest frequencies (once at 90 d and twice at 45 and 90 d after interseeding) and four interseeded annual warm‐season grass types–pearl millet [Pennisetum glaucum (L.) R. Br.], sudangrass [Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud) de Wet &amp; Harlan], a sorghum–sudangrass hybrid (S. bicolor × S. bicolor var. sudanense), and an unseeded control. Across environments, 90‐d CP and IVOMD concentrations increased while CP and IVOMD yields decreased in interseeded pastures when harvested twice, indicating presence of nutritive value‐yield tradeoffs. Pastures interseeded with sorghum–sudangrass had greater 90‐d IVOMD concentrations and CP and IVOMD yields when harvested once but only greater 90‐d IVOMD concentrations when harvested twice compared to unseeded pastures. Interseeding sorghum–sudangrass provided an effective strategy to increase CP and IVOMD yields in late summer in humid environments with tall fescue [Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.] and in mid‐ and late summer in humid environments with smooth bromegrass (Bromus inermis Leyss.) and semiarid environments with western wheatgrass [Pascopyrum smithii (Rydb.) Á. Löve]. Interseeding annual warm‐season grasses did not consistently increase CP and IVOMD yields in semiarid environments with smooth bromegrass and crested wheatgrass [Agropyrum cristatum (L.) Gaertn.].

Palisadegrass pastures with or without nitrogen or mixed with forage peanut grazed to a similar target canopy height. 1. Effects on herbage mass, canopy structure and forage nutritive value

AbstractNitrogen (N) inputs to pasture systems coupled with grazing management strategies based on monitoring and control of canopy structure may provide conditions for greater productivity and enhanced forage nutritive value. This 2‐year study assessed canopy structure and nutritive value responses of three pasture treatments, namely, (1) mixed Marandu palisadegrass (Brachiaria brizantha [Hochst. ex A. Rich.] R.D. Webster [syn. Urochloa brizantha Stapf]) cv. Marandu and forage peanut (Arachis pintoi Krapov. &amp; W.C. Greg.) cv. BRS Mandobi pastures without N fertilizer (GRASS + LEGUME); (2) monoculture Marandu palisadegrass pastures fertilized with 150 kg N/ha (GRASS + N); and (3) monoculture Marandu palisadegrass without N fertilizer (GRASS). Grazing management was similar across pasture treatments, using continuous stocking and a target canopy height of 20–25 cm. Herbage mass was greater in GRASS + N and GRASS + LEGUME pastures than in GRASS in summer and spring (p = .014). The leaf:stem ratio in the grass mass (p = .731) was similar between treatments. Grass crude protein (CP) and in vitro digestible dry matter (IVDDM) were greatest in the GRASS + N pasture (p &lt; .001). Grass neutral detergent fibre (NDF) concentration was greater at GRASS and GRASS + LEGUME pastures than in GRASS + N (p &lt; .001). Forage peanut had a greater IVDDM and CP concentration and a lower NDF concentration than Marandu palisadegrass. Nitrogen application or the presence of the legume increased green herbage mass and improved forage nutritive value in canopies with similar height.

Evaluation of alfalfa cultivars under rainfed Mediterranean conditions

AbstractTwenty alfalfa cultivars were tested, under rainfed conditions in central Greece, for forage yield, agronomic and nutritive value in order to identify adaptive responses contributing to high resilience and productivity. From 2014 to 2017, five harvests (H1 to H5) per season were conducted. Two cultivars were also grown as irrigated checks. Annual and total dry matter (DMA and DMT) and harvest ratios (RH) were estimated. DMT was reduced by 42.9–48.1% under ambient rainfall compared to irrigated checks, which received 50.2% more water. The seasonal yield distribution demonstrated two contrasting strategies, however, equally effective for high resilience under rainfed conditions. The winter-active imported cultivars were the most resilient in the driest year, potentially due to their ability to exploit autumn rains, whereas the locally adapted genotypes were more productive in summer. The spring harvest ratio (RH1) was more indicative (r = 0.94, P &lt; 0.01) of cultivar productivity, compared to plant survival (r = 0.65, P &lt; 0.01), whereas the autumn harvest ratio (RH5) was representative of productivity under extreme drought (r = 0.53, P &lt; 0.05). RH1 and RH5 were increased by 11.8 and 12.3%, respectively, whereas the summer ratios (RH3, RH4) were reduced by 47.3%, under rainfed v. irrigated conditions. Two Australian cultivars (‘Blue Ace’, ‘Icon’) achieved the highest RH5 suggesting an adaptive response by being more productive in autumn. However, the development of specifically adapted cultivars in terms of higher summer yield and plant survival may be necessary to cope with future climatic changes in the Mediterranean region.

Erratum

CSA NewsVolume 66, Issue 4 p. 2-2 ERRATUMFree Access Erratum This article corrects the following: Reduced-Lignin Alfalfa Can Extend Harvest Timing Volume 66Issue 3CSA News pages: 24-24 First Published online: February 17, 2021 First published: 19 April 2021 https://doi.org/10.1002/csan.20470AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat We wish to report an error in the March 2021 issue of CSA News magazine in the article “Reduced-Lignin Alfalfa Can Extend Harvest Timing” on p. 24. The author names in the “adapted from” text at the end were incorrect. The correct text should read, “Adapted from Sulc, R.M., Arnold, A.M., Cassida, K.A., Albrecht, K.A., Hall, M.H., Min, D., … & van Santen, E. (2020). Changes in forage nutritive value of reduced-lignin alfalfa during regrowth. Crop Science. https://doi.org/10.1002/csc2.20366.” We regret the error. Reference CSA News. (2021). Reduced-lignin alfalfa can extend harvest timing. CSA News, 66(3), 24. https://doi.org/10.1002/csan.20401. Google Scholar Volume66, Issue4April 2021Pages 2-2 ReferencesRelatedInformation

Introduction of four native legumes of the Canadian Prairies in monoculture and in mixtures with meadow bromegrass (Bromus riparius)

Many questions remain concerning the viability and productivity of seeding native legumes in the Canadian Prairies for forage production. Field research was conducted with four native legume species (Astragalus flexuosus, Dalea purpurea, Hedysarum boreale, and Vicia americana) to evaluate performance in Swift Current and Saskatoon, SK. The experimental design was a randomized complete block design with four replicates to evaluate legume–grass mixtures and monoculture performance, botanical composition, and effect of harvest dates (July and August) from 2016 to 2018. The native legume–grass mixtures performed differently at the sites, with greater foliar cover at Saskatoon but a greater proportion of legumes in mixtures at Swift Current. The mixtures had similar forage nutritive value as monoculture Bromus riparius, with legumes contributing 10% or less of the forage dry matter yield (DMY) at both sites. Astragalus flexuosus showed the greatest foliar cover and produced the greatest DMY in monoculture at both sites. Based on this study, native legumes would need to make up a larger proportion of forage dry matter yield to change the nutritional value of mixtures. In a subsequent seeding rate evaluation, the four legume species were planted at three seeding rates [300, 200, and 100 pure live seeds (PLS) per metre] and tested for DMY one year following establishment near Swift Current. Increasing seeding rates up to 300 PLS·m−1 corresponded with an increase in seedling density and foliar cover, but DMY was not affected. Additional research with A. flexuosus is needed to demonstrate its value as a forage.

Effects of Limited Irrigation on Forage Yield, Nutritive Value and Water Use Efficiency of Persian Clover (Trifolium Resupinatum) Compared to Berseem Clover (Trifolium Alexandrinum)

ABSTRACT To evaluate the forage yield and quality of Berseem and Persian clover cultivars, a two-year experiment was conducted during two growing seasons (2017–2018 and 2018–2019). Irrigation was the main factor, including full irrigation (I100), moderately limited (I75), and severely limited irrigation (I50). The sub-factor consisted of ten cultivars of clover, five of which were Persian clover (Pars, Aleshtar, Eghlid, Harat, and Zabol) and five cultivars of Berseem clover (Karaj, Elite, Ekinaton, Vienna, and Alex). The results showed that the highest dry matter (DM) and crude protein (CP) yield under all irrigation levels were obtained from the Berseem clover cultivars. Imposing limited irrigation reduced the DM yield, digestible dry matter (DDM) yield and content, CP yield, dry matter intake (DMI), and relative feed value (RFV) of forage, whereas the content of CP, water-soluble carbohydrates (WSC), neutral detergent fiber (NDF), and acid detergent fiber (ADF) increased. Irrigation water use efficiency (IWUE) for DM, DDM, and CP yield under limited irrigation were also increased. Comparison of two groups of Persian and Berseem clover cultivars also showed that with increasing drought stress intensity, in Berseem cultivars, DM yield, DDM yield and content, and RFV decrease was higher. Increasing IWUE under limited irrigation was higher in Persian cultivars for DM and DDM yield. Overall, Berseem clover had higher forage yield and water use efficiency in all irrigation regimes, and the forage quality of this species showed more sensitivity to drought. Abbreviations :I100, I75, and I50, full, moderately limited, and severely limited irrigation (equivalent to 100, 75, and 50% weekly evaporation and crop water requirement, respectively); DM, dry matter; CP, crude protein; ADF, acid detergent fiber; NDF, neutral detergent fiber; DDM: digestible dry matter; WSC, water-soluble carbohydrates; DMI, dry matter intake; RFV, relative feed value; IWUE, irrigation water use efficiency.

Effects of alfalfa and alfalfa-grass mixtures with nitrogen fertilization on dry matter yield and forage nutritive value

Alfalfa (Medicago sativa L.) is an important forage legume grown in Kansas, USA and its productivity with cool-season grasses however is unknown. The objective of this study was to determine the dry matter yield (DMY) and forage nutritive value of alfalfa-grass mixtures compared to those of alfalfa and grasses grown in monoculture with and without nitrogen fertilization. Three different alfalfa varieties were planted (reduced-lignin alfalfa, Roundup Ready, and conventional alfalfa) and two kinds of cool-season grasses (smooth brome, Bromus inermis Leyss, and tall fescue, Festuca arundinacea Schreb) were planted as a monoculture or in alfalfa-grass mixtures. Nitrogen fertilizer (urea) was applied at green-up at a rate of 56 kg/ha and after the second cutting at a rate of 56 kg/ha in 2016 and 2017, respectively. and control treatments received no nitrogen. DMY was significantly higher in monoculture alfalfa and alfalfa-grass mixtures than in grass monocultures. Between alfalfa monoculture and alfalfa-grass mixtures, no significant differences in DMY were found. For all treatments, nitrogen application significantly increased DMY compared to the control. In 2016 and 2017, the low-lignin alfalfa monoculture had the lowest acid detergent fiber (ADF) and the grass monocultures had the highest ADF. In 2016 and 2017, neutral detergent fiber (NDF) in smooth bromegrass and tall fescue was higher than in other species treatments. A low-lignin alfalfa monoculture had significantly lower NDF concentration compared to alfalfa-grass mixtures. When averaged over 2016 and 2017, relative feed value (RFV) was highest in low-lignin alfalfa and lowest in the grass monocultures. In both years, nitrogen fertilizer application did not affect nutritive values.

Establishment and productivity of cicer milkvetch (Astragalus cicer L.) in alfalfa (Medicago sativa L.) or alfalfa–hybrid bromegrass mixtures

Cicer milkvetch (Astragalus cicer L.) (CMV) is a non-bloating, perennial legume that has shown persistence under grazing. Limited information is available on its seedling establishment and subsequent forage yield and nutritive value in alfalfa (Medicago sativa L.) mixtures. Field plots were seeded in May 2013 at Melfort, SK, Canada, to evaluate ‘Oxley II’ cicer milkvetch performance in ‘AC Grazeland’ alfalfa or alfalfa and ‘AC Success’ hybrid bromegrass (Bromus riparius Rehmann× Bromus inermis Leyss.) mixtures from 2014 to 2017. Two controlled environment tests were also conducted by treating seeds of CMV using alfalfa root aqueous extract. Seed germination and seedling height of CMV were significantly reduced in aqueous extract. In the field, establishment of CMV in a mixture containing alfalfa was reduced, and CMV dry matter proportion in the mixture increased only 3.5% over three years. Increasing CMV seeding rate did not increase its dry matter (DM) percent in the mixtures, indicating a high allelopathic effect of alfalfa. Forage DM yield of all mixtures was linearly correlated to the proportion of alfalfa, and adding hybrid brome did not increase the DM yield. Forage DM yield was higher for the three-cut than the two-cut treatments for CMV–alfalfa mixtures, but there was no difference between the cutting frequency for CMV–alfalfa–hybrid brome mixtures. Fiber concentrations decreased linearly with increased CMV seeding rate in the mixtures. This study showed that CMV establishment in alfalfa mixtures was reduced in a same-row seeding, and the allelopathic effect was not reduced by lower alfalfa seeding rates or adding a grass.

Breeding strategies in evaluation of forage barley

AbstractProducers on the Canadian Prairies grow barley (Hordeum vulgare L.) as a forage crop for ruminants, especially cattle. The purpose of our study was to determine methods to improve our selection of barley lines with superior forage value for ruminants. Data from the Western Cooperative Forage Barley Registration Test were used with permission of the Prairie Recommending Committee for Oat and Barley (PRCOB) and the breeders. Data were analyzed from 20 environments collected from 3 yr (2012–2014) and seven sites. We measured forage accumulation (FA) at the soft dough stage, five nutritive value traits, and three derived cow–calf variables. Although the variation in FA and forage nutritive value traits attributed to environment (E) was large, significant genotypic (G) effects were found for all traits measured. Whereas G× E effects were also significant, the mean square effect for G was up to 40 times higher than the mean squares for G×E. The proportion of variance attributed to G was greater for nutritive value traits than for FA. Significance of G means there was variability in the germplasm tested, and improvement through selection should be possible. The two parametric methods of stability analyses (Francis–Kannenberg method and Eberhart–Russell method) often identified the same lines as superior. Lines that were superior for FA and carrying capacity (cow on swath grazing, CC) were often different from those identified as superior for nutritive value, empty body weight gain (cow, EBWG) and average daily gain (backgrounding calf, ADG). A nonparametric method used to determine dynamic stability (Nassar–Hühn method) identified different lines as superior from the parametric methods. Breeders can use a combination of these selection criteria in breeding forage barley varieties with enhanced forage value for ruminants.

Estimating the daily nutritive value of bermudagrass for grazing livestock

ABSTRACT Objective Our objective was to develop models to estimate the CP, NDF, lignin, and ash concentrations of bermudagrass [Cynodondactylon (L.) Pers.] forage daily throughout the grazing season and use them to estimate TDN daily. We hypothesized that the CP, NDF, lignin, ash, and TDN concentrations might change daily. Materials and Methods Coastal bermudagrass forage CP, NDF, lignin, and ash concentrations spanning several years were obtained from Overton, Texas. The forage samples used comprised hand-plucked plant parts intended to estimate animal-selected diets. We developed an empirical model for each nutritive variable with the day of the year (DOY) as a predictor. By incorporating these models into a pre-existing summative equation, we estimated the daily values of TDN. These nutritive value models were evaluated using the Willmott index, modeling efficiency, root mean squared error, and R2 as the measures of fit. Results and Discussion Bermudagrass CP concentration had a negative, curvilinear association with DOY, whereas lignin and NDF concentrations were positively, curvilinearly related to DOY. The ash concentration had a negative, linear association with DOY. The likely causal factors for these relationships were plant maturity and weather conditions, especially temperature. The Willmott index, modeling efficiency, and R2 values were greater than 0.87, 0.64, and 0.65, respectively. The root mean squared error and percent error values were less than 3.1 and 11%, respectively. These values indicated that the nutritive value models were reliable. Implications and Applications We showed that the CP, NDF, lignin, ash, and TDN values of bermudagrass forage changed daily. By incorporating these trends into a nutritive value prediction system, accurate estimates of daily TDN could be made. These nutritive value models could be a valuable asset in forage-animal modeling for more accurately studying the effects of various management strategies and environmental factors on forage nutritive value and animal performance.

Comparison of forage production and nutritive value of 10 &lt;i&gt;Grona&lt;/i&gt; spp. accessions in Danzhou, Hainan, China

The demand for high-quality forages is increasing in tropical regions, and could be filled with legume species of the genus Grona, which have good nutritive value. In this study, a comparison of the forage production and nutritive value of 10 accessions of Grona spp. was carried out in the field at Danzhou, Hainan from 2016 to 2018. Yield, plant height, survival rate, leaf:stem ratio and concentrations of crude protein, crude fiber, crude fat (ether extract), nitrogen free extract, crude ash, calcium and phosphorus were measured. Results showed that Grona strigillosa (syn. Desmodium strigillosum) cv. Reyan No. 27 and G. heterocarpa subsp. ovalifolia (syn. Desmodium ovalifolium) cv. Maquenque displayed the best performance, owing to their 261.3% and 235.6% higher dry matter yields, respectively, compared with the Control germplasm, G. heterocarpa subsp. ovalifolia cv. Reyan No. 16 in 2018. Cultivar Maquenque had a higher survival rate than the Control (P&lt;0.05). Regarding nutritive value, cv. Reyan No. 27 exhibited higher crude fat and crude fiber but lower Ca concentrations than the Control (P&lt;0.05). Based on PCA ranking, we concluded that cvv. Maquenque and Reyan No. 27 could be used as suitable candidate materials for livestock production in tropical regions of China. Further studies on their tannin concentrations and their acceptability by animals are needed before practical recommendations can be made.

Effects of cultivar and growing degree day accumulations on forage partitioning and nutritive value of common vetch (Vicia sativa L.) on the Tibetan plateau.

The use of common vetch in grassland-livestock systems has expanded greatly within recent years, partly because of its value as a high-quality forage crop but also to improve the soil nitrogen availability. In-field estimation of forage yield potential and nutritional characteristics is required for providing management decision to farmers on how to optimize the management and use of common vetch forages. The aim of this work was to study changes in forage partitioning and nutritive value responses of a late-maturing and an early maturing cultivar of common vetch in a two-year study on the Tibetan Plateau. This study provided evidence for differential patterns of forage accumulation for common vetch with contrasting maturity over 2 years. The late-maturing cultivar exhibited greater forage yield and a lower proportion of pods, compared to the early maturing cultivar. There was a tendency towards lower forage nutritive value with the late-maturing cultivar. Regressions of nutritive value parameters of common vetch forages on growing degree days were explained by the cubic (P < 0.001) models, all with high coefficients of determination (R2 ≥ 0.792). This study shows that the late-maturing cultivar harvested at end of the pod-filling stage produces high forage yield, increasing the availability of high-quality forage for ruminants, thereby improving the self-sufficiency of farmers, in terms of forage yield and high-concentration protein. For early maturing cultivars, it may be better to harvest at the early flowering stage for better nutritive value and in part to enable a subsequent double crop of oat. © 2020 Society of Chemical Industry.

Nutritive value and in vitro methane production of Urochloa brizantha cv. Marandu under fixed time or variable stocking cycles

AbstractThe aim of this study was to evaluate the chemical composition, digestibility, gas production kinetics and in vitro methane (CH4) production of Urochloa brizantha cv. Marandu under two stocking methods over three consecutive stocking cycles. The stocking methods were (1) a fixed‐time stocking cycle of 33 days (33‐SC) with a 30‐day rest period and a 3‐day grazing period, and (2) a variable stocking cycle, with the end of the rest period when the canopy intercepted 95% of the light and a 3‐day grazing period (95‐LI). The average rest period was 24.5‐day (standard deviation of 5.2‐day) for 95‐LI. The in vitro dry matter digestibility (IVDMD) was higher (p &lt; .01) for 95‐LI (646 g/kg) relative to 33‐SC (628 g/kg). Crude protein concentration was higher (p &lt; .01) for 95‐LI (154 g/kg) relative to 33‐SC (136 g/kg). The ADF (303 g/kg DM) and aNDF (623 g/kg) were higher (p &lt; .01) for 33‐SC compared to 95‐LI (287 and 605 g/kg respectively). The gas production potential from non‐fibrous carbohydrates was 9.4% higher for 33‐SC. The in vitro CH4 production per unit of degraded dry matter (DDM) was higher (p &lt; .01) for 33‐SC (19.9 CH4 ml/g), compared to 95‐LI (17.9 CH4 ml/g). The 33‐SC management resulted in rest periods that were too long for the time needed for optimal regrowth. The variable SC based on the 95‐LI was more favourable, because it resulted in maximum yield of dry matter with improved forage nutritive value, while decreasing CH4 yield.

The Impact of Tedding on Alfalfa Nutritive Value in a Silage Production System

HighlightsTedding alfalfa reduced moisture content by 108 g kg-1 on a wet basis over a 24 h period.Tedding increased water soluble carbohydrates in harvested alfalfa which could improve silage nutritive value.Tedded alfalfa had similar or lower ash content compared to non-tedded alfalfa.Tedding did not have an observable impact on total digestible nutrients.Abstract. Two treatments, tedded and untedded, were applied to an alfalfa field to determine their impact on the nutritive value of the resulting harvested forage. The tedded treatment area was tedded immediately after the cutting, and the untedded treatment was left in its original 1.5 m width windrow. The tedded alfalfa dried faster (p = 0.001) than the untedded in all cuttings. When results were averaged across the three cuttings, crude protein (p = 0.006), water soluble carbohydrates (p = 0.05), and ash content (p &amp;lt; 0.001) were also observed to be different. The tedded treatment had a 6 g kg-1 lower crude protein content, a 9 g kg-1 higher water soluble carbohydrate content and an 8 g kg-1 lower ash content than the untedded treatment. A difference was not observed between the treatments for neutral detergent fiber (p = 0.49) or total digestible nutrients (p = 0.89). Producers can rely on a tedding intervention to hasten alfalfa drying for silage production while having a minimal impact on forage nutritive value. Keywords: Alfalfa, Forage nutritive value, Medicago sativa, Tedder

Space use, herbage selection, and animal performance of grazing heifers on a peaty river valley section

ABSTRACT Grazing is a suitable option for managing the habitat functions of restored fen grasslands. Nevertheless, nutritional requirements of the grazing livestock need to be considered to make such grazing systems sustainable. In order to analyze the interactions between the development of forage nutritive values, grazing behaviour and resulting liveweight gains, we implemented a grazing experiment at a typical river valley section in Northeast-Germany. We tested the hypothesis that heifers were able to compensate the decreasing digestibility of pasture growth over the course of the grazing period by selective grazing. Herbage on offer and faeces of heifers were sampled and analyzed biweekly from May to October over three grazing seasons. The nitrogen content of the faeces was used to estimate the digestibility of the selected herbage. The sedge-dominated peat area was not used for grazing before the grass-dominated sections of the moraine area were depleted, despite acceptable energy contents of the sedge-dominated plant communities during spring and early summer. This behaviour limited the degree of energy selection. The energy content of the herbage on offer explained 67% of the variations in daily liveweight gain. Results indicate the need to modify the management of continuous stocking systems for achieving economically feasible gains.

Nutritive value of fall‐stockpiled tall fescue pastures on southeastern U.S. farms

AbstractStockpiling of tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] may be a useful strategy to avoid fescue toxicosis in autumn and to reduce winter hay feeding costs of beef cattle grazing systems. Typical recommendations are to fertilize with N prior to fall growth. However, little information is available on how soil and pasture conditions affect forage nutritive value responses to fall fertilization. We analyzed the nutritive value of fall‐stockpiled forage in response to N fertilization on 92 fields in North Carolina and neighboring states from 2015 to 2018. We hypothesized that inherent soil nutrient cycling might minimize the need for exogenous N fertilizer inputs. Increasing N fertilization led to (a) greater crude protein, macronutrient concentrations (i.e., K, Ca, and P), and relative feed value and (b) lower acid detergent fiber, neutral detergent fiber, and lignin. However, changes were small, and effects were modified by surface soil properties. For example, crude protein increased from an average of 114 g kg–1 without N fertilization to 131 g kg–1 with 100 kg N ha–1, but this significant N fertilization effect diminished with increasing total organic C and inorganic N of a field. Small changes in nutritive value may have been a consequence of trials conducted on well‐managed farms with relatively high soil‐test biological activity and net N mineralization potential. Therefore, a single recommendation for fall N fertilization may not always be appropriate for enhancing nutritive value. Stockpiled tall fescue had sufficient nutritive value for pregnant cows, and N fertilization may not always be necessary.