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Throughout the Rolling Plains and Cross Timbers ecoregions of Texas, native grassland plant communities have been converted into low-diversity plant communities by long-term, intensive overgrazing by cattle and fire suppression. Much of the historical plant community has become dominated by annuals, Texas wintergrass (Nassella leucotricha), and honey mesquite (Prosopis glandulosa). This degradation has been so severe that many native bird species, including Northern bobwhite (Colinus virginianus), have experienced drastic population declines. We conducted a small-plot study to determine effective management actions for transforming mesquite savanna−Texas wintergrass communities to diverse native plant communities supportive of native wildlife species. We tested multiple management practices following mechanical mesquite brush removal, including seeding, timed treatments of herbicide, prescribed burns, and high-intensity, short-duration cattle grazing. Results indicated that plots receiving early spring treatments of herbicide followed by burning and grazing over 2 consecutive yr best reduced cool-season grasses and promoted overall restoration goals by increasing native warm-season grass and forb establishment.

Context Plant bioactive compounds such as condensed tannins (CT) are seen as an alternative to rumen chemical modulators to mitigate rumen methanogenesis in livestock; however, the presence of CT in ruminant faeces also produces a series of changes in soil microbiomes. Little is known about these effects on soil nutrient dynamics. Therefore, whether CT affect the decomposition process of faecal organic matter, delaying it and consequently increasing soil carbon and nitrogen (N) sequestration, merits study. Aims Our study investigated the effects of a diet rich in CT on bovine faecal composition and on subsequent dynamics of a soil microbial population. Methods Faeces were analysed from cattle fed the following diets: control (no CT), 1.25% CT, 2.5% CT. In a greenhouse pot experiment over a period of 60 days, faeces from the three dietary treatments were applied to soil and the soil microbial populations were measured against a control with no faeces applied. Key results The presence of CT increased the excretion of faecal N and of neutral and acid detergent fibres and lignin, and the higher rate of CT reduced the rate of soil organic matter decomposition. Treatments with dietary CT resulted in greater total numbers of bacteria in the soil than in the no-faeces control and stimulated numbers of Actinobacteria, Proteobacteria (α-Proteobacteria) and Firmicutes. Conclusions The study showed that CT alter N recycling and other nutrient inputs in a soil–animal ecosystem by increasing faecal N inputs, delaying organic matter breakdown, and changing soil microbial dynamics. Implications The presence of CT in ruminant diets can be beneficial to the soil environment. Sustainable management practices should be encouraged by providing ruminants with feed including high-CT legumes in silvopastoral systems.

The grazing of Zebu cattle in poor-quality tropical pastures during the dry season has an increased environmental impact and cost of production. The use of condensed tannins (CT) as a natural feed additive to modulate ruminal archaea can mitigate the methane emissions from cattle in tropical systems. We investigated the effects of CT on in vivo methane emissions and rumen microbiota ecology in beef cattle. Batch experiments were also conducted to evaluate the impact of dietary CT on the biogas production from beef cattle manure. Six adult rumen-cannulated Nellore cattle were used in a double 3 × 3 Latin square design. Treatments consisted of three diets containing either a 0%, 1.25% or 2.5% CT additive from Acacia mimosa extract. The experimental period consisted of 63 days, and methane production was measured using the sulfur hexafluoride (SF6) technique from Day 16 to 21 of each feeding period. Adding Acacia extract to the diets reduced daily methane emissions per animal. Methane suppression occurred more by reduction of intake than by the direct effect on methanogenic archaea. We verified that CT directly suppresses archaea rumen communities and increases total rumen bacteria. Our study indicates that CT benefit rumen Fibrobactersuccinogenes and Ruminoccous flavefaciens populations and have no negative effect on biogas production from cattle manure. Acacia extract as a feed additive has promising potential as part of an overall nutritional strategy to reduce the methanogenesis from Zebu beef cattle in tropical systems.

Temperate grass and legume yield and quality are markedly reduced during hot, dry summer months in the southern USA; therefore, browse species could add feed options for small ruminants during this season. Our objective was to compare total biomass yield and forage nutritive value of two browse species, leguminous bristly locust (Robinia hispida) and smooth sumac (Rhus glabra), as well as a leguminous shrub known as sericea lespedeza (Lespedeza cuneate), during summer months (June, July, August and September). Plants were sampled monthly during growing-seasons in 2012 and 2013 to determine biomass yield (foliar, shoot, and total above ground) and foliar nutritive value [crude protein (CP), acid detergent fiber (ADF), acid detergent lignin (ADL), and condensed tannins (CT)]. There was a species × harvest time interaction for foliar biomass yield (P = 0.0125). This interaction was likely due to low yield in June for bristly locust compared with sericea lespedeza and smooth sumac, but in all other months (July, August, and September) yields were similar for each species. Bristly locust had the highest CP (16.9%), followed by sericea lespedeza (14.8%), and smooth sumac (12.3%). Acid detergent fiber and ADL were similar between bristly locust (ADF 38.5%; ADL 24.1%) and sericea lespedeza (ADF 38.4%; ADL 23.1%), but was lower for smooth sumac (ADF 22.1%, ADL 6.3%; P Schedonorus arundinaceus) and bermudagrass (Cyanodon dactylon)] in this region and may provide high-yielding, low input, anti-parasitic fodder for small ruminants during this period in the Southeastern U.S.

Tropical pastures can be important natural sources of antioxidant compounds and may impact production and quality of animal protein with repercussions on human health. The objective of this study w...

The objective of this study was to identify by microhistological technique the reference chemical components for use as indicators of the nutritive value of Caatinga plants forage grazed by sheep throughout the year. A flock of twenty mixed-race meat ewes, multiparous, in production, with an average 34.84 ± 1.75 kg live weight and 36 months of age was assigned to supplement treatment of 0, 200, 350, and 500 g concentrate/head/day for 3 years. The experiment was designed as a randomized complete design with repeated measures over time. Supplementation with concentrate did not influence chemical composition of selected forage. In contrast, season heavily influenced diet chemical composition. Canopy stratum, season, and plant botanical family of selected species affected forage chemical composition selected by ewes. The ewes selected forage with greater nutritive value during the rainy season. Based on principal component analysis of the nutritive value of the primary forage species selected, ewes preferentially grazed plants contained greater neutral detergent fiber, acid detergent fiber, crude protein (CP), C fraction of nitrogenous compounds, and carbohydrate fractions A + B1 and C compared to the average native Caatinga herbage. Rangeland botanical composition and ewe diet varied during the year, affecting forage nutrients on offer, with the best diet selected during the rainy season because of the presence of dicotyledonous herbaceous species rich in CP as well as soluble carbohydrates and nitrogenous compounds. Concentrate supplement strategies for ewes on rangelands, such as Caatinga, should be determined by herbaceous species nutritive value during the rainy season and deep-rooted perennial dicotyledons during the dry season. These include the need to monitor ewe selection of forage species and their nutritive value, which is effectively accomplished with fecal microhistological techniques.

Due to the predictions of climate change, there is a need to identify forage plants that can keep their productivity and nutritive value under hydric stress. The objective of this study was to evaluate the biomass and chemical responses of three Desmanthus spp. accessions under two water deprivation regimens (7 and 21-day). The experimental design used was randomized blocks in a 3 × 2 factorial arrangement (access and water deprivation) with four replications. There were reductions in the biomasses of leaf and stem fractions of 64% and 51%, respectively. The 43F accession showed greater leaf (1.86 g.plant-1) and stem (1.97 g.plant-1) biomasses under a total water restriction of 21 days, compared to the 89F and AusT accessions. In accessions 43F and 89F, there were carbohydrate accumulations in the leaves of 28% and 51%, respectively, under the 21-day water restriction, while AusT decreased 38% within a 7-day interval. Water deprivation affected the chemical characteristics of the accessions. Free proline was similar among accessions and accumulated 463% more in the leaves of plants submitted to 21-day water deprivation (90.22 mg.kg-1) compared to those subjected to water deprivation for 7 days (16.03 mg.kg-1). Proline and total soluble carbohydrate accumulation in 43F and 89F were insufficient to regulate crude protein, C content, and C:N ratios. These results demonstrate the variability in drought tolerance among accessions. Accessions 43F and 89F were more susceptible to 21-day water deprivation, while AusT showed greater drought tolerance. RESUMO Devido às previsões de mudanças climáticas, é necessário identificar plantas forrageiras que sob estresse hídrico possam manter a produtividade e o valor nutritivo. O objetivo foi avaliar a biomassa e as respostas químicas de três acessos de Desmanthus spp. em dois regimes de privação de água (7 e 21 dias). O delineamento experimental foi em blocos ao acaso em esquema fatorial 3 × 2 (acesso e privação de água), com quatro repetições. Houve redução da biomassa de folha e caule de 64% e 51%, respectivamente. O 43F apresentou maior biomassa de folha (1,86 g.planta-1) e caule (1,97 g.planta-1) que os acessos 89F e AusT, na privação de água de 21 dias. Nas folhas dos acessos 43F e 89F, os carboidratos acumularam em torno de 28% e 51%, respectivamente, sob privação de 21 dias, enquanto o AusT diminuiu 38% no intervalo de 7 dias. A privação de água afetou as características químicas dos acessos. A prolina livre foi semelhante entre os acessos e acumulou 463% a mais nas folhas de plantas com 21 dias de privação de água (90,22 mg.kg-1) em relação às submetidas a 7 dias (16,03 mg.kg-1). O acúmulo de prolina e carboidratos solúveis totais em 43F e 89F foram insuficientes para regular a proteína bruta, o teor de C e a relação C:N. Há variabilidade na tolerância à seca entre espécies e acessos. Os acessos 43F e 89F foram mais suscetíveis à privação de água por 21 dias, enquanto AusT mostrou maior tolerância à seca.

Dried distillers grains with solubles (DDGS) is commonly used as supplemental feed in cattle rations. However, the systemic effects of overfeeding DDGS, especially to potential fertilizer benefits of pass-through nitrogen, are widely unknown. Therefore, our objective was to evaluate plant and soil response to fertilization with manure from steers supplemented with titrated levels of DDGS. Manure utilized was collected from steers supplemented with DDGS (0%, 0.25%, 0.5%, and 1% BW) during a 2-yr experiment. The experimental design was a randomized complete block design with an augmented factorial treatment structure wherein benches represented blocks. The factorial was made up of manure treatment (0, 0.25, 0.5, or 1% BW DDGS, chemical fertilizer, or none) soil type (Windthorst or Purves), and plant species (none, crimson clover, or rye). Pots were sown (5 seeds/pot) and grown in a greenhouse for 35 d. Water was applied daily at 90% evapotranspiration. After harvest, soils were sifted, dried for 72 h at 55°C, then assayed for C, N, NO3-N, P, K, Ca, Mg, Na, and S. There was an interaction of manure and soil type for soil C (P < 0.01). Purves soils amended with any manure had a greater (P < 0.05) concentration of C (1.8%) than did the negative control (1.3%). From Windthorst, soil C was greatest from 1% BW DDGS manure (1.9%), and least from 0% DDGS manure (1.5%), with 0.25 and 0.5% manures and the negative control intermediate. There was an interaction of manure, soil type, and forage for soil N (P < 0.01). Manures with higher levels of supplementation had greater (P < 0.05) soil N than lower levels of supplementation or the negative control. Legumes had greater soil N than grasses. Results are interpreted to mean that moderate supplementation of steers with DDGS may yield soil nutrient benefits through nutrient deposition.

Recently, biochar has been proposed for various agronomic applications including improved plant growth and soil fertility. In this study, the effects of dairy effluent-saturated (SBC) and unsaturated wood-derived biochar (UBC) on Bermudagrass (Cynodon spp.) growth, soil fertility and microbial communities were investigated in a greenhouse pot study. SBC and UBC were mixed with sandy loam soil at various loading rates (0, 1, 2, 4, and 8%) to grow Bermudagrass for 10 weeks. Soil physicochemical properties and plant growth measurements were taken, followed by 16S rRNA (V3-V4) amplicon sequencing of soil bacterial communities. Amendment of SBC to soil altered the soil physicochemical properties and increased the concentrations of N and P in the soil at 2 to 8% loading rates compared to UBC treated soil. The addition of SBC to soil also increased the overall plant biomass compared to UBC with more effects on aboveground biomass. Differential abundance analysis of taxa showed enrichment of Proteobacteria in UBC-amended soil, whereas Firmicutes and Nitrospirae were abundant in SBC-amended soil. Interestingly, enrichment of photosynthetic and N-fixing bacteria was observed in both SBC and UBC-amended soils after 10 weeks of treatments. However, oxidative phosphorylation and biotin metabolisms were found to be more abundant in SBC-amended soil compared to UBC-amended soil. Overall, our study suggested that amendment of SBC to soil resulted in enhanced soil nutrients, microbial capacity and Bermudagrass growth than that of UBC. Therefore, application of SBC to soil in field trials would be merited to identify sustainable and effective practices for enhancing plant growth, soil fertility and soil bacterial community.

Yeast products are used worldwide to stabilize the anaerobic rumen environment in dairy cattle. Multiparous lactating ruminally fistulated dairy cows (n = 4; ±150 DIM) were used in an 84-d 4×4 Latin square design to evaluate the effect of yeast on rumen pH and redox potential (eH). Periods were 21 d with 16 d used for treatment acclimation and HOBO pH and Temperature Data Loggers were placed in the rumen cranial sac on d 16 and removed on d 17 after a period of 24 hr for data collection. Cows were housed in a single pen and individually fed a basal dairy diet (CON) with no yeast culture or probiotics formulated for high milk yield targeting 5% feed refusals using a Calan Broadbent feeding system. Cows were randomly assigned to 1 of 4 treatments in period 1: CON, 14 g Diamond V XPC (XPC), 5 g Phileo-Lesaffre Actisaf HR+ (HR+), and HR+ 5 g Phileo-Lesaffre Safmannan (HR+Saf). Feed was delivered twice daily. Treatments were top-dressed at 0630 hr to ensure treatment consumption. Data were analyzed using GLIMMIX procedure of SAS 9.4. Significance was determined at P ≤ 0.05 and tendencies were considered at P ≤ 0.15. A treatment by time interaction occurred for rumen pH (P = 0.02). All yeast treatments were different than CON (P < 0.01), with no differences between yeast treatments (P > 0.52). A treatment by time interaction for eH (P = 0.04) occurred. Yeast eH was less than CON (P < 0.01). Redox potential decreased for HR+ compared to XPC (P = 0.04), while HR+Saf tended to decrease eH compared to XPC (P = 0.11). Over time, eH increased after feedings (P < 0.01). Data indicated that adding yeast to a dairy diet promoted an anaerobic environment, increasing rumen efficiency in lactating dairy cattle.

The objective of this study was to evaluate the metabolic profile of Santa Ines ewe lambs fed diets for early or late-maturing diets with or without nutrient restrictions. The experiment consisted of a 2 × 2 completely randomized factorial experiment with either early- or late-maturity feed formulation according to "Nutrient Requirements of Small Ruminants" with or without 15% crude protein (CP) and total digestible nutrients (TDN) restrictions in diets formulated, five replications, and 20 ewe lambs averaging 15.1±2.6 kg. Lambs on early-maturity diets consumed greater (P

Terpenes, volatile plant secondary compounds produced by woody plants, have historically been thought to act as feeding deterrents for mammalian herbivores. However, three species of woodrats, Neotoma stephensi, N. lepida, and N. albigula, regularly consume juniper, which is high in terpenes, and N. stephensi and N. lepida are considered juniper specialists. By investigating the terpene profiles in Juniperus monosperma and J. osteosperma, which are browsed or avoided by woodrats in the field, and recording the caching and consumption of juniper foliage by woodrats in the lab, we have evidence that terpenes may serve as feeding and/or foraging cues. The obligate specialist N. stephensi chose to forage on trees higher in p-cymene and preferred to consume juniper rather than caching it in a laboratory setting. These observations provide evidence that terpenes serve as a feeding cue and that the obligate specialist's physiological mechanism for metabolizing the terpenes present in juniper may negate the need for caching. The facultative specialist N. lepida chose to forage on trees lower in four terpenes and cached more juniper than the obligate specialist N. stephensi, providing evidence that terpenes serve as a feeding deterrent for N. lepida and that this woodrat species relies on behavioral mechanisms to minimize terpene intake. The generalist N. albigula foraged on trees with higher terpenes levels but consumed the least amount of juniper in the lab and preferred to cache juniper rather than consume it, evidence that terpenes act as foraging but not feeding cues in the generalist. Our findings suggest that volatile plant secondary compounds can act as feeding and/or foraging cues and not just feeding deterrents in mammalian herbivores.

Rangelands and other native pastures occupy a large area of the planet, with greater temporal and spatial botanical composition and productivity variability. Despite the continuous and historical use of these areas, including overgrazing and fire exclusion, endemic legume species persist in some semiarid rangelands. The objective this work was to review current knowledge of legume use, especially those of the Brazilian Caatinga rangeland. Studies that measure the qualitative and quantitative variations of native legumes are essential for ruminant feed supplementation, to the sustainability of animal production, as well as for economic and environmental improvements in rangelands. Caatinga vegetation of northeastern Brazil consists of deciduous shrubs and small trees which mostly lose their leaves at the beginning of the dry season. The legume family contributes to the greatest number of endemic species but little is known about their productivity or nutritive values. Livestock select Orelha de onca [Macroptilium martii (Benth.) Marechal & Baudet] and Mororo (Bauhinia cheilantha (Bong.) Steud.) and these should, during rangeland clearing, be preserved. In addition, although Caatinga legumes have great crude protein content, their biological fixation of atmospheric N has yet to be thoroughly studied. On the negative side, some native Caatinga legumes have great levels of neutral detergent fiber-bound N (NDFN) and condensed tannin. As a result, animal performance in Caatinga is often poor, notably in the dry period. Forage legumes also provide several environmental services such as N input via BNF and rehabilitation of degraded land.

Knowledge of free-living stages of endoparasite population ecology may guide their control in domesticated ruminants. Our objective was to evaluate sheep gastro-intestinal nematode (GIN) L3 distribution in tropical pasture profiles (grass and legume). Three different swards (treatments) were compared: 1) grass-only (G), 2) legume-only (L), and 3) one half of the paddock with grass and another half with legume (GL). We assessed pasture larval counts (PLC) in upper, medium and bottom strata, each representing one third of the sward height. Lamb health and performance characteristics were also evaluated. The PLC per kg of herbage dry matter (DM) tended to be 129% greater (P = 0.08) in the upper pasture profile compared to the lower stratum in GL pasture. However, the largest PLC dispersed per area (PLC/m²) was found (P

This review provides an update of ecologically relevant phytochemicals for ruminant production, focusing on their contribution to advancing nutrition. Phytochemicals embody a broad spectrum of chemical components that influence resource competence and biological advantage in determining plant species' distribution and density in different ecosystems. These natural compounds also often act as plant defensive chemicals against predatorial microbes, insects, and herbivores. They may modulate or exacerbate microbial transactions in the gastrointestinal tract and physiological responses in ruminant microbiomes. To harness their production-enhancing characteristics, phytochemicals have been actively researched as feed additives to manipulate ruminal fermentation and establish other phytochemoprophylactic (prevent animal diseases) and phytochemotherapeutic (treat animal diseases) roles. However, phytochemical-host interactions, the exact mechanism of action, and their effects require more profound elucidation to provide definitive recommendations for ruminant production. The majority of phytochemicals of nutritional and pharmacological interest are typically classified as flavonoids (9%), terpenoids (55%), and alkaloids (36%). Within flavonoids, polyphenolics (e.g., hydrolyzable and condensed tannins) have many benefits to ruminants, including reducing methane (CH4) emission, gastrointestinal nematode parasitism, and ruminal proteolysis. Within terpenoids, saponins and essential oils also mitigate CH4 emission, but triterpenoid saponins have rich biochemical structures with many clinical benefits in humans. The anti-methanogenic property in ruminants is variable because of the simultaneous targeting of several physiological pathways. This may explain saponin-containing forages' relative safety for long-term use and describe associated molecular interactions on all ruminant metabolism phases. Alkaloids are N-containing compounds with vast pharmacological properties currently used to treat humans, but their phytochemical usage as feed additives in ruminants has yet to be exploited as they may act as ghost compounds alongside other phytochemicals of known importance. We discussed strategic recommendations for phytochemicals to support sustainable ruminant production, such as replacements for antibiotics and anthelmintics. Topics that merit further examination are discussed and include the role of fresh forages vis-à-vis processed feeds in confined ruminant operations. Applications and benefits of phytochemicals to humankind are yet to be fully understood or utilized. Scientific explorations have provided promising results, pending thorough vetting before primetime use, such that academic and commercial interests in the technology are fully adopted.

Este artículo se encuentra disponible en la página web de la revista en la siguiente URL: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0248499 En este artículo también participan: Isabelle Naemi Kaneko, Laura Adriane de Moraes Pinto, Antônio Alves de Melo Filho, Vany Perpétua Ferraz, Gisele Maria Fagundes y James Pierre Muir. We evaluated the effects of the inclusion of copaı´ba (Copaifera officinalis L.) essential oil at 0.05 and 0.1% as a possible replacement of synthetic additive butylated hydroxytoluene (BHT) in sheep burgers during 14 days of storage in a refrigerated display case (4˚C). During the shelf life days, analyzes of antioxidant activity, lipid oxidation, pH, color, cooking loss, texture and consumer acceptability were carried out on refrigerated burgers. The addition of copaı´ba essential oil showed an antioxidant effect in sheep burgers (P > 0.05), reducing lipid oxidation. Copaiba essential oil added at 0.05% showed the highest antioxidant activity, decreased cooking losses and delaying discoloration (loss of redness) during storage; it further improved, the tenderness of sheep burgers (P < 0.05). The treatments had no effect (P > 0.05) on consumer acceptability. Copaiba essential oil is a promising natural antioxidant to increase the shelf life of meat products, as well as being a viable solution to replace synthetic antioxidant BHT, thereby promoting the fresh-like quality appeal of sheep burgers.

The addition of natural plant secondary compounds to ruminant feed has been extensively studied because of their ability to modify digestive and metabolic functions, resulting in a potential reduction in greenhouse gas emissions, among other benefits. Condensed tannin (CT) supplementation may alter ruminal fermentation and mitigate methane (CH4) emissions. This study’s objective was to determine the effect of quebracho CT extract [QT; Schinopsis quebracho-colorado (Schltdl.) F.A. Barkley & T. Meyer] within a roughage-based diet on ruminal digestibility and kinetic parameters by using the in situ and in vitro gas production techniques, in addition to blood urea nitrogen (BUN) and ruminal (volatile fatty acid [VFA], NH3-N, and protozoa count) parameters. Twenty rumen-cannulated steers were randomly assigned to four dietary treatments: QT at 0%, 1%, 2%, and 3% of dry matter (DM; QT0: 0% CT, QT1: 0.70% CT, QT2: 1.41% CT, and QT3: 2.13% CT). The in situ DM digestibility increased linearly (P = 0.048) as QT inclusion increased, whereas in situ neutral detergent fiber digestibility (NDFD) was not altered among treatments (P = 0.980). Neither total VFA concentration nor acetate-to-propionate ratio differed among dietary treatments (P = 0.470 and P = 0.873, respectively). However, QT3 had lower isovalerate and isobutyrate concentrations compared with QT0 (P ≤ 0.025). Ruminal NH3 and BUN tended to decline (P ≤ 0.075) in a linear fashion as QT inclusion increased, suggesting decreased deamination of feed protein. Ruminal protozoa count was reduced in quadratic fashion (P = 0.005) as QT inclusion increased, where QT1 and QT2 were lower compared with QT0 and QT3. Urinary N excretion tended to reduce in a linear fashion (P = 0.080) as QT increased. There was a treatment (TRT) × Day interaction for in vitro total gas production and fractional rate of gas production (P = 0.013 and P = 0.007, respectively), and in vitro NDFD tended to be greater for QT treatments compared with no QT inclusion (P = 0.077). There was a TRT × Day interaction (P = 0.001) on CH4 production, with QT3 having less CH4 production relative to QT0 on day 0 and QT2 on days 7 and 28. Feeding QT up to 3% of the dietary DM in a roughage-based diet did not sacrifice the overall DM digestibility and ruminal parameters over time. Still, it is unclear why QT2 did not follow the same pattern as in vitro gas parameters. Detailed evaluations of amino acid degradation might be required to fully define CT influences on ruminal fermentation parameters and CH4 production.

Sheep production on pasture plays an important role in subtropical climates around the world, with great economic and environmental relevance to those regions. However, this production is much lower than its true potential in subtropical regions, largely due to lack of knowledge of how to feed grazing lambs, and mitigate gastrointestinal parasite infections. Due to weather instability and the high growth rate of tropical grasses, it is difficult to adjust the quality and quantity of feed consumed by lambs. In addition, due to warm, wet weather during spring, summer, and autumn, gastrointestinal parasite infection can be intense on subtropical pastures. Thus, the objective of this paper is to summarize 17 years of research in southern regions of Brazil testing alternative management for sheep farmers under these challenging conditions. Our review indicates that ewes play important roles raising their lambs. Besides protecting and providing milk, they leave a better pasture structure for lamb nutrition. The use of creep feeding and creep grazing are additional alternatives to improve lamb growth. However, feeding supplementation with concentrate can deteriorate pasture quality at the end of the summer?autumn season. Gastrointestinal parasitic infections can be reduced with improved lamb nutrition, although L3 larvae of Haemonchus contortus can be present at various pasture heights. This indicates that it is difficult to control L3 ingestion solely by manipulating grazing heights. We summarize important technologies for raising lambs on pasture-based systems to make the best of high herbage growth and minimize intense parasitic infections common in subtropical regions. We discuss research results in light of the latest studies from other ecoregions and climates, although there is a lack of similar research in subtropical regions of the world. Made available in DSpace on 2020-09-24T09:12:04Z (GMT). No. of bitstreams: 1 CNPC-2020-Art-18.pdf: 269365 bytes, checksum: 34b8b416c5d869df96ea11e992d8e96e (MD5) Previous issue date: 2020

Condensed tannins (CTs) are plant anti-herbivore compounds with antimicrobial activity that can be used in ruminant diets as ruminal microbiome manipulators. However, not all CTs from fodder legumes are bioactive due to their wide structural diversity. The aim of our study was to investigate the effect of 10 CT-containing plants (Flemingia macrophylla, Leucaena leucocephala, Stylosanthes guianensis, Gliricidia sepium, Cratylia argentea, Cajanus cajan, Desmodium ovalifolium, Macrotiloma axilare, D. paniculatum, and Lespedeza procumbens) on in vitro fermentation kinetics of Nelore beef cattle. Polyethylene glycol (PEG), a specific CT-binding agent, was added to neutralize condensed tannin. Tifton and alfalfa hay were used as controls lacking CT. The experimental layout included a randomized complete block with factorial design and four blocks. The data were subjected to analysis of variance followed by Duncan’s test to determine differences (p &lt, 0.05) among treatment means. The addition of PEG in browse incubations resulted in increased gas production, fermentation rate, short-chain fatty acid (SCFA) and N-NH3 release. Within our study, Lespedeza procumbens, Desmodium paniculatum, Leucaena leucocephala, Desmodium ovalifolium, and Flemingia macrophylla showed superior bioactivity compared to other species evaluated, suggesting a natural alternative for replacing ionophores to modify ruminal fermentation. Condensed tannins from L. pocumbens, D. paniculatum, L. leucocephala, D. ovalifolium, and F. macrophylla have the potential to modify rumen fermentation in beef cattle.

Animal feeding behavior and diet composition determine rumen fermentation responses and its microbial characteristics. This study aimed to evaluate the rumen fermentation kinetics of domestic ruminants feeding diets with or without condensed tannins (CT). Holstein dairy cows, Nelore beef cattle, Mediterranean water buffalo, Santa In&ecirc, s sheep and Saanen goats were used as inoculum donors (three animals of each species). The substrates were maize silage (Zea mays), fresh elephant grass (Pennisetum purpureum), Tifton-85 hay (Cynodon spp.) and fresh alfalfa (Medicago sativa). Acacia (Acacia molissima) extract was used as the external CT source. The in vitro semi-automated gas production technique was used to assess the fermentation kinetics. The experimental design was completely randomized with five inoculum sources (animal species), four substrates (feeds) and two treatments (with or without extract). The inclusion of CT caused more severe effects in grazing ruminants than selector ruminants.

Biofuels produced from non-food lignocellulosic feedstocks have the potential to replace a significant percentage of fossil fuels via high yield potential and suitability for cultivation on marginal lands. Commercialization of dedicated lignocellulosic crops into single biofuels, however, is hampered by conversion technology costs and decreasing oil prices. Integrated biorefinery approaches, where value-added chemicals are produced in conjunction with biofuels, offer significant potential towards overcoming this economic disadvantage. In this study, candidate lignocellulosic feedstocks were evaluated for their potential biomass and silica yields. Feedstock entries included pearl millet-napiergrass (&ldquo, PMN&rdquo, Pennisetum glaucum [L.] R. Br. &times, P. purpureum Schumach.), napiergrass (P. purpureum Schumach.), annual sorghum (Sorghum bicolor [L.] Moench), pearl millet (P. glaucum [L.] R. Br.), perennial sorghum (Sorghum spp.), switchgrass (Panicum virgatum L.), sunn hemp (Crotalaria juncea L.), giant miscanthus (Miscanthus &times, giganteus J.M. Greef and Deuter), and energy cane (Saccharum spp.). Replicated plots were planted at three locations and characterized for biomass yield, chemical composition including hemicellulose, cellulose, acid detergent lignin (ADL), neutral detergent fiber (NDF), crude protein (CP), and silica concentration. The PMN, napiergrass, energy cane, and sunn hemp had the highest biomass yields. They were superior candidates for ethanol production due to high cellulose and hemicellulose content. They also had high silica yield except for sunn hemp. Silica yield among feedstock entries ranged from 41 to 3249 kg ha&minus, 1. Based on high bioethanol and biosilica yield potential, PMN, napiergrass, and energy cane are the most promising biorefinery feedstock candidates for improving biofuel profitability.

Increasing milk production in countries such as Brazil, India and Pakistan implies the generation of dairy by-products such as nutrient-rich bovine whey which, if used in feeding small ruminants would reduce environmental waste and add value to this by-product. Twenty entire male kids weighing an average 17 kg and 5 months age were used. The diet control was composed by Aruana hay, milled whole maize, pelleted soybean and limestone. Bovine cheese whey at 1.5; 3.0 and 4.5% (DM basis) was added to experimental diets. Variables measured included intake, nutrient apparent digestibility, energy balance, and nitrogen balance. Regression equations and Pearson correlations (P ? 0.05) were determined. The 3% diet resulted in greater ether extract (EE) (g/kg0.75) and digestible EE (P ? 0.05) concentrations compared to 0% whey. The consumption of cellulose (g/kg0.75) was greater (P ? 0.05) for kids on the 3.0% diet compared to 0 or 1.5%. Nutrient apparent digestibility was not affected (P > 0.05) by the inclusion of whey. Kids on the 4.5% diet excreted more (P - 0.05) fecal N than those fed no whey; these also retained less N (P ? 0.05) compared to animals fed 3.0% or less whey in their diet. All diets resulted in positive energy and nitrogen balances. Bovine whey can be included in male kid diets up to 4.5% of diet without negatively affecting consumption or apparent digestibility of those diets. [Consumo, digestibilidade aparente e balanço de nutrientes de dietas com soro de leite bovino para caprinos]. Made available in DSpace on 2020-11-20T09:11:45Z (GMT). No. of bitstreams: 1 CNPC-2020-Art-37.pdf: 281645 bytes, checksum: ad968c3f9f1b6c4e886a861f400129ca (MD5) Previous issue date: 2020

Context Methane from ruminant livestock systems contributes to the greenhouse effect on the environment, which justifies the adoption of novel feed strategies that mitigate enteric emissions. Aims We investigated the effects of the condensed tannin (CT)-rich legumes Flemingia macrophylla, Leucaena leucocephala, Stylosanthes guianensis, Gliricidia sepium, Cratylia argentea, Cajanus cajan, Desmodium ovalifolium, Macrotyloma axillare, Desmodium paniculatum and Lespedeza procumbens on in vitro methane emissions and rumen microbiota for beef cattle. Methods Four rumen-cannulated Nellore cattle grazing a tropical grass pasture were used as inoculum donors. Key results Real-time quantitative polymerase chain reaction analysis revealed that the abundance of Ruminococcus flavefaciens, methanogenic archaea and protozoa populations were reduced (P £ 0.05), whereas total ruminal bacteria were enhanced in the presence of CT. Our study also revealed a positive (P £ 0.05) relationship between CT and Fibrobacter succinogenes abundance. Reactive CT from L. leucocephala, D. paniculatum and L. procumbens resulted in decreased (P £ 0.05) isoacid content and methane production. Conclusions L. leucocephala, D. paniculatum and L. procumbens have the potential to suppress rumen methanogenesis. However, in vitro fermentation of L. leucocephala resulted in greater (P £ 0.05) degradability percentages than the other two species. Implications CT in legume species will have potential as part of an overall nutritional strategy to manipulate rumen microbiota and mitigate enteric methanogenesis in livestock production systems.

Semiarid rangeland plays an important multifunctional agricultural system and plant nutritive value can vary according to soil and climate conditions, and land use such as grazing pressure. This study investigated the impact of four forage allowances (2, 2.5, 3 and 3.5 kg dry matter per kg body weight) on condensed tannin biological activity and nutritional value of Bauhinia cheilantha (Bong) Steud.). The experiment was conducted in a manipulated shrub-tree tropical rangeland under sheep grazing in a two-year field trial, during the rainy season. Forage allowance and time influenced condensed tannin biological activity and nutritional value. B. cheilantha with up to 167 g kg−1 condensed tannins inhibited up to 38.3% rumen methane, indicating possible sheep metabolizable energy intake increases and also reduced up to 29% larval motility, which may reduce gastrointestinal parasite infections. B. cheilantha nutritional values vary over years and have a negative relationship with forage allowance. Forage allowance can be manipulated depending on management goals as forage or environmental mitigation. Low forage allowance promotes great condensed tannins which impacts on great larval motility and less methane production, but great nutritive value. The findings suggest that the legume B. cheilantha can contribute to meeting the nutritional requirements of ruminants.

The objective of this study was to evaluate the impact of concentrate feed supplements associated to seasonal conditions on performance and behavior of ewe grazing Caatinga rangeland from late gestation to lamb weaning. Treatments included supplements at 0, 200, 350 and 500 g concentrate/head/day during the rainy, transition or dry season for 3 years. Supplement during the rainy season stimulated dry matter intake (DMI), digestible protein (DCPI) and total digestible nutrients (TDNI). Feed supplement during the rainy season, when ewes were in their last third of gestation, resulted in greater nutrient offered than required for their elevated nutritional demands, allowing them to utilize forage of better nutritive value when grazing Caatinga rangeland. Greater reproductive efficiency and birth rates resulted. Supplementing feed at 350 g/day or more increased dietary total digestible nutrients (TDN) and crude protein (CP), contributing to greater ewe performance, favoring body weight and condition score maintenance from lambing to lamb weaning while supplementing at 500 g/day during the rainy season increased twinning rates. During the dry season, feed supplement partially substituted rangeland forage but increased overall ewe diet DMI and nutrient digestibility due to greater diet TDN and CP during lamb weaning. Global positioning system data indicated a seasonal impact on ewe behavior and energy use during foraging and seeking out water on semiarid tropical rangeland, notably greater energy expenditure moving during the dry season while ingesting 26.1 % less forage DM that did not meet reproductive requirements. Supplements met this deficit and increased ewe reproductive efficiency.