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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.

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...

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.

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.

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.

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.

Our objective was to evaluate how quebracho tannin (QT; Schinopsis balansae) within a roughage-based diet affected energy partitioning of growing beef steers. Ruminant production is essential to meeting the protein requirements of an increasing global population. However, gaseous byproducts from ruminant production, such as methane (CH4), not only reduce energetic efficiency, it can also be detrimental to the environment. Feed-grade antibiotics have traditionally been utilized for improved feed efficiency; however, consumer perception has prompted the pursuit of natural rumen modulators. Condensed tannins are a potential alternative due to their capacity for enhancing protein efficiency and reducing CH4. In our study, a 4 x 8 Latin rectangle design utilizing four periods and 8 British crossbred steers (236 ± 16 kg) were used to determine the effects of QT fed at 0 (control), 1.5, 3, and 4.5% of DM, within a roughage-based ration. Following 12-d dietary adaptation, animals were relocated to open-circuit respiration calorimetry chambers fitted with metabolism stands for gas exchange measurements and collection of total feces and urine over 48 h. Data were analyzed using a random coefficients model with animal and period as random factors. Inclusion of QT had no effect on intake, fiber digestibility, or nitrogen retention (P > 0.10). Provision of QT increased fecal energy, resulting in reduced digestible energy (DE) (P < 0.01). Urinary energy was not different (P = 0.49) but gas energy decreased (P < 0.01) as QT inclusion increased. Metabolizable energy (ME) decreased linearly as QT increased (P < 0.01), but all treatments maintained a ME-to-DE ratio of 0.86. Heat energy decreased (P = 0.01) with increased QT rate; however, there was no difference in retained energy. Although QT reduced gas and heat energy, this could not compensate for the reduction in digestible energy, leading to decreased energetic efficiency with QT inclusion.

The use of by- or co-products in livestock production is not a novel concept. However, as adoption of a novel feed ingredient increases, the cost efficiency of its use generally decreases. Therefore, discovery of novel feed ingredients is a worthwhile academic pursuit. Our objective was to determine the storage stability of popcorn (Zea mays L.) in terms of gain or loss in nutritive value. Popcorn was collected on consecutive weekdays in two wk from a local cinema. Samples (n = 10) were subdivided into 9 aliquots and subjected to storage, uncovered, for 0, 1, 2, 3, 7, 35, 70, 105, and 140 d. Following the assigned storage time, samples were dried at 55°C to determine weight loss. Samples were dried at 55°C, ground to pass through a 2-mm screen, and subjected to a batch-culture in vitro assay for digestibility estimates [in vitro true digestibility (IVTD) and in vitro NDF digestibility (IVNDFD)]. Subsamples were ground to 1 mm assayed for neutral detergent fiber and acid detergent fiber. There was a linear increase (P < 0.01) in weight following open storage which was attributed to absorption of ambient moisture. There was a linear decrease (P = 0.03) in NDF, with values decreasing from 20.2% at d 0 to 16.6% at d 140. However, there was no effect of storage on ADF (P = 0.29), IVTD (P = 0.38), or IVNDFD (P = 0.37). Results are interpreted to mean that waste popcorn is relatively shelf stable and may be a viable candidate as a feedstock for diet formulation.

Our objective was to investigate how quebracho tannin (QT; Schinopsis balansae) fed at differing rates within a roughage-based diet affected manure gas emissions of growing steers. The utilization of ruminant species is required for efficient production of human-edible protein to meet global nutrient demands. However, gaseous byproducts from ruminant production systems, such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are deleterious to the environment. It is estimated that CO2, CH4, and N2O from managed waste and grazed lands account for roughly 54% of emissions from the livestock sector within the United States, with approximately 80% being associated with beef and dairy cattle. Supplementation of condensed tannins is a plausible method for improving environmental efficiency through the mitigation of enteric CH4 and shifting route of N excretion. During two experimental periods, 12 crossbred steers (236 ± 16 kg) were fed a roughage-based diet at maintenance level with the addition of QT at 0, 1.5, 3, and 4.5% of DM serving as dietary treatments. Following adaptation, feces were collected and gas fluxes measured using vented static chamber technique with manure incubated on the soil surface at two locations, College Station and Stephenville, during two periods corresponding to winter and spring. The daily flux of CO2 was influenced by soil moisture and temperature (r = 0.34; P < 0.01), whereas CH4 and N2O were associated with soil moisture. Cumulative CO2 and gross CO2 equivalent (CO2e) exhibited a dietary treatment effect at College Station (P ≤ 0.01), with a linear reduction with increased dietary QT. At both locations, we observed significance or tendencies for period effects for CO2, CH4, N2O, and CO2e (P ≤ 0.07) with period 2 having higher gas production. Within certain environments, QT supplementation could potentially reduce manure gas emissions, but additional investigation into animal variation is required.

It is important for researchers, as progressive producers, to consider human enterprise wastes as one of the next steps in feedstuff investigation. In an effort to reuse a seemingly useless and disposable component of one of America’s most enjoyed aquatic delicacies, our objective was to determine the nutritive value of crawfish and shrimp shells in relation to ruminant nutrition. These discarded items were collected from local events and sorted into four different groups: crawfish heads, crawfish tails, shrimp shells, and shrimp tails. Crawfish and shrimp wastes were tested independent of each other. These groups were dried at 55°C for 72 h and ground to pass through a 2-mm screen. Samples were subjected to a batch-culture in vitro true digestibility (IVTD) assay. A separate set of samples (1 mm) were assayed for dry matter, neutral detergent fiber (NDF), and acid detergent fiber (ADF), and acid detergent lignin (ADL; inclusive of residual ash). Data were analyzed as a completely randomized design using the MIXED procedure of SAS. Crawfish heads were assayed to contain 26.2% NDF, 13.4% ADF, and 1.0% ADL, while crawfish tails contained 23.7% NDF, 16.3% ADF, and 1.1% ADL. Crawfish heads and tails did not differ in IVTD (P = 0.48) or in vitro NDF digestibility (IVNDFD; P = 0.13; 76.7 vs. 77.2% and 86.8 vs. 91.0%, respectively). Shrimp shells contained 36.1% NDF, 26.9% ADF, and 4.1% ADL, whereas shrimp tails contained 29.1% NDF, 17.9% ADF, and 0.7% ADL. Shrimp tails had greater (P < 0.01) IVTD (74.2 vs. 66.4%) but lesser (P = 0.01) IVNDFD than shrimp shells (80.6 vs. 85.0%). Results are interpreted to mean that crustacean waste may represent a suitable prospective feedstuff for further evaluation.

The 2018 Farm Bill, with its groundbreaking hemp legislation, offered an alternative protein source to livestock producers. Hemp is the agricultural product of Cannabis sativa L. which must contain less than 0.3% tetrahydrocannabinol, the psychoactive component common to marijuana. Hemp oil, cold-pressed from C. sativa seed, has been gaining popularity over recent years for its use in cosmetics, pharmaceuticals, and human food products. Like most oilseeds, this leaves an oilseed meal with a potential for inclusion in livestock feeds. Thus, our objective was to quantify the sources of variation in the nutritive value of hempseed meal. Hempseed meal samples were obtained from commercial oil processing facilities (n = 4). Across these facilities, samples represented 15 independent hempseed meal batches. Our experimental design was a completely randomized design including the random effects of source, batch within source, and replicate within batch by source (laboratory replication). Samples were assayed for NDF, ADF, ADL, CP, and IVTD. Source had no contribution to variance for NDF, ADF, ADL, or CP (P ≥ 0.20). However, batch within source had a significant contribution to variation for NDF (μ = 50.1%; P = 0.01), ADF (μ = 36.8%; P = 0.01), ADL (μ = 12.9%; P < 0.01), and CP (μ = 30.9%; P < 0.01). Irrespective of the differences in nutritive value, there was no contribution to variation (P ≥ 0.23) of any measured effect on IVTD (μ = 53.0%). Results are interpreted to mean that, while variation exists among hempseed meal samples with respect to nutritive value, the viability of hempseed meal as a livestock feed source is strong.

Effects of using ground woody plants in Rambouillet wether lamb feedlot diets on growth performance, blood serum, and rumen parameters were evaluated. A randomized design study was used with 2 feeding periods (70% concentrate diet from d 0 to 27 [Period 1] and 86% concentrate diet from d 28 to 57 [Period 2]); the concentrate portion of the diets mainly consisted of dried distiller's grains with solubles and sorghum grain. Lambs were individually fed 6 diets that differed only by roughage source ( = 8 animals/treatment; 32.9 ± 3.2 kg initial BW): either cottonseed hulls (CSH; control) or ground wood consisting of redberry juniper (RED), blueberry juniper (BLUE), one-seeded juniper (ONE), or eastern red cedar (ERC) spp. or honey mesquite (MESQ; ). Using ground wood vs. CSH as the roughage source did not affect ( > 0.12) BW. There tended to be a treatment × day interaction ( = 0.07) for lamb DMI, attributed to Period 1 when DMI was greater ( 0.10) among all lambs. Dietary treatments did not affect ( > 0.15) ruminal pH, but treatment × day interactions ( 0.10) were observed within day. Treatment × day interactions ( < 0.05) were observed for blood serum glucose, γ-glutamyl transferase, the albumin:globulin ratio, total bilirubin, β-hydroxybutyrate, P, Cl, and Mg, with most results being less for lambs fed the wood-based diets than for lambs fed the CSH diets. Results suggested that even though lamb DMI was reduced during the growing period when diets contained 30% ground woody products (RED, ONE, ERC, and MESQ), animal health and rumen fluid parameters were not negatively affected by ground woody plants.

Tropical tree or shrub leaves are an important source of nutrients for ruminants and a potential source of biologically active compounds that may affect ruminal metabolism of nutrients. Therefore, eight woody species from the native flora of Argentinean Dry Chaco, rich in secondary compounds such as condensed tannins (CT), were assessed for their nutritional value, CT fractions and in vitro true digestibility of dry matter, as well as biological activity (BA).; Results: Differences among species were found in contents of total phenol, protein-precipitating phenols (PPP), bound proteins to PPP (BP) and BP/PPP (P < 0.0001). The BP/PPP ratio reveals differences among species in potential BA as indicated by protein precipitation. The major CT of each species were isolated and purified for use as a standard. Although Schinopsis balansae had the most (P ≤ 0.05) total CT (19.59% DM), Caesalpinia paraguariensis had greater (P ≤ 0.05) BA with the most PPP (530.21% dry matter). Larrea divaricata, at 0.97, followed by Acacia aroma, at 0.89, had CT with the highest (P ≤ 0.05) BP/PPP ratios, followed by Prosopis alba (0.59).; Conclusion: There were differences in nutritive value and bioactivity among species. Those with the greatest CT were not necessarily those with the most BA. Caesalpinia paraguariensis, S. balansae and L. divaricata were the most promising species as native forage CT sources. Cercidiurm praecox (20.87% CP; 18.14% acid detergent fiber) and Prosopis nigra (19.00% CP; 27.96% acid detergent fiber) showed the best (P ≤ 0.05) nutritive values. According to their nutritive traits, these species might be complementary in grass-based ruminant diets. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

Condensed tannins (CT) might improve animal and system-level efficiency due to enhanced protein efficiency and reduced CH4. This study evaluated the impact of quebracho tannin (QT) extract fed at 0%, 1.5%, 3%, and 4.5% of dry matter (DM), within a roughage-based diet on apparent digestibility of DM, organic matter (OM), fibrous fractions, and N retention and energy partitioning of growing steers (236 ± 16 kg BW). A Latin rectangle design with eight animals and four periods was used to determine the whole-animal exchange of CO2, O2, and CH4 as well as the collection of total feces and urine over a 48-h period, using two open-circuit, indirect calorimetry respiration chambers. Following the removal of steers from respiration chambers, rumen inoculum was collected to determine ruminal parameter, including volatile fatty acids (VFA) and ammonia. Animals were fed a 56.5% roughage diet at 1.7% BW (dry matter basis). Dry matter and gross energy intakes were influenced by the level of QT inclusion (P ≤ 0.036). Digestibility of DM, OM, and N was reduced with QT inclusion (P < 0.001), and fiber digestibility was slightly impacted (P > 0.123). QTs altered the N excretion route, average fecal N-to-total N ratio excreted increased 14%, and fecal N-to-urinary N ratio increased 38% (P < 0.001) without altering the retained N. Increased fecal energy with QT provision resulted in reduced dietary digestible energy (DE) concentration (Mcal/kg DM; P = 0.024). There were no differences in urinary energy (P = 0.491), but CH4 energy decreased drastically (P = 0.007) as QT inclusion increased. Total ruminal VFA concentration did not differ across treatments, but VFA concentration increased linearly with QT inclusion (P = 0.049). Metabolizable energy (ME) was not affected by the QT rate, and the conversion efficiency of DE-to-ME did not differ. Heat energy decreased (P = 0.013) with increased QT provision likely due to changes in the DE intake, but there was no difference in retained energy. There were no differences for retained energy or N per CO2 equivalent emission produced (P = 0.774 and 0.962, respectively), but improved efficiency for energy retention occurred for 3% QT. We concluded that QT provided up to 4.5% of dry matter intake (about 3.51% of CT, dry matter basis) does not affect N and energy retention within the current setting. Feeding QT reduced energy losses in the form of CH4 and heat, but the route of energy loss appears to be influenced by the rate of QT inclusion.

Reliable assessments of indigestible dietary components are required when using internal markers to estimate diet digestibility and determine the potentially digestible portion of the fiber. The lack of a standardized methodology and understanding of how antinutritional factors influence indigestible residues can result in erroneous estimates with inconsistent variation across trials and among studies. Previous studies have detailed suitable bag porosity and sample size (SS) with incubation length (IL) varying from 96 to 504 h, with many assuming that 288-h IL yields truly indigestible components. Recent studies have primarily investigated the variation that exists among feedstuffs, but most have failed to account for possible effects of secondary compounds. Using 2 similar concentrate diets, one of which contained supplemental condensed tannins (CT), we investigated the effect of bag type (BT; 10 and 25 μm), SS (20 and 40 mg/cm2), and IL (288 and 576 h) on in situ indigestible DM (iDM) and neutral detergent fiber (iNDF) residues of feed and feces, and resultant DM and NDF digestibilities. There were no 3-way interactions (P > 0.05), but 2-way interactions were present for iDM and iNDF residues with BT × SS influencing the control (no CT) ration (P < 0.01), SS × IL impacting feed containing CT (P < 0.01), and BT × IL affecting both feedstuffs (P ≤ 0.01). For the control diet, only BT × SS affected DM and NDF digestibilities. Whereas the CT diet did not demonstrate any significant interactions for digestibilities. Values of iDM were largely influenced by contamination that varied greatly based on intrinsic factors associated with the bag and incubation duration. The presence of CT influenced iDM and iNDF to varying degrees due to possible trapping of CT–substrate complexes. For the control diet, the use of 25-μm bags resulted in lower fecal recoveries relative to the 10 μm (P < 0.01). However, there appears to be a dynamic relationship among BT, SS, and IL within respective diets and sample types that can affect indigestible components and resultant digestibility estimates. Based on simulations from these data, the sample size required to attain 90% power when utilizing 2 incubation animals exceeds the triplicate and quadruplicate replications commonly utilized. Further emphasizing the necessity for a more complete understanding of incubation dynamics to design biologically and statistically valid investigations.

Per unit energy, fiber is among the most expensive components of the ruminant diet. While the use of by- or co-products can help offset the costs of feeding cattle, these feeds often increase in price with increased adoption. Wastes from human enterprises may represent the next step in feedstuff investigation. Our objective was to evaluate the suitability of newspaper as a component of silage for ruminant feeding. Newspapers were obtained from the Dick Smith Library and JTAC News at Tarleton State University (Stephenville, TX). Samples were cut into strips (approximately 4.0 × 30.2 mm) using an office shredder. Sorghum-sudangrass [Sorghum bicolor (L.) Moench ssp. drummondii (Nees ex Steud.) de Wet & Harlan] was harvested and cut by hand to lengths of approximately 10 cm. Samples were combined to achieved DM ratios of 100:0, 75:25, 50:50, 25:75, and 0:100% newspaper and sorghum-sudangrass. Distilled water was added to achieve 45% DM. Samples were packed in a double layer of plastic sheeting and sealed in 19 L buckets. Laboratory silos were arranged in a Latin square design in a laboratory and allowed to ferment for 35 d. Ensiled samples were assayed for DM, particle size, and silage acids. There was no effect of newspaper percentage (P = 0.47) on silage pH. Ammonia (0.04 to 1.2% DM), total VFA (0.01 to 4.8% DM), lactic acid (0 to 46.6% VFA), and acetic acid (0.01 to 2.4% DM) increased linearly (P < 0.01) with increased concentration of sorghum-sudangrass. Results indicated that newspaper alone was not an effective feedstuff to ensile. However, addition of newspaper to grass silages could represent a viable means to decrease cost and extend resources for ruminant animal producers.

Ruminant animals develop a diverse and complex microbial ecosystem for digesting fibrous feedstuffs, but this material represents a cost to the industry when bound for rendering at harvest. Our objective was to determine the feed value of paunch manure recovered from an abattoir. Twelve paunch samples were collected from slaughtered cattle at the Tarleton State University Meat Laboratory, Stephenville, TX. Samples were dried under forced air at 55°C to a constant weight and ground to pass through 2-mm screen. A subsample was ground to 1-mm and assayed for DM, CP, and sequential NDF and ADF. Physically effective fiber (peNDF) was calculated with 2 L of unground, dried at 55 ˚C, paunch material using the manually-operated Penn State Particle Separator. Paunch peNDF was determined by multiplying the physical effectiveness factor by the total NDF content of the sample. Samples (2-mm) were subject to batch culture in vitro digestibility assays for determination of digestibility coefficients. Data were analysed as a random effects model using PROC GLIMMIX in SAS. Neutral detergent fiber, ADF, ADL, CP, and peNDF values were 68.1, 39.9, 10.9, 15.0, and 38.7%, respectively. Contribution to variance of the individual animal for NDF, ADF, ADL, CP, and peNDF was 97.2, 97.9, 95.4, 19.1, and 97.5%, respectively. In vitro true digestibility (IVTD) and in vitro neutral detergent fiber digestibility (IVNDFD) was recorded as 46.2% and 21.6%, respectively. Contribution to variance of the animal for IVTD and IVNDFD was 99.05 and 98.49%, respectively. Data collected suggest paunch manure could provide valuable nutrients for livestock production, specifically fiber and protein. For full viability of application in a sustainable system, a centralized receiving and compositing system may be useful for development of a consistent product.

Ruminant animals develop a diverse and complex microbial ecosystem for digesting fibrous feedstuffs, but this material represents a cost to the industry when bound for rendering at harvest. Our objective was to determine the feed value of paunch manure recovered from an abattoir. Twelve paunch samples were collected from slaughtered cattle at the Tarleton State University Meat Laboratory, Stephenville, TX. Samples were dried under forced air at 55°C to a constant weight and ground to pass through 2-mm screen. A subsample was ground to 1-mm and assayed for DM, CP, and sequential NDF and ADF. Physically effective fiber (peNDF) was calculated with 2 L of unground, dried at 55 ˚C, paunch material using the manually-operated Penn State Particle Separator. Paunch peNDF was determined by multiplying the physical effectiveness factor by the total NDF content of the sample. Samples (2-mm) were subject to batch culture in vitro digestibility assays for determination of digestibility coefficients. Data were analysed as a random effects model using PROC GLIMMIX in SAS. Neutral detergent fiber, ADF, ADL, CP, and peNDF values were 68.1, 39.9, 10.9, 15.0, and 38.7%, respectively. Contribution to variance of the individual animal for NDF, ADF, ADL, CP, and peNDF was 97.2, 97.9, 95.4, 19.1, and 97.5%, respectively. In vitro true digestibility (IVTD) and in vitro neutral detergent fiber digestibility (IVNDFD) was recorded as 46.2% and 21.6%, respectively. Contribution to variance of the animal for IVTD and IVNDFD was 99.05 and 98.49%, respectively. Data collected suggest paunch manure could provide valuable nutrients for livestock production, specifically fiber and protein. For full viability of application in a sustainable system, a centralized receiving and compositing system may be useful for development of a consistent product.

Our objective was to determine the effect of quebracho tannin extract (QT; Schinopsis balansae) within a high roughage diet upon digestibility and N balance. Use of natural compounds as rumen modulators has remained a critical area of research due to increased regulation upon feed additive use, environmental emissions, and consumer perception of the animal industry. Condensed tannins (CT) show promise as a feed additive due to the potential for improved N efficiency and decreased CH(4) emissions. However, there is limited data regarding the effect of CT on digestibility and N balance when limit-feeding a high roughage diet. A 4x8 Latin rectangle design with eight steers (443 ± 20 kg) and four dietary treatments was utilized to evaluate the following dietary treatments: no QT (QT(0)) or addition of QT at 1.5, 3, or 4.5% of DM. Diets were fed at 1.7% of shrunk body weight. Steers were adapted to diets for 10-d and placed into metabolism crates on days 11 to 14 for total urine and feces collection. Samples were composited by animals within periods and analyzed for total N and gross energy (GE), as well as neutral detergent fiber (NDF) and acid detergent fiber (ADF) for feed and fecal samples. Dietary treatment impacted dry matter digestibility, NDF digestibility, and ADF digestibility (P≤ 0.001) in which QT(0) and QT(1.5) had the greatest digestibilities. This resulted in a 10% greater efficiency, on average, for digestible energy to GE ratio (P = 0.0001) for QT(0) and QT(1.5). In contrast, there were no observed differences for N retention (P = 0.22), but the proportion of N excreted within the feces increased with QT inclusion rate (P = 0.005). The addition of QT at 1.5% DM to a limit fed high roughage diet does not sacrifice digestibility, digestible energy to GE ratio, or N balance.

Context Interest in sheep production has grown considerably, mainly in the meat market segment in large urban centres. This growth is due to improved efficiencyand quality products, which makes the segment attractive for production. Aims Our objective was to evaluate the effects of dietary nutrient restrictions on the feed efficiency and productivity of Santa Inês ewe lambs. Methods Twenty Santa Inês ewe lambs were weaned at an average weight of 15.09 ± 2.63 kg and were randomly assigned in a 2 × 2 factorial design to nutritional plans for carcass finishing (early and late maturity) and levels of nutrient restriction (0% and 15% reduction of both crude protein (CP) and total digestible nutrients (TDN) relative to requirements) with five replications per treatment. The trial was divided into two phases: lambs aged 4–8 months (8 months old. Key results There were no differences (P > 0.05) between diets for average daily gain (ADG), dry matter intake (DMI), feed efficiency and residual feed intake. Ratios of ADG:DMI (% of liveweight (LW) and LW0.75) were affected (P ≤ 0.05) by restriction in ewe lambs >8 months old. Restriction model tests (ω1, ω2, ω3 and ω4) did not differ (P > 0.05) from complete models for diets formulated for early maturity; therefore, a single standard growth curve fitted this nutritional plan. On the other hand, the restriction model responses for diets formulated to late maturity differed (P ≤ 0.05) from the complete model, generating different standard growth curves according to the applied restriction. Feeding Santa Inês ewe lambs a restricted diet (by 15% CP and TDN) in an early-maturity nutritional plan will allow lambs to reach slaughter LW earlier than those fed unrestricted diets. Conclusions and implications When the objective is to terminate animals at a later age (>8 months), unrestricted diet formulated to a late-maturity nutritional plan will produce higher LW and subsequent reproductive efficiency. By contrast, reducing CP and TDN by 15% for ewe lambs >8 months of age may reduce growth rates at an initial phase.

Studies using goats to control red cedar (Juniperus virginiana) have shown that goats more readily consume red cedar at some locations while in other locations, they consume relatively little, but consume more during the winter. It was hypothesized that differences in red cedar intake may be caused by tannins acting as an antinutritive chemical. The purpose of this study was to characterize the levels and types of tannins in red cedar from different locations and seasons of the year. Thirty-seven samples of red cedar needles were obtained from four locations (LOC; Langston, OK; Midwest City, OK; Mannford, OK; Neosho, MO) at monthly intervals (SEA) over a 1-yr period. Needles were manually stripped from branches at approximately 1.5 m high from at least 25 plants at each location. Samples were refrigerated until analyzed for extractable condensed tannin (ECT) and total tannin (TOT) by procedure of Terrill et al. (1992). Data were analyzed by SAS GLM with main effects of LOC and SEA. ECT was significantly lower for Neosho (1.53%) than for Mannford (2.69%), Midwest City (2.79%), and Langston (2.37%), which were similar. ECT was lowest for Summer (1.76%), similar to Fall (1.85%) and both were significantly lower than for Winter (3.32%) and Spring (2.39%). TOT followed a similar pattern being highly correlated to ECT (R = 0.955; P < 0.001) and was significantly lower for Neosho (2.61%) than for Langston (3.79%), Mannford (3.81%) or OKC (4.15%). Total tannins were significantly higher in the winter (4.71%) than for the other seasons (Spring 3.64, Fall, 3.18% and Summer 2.87%). Tannins were lowest for Neosho where goats browsed red cedar most aggressively, killing >85% of the trees whereas goats killed

Microbes and chemical constituents in the rumen fluid play an important role when re-establishing the rumen microbial population. Identification of a viable preservation method could have lasting implication of veterinary and research applications. Our objective was to determine the efficacy of preservation methods on rumen liquor. Twelve paunch samples were collected from slaughtered cattle at the Tarleton State University Meat Laboratory, Stephenville, TX. Rumen content was collected from different locations within the rumen, strained through eight layers of cheesecloth, and divided into five 500-mL aliquots. Aliquots were randomly allocated to one of five preservation methods (freezing or lyophilisation) and preservative (glycerol; yes or no). A fresh control was maintained from each sample. Three reference feeds and two roughage sources were used in the batch culture procedure. Reference feeds were dried to a constant weight at 55°C and ground to pass through a 2-mm screen. Ground samples were subjected to batch culture in vitro true digestibility (IVTD) assays using each of the four ruminal fluids (plus the control) for digestibility estimates. Original samples and incubated residues were assayed for DM, CP, NDF, and ADF. Data were analyzed in a 2 × 2 + 1 augmented factorial design using GLIMMIX procedure of SAS. There were no differences (P > 0.05) in IVTD when using protein or energy feeds; however, there were differences in IVTD for all treatments for fiber concentrates and forage reference feeds. Despite lower degradation of feeds when frozen or lyophilized rumen fluid was used, preserved rumen fluid may be a viable option in the absence of fresh inoculum for veterinary and research applications

Per unit energy, fiber is among the most expensive components of the ruminant diet. Wastes from human enterprises may represent the next step in feedstuff investigation. In an effort to minimize the anthropogenic waste contribution, and as a means to find a more cost-efficient resource to feed ruminant animals, our objective was to determine the nutritive value of disposable coffee cups and warmer sleeves in relation to ruminant nutrition. Discarded cups and warmer sleeves were collected from employees at Tarleton State University in fall of 2017. Cups were obtained from five sources, and warmer sleeves were obtained from two sources. Cups and sleeves were dried at 55°C for 72 h and ground to pass through a 2-mm screen. Ground samples were subjected to a batch-culture in vitro true digestibility (IVTD) assay. Original samples and incubated residues were then assayed for DM, NDF, ADF, and CP. Data were analyzed as a random effects model completely randomized design using the MIXED procedure of SAS. There was no effect (P > 0.05) of source (n = 5) or type (cup or sleeve) for contribution to variance of NDF, ADF, IVTD, and in vitro NDF digestibility (IVNDFD). Mean values for NDF, ADF, IVTD, and IVNDFD across samples were 89.5, 81.4, 24.5, and 18.7%, respectively. Results indicate a low digestibility coefficient for these waste products, thus meaning its use as a feedstuff could be questionable. However, such results provide insight into niches where this product and other anthropogenic wastes may fit in the larger picture of ruminant nutrition

The goal of forage agronomy research seems simple: provide livestock with year-round feed derived from plants. Plants, however, are only one component within livestock systems research. Forage selection and management depend on climate, hydrology, soils, animal species’ or breed nutrition, markets, societal priorities, and myriad other factors that dictate which species to focus, how to manage them and where these fit into livestock systems. Historical fissures among these disciplines impeded forage agronomy. Past forage agronomists simply addressed livestock nutritional bottlenecks that limited animal production. Ever greater plant yields and nutritive values were almost all that mattered. This often led to a reductionist approach with a consequent decline in perceived importance of forage research. The current generation of forage agronomists has slowly come to understand that cooperation with other disciplines is essential for pasture research design and interpretation. The gradual rehabilitation of forage legume condensed tannins from bane to asset within paddocks is a case in point as their role in plant persistence or beneficial secondary effects on livestock are better understood. Forage agronomy research and ruminant nutrition that focus long-term livestock systems are even more complex. Identifying and resolving future agronomic forage challenges before they occur requires insights unfettered by disciplinary blinders. For example, increasing pressure to mitigate greenhouse gas coupled with low animal performance in grazing systems trigger questions about how livestock contribute to global warming, further undermining livestock and forage sciences if not addressed. Future forage agronomic research might address these concerns by developing sustainable, resilient production systems that not only feed a growing population but also provide multiple benefits including environmental or social services. Forage livestock research teams populated by generalists or teams able to see under, in, and beyond the paddock will more likely contribute to resolving future agronomic challenges.

Rising feed costs and recurring feed shortages necessitate the investigation into alternative and underutilized feed resources. Nutritional characteristics of species are either unknown or limited to leaves and ground material from small stems. Therefore, the objective was to quantify nutritional characteristics, 48-h true IVDMD (tIVDMD), microbial gas production, and secondary compound characteristics of entire woody plant material of 4 species-, , , and -at immature and mature stages of growth. Immature plants had greater CP concentrations and lower NDF concentrations ( < 0.001) than mature plants regardless of species. Mature plants also had greater ( < 0.001) concentrations of ADF compared with immature plants with the exception of . In general, immature , , and had greater ( < 0.02) tIVDMD and total 48-h and asymptotic gas production than mature plants. Immature and plants were more digested (tIVDMD; < 0.001) than immature and , but tIVDMD did not differ in mature plant material across species. Condensed tannins (CT) were greater ( < 0.001) in immature and than mature plants; differences in CT concentrations among immature species were also detected ( < 0.04). Volatile oil yields were similar across maturity and species with 1 exception: immature yielded more ( < 0.02) volatile oil than mature material. Volatile oil composition across species varied and contained a range of 65 to 70 terpene compounds. The dominant terpenes across species were generally greater ( < 0.05) in immature vs. mature plant material with the exception of . Labdane acids were negligible in , , and and greater in ( < 0.001). Ground material from mature juniper species, although inferior in nutritional quality compared with immature plants, is comparable to traditional low-quality roughage ingredients. Given that has been successfully fed in lamb feedlot diets, the similarities of , and suggest that all three species have potential to be effective roughage ingredients.

Effects of using ground redberry juniper and dried distillers grains with solubles (DDGS) in Rambouillet lamb (n = 45) feedlot diets on growth, blood serum, fecal, and wool characteristics were evaluated. In a randomized design study with 2 feeding periods (Period 1 = 64% concentrate diet, 35 d; Period 2 = 85% concentrate diet, 56 d), lambs were individually fed 5 isonitrogenous diets: a control diet (CNTL) that contained oat hay but not DDGS or juniper or DDGS-based diets in which 0 (0JUN), 33 (33JUN), 66 (66JUN), or 100% (100JUN) of the oat hay was replaced by juniper. During Period 1, lambs fed CNTL had greater (P 0.41). Compared to 0JUN, lambs fed CNTL had similar (P = 0.12) G:F and tended to have less G:F (P = 0.07) than lambs fed DDGS-based diets. Among lambs fed DDGS-based diets, DMI was similar (P > 0.19), ADG increased linearly (P = 0.03), and G:F tended to decrease quadratically (P = 0.06) as juniper increased in the diet. Serum IGF-1, serum urea N (SUN), and fecal N were greater (P 0.13) for lambs fed CNTL vs. lambs fed DDGS-based diets (CNTL). Within lambs fed DDGS-based diets, SUN increased quadratically (P = 0.01) and fecal N increased linearly (P = 0.004), which can partially be attributed to increased dietary urea and condensed tannin intake. Most wool characteristics were not affected, but wool growth per kilogram of BW decreased quadratically (P = 0.04) as percentage of juniper increased in the DDGS-based diets. When evaluating the entire 91-d feeding trial, results indicated that replacing all of the ground oat hay with ground juniper leaves and stems in lamb growing and finishing diets is not detrimental to animal performance and that DDGS-based diets can reduce total feedlot costs, as compared to sorghum grain and cottonseed meal-based diets. However, compared to using juniper or oat hay as the sole roughage source, using both during the growing period (Period 1) enhanced growth performance and further reduced total feedlot costs.

Enteric methane (CH4) emissions from ruminants have compelled a wide range of research initiatives to identify environmental abatement opportunities. However, although such mitigations can theoretically be attained with feed additives and feeding strategies, the limited empirical evidence on plant extracts used as feed additives does not support extensive or long-term reductions. Nevertheless, their strategic use (i.e. alone or combined in a simultaneous or consecutive use) may provide not only acceptable CH4 abatement levels, but also relevant effects on animal physiology and productivity. Condensed tannins (CT) represent a range of polyphenolic compounds of flavan-3-ol units present in some forage species that can also be added to prepared diets. Methods to determine CT, or their conjugated metabolites, are not simple. Although there are limitations and uncertainties about the methods to be applied, CT are thought to reduce CH4 production (1) indirectly by binding to the dietary fibre and/or reducing the rumen digestion and digestibility of the fibre and (2) directly by inhibiting the growth of rumen methanogens. On the basis of their role in livestock nutrition, CT influence the digestion of protein in the rumen because of their affinity for proteins (e.g. oxidative coupling and H bonding at neutral pH) that causes the CT-protein complex to be insoluble in the rumen; and dissociate in the abomasum at pH 2.5 to 3.0 for proteolysis and absorption in the small intestine. CT may also reduce gastro-intestinal parasite burdens and improve reproductive performance, foetal development, immune system response, hormone serum concentrations, wool production and lactation. The objectives of this paper are to discuss some of the beneficial and detrimental effects of CT on ruminant production systems and to develop a conceptual model to illustrate these metabolic relationships in terms of systemic physiology using earlier investigations with the CT-containing legume Lotus corniculatus. Our conceptual model indicated four complex and long-lasting relationships (digestive, toxicological, physiological and morphological) that can alter the normal biology of the animal. These relationships are interdependent, integrative, and sometimes, complementary to each other. This conceptual model can be used to develop mechanistic models to improve the understanding of the interaction between CT and the ruminants as well as to guide research initiatives of the impact of polyphenol-rich foods on human health.

While the use of by- or co-products can help offset the costs of feeding cattle, these feeds often increase in price with increased adoption. Therefore, discovery and characterization of novel feedstuffs could benefit the producer. Our objective was to evaluate the viability of waste popcorn (Zea mays L.) as a feedstuff in ruminant diets. This objective was addressed through a series of two experiments. In Exp. 1, storage stability of popcorn was evaluated. Popcorn was collected on consecutive weekdays in 2 wk from a local cinema. Samples (n = 10) were subdivided into 9 aliquots and subjected to storage, uncovered, for 0, 1, 2, 3, 7, 35, 70, 105, and 140 d. Following the assigned storage time, samples were dried at 55°C to determine weight loss. Following open storage in a laboratory at approximately 24°C, popcorn gained (P < 0.05) between 2.6% (3 d) and 5.6% (105 d) of the original weight through moisture absorption. When dried, however, samples from any length of storage were within 1% of the original weight (P < 0.05). In Exp. 2, a composite sample of popcorn was used in comparison with cracked and steam-flaked corn (Zea mays L.), popped milo [Sorghum bicolor (L.) Moench ssp. bicolor], and rolled barley (Hordeum vulgare L.). Samples were dried at 55°C, ground to pass through a 2-mm screen, and subjected to a batch-culture in vitro assay for digestibility estimates. In vitro true digestibility of popcorn (77.8%) was less (P < 0.05) than estimates for cracked corn (94.8%), popped milo (93.6%), steam-flaked corn (92.6%), or rolled barley (90.3%). From these results, we may conclude that, while popcorn is not as digestible as other commercial energy sources, it may represent a viable option in the arsenal of feed formulation.

The objective of this research was to compare the National Research Council (NRC) 1985 (NRC85) and 2007 (NRC07) small ruminant nutrition recommendations for growing lambs in a tropical setting with tropical feeds. Twenty mixed breed Santa Ines males, 4 mo of age, with an average initial 19.5 ± 3.5 kg weight were randomly distributed to four treatments to measure apparent digestibility, intake as well as ruminal and blood parameters. The four treatments consisted of diets formulated according to NRC85 or NRC07 recommendations, the latter at 20% (NRC07-20), 40% (NRC07-40) and 60% (NRC07-60) rumen non-degradable protein (NDP) concentration. The trial consisted of 10 d for adaptation to diet and 7 d for data collection. The NRC07 diets showed no differences ( P > 0.05) in disappearance of dry matter (DM), organic matter (OM) or their fractions as a result of NDP level. All diets formulated according to NRC07 resulted in greater ( P ≤ 0.05) consumption of CP and digestible protein (DP) compared to NRC85. Greater ( P ≤ 0.05) disappearance of DM and OM disappearance rates were measured for the NRC85 diet compared to NRC07 diets, with no differences ( P > 0.05) for CP. The NRC85 diet resulted in lower ( P ≤ 0.05) fiber intake while non-structural carbohydrate (NSC) intake was greater ( P ≤ 0.05) compared to NRC07 diets. Total digestible nutrients (TDN) were greater ( P ≤ 0.05) for NRC85 diets compared to NRC07 while there were no differences ( P > 0.05) among digestible (DE) and metabolizable energy (ME). Coefficients of digestibility of total carbohydrates (TC) were greater ( P ≤ 0.05) for the NRC85 than the NRC07 diets. Greater ( P ≤ 0.05) N intake was measured for NRC07-20 and NRC07-40 NDP. Urinary N in the NRC85 diet was lower (2.24 ± 10% in ingested N; P ≤ 0.05) than in the NRC07 diets. There was a greater ( P ≤ 0.05) balance of N in the NRC07-20 compared to NRC85-60 and NRC07-60 diets, while these three were similar ( P > 0.05) to values from NRC07-40 diet. More ( P ≤ 0.05) retained N was obtained in NRC85 compared to NRC07 diets. For diet NRC85, there was a greater ( P ≤ 0.05) concentration of N-NH 3 at 2 h post-feeding compared to feeding time while this was reversed by 5 h post-feeding. Rumen pH levels were greater ( P ≤ 0.05) in the NRC07-40 diet than the others. The greater digestibility of nutrients in diets with greater concentrate does not imply an increase in consumption of digestible nutrients. The NRC07 diets with proportional amounts of fiber and concentrate resulted in neutral detergent fiber (NDF) concentrations adequate for ruminal function. In contrast, the NRC85 diet resulted in greater ( P ≤ 0.05) N retention, possibly due to better protein:energy ratios. Diets NRC07-20 and NRC07-40 resulted in greater ( P ≤ 0.05) rumen liquid N-NH 3 than NRC85 of NRC07-60. Lambs on NRC07 diets also had an increase ( P ≤ 0.05) in blood urea that can be used as recycled N. None ( P > 0.05) of the diets resulted in a drop in ruminal pH.

Phosphorus nutrition in cattle is increasingly becoming an important topic because excess dietary P is excreted in manure and can be washed into surface water, causing increased algal growth and eutrophication. However, little is known about the mechanism or regulation of P absorption in dairy cattle. Phosphorus transporters have been characterized in other species and homologous genes have been found to be expressed in bovine cell cultures. However, no other information is available regarding the active transport of phosphate in the digestive tract of cattle. The objective of this study was to determine the patterns of expression of a known phosphate transporter, NaPi-IIb, in 4 sections of the small intestine of Holstein cows. Ribonucleic acid was isolated from the duodenal, proximal jejunal, distal jejunal, and ileal mucosa of 20 Holstein cows. Relative amounts of NaPi-IIb mRNA expression were determined using real-time reverse-transcription PCR. Expression of NaPi-IIb was highest in the 2 distal sections and almost absent in the proximal sections. Expression did not differ between the 2 proximal sections or the 2 distal sections. These data suggest that a Na+-dependent secondary active P transport system is not responsible for P absorption in the proximal portion of the bovine small intestine, whereas it does contribute to the P absorbed in the distal sections of the bovine small intestine.

BACKGROUND: The role of condensed tannins (CT) in ruminant nutrition and health makes changes in leaf litter (LL) after abscission of interest. This study compared the effect of different drying methods of green leaves (GL) with that of natural drying of LL on CT, fibre, crude protein (CP) and phosphorus (P) concentrations in nine Texas browse species. Leaves harvested before autumn shedding were oven-dried (OD) or freeze-dried (FD). RESULTS: Where different (P 0.05) from GL to LL, with CP concentrations ranging from 63 to 151 g kg−1 in the latter. CONCLUSION: Browse LL had high nutritive value and CT concentrations, explaining why browsing ruminants utilise this feed resource. However, changes in nutrient and CT concentrations as leaves become litter in some species mean that information on one is not necessarily applicable to the other. Copyright © 2010 Society of Chemical Industry

Effects of replacing cottonseed hulls with dry redberry juniper leaves on performance and serum NEFA, urea N, and IGF-1 were investigated in Rambouillet lambs (n = 24, initial BW = 28.6 +/- 4.94 kg). In a study with 2 feeding periods (period 1 = 65% concentrate ration, 28 d; period 2 = 85% concentrate ration, 49 d), lambs were individually fed ad libitum treatment diets containing cottonseed hulls (control; CSH), one-half of the cottonseed hulls replaced by dry juniper leaves (CSHJ), or all the cottonseed hulls replaced by dry juniper leaves (JUN). Lamb BW was similar on d 0 and 14, but increasing juniper in the diet linearly reduced (P = 0.04) BW on d 28. Differences in BW during period 1 are attributed to ADG and average daily DMI linearly decreasing (P 0.12) among lambs, but serum IGF-1 tended to be linearly reduced (P = 0.09) by increasing juniper in the diet. At times during period 2, lambs fed CSHJ had the greatest (P < 0.02) serum urea N (d 40 and 82) and IGF-1 (d 54) concentrations. Results were interpreted to indicate that air-dried redberry juniper leaves can replace all of the cottonseed hulls in lamb feedlot rations. Feeding 30% juniper in the diet for a longer period of time during the initial feeding period probably would have further reduced growth performance.

The objective of this study was to further the understanding of the effects of dietary protein and energy supplements on growth, performance, feed intake and grass forage digestibility in growing meat goat wethers. In Experiment 1, an 18% CP complete goat pellet was offered alone (control diet, C) or added (+), or not, as supplement to three grass hays (coastal bermudagrass, CB; Tifton 85 bermudagrass, T; and sorghum-Sudan grass hay, SS), to Boer-cross wethers (n = 72). The resulting seven diets were offered ad libitum. In Experiment 2, four wether goats in metabolism crates were used in a 4 × 4 Latin square design and fed a SS basal diet ad libitum with treatments consisting of no supplement, supplemental urea (200 mg/kg BW daily), supplemental dextrose (0.2% BW daily), or urea + dextrose (200 mg/kg BW daily and 0.2% BW daily, respectively). In Experiment 1, average daily gain (ADG) were −3.8, −5.0 and −6.6 g/day for goats consuming CB, T and SS, respectively, and 69.2, 61.6 and 58.1 g/day for supplemented CB (CB+), T (T+) and SS (SS+), respectively, as compared to 245.8 g/day for ad libitum access to C. Supplementation in Experiment 1 increased (P < 0.01) ADG for all hays when compared to hay-only diets. In Experiment 2, protein and energy supplementation increased (P < 0.01) nitrogen retention but did not impact diet digestibility. The beneficial effects of supplements in Experiment 1 and the increase in nitrogen retention in Experiment 2 cannot be explained by improvements in ruminal fiber utilization, but could be due to post-ruminal nutrient supply and/or increased ruminal microbial protein synthesis.

BACKGROUND: Several factors affect condensed tannin (CT) levels in plants and accuracy of the butanol-HCl assay for total CT. Six native, perennial, herbaceous legumes from Texas were harvested at three stages of growth over a growing season; young vegetation, initial flowering, and late season. The samples were subjected to oven-drying and freeze-drying and analyzed for extractable (ECT), protein-bound (PBCT), and fiber-bound (FBCT) CT using a butanol-HCl procedure, comparing several types of purified CT as standards. RESULTS: There was a wide range of CT concentration in the legumes, but little change in ECT and total (TCT) tannin concentrations over the growing season. Oven-drying decreased (P < 0.05) ECT and increased (P < 0.05) PBCT and FBCT concentrations compared with freeze-drying, but both methods ranked the forages similarly throughout the growing season relative to TCT. Quebracho tannin as a standard increased CT values for the forages compared with purified legume CT standards, but all standards ranked the forages similarly relative to tannin concentration. Modifications to the procedure increased speed and ease of using the CT analysis method. CONCLUSION: Quantitative CT values have limited value except to allow a relative ranking of forages. Selection of appropriate standards is important in providing realistic CT values. Improvements in the total (extractable + bound) CT analysis method will allow wider use of this procedure. Although ECT and TCT values changed little in native legumes over a growing season, biological activity and potential nutritional/medicinal benefits of CT in these plants needs further evaluation. Copyright © 2008 Society of Chemical Industry

Methane emissions from ruminant livestock contribute to total anthropogenic greenhouse gas emissions and reduce metabolizable energy intake by the animal. Condensed tannins (CT) are polyphenolic plant secondary compounds commonly produced by some perennial forage legumes that characteristically bind to protein, carbohydrates, and minerals. The degree to which CT may affect ruminant nutrition depends upon the concentration, structural composition, and biological activity of the CT. The objective of our experiment was to determine the effect of replacing alfalfa in a corn-alfalfa-based substrate with a legume containing CT on in vitro CH4 production and the dynamics of fermentation using an in vitro gas production technique. All fermented substrates contained 50% ground corn as the energy concentrate portion, whereas the forage portion (50%) of each diet was comprised of alfalfa (control) or some combination of alfalfa and sericea lespedeza (SL) or panicled-tick clover (PTC). Our treatments consisted of PTC or SL 15, 30, and 45, which corresponded with 15, 30, or 45% replacement of the diet (alfalfa component) with either PTC or SL. Substrates containing 45% PTC or SL reduced in vitro CH4 production. Treatments did not affect total gas production as compared with that of the control. Replacement of alfalfa with SL or PTC increased fermentable organic matter (FOM). The PTC treatment increased FOM by as much as 1.8% at the 45% replacement level, whereas FOM of SL 45 was increased by less than 1%. The replacement of alfalfa with PTC increased substrate nutritive value greater than replacement with SL. There were no correlations between any physicochemical constituent of the substrates and CH4 production. A combination of factors associated with the inclusion of PTC and SL contributed to the in vitro CH4 production, and CT in these forages was likely a major contributing factor. Further confirmation of these results on in situ or in vivo animal systems is required. If proven effective in an in vivo production scenario, replacement of commonly fed non-CT-containing legumes, such as alfalfa, with legumes containing CT might be a viable method to decrease the effect of animal agriculture on greenhouse gas production.

Kenaf (Hibiscus cannibinus) var. “India”, lablab (Lablab purpureus) variety “Tecomate,” combine and iron-clay cowpeas (Vigna unguiculata), and sunflowers (Helianthus annuus) S682 and S573 were planted at the Stephenville Research and Extension Center in the spring seasons of 1998 and 1999. Dairy compost was incorporated into half the plots prior to seeding both years at 11.2 t DM ha−1. Average days to maturity and number of harvests per season varied from 66 to 84 d and 1 to 3 harvests, respectively. Average yields were highest for kenaf (13,762 kg DM ha−1 yr−1) followed by lablab (7,925 kg DM ha−1 yr−1). Acid detergent fiber and lignin DM concentrations were lowest in kenaf (average 26.9 and 3.57%, respectively) and cowpeas (average 25.9 and 4.39%, respectively). Crude protein and phosphorus (P) concentrations were high in the iron-clay cowpea (22.3 and 0.269, respectively), combine cowpea (18.3 and 0.276%, respectively), lablab (16.8 and 0.268%, respectively), and kenaf (14.9 and 0.204%, respectively) and relatively low in the sunflower (9.7 and 0.174%, respectively). Compost increased forage yields 21.6% and forage P concentration 18.8% following the second year’s application. Compost was applied to supply 130 kg P ha−1 yr−1; on average, forages removed only 34.2 kg P ha−1 yr−1. As a result, soil P was 2.4 times higher in plots with compost (26.9 ppm) by the end of the 2-yr trial. Kenaf had the highest P uptake, averaging 56.6 kg P ha−1 over 2 yr, accounting for 43% of the P applied.

BACKGROUND: Browse species containing condensed tannins (CTs) are an important source of nutrition for grazing/browsing livestock and wildlife in many parts of the world, but information on fiber concentration and CT–fiber interactions for these plants is lacking. RESULTS: Ten forage or browse species with a range of CT concentrations were oven dried and freeze dried and then analyzed for ash-corrected neutral detergent fiber (NDFom) and corrected acid detergent fiber (ADFom) using separate samples (ADFSEP) and sequential NDF-ADF analysis (ADFSEQ) with the ANKOM™ fiber analysis system. The ADFSEP and ADFSEQ residues were then analyzed for nitrogen (N) concentration. Oven drying increased (P < 0.05) fiber concentrations with some species, but not with others. For high-CT forage and browse species, ADFSEP concentrations were greater (P < 0.05) than NDFom values and approximately double the ADFSEQ values. Nitrogen concentration was greater (P < 0.05) in ADFSEP than ADFSEQ residues, likely due to precipitation with CTs. CONCLUSION: Sequential NDF-ADF analysis gave more realistic values and appeared to remove most of the fiber residue contaminants in CT forage samples. Freeze drying samples with sequential NDF-ADF analysis is recommended in the ANKOM™ fiber analysis system with CT-containing forage and browse species. Copyright © 2010 Society of Chemical Industry

Anthelmintic effects of plant secondary compounds may be occurring in the rumen, but in vitro larvae migration inhibition (LMI) methods using rumen fluid and forage material have not been widely used. Forage material added to an in vitro system can affect rumen pH, ammonia N, and volatile fatty acids, which may affect larvae viability (LV). Validating a LMI assay using rumen fluid and a known anthelmintic drug (Ivermectin) and a known anthelmintic plant extract (Quebracho tannins; QT) is important. Rumen fluid was collected and pooled from 3 goats, mixed with buffer solution and a treatment (1 jar/treatment), and placed into an anaerobic incubator for 16h. Ensheathed larvae (3 months old) were then anaerobically incubated with treatment rumen fluid for 2, 4, or 16h depending on the trial. Larvae (n=15-45) were then transferred onto a screen (n=4-6 wells/treatment) within a multi-screen 96-well plate that contained treatment rumen fluid. Larvae were incubated overnight and those that passed through the 20-μm screen were considered viable. Adding dry or fresh juniper material reduced (P0.05) pH, ammonia N, and isobutyric, butyric, isovaleric, and valeric acids, and increased (P0.001) acetic, propionic, and total VFA. Including 4.5% (w/v) polyethylene glycol (PEG) in rumen fluid mixture with or without forage material reduced (P0.01) LV. However, LV was similar at all PEG concentrations tested (0-2%, w/v; 89.4, 78.9, 76.5, 75.5, and 77.5% viable). Q. tannin concentrations from 0 to 1.2% (w/v) quadratically reduced (P0.001) LV; 89.4, 65.5, 22.8, and 9.2%. Ivermectin concentrations from 0 to 15μg/mL quadratically reduced (P0.001) LV; 90.2, 82.6, 73.6, 66.3, 51.9, 56.5, 43.5, 41.9, 29.3, and 19.9% viable, respectively. Effects of altering in vitro rumen fluid pH, ammonia N, and VFA and using PEG when evaluating LV need to be further investigated. In vitro rumen fluid assays using QT and Ivermectin resulted in decreased LV, validating the efficacy of this technique for measuring Haemonchus contortus larval viability.