Dietary replacement of soybean meal with heat-treated grain soybean in diets of feedlot-finished beef cattle: impacts on intake, digestibility, and ruminal parameters.

The objective of this study was to assess the impact of increasing levels of heat-treated soybean in the diet of crossbred cattle during the finishing phase on nutrient intake and digestibility, ruminal parameters, digesta passage rate, nitrogen balance, and microbial protein synthesis. Five steers, crossbred 7/8 Jersey x Zebu, fitted with rumen cannulas and with an average weight of 350 ± 50 kg, were utilized. The experimental treatments consisted of 0, 7, 14, 21, and 28% inclusion of heat-treated soybean in the total diet dry matter. The animals were randomly allocated in a 5 × 5 Latin square design. Evaluation of the animals took place over five experimental periods, each lasting 20 days. During each experimental period, the first 15 days were allocated for animal adaptation to the experimental diets, followed by five days of data collection. No significant differences were observed among the diets in terms of dry matter intake (average of 6.57 kg day-1; P = 0.615) and organic matter intake (average of 6.23 kg day-1; P = 0.832). However, heat-treated soybean had a significant impact on the digestibility of dry matter (P = 0.02), organic matter (P = 0.01), crude protein (P < 0.01), and neutral detergent fiber (P < 0.01). There was no observed change on microbial protein synthesis (average of 409.6 g day-1) in animals with the inclusion of heat-treated soybean in the diets. With each 1% inclusion of heat-treated soybean in the cattle diet, there was an increase of 0.00754 units in ruminal pH values and a reduction of 0.75839 mg dL-1 in ruminal ammoniacal nitrogen values. This study suggests that heat-treated soybean can be included in up to 15% of the dry matter in diets for finishing feedlot cattle.

3-Nitrooxypropanol substantially decreased enteric methane emissions of dairy cows fed true protein- or urea-containing diets.

Methane is a potent but short-lived greenhouse gas targeted for short-term amelioration of climate change, with enteric methane emitted by ruminants being the most important anthropogenic source of methane. Ruminant production also releases nitrogen to the environment, resulting in groundwater pollution and emissions of greenhouse gas nitrous oxide. We hypothesized that inhibiting rumen methanogenesis in dairy cows with chemical inhibitor 3-nitrooxypropanol (3-NOP) would redirect metabolic hydrogen towards synthesis of microbial amino acids. Our objective was to investigate the effects of 3-NOP on methane emissions, rumen fermentation and nitrogen metabolism of dairy cows fed true protein or urea as nitrogen sources. Eight ruminally-cannulated cows were fed a plant protein or a urea-containing diet during a Control experimental period followed by a methanogenesis inhibition period with 3-NOP supplementation. All diets were unintentionally deficient in nitrogen, and diets supplemented with 3-NOP had higher fiber than diets fed in the Control period. Higher dietary fiber content in the 3-NOP period would be expected to cause higher methane emissions; however, methane emissions adjusted by dry matter and digested organic matter intake were 54% lower with 3-NOP supplementation. Also, despite of the more fibrous diet, 3-NOP shifted rumen fermentation from acetate to propionate. The post-feeding rumen ammonium peak was substantially lower in the 3-NOP period, although that did not translate into greater rumen microbial protein production nor lesser nitrogen excretion in urine. Presumably, because all diets resulted in low rumen ammonium, and intake of digestible organic matter was lower in the 3-NOP period compared to the Control period, the synthesis of microbial amino acids was limited by nitrogen and energy, precluding the evaluation of our hypothesis. Supplementation with 3-NOP was highly effective at decreasing methane emissions with a lower quality diet, both with true protein and urea as nitrogen sources.

Inclusion Prosopis juliflora Pod Meal in Grazing Lambs Diets: Performance, Digestibility, Ingestive Behavior and Nitrogen Balance.

Prosopis juliflora is an arboreal legume that concentrates its nutritive value in pods (fruits), constituting a rich source of carbohydrates and with a crude energy concentration comparable to ground corn. Therefore, we aimed to evaluate the effect of inclusion of Prosopis juliflora pod meal (0 or control, 250, 500 and 750 g/kg total DM) as a replacement for ground corn in the diet of lambs on performance, digestibility, ingestive behavior, and nitrogen balance of lambs grazing in the Megathyrsus maximus pasture. Forty Santa Inês uncastrated lambs with an average body weight (BW) of 24.2 ± 0.55 kg were distributed in a completely randomized design. There was a linear increase in the non-fiber carbohydrates (NFC), ether extract (EE) and neutral detergent fiber (NDF) digestibility with Prosopis juliflora pod meal supplementation in the diet of the lambs. Dry matter (DM), crude protein (CP) and total digestible nutrients (TDN) intake, and digestibility and time spent ruminating were not affected by Prosopis juliflora meal supplementation. Prosopis juliflora pod meal inclusion increased time spent feeding and idling of lambs, however, without affecting spent time ruminating. Lambs fed with Prosopis juliflora pod meal presented greater final BW, gain: feed ratio, N-balance, microbial protein production ef-ficiency, N-urea urinary (NUU) and blood urea nitrogen (BUN). However, the average daily weight (ADG), total weight gain and hot carcass yield as well as N ingested, N excreted in feces and urine, total purines, ab-sorbed purines and N microbial production in lambs were not influenced by Prosopis juliflora pod meal inclusion. The Prosopis juliflora pod meal inclusion up to the 750 g/kg level in the concentrate supplement totally replace ground corn in the diet of grazing lambs improving the NFC intake and NDF digestibility, supplement acceptability, microbial protein production efficiency and consequently the performance. The addition of Prosopis juliflora pod meal as a replacement for ground corn in the concentrate does not influence the microbial protein production; however, there was an improvement in the efficiency of microbial synthesis.

Nutritional and productive performance of grazing system beef heifers receiving multiple supplementation in the dry season / Desempenho nutricional e produtivo de novilhas de corte em sistema de pastejo recebendo suplementação múltipla na estação seca

This research was conducted to evaluate the effects of supplementation multiple on intake, digestibility, and microbial protein synthesis and, productive performance of grazing system receiving multiple supplementation in the dry season. Twelve Nellore heifers (averaging 214.6 ± 7.3 kg initial BW and 8.0 ± 0.10 months) were distributed to a completely randomized design in two treatments: unsupplemented (only mineral) and; supplemented (1 kg per animal day-1 of multiple supplement). Only the crude protein (CP) intake was increased by supplementation (P < 0.05). In addition, the supplementation increased the digestibility of organic matter (OM), CP, ether extract (EE), non-fibrous carbohydrates (NFC) and dietary content of digested OM (DOM) (P < 0.05). The supplementation decreased microbial nitrogen to ingested nitrogen ratio (MICNR) (P < 0.05) and increased the serum urea nitrogen (SUN) concentration and urinary nitrogen excretion (UNE) (P < 0.05) in the animals. Finally, average daily gain (ADG) and final BW (FBW) were not affected by supplementation (P > 0.05). In summary, the provision 1 kg per animal day-1 of multiple supplement for beef heifers in grazing system does not improve productive performance in dry season when there is adequate qualitative and quantitative availability of forage mass. However, provision of supplement increases the total nutrients digestibility and nitrogen statuses in the animals.(AU)

Esta pesquisa foi conduzida para avaliar os efeitos da suplementação múltipla sobre o consumo, digestibilidade e síntese de proteína microbiana e, desempenho produtivo de novilhas de corte em sistema de pastejo na época seca. Doze novilhas Nelore (média de 214,6 ± 7,3 kg de peso corporal inicial e 8,0 ± 0,10 meses) foram distribuídas em delineamento inteiramente casualizado em dois tratamentos: não suplementado (apenas mistura mineral) e; suplementado (1 kg por animal dia-1 de suplemento múltiplo). Apenas o consumo de proteína bruta (PB) aumentou com a suplementação (P < 0,05). Além disso, a suplementação aumentou a digestibilidade da matéria orgânica (MO), PB, extrato etéreo (EE), carboidratos não fibrosos (CNF) e teor dietético de MOD (P < 0,05). A suplementação diminuiu a relação nitrogênio microbial nitrogênio ingerido (MICNR) (P < 0,05) e aumentou a concentração de nitrôgeno ureico no soro (NUS) e excreção urinário de ureia (ENU) (P < 0,05) nos animais. Finalmente, o ganho médio diário (GMD) e o peso corporal final (PCF) não foram afetados pela suplementação (P > 0,05). Em resumo, o fornecimento de 1 kg por animal dia-1 de um suplemento múltiplo para novilhas de corte em sistema de pastejo não melhora o desempenho produtivo na época seca, quando existe uma adecuada disponibilidade qualitativa e quantitativa da massa de forragem. No entanto, o fornecimento do suplemento múltiplo aumenta a digestibilidade total dos nutrientes e status de nitrogênio dos animais.(AU)

Carcass traits, commercial cuts, tissue composition, intake, digestibility, and performance of Sindhi bulls subjected to feed restriction / Características da carcaça cortes comerciais, composição tecidual, consumo, digestibilidade e desempenho de touros Sindi submetidos à restrição alimentar

This study showed the effect of feed restriction on performance, nitrogen balance (NB), microbial protein synthesis, carcass traits and meat cut of the thirty-two Sindhi non-castrated males (296 ± 21.3 kg initial BW and 21 ± 1.5 months old). All bulls were distributed in a completely randomized design with four treatments (feed restriction levels) (0, 15, 30, and 45% in total dry matter -DM) and the data were subjected to analysis of variance and regression. Nutrient intake, NB, final BW, total gain, feeding efficiency, carcass gain, hot and cold carcass weight, subcutaneous fat thickness, commercial cuts and fat tissue decreased linearly (P 0.05) by feed restriction level. A linear increased on digestibility of DM, NDFap, total carbohydrates and on the proportion of muscle tissue, as well as quadratic increase on non-fibrous carbohydrates and bone tissue percentage with the restriction level imposed on bulls (P 0.05). The feed restriction did not affect (P>0.05) the digestibility of crude protein, synthesis and microbial efficiency, deposition efficiency, longissimus dorsi area and muscle + fat/bone ratio. The feed restriction reduced intake and consequently performance, carcass traits and meat cuts of Sindhi bulls; however, it promoted a reduction in the N excretion, which can be important if conducted a subsequent compensatory weight gain.(AU)

Este estudo mostrou o efeito da restrição alimentar no desempenho, balanço de nitrogênio, síntese microbiana de proteínas, característica da carcaça e corte de carne de 32 machos Sindi não castrados (296 ± 21,3 kg de peso corporal inicial e 21 ± 1,5 meses de idade). Todos os touros foram distribuídos em delineamento inteiramente casualizado, com quatro tratamentos (níveis de restrição alimentar) (0, 15, 30 e 45% no total de matéria seca - MS) e os dados foram submetidos à análise de variância e regressão. Consumo de nutrientes, balanço de nitrogênio, peso corporal final, ganho total, eficiência alimentar, ganho de carcaça, peso de carcaça quente e fria, espessura subcutânea de gordura, cortes comerciais e tecido adiposo diminuíram linearmente (P 0,05) com o nível de restrição alimentar. Houve aumento linear na digestibilidade do DM, FDNap, carboidratos totais e quantidade de tecido muscular, além de aumento quadrático de carboidratos não fibrosos e porcentagem de tecido ósseo com o nível de restrição imposto aos touros (P 0,05). A restrição alimentar não afetou (P>0,05) a digestibilidade da proteína bruta, balanço de N, síntese e eficiência microbiana, eficiência de deposição, área do longissimus dorsi e relação músculo + gordura / osso. A restrição alimentar reduziu a ingestão e, consequentemente, o desempenho, as características da carcaça e os cortes de carne de touros Sindi, porém promoveu redução na excreção de N, o que pode ser importante se for realizado um subsequente ganho compensatório.(AU)

Carcass traits, commercial cuts, tissue composition, intake, digestibility, and performance of Sindhi bulls subjected to feed restriction / Características da carcaça cortes comerciais, composição tecidual, consumo, digestibilidade e desempenho de touros Sindi submetidos à restrição alimentar

ABSTRACT: This study showed the effect of feed restriction on performance, nitrogen balance (NB), microbial protein synthesis, carcass traits and meat cut of the thirty-two Sindhi non-castrated males (296 ± 21.3 kg initial BW and 21 ± 1.5 months old). All bulls were distributed in a completely randomized design with four treatments (feed restriction levels) (0, 15, 30, and 45% in total dry matter -DM) and the data were subjected to analysis of variance and regression. Nutrient intake, NB, final BW, total gain, feeding efficiency, carcass gain, hot and cold carcass weight, subcutaneous fat thickness, commercial cuts and fat tissue decreased linearly (P<0.05) by feed restriction level. A linear increased on digestibility of DM, NDFap, total carbohydrates and on the proportion of muscle tissue, as well as quadratic increase on non-fibrous carbohydrates and bone tissue percentage with the restriction level imposed on bulls (P<0.05). The feed restriction did not affect (P>0.05) the digestibility of crude protein, synthesis and microbial efficiency, deposition efficiency, longissimus dorsi area and muscle + fat/bone ratio. The feed restriction reduced intake and consequently performance, carcass traits and meat cuts of Sindhi bulls; however, it promoted a reduction in the N excretion, which can be important if conducted a subsequent compensatory weight gain.

RESUMO: Este estudo mostrou o efeito da restrição alimentar no desempenho, balanço de nitrogênio, síntese microbiana de proteínas, característica da carcaça e corte de carne de 32 machos Sindi não castrados (296 ± 21,3 kg de peso corporal inicial e 21 ± 1,5 meses de idade). Todos os touros foram distribuídos em delineamento inteiramente casualizado, com quatro tratamentos (níveis de restrição alimentar) (0, 15, 30 e 45% no total de matéria seca - MS) e os dados foram submetidos à análise de variância e regressão. Consumo de nutrientes, balanço de nitrogênio, peso corporal final, ganho total, eficiência alimentar, ganho de carcaça, peso de carcaça quente e fria, espessura subcutânea de gordura, cortes comerciais e tecido adiposo diminuíram linearmente (P<0,05) com o nível de restrição alimentar. Houve aumento linear na digestibilidade do DM, FDNap, carboidratos totais e quantidade de tecido muscular, além de aumento quadrático de carboidratos não fibrosos e porcentagem de tecido ósseo com o nível de restrição imposto aos touros (P<0,05). A restrição alimentar não afetou (P>0,05) a digestibilidade da proteína bruta, balanço de N, síntese e eficiência microbiana, eficiência de deposição, área do longissimus dorsi e relação músculo + gordura / osso. A restrição alimentar reduziu a ingestão e, consequentemente, o desempenho, as características da carcaça e os cortes de carne de touros Sindi, porém promoveu redução na excreção de N, o que pode ser importante se for realizado um subsequente ganho compensatório.

Effect of soybean meal replacement by slow-release urea on ruminal parameter, blood metabolites, and microbial protein synthesis in Zel ram

The objective of this study was to determine the effect of soybean meal replacement by slow-release urea on feed intake, ruminal parameters, blood metabolites, dry matter, nutrients digestion, and microbial protein synthesis (MPS) in ram. Rams were used for four 21-day periods. The experimental design was a 4×4 Latin square design. The experiment has consisted of the following four rations: 1) basic diet with soybean meal as a protein source, 2) basic diet with soybean meal plus 0.5 % of DM slow-release urea (SRU), 3) basic diet with soybean meal plus 1 % of DM SRU, and 4) basic diet with soybean meal plus 1.5 % of SRU, respectively. Soybean meal replacement by SRU decreased ruminal ammonia and blood urea. SRU increase in diets significantly increased acetic acid 3 hours after morning feeding, blood glucose, total purine, uric acid excretion, microbial nitrogen, and microbial protein. The results showed that soybean meal replacement by SRU sources had no negative effect on rams performance.(AU)

Effect of soybean meal replacement by slow-release urea on ruminal parameter, blood metabolites, and microbial protein synthesis in Zel ram

The objective of this study was to determine the effect of soybean meal replacement by slow-release urea on feed intake, ruminal parameters, blood metabolites, dry matter, nutrients digestion, and microbial protein synthesis (MPS) in ram. Rams were used for four 21-day periods. The experimental design was a 4×4 Latin square design. The experiment has consisted of the following four rations: 1) basic diet with soybean meal as a protein source, 2) basic diet with soybean meal plus 0.5 % of DM slow-release urea (SRU), 3) basic diet with soybean meal plus 1 % of DM SRU, and 4) basic diet with soybean meal plus 1.5 % of SRU, respectively. Soybean meal replacement by SRU decreased ruminal ammonia and blood urea. SRU increase in diets significantly increased acetic acid 3 hours after morning feeding, blood glucose, total purine, uric acid excretion, microbial nitrogen, and microbial protein. The results showed that soybean meal replacement by SRU sources had no negative effect on rams performance.

Study of morphometric and ruminal parameters in santa inês sheep fed spineless cactus (Opuntia ficus-indica, MILL) / [Estudo dos parâmetros morfométricos e ruminais em ovinos Santa Inês alimentados com cactus sem espinhos (Opuntia ficus-indica, MILL)]

The present study aimed to morphometrically evaluate the ruminal mucosa and ruminal fluid characteristics of Santa Inês sheep fed different levels of spineless cactus as a replacement for Tifton grass hay. A total of 32 intact male Santa Inês sheep, approximately 180 days old and with a mean weight of 32.0±1.6kg, were studied in a completely randomized design with four treatments and eight replicates. The morphometric measurements evaluated in the ruminal epithelium (papilla height and surface area) were significantly affected (P< 0.05) by supplementation of the diet with spineless cactus, and these effects showed increasing linear trends. Evaluations of the ruminal fluid also showed a significant increasing linear effect (P< 0.05) for ammonia and a quadratic effect for microbial protein. The inclusion of spineless cactus in the sheep diet affects the ruminal epithelium morphology, including the papilla height and surface area, and favors the absorption process in the rumen. The diet containing higher levels of spineless cactus led to maximum microbial protein production. These results characterize spineless cactus as a feasible alternative for feeding sheep during periods of drought, when the typical food source is scarce.(AU)

O presente estudo teve como objetivo avaliar morfometricamente a mucosa ruminal e as características do líquido ruminal de ovinos Santa Inês alimentados com diferentes níveis de palma forrageira como substituta do feno de capim-Tifton. Um total de 32 ovinos, machos inteiros, da raça Santa Inês, com aproximadamente 180 dias de idade e peso médio de 32,0±1,6kg, foi estudado em delineamento inteiramente ao acaso, com quatro tratamentos e oito repetições. As medidas morfométricas avaliadas no epitélio ruminal (altura e área superficial da papila) foram significativamente afetadas (P<0,05) pela suplementação da dieta com palma forrageira, e esses efeitos mostraram tendências lineares crescentes. As avaliações do fluido ruminal também mostraram um efeito linear crescente significativo (P<0,05) para a amônia e um efeito quadrático para a proteína microbiana. A inclusão de palma forrageira na dieta de ovinos afeta a morfologia do epitélio ruminal, englobando a altura e a área da papila, e favorece o processo de absorção no rúmen. A dieta contendo níveis mais altos de palma forrageira levou à produção máxima de proteína microbiana. Esses resultados caracterizam a palma forrageira como uma alternativa viável para a alimentação de ovelhas durante períodos de seca, quando a fonte típica de alimento é escassa.(AU)

Acacia mearnsii tannin extract as a feed additive: impact on feed intake, digestibility and nitrogen excretion by sheep fed a tropical grass-based diet / Extrato tanífero de Acacia mearnsii como aditivo alimentar: impacto sobre o consumo, digestibilidade e excreção de nitrogênio em ovinos alimentados com uma dieta a base de gramínea tropical

The aim of this study was to evaluate the effect of the dietary inclusion of Acacia mearnsii tannin extract (TA) on nutrients intake and digestibility, and nitrogen (N) retention by sheep given a tropical grass-based diet. The trial was conducted with six castrated male sheep in a cross-over design in two 21-days experimental periods. The sheep were housed in metabolic cages and offered Tifton 85 hay (Cynodon dactylon) ad libitum plus concentrate at a rate of 12 g of dry matter (DM)/kg body weight (BW). The treatments were concentrate without (Control) or with 10 g TA/kg DM (Tannin). Concentration of TA in the diet was 3.8 g/kg DM and did not affect the feed intake or apparent digestibility. The TA decreased the true digestibility of n compounds (P 0.05) whereas did not impact the N retention, microbial N flow to the small intestine or the efficiency of rumen microbial protein synthesis. In conclusion, a low dietary concentration of TA did not impact the nutrients supply and N use by sheep fed with a tropical grass-based diet.(AU)

O objetivo do presente estudo foi avaliar o efeito da inclusão alimentar de extrato tanífero de Acacia mearnsii (TA) sobre o consumo, a digestibilidade e a retenção de nitrogênio (N) em ovinos alimentados com uma dieta a base de gramínea tropical. O experimento foi conduzido com seis ovinos machos castrados, em delineamento em reversão simples, com dois períodos experimentais de 21 dias cada. Os animais foram alojados em gaiolas metabólicas e alimentadas ad libitum com feno de Tifton 85 (Cynodon dactylon) mais concentrado oferecido a uma taxa de 12 g de matéria seca (MS)/kg de peso corporal. Os tratamentos foram: concentrado sem (Controle) ou com 10 g de TA/kg MS (Tanino). A concentração de TA na dieta foi de 3,8 g/kg MS e não afetou o consumo e nem a digestibilidade aparente dos nutrientes. O TA diminuiu a digestibilidade verdadeira do N (P 0,05), mas não afetou a retenção de N, o fluxo microbiano de N para o intestino delgado ou a eficiência de síntese de proteína microbiana no rúmen. Em conclusão, a inclusão de uma baixa dose de TA/kg MS na dieta não afetou a oferta de nutrientes nem o uso de N em ovinos alimentados com uma dieta baseada em uma gramínea tropical.(AU)

Milk production responses and rumen fermentation of dairy cows supplemented with summer brassicas.

Forage brassicas, such as summer turnip (ST; Brassica rapa) and forage rape (FR; Brassica napus), are used as supplementary crops during summer. However, studies with lactating dairy cows fed these forages are limited and report inconsistent productive responses. The aim of this study was to determine dry matter intake, rumen fermentation and milk production responses of dairy cows in mid-lactation supplemented with and without summer ('ST' or 'FR') brassicas. Twelve multiparous lactating dairy cows were randomly allocated to three dietary treatments in a replicated 3 × 3 Latin square design balanced for residual effects over three 21-day periods. The control diet consisted of 16.2 kg DM of grass silage, 2.25 kg DM of commercial concentrate and 2.25 kg DM solvent-extracted soybean meal. For the other two dietary treatments, 25% of the amounts of silage and concentrates were replaced with FR or ST. The inclusion of forage brassicas had no effects on milk production (24.2 kg cow/day average) and composition (average milk fat and protein 43.2 and 33.6 g/l, respectively). Dry matter intake was 0.98 kg and 1.12 kg lower for cows supplemented with FR and ST, respectively, resulting in a greater feed conversion efficiency (1.35 kg milk/kg DM for ST and FR v. 1.27 kg milk/kg DM for the control diet). Intraruminal pH was lower for cows supplemented with ST compared to the control diet; however, it did not decrease below pH 5.8 at any time of the day. After feeding, the concentrations of total short-chain fatty acids (SCFAs) in rumen contents increased with ST supplementation compared to the control diet. Inclusion of FR in the diet increased the molar proportion of acetate (68.5 mmol/100 mmol) in total SCFA at the expense of propionate, measured 6 h after feeding of the forage. The molar proportion of butyric acid was greater with ST and FR supplementation (13.1 and 12 mmol/100 mmol, respectively) than in control cows. The estimated microbial nitrogen (N) flow was 89.1 g/day greater when supplementing FR compared to the control diet. Based on the haematological measures, the inclusion of summer brassica forages did not affect the health status of the animals. These results indicate that mid-lactation dairy cows fed brassicas are able to maintain production despite the reduced intake, probably due to improved rumen fermentation and therefore nutrient utilization.

Ruminal and histological characteristics and nitrogen balance in lamb fed diets containing cactus as the only roughage.

This study examined rumen fermentation, histological, blood, and urinary characteristics as well as ammoniacal nitrogen concentration, pH, nitrogen balance, and microbial protein in lamb fed diets containing spineless cactus as the sole roughage source plus levels of wheat bran (WB) in comparison with a control diet based on spineless cactus and buffelgrass. Twenty-eight uncastrated, crossbreed lambs with an average initial weight of 22.6 ± 2.37 kg were used in the experiment. The treatments consisted of a standard diet (control) containing buffelgrass and spineless cactus and three diets containing cactus as the only roughage source plus varied concentrations of WB (30, 37, and 44%, on a dry matter basis). Results were evaluated by analysis of variance, and contrasts were applied at the 5% probability level for mean comparison. Rumen villus height and width were greater and musculature was lower in the lamb fed diets containing 37% and 44% WB compared with those fed control diet. In the intestine, the crypts were smaller in the animals which consumed the diets with 30, 44, and 37% WB. All WB levels resulted in lower nitrogen intake and retention. Microbial protein concentration, microbial protein efficiency, microbial nitrogen, urea, and glucose were not significantly affected. Feeding lamb with diets containing levels of wheat bran, with cactus as the only roughage source, does not negatively affect their ruminal-fermentation, blood, and urinary characteristics; ammoniacal nitrogen concentration; pH; or microbial protein. However, nitrogen balance and ruminal and intestinal morphometric characteristics are impaired.

Acacia mearnsii tannin extract as a feed additive: impact on feed intake, digestibility and nitrogen excretion by sheep fed a tropical grass-based diet / Extrato tanífero de Acacia mearnsii como aditivo alimentar: impacto sobre o consumo, digestibilidade e excreção de nitrogênio em ovinos alimentados com uma dieta a base de gramínea tropical

ABSTRACT: The aim of this study was to evaluate the effect of the dietary inclusion of Acacia mearnsii tannin extract (TA) on nutrients intake and digestibility, and nitrogen (N) retention by sheep given a tropical grass-based diet. The trial was conducted with six castrated male sheep in a cross-over design in two 21-days experimental periods. The sheep were housed in metabolic cages and offered Tifton 85 hay (Cynodon dactylon) ad libitum plus concentrate at a rate of 12 g of dry matter (DM)/kg body weight (BW). The treatments were concentrate without (Control) or with 10 g TA/kg DM (Tannin). Concentration of TA in the diet was 3.8 g/kg DM and did not affect the feed intake or apparent digestibility. The TA decreased the true digestibility of n compounds (P<0.05) whereas did not impact the N retention, microbial N flow to the small intestine or the efficiency of rumen microbial protein synthesis. In conclusion, a low dietary concentration of TA did not impact the nutrients supply and N use by sheep fed with a tropical grass-based diet.

RESUMO: O objetivo do presente estudo foi avaliar o efeito da inclusão alimentar de extrato tanífero de Acacia mearnsii (TA) sobre o consumo, a digestibilidade e a retenção de nitrogênio (N) em ovinos alimentados com uma dieta a base de gramínea tropical. O experimento foi conduzido com seis ovinos machos castrados, em delineamento em reversão simples, com dois períodos experimentais de 21 dias cada. Os animais foram alojados em gaiolas metabólicas e alimentadas ad libitum com feno de Tifton 85 (Cynodon dactylon) mais concentrado oferecido a uma taxa de 12 g de matéria seca (MS)/kg de peso corporal. Os tratamentos foram: concentrado sem (Controle) ou com 10 g de TA/kg MS (Tanino). A concentração de TA na dieta foi de 3,8 g/kg MS e não afetou o consumo e nem a digestibilidade aparente dos nutrientes. O TA diminuiu a digestibilidade verdadeira do N (P<0,05), mas não afetou a retenção de N, o fluxo microbiano de N para o intestino delgado ou a eficiência de síntese de proteína microbiana no rúmen. Em conclusão, a inclusão de uma baixa dose de TA/kg MS na dieta não afetou a oferta de nutrientes nem o uso de N em ovinos alimentados com uma dieta baseada em uma gramínea tropical.

Ruminal and morphometric parameters of rumen and intestine in lambs fed guava (Psidium guajava L) agroindustrial waste

The objective of this study was to evaluate the effect of guava agroindustrial waste (GAW) on ruminal parameters (pH, N-NH3, and microbial protein), volatile fatty acid (VFA), and morphometry of the rumen and intestine of sheep. A total of forty Santa Inês sheep (120 days old and 21.3±2.62 kg) were used. The animals were fed diets with 0, 7.5, 15, 22.5, and 30% inclusion of GAW. The pH, ammonia nitrogen, microbial protein, and VFA were evaluated in the ruminal fluid, alongside the morphometric characteristics of the rumen and intestine. The inclusion of GAW linearly increased fasting and postprandial pH, N-NH3 only showed a quadratic effect for fasting animal, whereas MP presented a quadratic effect for pre- and post-prandial animals. There was a quadratic effect for papilla width, with a maximum value of 393.33 µm at the level of 34.43% GAW in the diet. The papilla absorption area showed a linear effect, in which increasing levels of GAW in the diet had a smaller area of papillae absorption. The inclusion of GAW in the diet of Santa Inês sheep favored pH neutrality, reduced N-NH3 and ruminal MP concentrations, decreased the thickness of the rumen muscular layer, and increased the intestinal mucosa, favoring greater absorption of nutrients.(AU)

Estimación del balance de metionina y lisina metabolizable en vacas de leche en pastoreo / Estimation of the balance of metabolizable lysine and methionine for grazing dairy cows

RESUMEN Objetivos. El objetivo de este trabajo fue estimar en vacas en pastoreo, tanto la reproducibilidad como la precisión del balance de metionina (Met) y lisina (Lis), aminoácidos más limitantes en la producción de leche, cuando se comparan los valores predichos versus los valores observados. Materiales y métodos. Se usaron 12 vacas durante un periodo de 20 días. Control: animales pastoreando y suplementados con alimento balanceado; Met-Lis: igual al control y el suplemento se ajustó con Lis y Met protegida. Para los valores predichos para la suplementación de Met y Lis, se tuvo en cuenta el promedio del consumo de materia seca (CMS) del hato, basado en la oferta y el consumo de pasto y los valores de proteína microbiana. Los valores observados se determinaron con base en el CMS individual usando marcadores externos e internos, además, la producción individual de proteína microbiana. Se realizó una prueba de t pareada y un modelo de predicción para determinar la eficiencia fue determinado usando el error cuadrático medio de predicción (ECMP) y el coeficiente de concordancia (CCC). Resultados. Se encontraron diferencias significativas entre la suplementación y el balance de Met y Lis, entre los valores predichos y los valores observados para el CMS del forraje, la digestibilidad de la proteína microbiana, la producción de proteína microbiana, el suministro y el balance de Lis y Met. El CCC del balance de Lis y Met fue bajo (0.10), el ECMP fue alto, excepto para el CMS, que tuvo una concordancia moderada (0.63) y un bajo ECMP(4.42). Conclusiones. Estos resultados demuestran la falta de precisión de las herramientas que se usan para balancear las raciones individuales de vacas en pastoreo, ya que subestiman la suplementación y el balance de los aminoácidos.

ABSTRACT Objective. The aim of this study was to determine in grazing cows, the reproducibility and accuracy of the balance between predicted values, when compared with the observed values for the most limiting amino acids in milk protein synthesis, the methionine (Met) and Lysine (Lys). Materials and methods. Twelve lactating cows were used for a 20-day experimental period. Control: animals grazing and supplemented with balanced food; Met-Lys: same as control and supplemented with adjusted rumen protected Met and Lys. For Met and Lys supply predicted values, it was taking in account the average of the dry matter intake (DMI) of the herd, based in offer and foraging control and values of microbial protein data. Observed values were determined based in the individual DMI intake, using external and internal markers and the individual microbial protein production. A t-paired-sample test was performed and the efficiency of the model's prediction was determined using the mean square prediction error (MSPE) and the concordance coefficient (CCC). Results. Significant differences were found between the predicted and observed values for DMI forage, digestible microbial protein and microbial protein production, supply and the balance of Lys and Met. The CCC for Lys and Met balance were low (0.10), the MSPE was high except for the total DMI with a moderate concordance (0.63) and low MSPE (4.42). Conclusions. These results indicate a lack of precision of the tools, which underestimates the supply and balance of amino acids in individual grazing cows.

Inclusion of licuri meal in the diet of pasture dairy cows.

The objective of this study was to evaluate the inclusion of increasing levels of licuri meal as a substitute for soybean bran in the diet of pasture-based dairy cows and its effects on the intake, nutrient digestibility, and milk production and composition. Eight crossbred Holstein/Zebu cows were used in two 4 × 4 Latin square plots. The diets contained increasing percentage of licuri meal (0.0, 4.16, 7.09, and 9.45%) in the total diet, replacing soybean bran. The inclusion of licuri meal in the diet affected total dry matter intake and dry matter intake in relation to body weight, which presented a quadratic effect. The same behavior was observed for the consumption of EE, CP, TDN, and NDFap. The NFC consumption showed a linear decrease with the addition of the by-product in the diet. There was no influence of the inclusion of the licuri meal on the digestibility of the DM, CP, NFC, and TDN, while the digestibility of the NDFap and EE presented increasing linear effect. There was a reduction of milk production and food efficiency with the inclusion of increasing levels of the meal. The fat content in milk showed a linear increasing effect. Ditto for cholesterol. It is recommended to include not more than 7.00% of licuri meal for lactating cows with an average production of 20 kg day-1.

Relationship between forage neutral detergent fiber and non-fibrous carbohydrates on ruminal fermentation products and neutral detergent fiber digestibility in goats / Relación entre la fibra detergente neutra del forraje y los carbohidratos no fibrosos sobre los productos de la fermentación ruminal y digestibilidad de la fibra detergente neutra en cabras / Efeito da relação da fibra em detergente neutro advindo de forragem e carboidratos não fibrosos sobre os produtos da fermentação ruminal e digestibilidade da fibra em detergente neutro em caprinos

Abstract Background: There is a comprehensive understanding of the role of dietary fiber as a nutrient and its function during digestion in cattle. On the other hand, the role of fiber digestion in goats has not received similar attention. Objective: To evaluate the effects of different ratios of forage neutral detergent fiber (fNDF) and non-fibrous carbohydrates (NFC) on ruminal fermentation products, and in vitro neutral detergent fiber (NDF) digestibility in goats. Methods: A 3 × 5 factorial arrangement in a completely randomized design with three fNDF levels (100, 190, and 290 g/kg) and five NFC levels (350, 400, 450, 500, and 550 g/kg) was used. The experiment was performed in vitro. Two ruminally fistulated goats were used as rumen liquid donors. Results: The ratios between fNDF and NFC affected all ruminal parameters (p<0.05). Increasing NFC levels in diets containing 100 and 290 g/kg fNDF resulted in linear increase (p<0.05) in ammonia concentration after 48 h fermentation. There was no adjustment of linear models (p>0.05) for pH values. Total volatile fatty acids (VFA) and their individual molar proportions were affected (p<0.05) at all fNDF and NFC levels. The NDF digestibility was not affected (p>0.05) by fNDF or NFC levels, except for diets containing 290 g/kg fNDF, which were fit to a quadratic model (p<0.05). Conclusion: The relationship between fNDF and NFC concentrations affect the fermentation end products and in vitro NDF digestibility. NFC plays a more consistent role than fNDF in the ruminal microbial ecosystem of goats during in vitro fermentation.

Resumen Antecedentes: Aunque hay una amplia comprensión del papel que juega la fibra dietética como nutriente y su función durante la digestión en el ganado vacuno, el papel de la digestión de la fibra en las cabras no ha recibido una atención similar. Objetivo: Evaluar los efectos de diferentes proporciones de fibra detergente neutra proveniente del forraje (fNDF) y carbohidratos no fibrosos (NFC) sobre los productos de la fermentación ruminal y la digestibilidad in vitro de la fibra detergente neutra (NDF) en cabras. Métodos: Se utilizó un arreglo factorial de 3 × 5, distribuidos en un diseño completamente aleatorizado con tres niveles de fNDF (100, 190 y 290 g/kg) y cinco niveles de NFC (350, 400, 450, 500 y 550 g/kg). El experimento se realizó in vitro. Se utilizaron dos cabras fistuladas en rumen como donantes de líquido ruminal. Resultados: La relacion entre fNDF y NFC afectó todos los parámetros ruminales estudiados (p<0,05). El aumento de los niveles de NFC en dietas con 100 y 290 g/kg de fNDF resultó en aumento lineal (p<0,05) de la concentración de amoníaco después de 48 h de fermentación. No hubo ajuste de modelos lineales (p>0,05) para valores de pH. Los ácidos grasos volátiles totales y sus proporciones molares individuales se afectaron (p<0,05) en todos los niveles de fNDF y NFC. La digestibilidad de NDF no fue afectada (p>0,05) por los niveles de fNDF ni NFC, con excepción de las dietas con 290 g/kg fNDF, que se ajustaron a un modelo cuadrático (p<0,05). Conclusión: La relación entre las concentraciones de fNDF y NFC afecta los productos finales de fermentación y la digestibilidad in vitro de NDF. Los niveles de NFC juegan un papel más consistente que fNDF en el ecosistema microbiano ruminal de la cabra durante la fermentación in vitro.

Resumo Antecedentes: Embora exista um compreensível entendimento do papel que a fibra dietética desempenha como nutriente e sua função durante a digestão em bovinos, o papel da digestão das fibras em caprinos não recebeu atenção semelhante. Objetivo: Avaliar os efeitos de diferentes relações da fibra em detergente neutro advindo de forragem (fNDF) e carboidratos não-fibrosos (NFC) sobre produtos da fermentação ruminal e digestibilidade in vitro da fibra em detergente neutro (NDF) em caprinos. Métodos: Utilizou-se um esquema fatorial de 3 × 5 distribuídos em um delineamento inteiramente casualizado com três níveis de fNDF (100, 190 e 290 g/kg) e cinco níveis de NFC (350, 400, 450, 500 e 550 g/kg). O experimento foi realizado in vitro. Duas cabras fistuladas no rúmen foram utilizadas como doadoras de líquido ruminal. Resultados: As relações entre fNDF e NFC impactaram todos os parâmetros ruminais estudados (p<0,05). O aumento dos níveis de NFC em dietas contendo 100 e 290 g/kg de fNDF resultou em um aumento linear (p<0,05) na concentração de amônia após 48 h de fermentação. Não houve ajuste de modelos lineares (p>0,05) para valores de pH. Os ácidos graxos voláteis totais e suas proporções molares individuais foram afetados (p<0,05) em todos os níveis de fNDF e NFC. A digestibilidade NDF não foi afetada (p>0,05) pelos níveis de fNDF e NFC, com exceção de dietas experimentais contendo 290 g/kg fNDF, que foram ajustadas a um modelo quadrático (p<0,05). Conclusão: A relação entre as concentrações de fNDF e NFC afeta os produtos finais de fermentação e a digestibilidade in vitro de NDF de dietas experimentais. Os níveis de NFC desempenham um papel mais consistente do que o fNDF no ecossistema microbiano ruminal de cabras durante a fermentação in vitro.

Can cactus (Opuntia stricta [Haw.] Haw) cladodes plus urea replace wheat bran in steers' diet?

OBJECTIVE: The study aimed to evaluate the effect of replacing wheat bran for cactus cladodes plus urea (0%, 25%, 50%, 75%, and 100%) on the intake of nutrients, nitrogen balance, microbial protein synthesis, and rumen fermentation for steers. METHODS: Five crossbred steers (1/2 Holstein-Zebu), with rumen cannula and an average body weight of 180±5.3 kg, were assigned to a 5×5 Latin square design. Dietary treatments consisted of the replacement of the total of wheat bran in basal diet by cactus cladodes using the following proportions: 0% for basal diet, 25%, 50%, 75%, and 100% cactus cladodes replacing wheat bran. Urea was added to the diets to adjust the crude protein (CP) content to 130 g/kg dry matter. RESULTS: Maximum dry matter intake (5.73 kg/d) and maximum nitrogen balance (103 g/d) were estimated for 54.6% and 70.8% replacement levels of wheat bran. The maximum microbial protein production (44.6 g/d) was obtained at a replacement level of 49.7%, and a medium value (125 g CP mic/kg total digestible nutrients) of microbial protein efficiency was observed. The rumen pH increased linearly according to cactus cladodes inclusion, while the ammonia nitrogen medium value was 24.5 mg/dL. CONCLUSION: The replacement of 55% wheat bran for cactus cladodes plus urea in the diet of crossbred steers is recommended.

Sugarcane bagasse as exclusive roughage for dairy cows in smallholder livestock system.

OBJECTIVE: The study aimed to evaluate sugarcane bagasse as roughage in lactating cow on feed intake, digestibility, ingestive behavior, milk production and composition, and microbial protein synthesis. METHODS: Ten Girolando cows at initial body weight of 450±25.6 kg and at 143.7±30.7 days in milk were assigned in two 5×5 Latin square designs. Five 21-day experimental periods were adopted (1° to 14-day: diets adaptation period; 15° to 21-day: data collection and sampling period). The diets consisted of four different levels of sugarcane bagasse (45%, 50%, 55%, and 60%) and a control diet, commonly adopted in the region, based on spineless cactus (25% sugarcane bagasse), formulated to meet 12 kg/d milk yield. RESULTS: The dry matter (DM), organic matter (OM), and total digestible nutrients intakes and DM and OM digestibilities observed for 45% and 50% bagasse inclusion were similar to control diet, while that 55% and 60% bagasse inclusion were lower. Cows fed control diet, and bagasse diets of 45%, and 50% levels had the nutritional requirements attended, that guaranteed 12 kg/d of milk yield. The crude protein intake and digestibility of cows fed 45%, 50%, and 55% of bagasse inclusion were similar to control diet. The neutral detergent fiber (NDF) intake and digestibility differ for all bagasse diets related to control diet, while the non-fiber carbohydrates intake and digestibility for cows fed 45% of bagasse were similar for control diet. The intakes and digestibilities of nutrients decreased linearly in function of bagasse inclusion; NDF and indigestible NDF intakes did not vary. The ruminating time, feeding and rumination efficiency, microbial protein synthesis and milk yield decreased linearly with sugarcane bagasse inclusion. CONCLUSION: Sugarcane bagasse decreases milk production; however, its inclusion level in between 45% to 50% associated to concentrate could replace diets based on spineless cactus for crossbred dairy cow's producing 12 kg/d of milk.

Effect of spineless-cactus mucilage on the in vitro rumen fermentation of cellulose, starch, and protein / Efeito da mucilagem da palma forrageira sobre a fermentação ruminal in vitro da celulose, amido e proteína

The aim of this study was to evaluate the effect of the levels of spineless-cactus mucilage on the in vitro rumen fermentation of cellulose, starch, and protein. A completely randomized experimental design was adopted with a 5 × 3 factorial arrangement consisting of five levels of spineless-cactus mucilage (0, 5, 10, 20, and 40%) and three substrates (carboxymethylcellulose, starch, and trypticase). Treatments were evaluated in a ruminal environment simulated by in vitro incubation at different times of assessment: 0, 3, 6, 12, 24, and 48 h. The incubation procedure was repeated three times, totaling three evaluations per incubation time for each treatment. There was an interaction (P<0.05) between the mucilage levels and substrate for all evaluated ruminal parameters, except for the concentration of microbial protein after 48 h of fermentation and for the proportions of acetate and butyrate fermentation at time 0 h. There was a quadratic increase (P<0.05) in the concentration of ammoniacal nitrogen after 48 h of incubation in the media containing carboxymethylcellulose and trypticase. pH values decreased quadratically (P<0.05) as a function of the mucilage levels in the media containing carboxymethylcellulose and trypticase. Overall, no expressive alterations were observed between the individual molar proportions of acetate, propionate, and butyrate with the addition of spineless-cactus mucilage levels to the different substrates. Spineless- cactus mucilage affects the pattern of fermentation of starch, cellulase, and protein performed by rumen microorganisms.(AU)

Objetivou-se com esta pesquisa avaliar o efeito dos níveis de mucilagem de palma forrageira sobre a fermentação ruminal in vitro de celulose, amido e proteína. Utilizou-se um delineamento experimental inteiramente casualizado, disposto em um esquema fatorial 5 × 3, com 5 níveis de mucilagem de palma forrageira (0, 5, 10, 20 e 40%) e três substratos (carboxymetilcelulose, amido e trypticase). Os tratamentos foram avaliados em ambiente ruminal simulado por incubação in vitro em diferentes tempos de incubação: 0, 3, 6, 12, 24 e 48 horas. O procedimento de incubação foi repetido três vezes, perfazendo-se o total de três avaliações por tempo de incubação para cada tratamento. Houve interação (P<0,05) entre os níveis de mucilagem e substratos para todos os parâmetros ruminais avaliados, com exceção da concentração de proteína microbiana após 48 horas de fermentação e para as proporções de acetato e butirato às 0 hora de fermentação. Houve aumento quadrático (P<0,05) para a concentração de nitrogênio amoniacal após 48 horas de incubação nos meios, contendo carboxymetilcelulose e trypticase. Os valores de pH reduziram de forma quadrática (P<0,05) em função dos níveis de mucilagem nos meios contendo carboxymetilcelulose e trypticase. De maneira geral, não foram observadas alterações expressivas entre as proporções molares individuais de acetato, propionato e butirato com a adição dos níveis de mucilagem de palma forrageira aos diferentes substratos. A inclusão de níveis de mucilagem de palma forrageira afeta o padrão de fermentação do amido, celulose e proteína realizada por microrganismos ruminais.(AU)