ABSTRACT The objective of this study was to assess the effects of two levels of soybean hulls (0 and 400.1 g/kg) and whole or ground corn in the diet of newborn crossbred dairy male calves on intake, performance, blood indicators, and feeding cost. Twenty-eight calves with an average weight of 33.0±6.2 kg and four days of age were distributed into four treatment groups in a completely randomized design (n = 7) for 56 days. Weekly samples of feed, diets, and leftovers were collected to determine dry matter and nutrient intakes. To evaluate apparent digestibility, samples were taken using titanium dioxide as a maker. Blood samples were also collected to evaluate blood indicators. The inclusion of soybean hulls resulted in greater neutral detergent fiber intake by the calves, but reduced their non-fibrous carbohydrates intake, which was also reduced by the use of whole corn in the diet. Although the total digestible nutrients content of diets decreased with the use of whole corn and inclusion of soybean hulls, its intake did not vary (0.75 kg/d), regardless of the factors analyzed. The apparent digestibilities of dry matter (0.87 kg/kg) and crude protein (0.89 kg/kg) were similar, resulting in similar performance between the animals, regardless of the factors analyzed. In the quantities evaluated, the use of soybean hulls or whole corn did not affect blood indicators and was insufficient to reduce feed costs; the cost of daily feed was $2.06, while the cost per kilogram of gain was $3.74. The inclusion of up to 400.1 g/kg of soybean hulls or the replacement of ground corn with whole corn does not affect the performance of crossbred dairy calves during the preweaning period, demonstrating that both can be used in animal feed during this phase of production.

ABSTRACT The objective of this study was to evaluate performance, apparent digestibility, blood parameters, and quantitative characteristics of carcass and internal organs of crossbred dairy calves fed different levels of crude glycerin in corn grain-based diets. Twenty-four calves of three months of age and average initial weight of 95.5±11.8 kg were used. The experimental design was completely randomized with four treatments (0, 80, 160, and 240 g kg−1 of crude glycerin of DM of diets). The calves were fed in feedlot until six months of age (195.68±2.38 kg of BW). Dry matter (4.14, 4.11, 3.80, and 3.49 kg day−1) and apparent digestible energy intake (0.43, 0.41, 0.37, and 0.35 MJ kg−1 BW) decreased with increasing levels of glycerin in the diets. There was no effect on the apparent digestibility of nutrients, average daily gain, feed efficiency, carcass characteristics, and blood parameters. The diets did not influence the weights [g kg−1 of empty body weight (EBW)] of lungs, heart, kidneys, liver, omasum, abomasum, and large intestine. The reticulorumen weight (g kg−1 EBW) increased, whereas the small intestine weight decreased with increased levels of glycerin in the diets. The area, height, and width of the rumen papillae were not changed with increasing levels of glycerin. The rumen wall thickness increased with increasing levels of glycerin in the diets. The inclusion up to 240 g kg−1 DM of crude glycerin of in corn grain-based diets for the production of dairy calves does not alter animal performance, carcass characteristics, and weights of internal organs.

RESUMO: O objetivo do estudo foi avaliar a viabilidade econômica relacionada ao risco da substituição de milho por milheto em dietas com 80% de concentrado no confinamento de bovinos por 89 dias. Os níveis de substituição foram: 0, 33, 66 e 100%. O risco foi estimado usando simulação de Monte Carlo, correlação de Spearman entre as variáveis de entrada, dominância estocástica e análise de sensibilidade. Os valores médios esperados ± desvio padrão para o valor presente líquido (R$/animal) foram de ± 71,74 ± 283,32, 91,23 ± 285,18, 196,05 ± 273,79 e 223,80 ± 267,96 para dietas contendo 0, 33, 66 e 100% de milheto, respectivamente. A probabilidade de valor presente líquido ≥0 foi de 63,4, 66,1, 78,4 e 82,4%, respectivamente. Os valores presentes líquidos foram estatisticamente diferentes (p<0,05), e os níveis mais elevados dominaram os valores mais baixos. Os itens que mais influenciaram os valores presentes líquidos foram, em ordem decrescente, os preços de bovinos não terminados e acabados, pesos inicial e final, preços de concentrado e forragem, consumo de concentrado e forragem. Com base nos resultados da simulação, a dieta de 100% de milheto mostrou a melhor viabilidade econômica.

ABSTRACT: The goal of the present study was to assess the economic viability relating to the risk of replacing corn with pearl millet in diets with 80% concentration for feedlot cattle confined for 89 days. Replacement levels were: 0, 33, 66, and 100%. The risk was estimated using Monte Carlo simulation, Spearman’s rank correlation test between input variables, stochastic dominance, and analysis of sensitivity. The expected average values ± standard deviation for net present value (R$/animal) were ± 71.74 ± 283.32, 91.23 ± 285.18, 196.05 ± 273.79, and 223.80 ± 267.96 for diets containing 0, 33, 66, and 100% of pearl millet, respectively. The probability of ≥0 net present value was 63.4, 66.1, 78.4, and 82.4%, respectively. The net present values were statistically different (P<0.05), and the higher levels dominated the lower values. The items that most influenced the net present values were, in descending order, prices of unfinished and finished cattle, initial and final weights, prices of concentrate and forage, concentrate and forage consumption. Based on the results of the simulation, diet of 100% pearl millet exhibited the best economic viability.

Resumo O rúmen é o órgão mais estudado no que se refere à interação simbiótica entre hospedeiro e a microbiota do trato digestivo dos ruminantes. Assim, objetivou-se avaliar os efeitos da inclusão de virginiamicina e de salinomicina ao suplemento para bovinos de corte com dieta de gramínea tropical no período das águas. Foram constituídos três tratamentos: controle - suplemento mineral COMIGO - Cria 61 - F2 (SM); virginiamicina - SM + virginiamicina (Phigrow(r)) 100 mg/animal/dia; salinomicina - SM + salinomicina (Posistac(r)) 108 mg/animal/dia, para o experimento 1 (desempenho) e experimento 2 (metabolismo ruminal). O controle apresentou maior CSM (P<0,05), o virginiamicina maior GMD (P>0,05) e melhor eficiência financeira. As medidas biométricas não apresentaram diferenças (P>0,05), sugerindo que haja uma mudança na composição do GMD. Não houve diferença (P>0,05) para DISMS, DISFDA, pH ruminal e N- amoniacal. A virginiamicina apresentou as maiores degradabilidade efetiva da FDN (P>0,05) nas taxas de passagem de 2 e 5%, e semelhante ao controle e maior que salinomicina na taxa de 8%/hora. A virginiamicina ou a salinomicina, podem ser veiculados ao SM, contudo não promovem efeitos significativos no pH ruminal, no N-amoniacal, na DISMS e da DISFDA, mas a virginiamicina promoveu maior degradabilidade efetiva da FDN.

Abstract The rumen is the most studied organ with regard to the symbiotic interaction between host and microbiota in the digestive tract of ruminants. Thus, this study aimed at evaluating the effects of including virginiamycin and salinomycin to the supplement for cattle fed tropical grass diet during the rainy season. Three treatments were set: control - mineral supplement COMIGO - Cria 61-F2 (MS); virginiamycin - MS + virginiamycin (Phigrow (r)) 100 mg/animal/day; salinomycin - MS + salinomycin (Posistac(r)) 108 mg/animal/day for the experiment 1 (performance) and experiment 2 (ruminal metabolism). The control showed higher Mineral supplement intake (MSI) (P <0.05), the virginiamycin had higher average daily gain (ADG) (P> 0.05) and better financial efficiency. Biometric measurements showed no differences (P> 0.05), suggesting a change in the ADG composition. There was no difference (P> 0.05) for dry matter digestibility (DMDIS), acid detergent fiber digestibility (ADFDIS), ruminal pH and ammoniacal-N. The virginiamycin had the highest effective neutral detergent fiber (NDF) degradability (P> 0.05) in the passage rates of 2 and 5%; the degradability rates were similar to control treatement and higher than that of salinomycin at the rate of 8%/hour. The virginiamycin or salinomycin can be conveyed to the MS, but do not promote significant effects on ruminal pH, ammoniacal-N, DMDIS and ADFDIS; but virginiamycin promoted greater effective degradability of NDF.

ABSTRACT. Carcass and meat characteristics of 48 Nellore heifers at 24 to 30 months of age, with an initial weight of 263.4 ± 13.9 kg, were evaluated. The experiment was set up as a completely randomized design with four treatments, which consisted of four slaughter-weight classes, namely <340, 340-370, 370-400, or >400 kg. Back fat thickness was not influenced (p > 0.05) by slaughter weight in any of the forms it was expressed (mm or %), averaging 5.3 mm. Loin eye area in cm2 increased (p < 0.05) with the increase in slaughter weight. Animals slaughtered at a live weight (LW) of more than 400 kg showed better (p < 0.05) carcass conformation than the other experimental groups (9.8 points). Heifers slaughtered at over 400 kg LW had a more compact (p < 0.05) carcass (1.65 cm kg-1 cold carcass). The marbling degree of meat was lower (p < 0.05) in the animals slaughtered at less than 340 kg LW. In conclusion, cull heifers must not be slaughtered at a LW of less than 340 kg and slaughter weights greater than 400 kg have positive implications on important carcass characteristics, notably conformation and marbling.

ABSTRACT The objective of this study was to assess the effects of including crude glycerin in the diet on intake, performance, rumen development, and carcass traits of dairy crossbred veal calves fed starter concentrate containing 0, 80, 160, and 240 g kg−1 crude glycerin. Twenty-eight calves with an average weight of 38.03±6.7 kg and five days of age were distributed in a completely randomized design with four treatments with seven replications. Calves were individually housed in covered stalls equipped with feeders and drinkers for 56 days. The calf response to inclusion of crude glycerin in the concentrate changed over the weeks and the inclusion level of 240 g kg−1 resulted in greater dry matter intake and average daily gain. There was no effect on the final weight and total weight gain of the animals, with mean values of 73.60 and 35.16 kg, respectively. The weight of the rumen-reticulum adjusted for body weight, empty body weight, and total stomach weight increased linearly with the inclusion of crude glycerin. Blood total protein, globulin, urea, cholesterol, gamma glutamyl transferase, aspartate aminotransferase, and alkaline phosphatase concentrations did not differ among treatments. Carcass traits and meat color were not affected. Crude glycerin can be added to dairy calf starter concentrate up to 240 g kg−1 dry matter because it benefits concentrate intake, performance, and rumen development without affecting animal health.

RESUMO. Conduziu-se o experimento no Centro Tecnológico Comigo, localizado no município de Rio Verde, Estado de Goiás, Brasil, com o objetivo de avaliar os efeitos da suplementação com butirato de cálcio, como agente promotor de crescimento da mucosa duodenal e com Bacillus subtilis como probiótico melhorador de desempenho em bovinos confinados. Adicionou-se butirato de cálcio (5 e 10 g animal-1 dia-1) e Bacillus (10 g animal-1 dia-1) em uma ração base. Utilizaram-se 85 bovinos machos inteiros, da raça Nelore, com peso vivo médio inicial de 315 ± 7 kg. O experimento transcorreu num período de 118 dias, incluindo o período de adaptação, até o abate aos 30 meses de idade. As dietas foram distribuídas em delineamento inteiramente casualizado sendo quatro tratamentos: T1 = Controle (ração basal); T2 = ração basal + 5 g de butirato de cálcio; T3 = ração basal + 10 g de butirato de cálcio e T4 = ração basal + 10 g de butirato de cálcio + 10 g de bacillus. Utilizou-se uma relação volumoso: concentrado de 30:70, o volumoso utilizado foi silagem de milho. Foram realizadas mensurações de altura e largura de vilosidade intestinal, avaliação de carcaça e qualidade de carne. A suplementação de butirato de cálcio e bacillus subtilis influenciou positivamente (p < 0,05) o grau marmoreio da carcaça e o butirato de cálcio aumentou a altura de vilosidade do intestino delgado.

ABSTRACT. The experiment was carried out at the Comigo Technology Center, in Rio Verde, State of Goiás, Brazil, with the objective of evaluating the effects of supplementation with calcium butyrate, as a growth promoting agent for the duodenal mucosa and Bacillus subtilis as a probiotic performance enhancer in feedlot cattle. Calcium butyrate (5 and 10 g per animal per day) and Bacillus (10 g per animal per day) were added to a basal diet. There were used 85 Nelore bulls, with average weight of 315 ± 7 kg. The experiment lasted 118 days, including the adaptation period, until slaughter at 30 months of age. Diets were distributed in a completely randomized design with four treatments, where: T1 = control (basal diet); T2 = basal diet + 5 g calcium butyrate; T3 = basal diet + 10 g calcium butyrate and T4 = basal diet + 10 g calcium butyrate + 10 g probiotic with four replications and five to six animals per replication. It was used a forage: concentrate ratio of 30:70, the roughage used was the corn silage. Height and width measurements of intestinal villi were taken, and carcass and meat quality were evaluated. The supplementation of calcium butyrate and Bacillus subtilis positively influenced (p < 0.05) the carcass marbling level and calcium butyrate increased the villus height in the small intestine.

Avaliaram-se as características químico-físicas da carne de tourinhos mestiços com predominância genotípica europeia ou zebuína alimentados em confinamento com dietas com alta proporção de concentrado e níveis de grão de milheto em substituição ao de milho (0, 33, 66 e 100%). Foram abatidos 24 tourinhos de cada predominância genética após 96 dias de confinamento. O delineamento experimental foi inteiramente casualizado, com os tratamentos em arranjo fatorial 4x2, utilizando-se seis repetições. As variáveis pH inicial (6,7) e final (5,9), a temperatura final (9,72), a perda de líquidos ao descongelamento (9,7%) e cocção (26,6%), a cor (3,7 pontos), a textura (3,1 pontos), o marmoreio (4,5 pontos), a força ao cisalhamento das fibras musculares (kgf/cm³) e os teores de umidade (72,9%), proteína bruta (23,0%) e extrato etéreo (1,5%) da carne não foram alterados pela substituição do grão de milho pelo de milheto. As características da carne não foram influenciadas pelas predominâncias genéticas, exceto o marmoreio, superior (4,99 vs 3,95 pontos) nos animais europeus. O pH final da carcaça foi correlacionado com a perda de líquidos ao descongelamento (r = -0,36) e a cor da carne (r = -0,62). A substituição do grão de milho pelo de milheto na dieta de tourinhos não altera a qualidade da carne.

We evaluated the physicochemical characteristics of crossbred bulls with European or zebu genetic predominance fed in feedlot with diets with high concentrate (80%) and grain millet levels to replace corn grain (0, 33, 66 and 100%). Twenty-four bulls of each genetic predominance were slaughtered after 96 days of confinement. The experimental design was completely randomized with treatments in a 4x2 factorial arrangement using six replicates. The variables initial (6.68) and final pH (5.9), final temperature of carcass (9,7), fluid loss during thawing (9.7%) and cooking (26.6%), color (3.7 points), texture (3.1 points), marbling (4.5 points), shear strength of the muscle fibers (kgf/cm³), and moisture (72.9%), crude protein (23.0%) and ether extract content (1.5%) of the meat were not affected by the replacement of corn grain by millet grain. Meat characteristics were not influenced by genetic predominance, except marbling, which was higher in European animals (4.99 vs. 3.95 points). Final pH was correlated with thawing loss (r = -0.36) and meat color (r = -0, 62). The replacement of corn grain by grain of millet in the diet did not affect meat quality of young bulls.

O objetivo deste trabalho foi avaliar o perfil de ácidos graxos da carne de novilhos mestiços alimentados, em confinamento, com dietas contendo níveis crescentes de grão de milheto moído em substituição ao grão de milho moído. Foram utilizados 24 tourinhos mestiços europeus e 24 mestiços zebuínos, abatidos aos 24 meses de idade, após 96 dias de confinamento. Utilizou-se o delineamento experimental inteiramente casualizado, com os tratamentos em arranjo fatorial 4x2 (quatro dietas com 0, 33, 66 e 100% de milheto no concetrado e dois grupos genéticos) com seis repetições. O aumento dos níveis de grão de milheto na dieta elevou linearmente a participação dos ácidos graxos, araquídico (C20:0), heneicosanoico (C21:0), α-linolênico (C18:3 n-3) e dihomo-γ-linolênico (C20:3 n-6). Tourinhos europeus apresentaram carne com menor teor dos ácidos graxos, mirístico (C14:0), heneicosanoico (C21:0) e γ-linolênico (C18:3 n-6) do que tourinhos zebuínos. A concentração total de ácidos graxos saturados (45,2%), monoinsaturados (41,2%) e poli-insaturados (8,7%), e a relação monoinsaturados/saturados (1,09) e poli-insaturados/saturados (0,18) não foi alterada pelos grupos genéticos e pelas dietas. O aumento da percentagem de grão de milheto na dieta de tourinhos europeus ou zebuínos melhora a relação entre os ácidos graxos ω-6/ω-3.

The objective of this work was to evaluate the fatty acid profile of crossbreed steers, in confinement, fed with diets containing increasing levels of ground millet grain in replacement to ground corn grain. Twenty-four European crossbred bulls and 24 Zebu crossbred bulls, slaughtered at 24 months of age, after 96 days in confinement, were used. The experimental design was completely randomized with treatments in a 4x2 factorial arrangement (four diets with 0, 33, 66, and 100% of pearl millet in the concentrate and two genetic groups) with six replicates. The increase in the levels of pearl millet grain in the diet increased linearly the participation of the arachidic (C20:0), heneicosanoic (C21:0), α-linolenic (C18:3 n-3), and dihomo-γ-linolenic (C20:3 n-6) fatty acids. European bulls showed meat with lower content of myristic (C14:0), heneicosanoic (C21:0), and γ-linolenic (C18:3 n-6) fatty acids than the Zebu bulls. The total concentration of saturated (45.2%), monounsaturated (41.2%), and polyunsaturated (8.7%) fatty acids, and the monounsaturated/saturated (1.09) and polyunsaturated/saturated (0.18) ratio were not affected by the genetic groups and diets. The increase in the percentage of millet grain in the diet of European and Zebu bulls improves the ratio between ω-6/ω-3 fatty acids.