Does vitamin blends supplementation affect the animal performance, carcass traits, and nutrient digestibility of young Nellore finishing bulls?

OBJECTIVE: This study was realized to evaluate the effects of supplementation with blends of water and fat-soluble vitamins on animal performance and carcass traits of young Nellore bulls. METHODS: Forty-three Nellore bulls, with an initial weight of 261±27.3 kg and a mean age of 8±1.0 months, were used. Five animals were slaughtered at the beginning of the experiment (reference group), to determine the initial empty body weight of the bulls that remained in the experiment. The remaining 38 bulls were fed ad libitum and distributed in a completely randomized design in a 2×2 factorial scheme, with or without supplementation of water-soluble (B-blend+ or B-blend-) and fat-soluble (ADE+ or ADE-) vitamin blends. Diets were isonitrogenous (120 g of crude protein/kg dry matter [DM] of total mixed ration) and consisted of a roughage:concentrate rate of 30:70 based on total DM of diet. The experiment lasted 170 days, with 30 days of adaptation and 140 days for data collection. At the beginning and end of the experimental period, the bulls were weighed to determine the average daily gain. To estimate the apparent digestibility of nutrients and microbial efficiency, spot collections of feces and urine were performed for five consecutive days. RESULTS: DM, ashes, organic matter, crude protein, ethereal extract, neutral detergent fiber corrected for residual ash and residual nitrogenous, and N intake and apparent digestibility were not influenced by vitamin supplementation, but total digestible nutrients intake and non-fibrous carbohydrates digestibility were influenced by B complex vitamin supplementation. Nitrogen balance, microbial efficiency, and performance data were not influenced (p>0.05) by vitamin supplementation. CONCLUSION: Vitamin supplementation (a blend of water-soluble and fat-soluble vitamins or their combinations) does not influence the animal performance and carcass traits of young Nellore bulls.

Development and validation of regression models from NIR spectra to predict the composition of sugarcane, soybean meal, and cornmeal / Construção e validação de modelos de regressão a partir de espectros NIR para predição da composição da cana-de-açúcar, farelo de soja e fubá de milho

This study aimed to develop and assess regression models for predicting the chemical composition of sugarcane, soybean meal, and cornmeal using portable near-infrared (NIR) spectroscopy combined with chemometric techniques. A total of 95 sugarcane samples, 92 soybean meal samples, and 120 cornmeal samples were used. The samples were ground, and NIR spectra were obtained for each sample. Reference values were determined through conventional chemical analysis. Partial least squares regression and leave-one-out cross-validation were employed to construct the models. Models with the lowest root mean squared error in cross-validation were further validated externally. The goodness-of-fit of the models was evaluated by comparing the predicted values with those obtained through conventional laboratory methods. The constructed models properly estimated all constituents evaluated for sugarcane, soybean meal, and cornmeal (P ≥ 0.056). The models developed for predicting the contents of samples oven-dried at 55 °C (ADS) and 105 °C (ODS), total dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), NDF corrected for ash and protein (NDFap), neutral detergent insoluble protein (NDIP), acid detergent fiber (ADF), crude protein (CP), non-fiber carbohydrates (NFC), and total digestible nutrients (TDN) in sugarcane; ODS, OM, NDF, ADF, indigestible NDF (iNDF), CP, TDN, and starch in soybean meal; and ODS and CP in cornmeal exhibited high accuracy and precision (R2 ≥ 0.50 and CCC ≥ 0.60). However, the models developed for predicting the levels of neutral detergent insoluble ash (NDIA) in sugarcane; ether extract (EE) and NDIA in soybean meal; and NDF, iNDF, NDIA, NFC, and EE in cornmeal demonstrated accuracy but lacked precision (R2 ≥ -0.04 and CCC ≥ 0.03). In conclusion, the portable NIR regression models provided accurate estimates and are therefore recommended for predicting the chemical composition of sugarcane, soybean meal, and cornmeal.(AU)

Objetivou-se desenvolver e avaliar modelos de regressão para a predição da composição química da cana-de-açúcar, farelo de soja e fubá de milho por NIR portátil aliado a técnicas quimiométricas. Foram utilizadas 95 amostras de cana-de-açúcar, 92 amostras de farelo de soja e 120 amostras de fubá de milho. Após a moagem das amostras, foi realizada aquisição dos espectros de cada amostra. Os valores referência foram obtidos através de análises químicas convencionais. Para construção dos modelos, foi utilizada a regressão por quadrados mínimos parciais e a validação cruzada leave one out. Os modelos com menor raiz quadrada do erro quadrático médio da validação cruzada foram submetidos a validação externa. Para avaliar a qualidade de ajuste dos modelos, os valores preditos foram comparados com os valores obtidos pelos métodos laboratoriais convencionais. Os modelos construídos estimaram corretamente todos os constituintes avaliados para a cana-de-açúcar, farelo de soja e fubá de milho (P ≥ 0,056). Os modelos construídos para predição dos teores de amostra seca em estufa a 55°C (ASA) e a 105°C (ASE), matéria seca total (MS), matéria orgânica (MO), fibra insolúvel em detergente neutro (FDN), FDN corrigida para cinzas e proteína (FDNcp), proteína insolúvel em detergente neutro (PIDN), fibra insolúvel em detergente ácido (FDA), proteína bruta (PB), carboidratos não fibrosos (CNF) e nutrientes digestíveis totais (NDT) da cana-de-açúcar; ASE, MO, FDN, FDA, FDN indigestível (FDNi), PB, NDT e amido de farelo de soja; e ASE, PB do fubá de milho apresentaram elevada acurácia e precisão (R2 ≥ 0,50 e CCC ≥ 0,60). Contudo os modelos construídos para predição dos teores de cinzas insolúveis em detergente neutro (CIDN) da cana-de-açúcar; extrato etéreo (EE) e CIDN do farelo de soja; e FDN, FDNi, CIDN, CNF e EE do fubá de milho foram acurados, porém pouco precisos (R2 ≥ -0,04 e CCC ≥ 0,03). Conclui-se que os modelos de regressão por NIR portátil estimaram acuradamente e, portanto, são recomendados para estimar a composição química da cana-de-açúcar, farelo de soja e fubá de milho.(AU)

Feed intake, nutrient digestibility, and selected rumen parameters in feedlot bulls fed diets with different feed additives.

An experiment was conducted to evaluate the feed intake, nutrient digestibility and selected rumen parameters in feedlot bulls fed diets containing different feed additives. Six rumen-cannulated Nellore bulls (age = 8 ± 1.0 months; initial BW = 225 ± 13.2 kg) were distributed in a 6 × 6 Latin square design. Six experimental diets based on 30% corn silage and 70% concentrate on a dry matter (DM) basis were evaluated. Diets differed in feed additive on a DM basis, as follows: 1.4% bicarbonate and magnesium oxide in 3:1 ratio (BOX); 36 ppm lasalocid sodium (LAS); 30 ppm monensin sodium (MON); 25 ppm virginiamycin (VIR); 30 ppm monensin sodium plus 25 ppm virginiamycin (MV); and 3.15% commercial mineral supplement containing D-limonene and exogenous α-amylase (EOA). The experiment lasted 144 d, with six periods of 24 d. Each period consisted of 14 d for dietary adaptation, 3 d for feces and urine collection, and 7 d for omasal and ruminal digesta collection. Bulls fed the BOX diet showed greater (P < 0.05) intake of DM, organic matter (OM), neutral detergent fiber (apNDF), crude protein (CP), and starch compared to the other diets. Diets with LAS, MON, VIR, MV, or EOA did not influence (P > 0.05) the DM, OM, apNDF, CP, or starch intake of feedlot bulls. Bulls fed the EOA diet showed greater (trend; P = 0.09) ruminal digestibility of starch compared to the other diets. The feed additives did not affect (P > 0.05) the intestinal or total tract digestibility of starch, rumen pH, microbial efficiency, total rumen fluid, dilution rate, rate of intake, rate of degradation, or passage rate of the DM, OM, apNDF, and starch. In conclusion, LAS, MON, VIR, MV, and EOA diets reduced nutrient intake compared to BOX. Although all feed additives presented similar effects on rumen pH, temperature, and kinetics the presence of exogenous α-amylase in the EOA diet may increase ruminal starch digestibility and apparent total tract digestibility of DM and OM.

Effect of restricted-feeding strategies on blood concentrations of hormones, metabolites, and minerals in Holstein × Zebu finishing steers / Efeitos de diferentes estratégias de restrição alimentar sobre as concentrações de hormônios, metabólitos e minerais de machos Holandês × Zebu não castrados em terminação

The objectives were to determine the effects of restricted-feeding strategies on blood concentrations of hormones, metabolites, and minerals in Holstein × Zebu finishing steers. Twenty steers (body weight = 319 ± 16.2 kg; age = 19 ± 1 months) were randomly allotted in 4 groups of 5 steers, which were restricted to 85% ad libitum feed intake for either 0 (R0; n = 5), 28 (R28; n = 5), 42 (R42; n = 5) or 84 (R84; n = 5) days of an 84-d finishing period. Steers were individually housed and considered the experimental unit. Blood samples were collected on d 0, 21, 42, 63, and 84, and were assayed for insulin-like growth factor 1 (IGF-1), thyroid hormones (T3 and T4), albumin, creatinine, urea, total protein, glucose, triglycerides, calcium, and phosphorus. Steers had increasing IGF-1 concentrations until d 42 when restricted-fed. Steers fed R84 had the greatest IGF-1 concentrations on d 84. Urea concentrations were greatest in steers fed R0 and least in steers fed R28; steers fed R42 and R84 were intermediate and not different from one another. Concentrations of IGF-1, urea, albumin, and calcium, but not T3, T4, glucose, triglycerides, creatinine, total protein, and phosphorus were affected by restricted-feeding strategies in Holstein × Zebu finishing steers.(AU)

Objetivou-se avaliar os efeitos de diferentes estratégias de alimentação restrita sobre as concentrações sanguíneas de hormônios, metabólitos e minerais de machos Holandês × Zebu castrados em terminação. Vinte machos Holandês × Zebu castrados (peso corporal inicial [PC] = 319 ± 16,2 kg; idade = 19 ± 1 meses) foram aleatoriamente distribuídos em 4 grupos de 5 animais, os quais receberam alimentação restrita a 85% do consumo ad libitum por 0 (R0; n=5), 28 (R28; n=5), 42 (R42; n=5) ou 84 (R84; n=5) dias. Os animais foram alojados individualmente e considerados como unidades experimentais. Amostras de sangue foram coletadas nos dias 0, 21, 42 e 84, e analisadas quanto às concentrações de fator de crescimento semelhante à insulina 1 (IGF-1), hormônios tireiodianos (T3 e T4), albumina, creatinina, ureia, proteína total, glicose, triglicerídeos, cálcio e fósforo. Animais que receberam alimentação restrita apresentaram aumento nas concentrações de IGF-1 até o dia 42 (P < 0,05). Animais R84 apresentaram as maiores (P < 0,05) concentrações de IGF-1 no dia 84. As concentrações de ureia foram maiores (P < 0,05) para os animais AL84 e menores (P < 0,05) para os animais R28; os animais R42 e R84 apresentaram valores intermediários e não diferentes (P > 0,05) entre si. As concentrações de IGF-1, ureia, albumina, e calcium, mas não as de T3, T4, glicose, triglicerídeos, creatinina, proteína total e fósforo, foram influencias pelas diferentes estratégias de alimentação restrita utilizadas em machos Holandês × Zebu castrados em terminação.(AU)

Effect of restricted-feeding strategies on blood concentrations of hormones, metabolites, and minerals in Holstein × Zebu finishing steers / Efeitos de diferentes estratégias de restrição alimentar sobre as concentrações de hormônios, metabólitos e minerais de machos Holandês × Zebu não castrados em terminação

The objectives were to determine the effects of restricted-feeding strategies on blood concentrations of hormones, metabolites, and minerals in Holstein × Zebu finishing steers. Twenty steers (body weight = 319 ± 16.2 kg; age = 19 ± 1 months) were randomly allotted in 4 groups of 5 steers, which were restricted to 85% ad libitum feed intake for either 0 (R0; n = 5), 28 (R28; n = 5), 42 (R42; n = 5) or 84 (R84; n = 5) days of an 84-d finishing period. Steers were individually housed and considered the experimental unit. Blood samples were collected on d 0, 21, 42, 63, and 84, and were assayed for insulin-like growth factor 1 (IGF-1), thyroid hormones (T3 and T4), albumin, creatinine, urea, total protein, glucose, triglycerides, calcium, and phosphorus. Steers had increasing IGF-1 concentrations until d 42 when restricted-fed. Steers fed R84 had the greatest IGF-1 concentrations on d 84. Urea concentrations were greatest in steers fed R0 and least in steers fed R28; steers fed R42 and R84 were intermediate and not different from one another. Concentrations of IGF-1, urea, albumin, and calcium, but not T3, T4, glucose, triglycerides, creatinine, total protein, and phosphorus were affected by restricted-feeding strategies in Holstein × Zebu finishing steers.

Objetivou-se avaliar os efeitos de diferentes estratégias de alimentação restrita sobre as concentrações sanguíneas de hormônios, metabólitos e minerais de machos Holandês × Zebu castrados em terminação. Vinte machos Holandês × Zebu castrados (peso corporal inicial [PC] = 319 ± 16,2 kg; idade = 19 ± 1 meses) foram aleatoriamente distribuídos em 4 grupos de 5 animais, os quais receberam alimentação restrita a 85% do consumo ad libitum por 0 (R0; n=5), 28 (R28; n=5), 42 (R42; n=5) ou 84 (R84; n=5) dias. Os animais foram alojados individualmente e considerados como unidades experimentais. Amostras de sangue foram coletadas nos dias 0, 21, 42 e 84, e analisadas quanto às concentrações de fator de crescimento semelhante à insulina 1 (IGF-1), hormônios tireiodianos (T3 e T4), albumina, creatinina, ureia, proteína total, glicose, triglicerídeos, cálcio e fósforo. Animais que receberam alimentação restrita apresentaram aumento nas concentrações de IGF-1 até o dia 42 (P 0,05) entre si. As concentrações de IGF-1, ureia, albumina, e calcium, mas não as de T3, T4, glicose, triglicerídeos, creatinina, proteína total e fósforo, foram influencias pelas diferentes estratégias de alimentação restrita utilizadas em machos Holandês × Zebu castrados em terminação.