Impact of replacing protein pellets with soybean grain on nutrient utilization and the rumen and blood parameters of feedlot cattle under tropical conditions.

The aim of this study was to explore the effect of replacing protein pellets with soybean grain in high-concentrate diets with or without the addition of silage, on the intake, digestibility, and rumen and blood parameters of feedlot cattle in tropical regions. Four cannulated, crossbred steers were used, 4.5 ± 0.5 years old, with an average weight of 685.55 ± 111.78 kg. The steers were distributed in a 4 × 4 Latin square, in a 2 × 2 factorial scheme (two sources of protein: protein pellets or whole soybean grain, with or without added dietary bulk). There was no effect (P ≥ 0.109) from the interaction between the source of protein and the addition of silage to the diet on dry matter (DM) and nutrient intake, or the digestibility (P ≥ 0.625) of DM or crude protein (CP). However, both factors affected (P ≤ 0.052) the intake of DM, neutral detergent fiber (NDF), and non-fiber carbohydrates (NFC), as well as the independent digestibility (P ≤ 0.099) of fat, NFC, total carbohydrates (TC), and total cholesterol concentration. There was an effect (P ≤ 0.053) from the interaction between the source of protein and the addition of silage to the diet on the digestibility of NDF and total digestible nutrients (TDN), as well as on the glycose concentration (P = 0.003). Blood parameters (i.e. protein, albumin, creatinine, triglycerides, aspartate aminotransferase (AST), and alanine aminotransferase (ALT)) were not affected (P ≥ 0.139) by the source of protein, the addition of silage, or their interaction. Lastly, including 150 g/kg silage DM in a high-grain diet, and using soybean grain as a source of protein in substitution of protein pellet could be a suitable nutritional strategy to ensure adequate DM and nutrient intake and digestibility, with no detrimental effects on rumen and blood parameters of feedlot cattle in the tropics.

Effects of increasing nitrogen levels in Mombasa grass on pasture characteristics, chemical composition, and beef cattle performance in the humid tropics of the Amazon.

Improving beef cattle production in pasture-based systems without expanding agricultural land has been the focus of several studies over the last decades. Nitrogen fertilization is one of the available strategies with high potential to optimize cattle performance in tropical systems. This study aimed to evaluate the effects of increasing nitrogen levels (150, 300, and 450 kg ha-1 of N year-1) in Megathyrsus maximus cv. Mombasa in the humid tropics of the Amazon. The following parameters were evaluated: pasture agronomic characteristics, herbage chemical composition, and beef cattle performance. A total of 24 nine-month-old Nellore bulls with initial mean weight of 173 ± 1.95 kg were used for the performance test. The experimental design was a randomized block with three treatments. Herbage mass and leaf mass contents were increased by the highest nitrogen level (P < 0.05). Nitrogen levels elevated the forage accumulation rate, final leaf blade length, and pre-grazing canopy height(P < 0.05). The crude protein content increased at the highest N level (P < 0.05). The neutral detergent fiber and acid detergent fiber contents decreased with increasing N levels. The stocking rate and total weight gain per hectare were higher in bulls grazing pastures fertilized with 450 compared with 150 kg ha-1 of N year-1(P < 0.05). The average daily gain was influenced by N levels (P < 0.05). Nitrogen levels at 300 and 450 kg increased animal weight gain and productivity per area by increasing forage yield and improving the chemical composition of Mombasa grass.

Carcass and meat characteristics from dairy-origin steers fed with diets based on ground pearl millet grain, containing inclusion levels of babassu mesocarp meal / Características de carcaça e carne de novilhos de origem leiteira alimentados com dietas à base de grão de milheto, contendo níveis de inclusão de farelo do mesocarpo do babaçu

This study aimed to evaluate carcass and meat characteristics of feedlot-finished steers of dairy origin fed with pearl millet grain-based diets, containing inclusion levels of babassu mesocarp bran (BMB) (0, 12, 24, 36 and 48%). A total of 30 Holstein-Zebu crossbred steers with an average initial weight of 371.02 ± 27 kg were randomly divided into six groups fed with different experimental diets (five pearl millet-based diets containing inclusion levels of BMB and one standard corn-based diet). Each diet had five replications. Isonitrogenous diets had a roughage/concentrate ratio of 20/80. BMB inclusion level in the diet reduced slaughter and carcass weight from 488.4 and 242.2 kg to 454.0 and 226.7 kg, respectively. The subcutaneous fat thickness, conformation, and pistol cut weight were also reduced to 38.8, 13.6, and 9%, respectively, as the BMB inclusion level in the diet increased. Meat characteristics were not affected by BMB inclusion levels in the diet. Regarding carcass and meat characteristics, no difference was observed in the analysis of contrasts between BMB diets and corn- or millet-based diets, or between corn- or millet-based diets. The inclusion of BMB in millet-based diets should consider the cost/benefit ratio, as it reduces slaughter and carcass weight, while the main meat characteristics remain unchanged. However, total substitution of corn by millet grains in feedlot diets does not altercaracteristics of carcass and meat of dairy steers.(AU)

Objetivou-se avaliar as características da carcaça e carne de novilhos mestiços de origem leiteira terminados em confinamento com dietas a base de grãos de milheto, contendo níveis de inclusão de farelo do mesocarpo do babaçu (0, 12, 24, 36 e 48%). Foram utilizados 30 novilhos mestiços Holandês-Zebu com peso inicial médio de 371,02 ± 27 kg distribuídos aleatoriamente em seis dietas experimentais (cinco dietas a base de milho contendo níveis de inclusão de farelo do mesocarpo do babaçu e uma dieta padrão a base de milho), cada uma com cinco repetições. As dietas isonitrogenadas apresentam relação volumoso/concentrado de 20/80. O aumento do nível de inclusão do FMB na dieta reduziu o peso de abate e de carcaça de 488,4 e 242,2 kg para 454,0 e 226,7 kg, respectivamente. A espessura de gordura subcutânea, conformação e peso do traseiro especial reduziram, respectivamente, 38,8; 13,6 e 9% pelo aumento do nível de farelo do mesocarpo de babaçu na dieta. As características da carne não foram alteradas pelos níveis de inclusão de farelo do mesocarpo de babaçu na dieta. Não foi verificada diferença, pela análise de contrastes, entre as dietas com farelo do mesocarpo do babaçu e as dietas com milho ou milheto, ou entre as dietas a base de milho ou milheto para as características de carcaça e carne avaliadas. A inclusão de farelo do mesocarpo do babaçu em dietas a base de grão de milheto deveconsiderar a relação custo/benefício, pois promove queda do peso de abate e de carcaça apesar de nãoalterar as principais características da carne. A substituição total do grão de milho pelo grão de milhetoem dietas de confinamento, por outro lado, não altera as principais características de carcaça e carne debovinos de origem leiteira.(AU)

Carcass and meat characteristics from dairy-origin steers fed with diets based on ground pearl millet grain, containing inclusion levels of babassu mesocarp meal / Características de carcaça e carne de novilhos de origem leiteira alimentados com dietas à base de grão de milheto, contendo níveis de inclusão de farelo do mesocarpo do babaçu

This study aimed to evaluate carcass and meat characteristics of feedlot-finished steers of dairy origin fed with pearl millet grain-based diets, containing inclusion levels of babassu mesocarp bran (BMB) (0, 12, 24, 36 and 48%). A total of 30 Holstein-Zebu crossbred steers with an average initial weight of 371.02 ± 27 kg were randomly divided into six groups fed with different experimental diets (five pearl millet-based diets containing inclusion levels of BMB and one standard corn-based diet). Each diet had five replications. Isonitrogenous diets had a roughage/concentrate ratio of 20/80. BMB inclusion level in the diet reduced slaughter and carcass weight from 488.4 and 242.2 kg to 454.0 and 226.7 kg, respectively. The subcutaneous fat thickness, conformation, and pistol cut weight were also reduced to 38.8, 13.6, and 9%, respectively, as the BMB inclusion level in the diet increased. Meat characteristics were not affected by BMB inclusion levels in the diet. Regarding carcass and meat characteristics, no difference was observed in the analysis of contrasts between BMB diets and corn- or millet-based diets, or between corn- or millet-based diets. The inclusion of BMB in millet-based diets should consider the cost/benefit ratio, as it reduces slaughter and carcass weight, while the main meat characteristics remain unchanged. However, total substitution of corn by millet grains in feedlot diets does not altercaracteristics of carcass and meat of dairy steers.

Objetivou-se avaliar as características da carcaça e carne de novilhos mestiços de origem leiteira terminados em confinamento com dietas a base de grãos de milheto, contendo níveis de inclusão de farelo do mesocarpo do babaçu (0, 12, 24, 36 e 48%). Foram utilizados 30 novilhos mestiços Holandês-Zebu com peso inicial médio de 371,02 ± 27 kg distribuídos aleatoriamente em seis dietas experimentais (cinco dietas a base de milho contendo níveis de inclusão de farelo do mesocarpo do babaçu e uma dieta padrão a base de milho), cada uma com cinco repetições. As dietas isonitrogenadas apresentam relação volumoso/concentrado de 20/80. O aumento do nível de inclusão do FMB na dieta reduziu o peso de abate e de carcaça de 488,4 e 242,2 kg para 454,0 e 226,7 kg, respectivamente. A espessura de gordura subcutânea, conformação e peso do traseiro especial reduziram, respectivamente, 38,8; 13,6 e 9% pelo aumento do nível de farelo do mesocarpo de babaçu na dieta. As características da carne não foram alteradas pelos níveis de inclusão de farelo do mesocarpo de babaçu na dieta. Não foi verificada diferença, pela análise de contrastes, entre as dietas com farelo do mesocarpo do babaçu e as dietas com milho ou milheto, ou entre as dietas a base de milho ou milheto para as características de carcaça e carne avaliadas. A inclusão de farelo do mesocarpo do babaçu em dietas a base de grão de milheto deveconsiderar a relação custo/benefício, pois promove queda do peso de abate e de carcaça apesar de nãoalterar as principais características da carne. A substituição total do grão de milho pelo grão de milhetoem dietas de confinamento, por outro lado, não altera as principais características de carcaça e carne debovinos de origem leiteira.