Influence of concentrate levels in diet and body biotypes on productive variables of Guzera beef cattle

Abstract

The goal of this study was evaluate diets (50 or 80% of concentrate) and body biotypes (late or early) on performance, behavior, carcass condition, meat quality, and feed cost estimates in feedlot finishing Guzera beef cattle. Use of concentrates in the diet may improve performance and carcass fat scores in ruminant animals, but Guzera beef cattle may be more efficient in forage conversion, which directly influences the economic viability of the production system. We evaluated 32 non-castrated male Guzera beef cattle at 32±2 months of age. The experimental design was completely randomized with four treatments and six replicates in a 2 × 2 factorial design (2 diets × 2 body biotypes). Initial and final body weights were 459.4±31.2 kg and 566.7±40.8 kg, respectively. There was no change (P > 0.05) in dry matter intake, feed conversion, or daily weight gain when the concentrate in the diet was increased to 80%. Animals fed a diet with 80% of concentrate spent less time (P < 0.05) ruminating (17.8±6.3 vs. 6.3±2.7% of the assessed time). Body biotype did not alter the variables. The rise from 50 to 80% in the proportion of dietary concentrate increased carcass fat, with positive returns in the production process, even given the reduction in rumination, which can lead to poor welfare of animals consuming 80% of dietary concentrate. Body biotype did not affect the variables studied, but it is worth emphasizing that the age at slaughter of these animals probably influenced this result. Thus, selection of the best diet should be based on feeding cost, and in accordance with the cost estimated in this study, the diet with 80% of concentrate is the most suitable for feedlot finished Guzera beef cattle. ou tardio) sobre o desempenho, comportamento, carcaça, qualidade de carne e estimativas de custos com alimento na terminação de bovinos de corte da raça Guzerá confinados. Aumentar os níveis de concentrado na dieta pode melhorar o desempenho e a gordura na carcaça em animais ruminantes, porém animais de corte da raça Guzerá podem ser mais eficientes na conversão de forragem, o que influenciaria diretamente a viabilidade econômica do sistema de produção. Foram utilizados 32 bovinos de corte da raça Guzerá, machos não castrados com 32±2 meses de idade. O delineamento experimental foi inteiramente casualizado com 4 tratamentos e 6 repetições, em esquema fatorial 2x2 (2 dietas x 2 biótipos corporais). O peso corporal inicial e final foi de 459,4±31,2 kg e 566,7±40,8 kg, respectivamente. Não houve alteração (P > 0,05) no consumo de matéria seca, conversão alimentar e ganho de peso diário pelo aumento de 80% de concentrado na dieta. Animais alimentados com 80% de concentrado na dieta passou um tempo menor (P < 0,05) em ruminação (17,8±6,3 vs 6,3±2,7% do tempo avaliado). O biótipo corporal não modificou (P > 0,05) as variáveis estudadas. O aumento de 50 para 80% na proporção de concentrado na dieta aumenta a gordura na carcaça, com retorno positivo no processo de produção, mesmo com uma redução de ruminação, o que pode leva...

Fatty acid composition of beef cattle finished on tropical pasture and supplemented with crude glycerin

“…The amount of protein in the bovine muscle was quite stable amongst the same genetic group at the same physiological stage; the same cannot be said about lipids. In this case, the diet energy level has a marked influence on the degree of fattening (HOMEM JUNIOR et al, 2016;MANNI et al, 2018). There was a small variation in the energy content of the supplements (3.92 to 4.09 Mcal of ME / kg of DM) and, therefore, there was not enough to affect the lipid concentration in the bovine meat.…”