Suplementação com análogo de metionina HMB (2-Hidroxi-4-(Metil) ácido Butânico) em dieta de bovinos da raça Nelore terminados em confinamento

Carregando...
Imagem de Miniatura

Data

2011-07-07

Título da Revista

ISSN da Revista

Título de Volume

Editor

Universidade Federal de Goiás

Resumo

Two experiments were conducted to evaluate the inclusion of levels of HMB (DL, 2-hydroxy-4-(methyl) botanical acid) methionine in diets of Nellore beef cattle finished in feedlot. In Experiment 1, 128 male, unneutered Nellore animals, with initial weight of 290 kg (± 20,50), were housed for 111 days (21 days of adaptation and 90 days of experiment) in 16 pens of 77 m2 with eight animals per pen. Isonitrogenous isocaloric diets, presenting 16% crude protein (CP) and 70% total digestible nutrients (TDN), constituted of fresh sugar cane bagasse (13.44%),soybean hulls (41.67% ), corn (18,15%), cottonseed (17,47%), soybean (5,38%), molasses (1,34%), urea (0,67%) and mineral mixture (1,88%), with four levels of HMB methionine analog inclusion were used. The treatments were T0 = control diet (no HMB), T5 = diet with 05 g HMB/animal.day-1; T10 = diet with 10 g HMB/animal.day-1; T15 = diet with 15 g HMB/animal.day-1. The experimental design was a randomized complete block, being the animals divided into blocks according to the initial weight. Final weight, total weight gain, average daily weight gain, dry matter intake and dry matter intake as % of body weight were not altered by inclusion of HMB in the diet (p>0,5). However, feed conversion (FC) (p<0,05)and feed efficiency (FE) (p<0,06) were affected by the inclusion of HMB in the diet, demonstrating that the inclusion of 10 g / animal.day-1 of HMB is the most recommended level to improve both FC and FE in cattle under these conditions. No difference was observed (p>0,05) among treatments for carcass characteristics, suggesting that under similar conditions to this experiment the inclusion of HMB in the diet does not affect the carcass quantitative characteristics. Experiment 2: was performed after adaptation to the experimentaldiet for ten days in a male Holstein animal, with approximately 200 kg of live weight with rumen cannula. Two samples of rumen fluid were collected with one week interval between each one. The samples were incubated for 0, 2, 4, 8, 12,24, 48 hours at 39°C in anaerobic conditions. A completely randomized design with four treatments and four replications was used. Diets and treatments were the same employed in Experiment 1. Fraction a (rapid degradation) of experimental diets was not altered by HMB inclusion (p>0,05). In contrast, fraction b potentially degradable) (p<0,05), fraction c (hourly rate of degradation of potentially degradable fraction) (p<0,05),Dp (potential degradability) (p<0,01) and de (effective degradability) to a passage rate (kp) at 2% per hour (p <0,01), 5% per hour (p<0.05) and 8% per hour (p<0,01) were affected by the inclusion of HMB in the diet. It was found that the inclusion of 15g/animal.day-1 of HMB in the diet positively influenced the degradability of fraction b (76,70%) and the potential degradability (90,60%). However, the effective degradability at Kp 2 and 5% h were favored for all treatments that included HMB, while at Kp 8% h, the inclusions of 5 and 10 g/animal.day-1 HMB showed higher results than other treatments (p<0,01). These results suggest that HMB has the potential to improve the degradation of high concentrate diets similar to this experiment.

Descrição

Citação

MELO, Antônio Humberto Fleury de. Supplementation with HMB (2-hydroxy-4-(methyithio) Butanoic acid) methionine analog in diet of Nellore cattle finished in feedlot. 2011. 79 f. Dissertação (Mestrado em Ciências Agrárias - Veterinaria) - Universidade Federal de Goiás, Goiânia, 2011.