Supplementation of BWH cows and ½ BWH ½ Jersey cows kept in tropical pasture with the isopropyl ester of methionine analog (HMBi) / Suplementação de vacas HPB e vacas 1/2 HPB 1/2 Jersey mantidas em pastagem tropical com o éster isopropílico do análogo de metionina (HMBi)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

In this trial, was tested the inclusion of isopropyl ester of methionine analogue (HMBi) in the concentrate of BWH cows and ½ BWH ½ Jersey cows kept in pastures of Elephant grass, with the goal of achieving lysine: methionine ratio of 3:1 in metabolizable protein. Variables analyzed were milk production and composition. The forage mass and the nutritional composition and morphology of the pasture were also evaluated. 16 Holstein cows and 12 ½ WBH ½ Jersey cows, with approximately 150 days in milk at the beginning of the trial period were used. The Elephant grass pasture was managed by rotational system with two days of occupation and variable rest period, determined by the sward height of 1m at the entry of animals in each paddock. The pasture was fertilized with 80 kg N per grazing cycle. The experimental cows were grazed in the first occupation day and extra animals of the herd grazed on the second occupation day of each paddock, ensuring the post grazing residue to be around 40 cm. The pasture contained on average 22% of CP, 66% of NDF and 71.5% of IVDDM. The concentrate was provided individually, the average dose of 6.6 kilograms of MN per cow per day, based on 1 kg of concentrate for every 3 kg of milk, established at the beginning of the trial period. The concentrate was similar among treatments, except for the inclusion or not of methionine ester analog (HMBi). The experimental design was a crossover (2x2), two treatments and two periods. Except the somatic cell count, the data were analyzed by the PROC MIXED (SAS ® version 9.1.3, 2003). For SCC data was used a Poisson distribution, and examined under approach of generalized linear models. There were no statistically significant differences in milk production (16.20 x 16.49), 3,50% fat corrected milk production (16.34 x 16.61), milk fat concentration (3.57 x 3.57%) and milk protein concentration (3.12 x 3.13%) respectively for cows from the control group and those receiving HMBi. Cows ½ BWH ½ Jersey, despite the lower body weight and lower concentrate intake, produced milk with higher protein content than cows BWH, and produced the same amount of milk fat and protein.

ASSUNTO(S)

methionine crossbreeding cruzamento animal vacas. aminoácidos suplementos concentrados para animais hmbi amino acid gado jersey leite - produção milk production. gado holandês

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