Resumo

HERNANDEZ, A.; PONCE DE LEON, R.; GUERRA, D.  e  GARCIA, S.M.. Estimation of genetic parameters for milk yield in lactations of Mambí Cuban cows. Arch. zootec. [online]. 2011, vol.60, n.232, pp.851-858. ISSN 1885-4494.  https://dx.doi.org/10.4321/S0004-05922011000400002.

The records of 25 036 lactations of milk yield up to 305 days (13 495 in first lactation (L1), 6067 in the second (L2), 3445 in the third (L3) and 2029 in the fourth (L4), respectively) from 13 495 Cuban Mambí (¾ Holstein ¼ Cebú) cows were used. The cows calved between 1981 and 2006 in 173 herds of four genetic farms. The goal of this study was to estimate the heritability and genetic correlations the first four lactations (L1-L4) and determine if the first lactation could be considered as selection criteria for cows and sires of the breed. The REMLF90 program was used for estimating the (co) variance components and the genetic parameters by means of a multivariate animal model that included the contemporary group (herd-yearcalving season) as fixed effect, calving age as linear and quadratic covariable, and the animal and the error as random effects. The means for L1 up to L4 were of 1957 kg, 2086 kg, 2099 kg and 2106 kg, and the heritability values were of 0.22 ± 0.03, 0.17 ± 0.04, 0.22 ± 0.05 and 0.26 ± 0.06, respectively. The genetic correlations between the first four lactations were high, with values between 0.76 and 0.95. It was concluded that it is possible to obtain genetic gain through milk yield selection, that a common group of genes are affecting the different lactations, and that milk yield in the first lactation is a good indicator for productive performance of Cuban Mambí cows, that can be used as selection criteria.

Palavras-chave : Local cattle.

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