02025naa a2200253 a 450000100080000000500110000800800410001910000170006024500760007726000090015352013410016265000100150365000290151365000120154265000280155465000210158265000100160365000150161365000140162865300240164265300140166670000190168077300720169920666202017-03-09 1980 bl uuuu u00u1 u #d1 aSINGH, R. N. aBeetal goatbgenetic selection for maximizing lifetime milk production. c1980 aAbstract: Data were analysed on the performance of 1439 goats in 3829 lactations recorded in 1931-67. Least-squares means are tabulated for age at 1st kidding, milk yield and lactation length (first 5 lactations), and kidding interval. Age at 1st kidding averaged 776.09 plus or minus 5.26 days. Milk yield ranged from 130.08 plus or minus 0.79 kg in the 1st lactation to 211.74 plus or minus 2.60 kg in the 3rd. Lactation length ranged from 172.70 plus or minus 2.71 days in the 3rd lactation to 188.24 plus or minus 2.52 in the 2nd, and kidding interval from 334.12 plus or minus 10.91 days (4th) to 381.64 plus or minus 3.14 (1st). The phenotypic and genetic variances and covariances are tabulated for the above traits and for lifetime milk production. 11 selection indices were calculated for different combinations of age at 1st kidding, 1st- lactation milk yield, length of the 1st lactation, and 1st kidding interval, separately for each of 4 measures of lifetime milk production. The efficiency of the indices, as indicated by the correlation between the index and lifetime production, was highest (0.508-0.693) for the indices which included all 4 traits. If selection were to be based on only 1 trait, 1st-lactation milk yield would give a higher correlated response in lifetime production than selection for any other trait. aGoats aReproductive performance aCaprino aEficiência reprodutiva aGenética animal aLeite aProdução aSeleção aLifetime production aSelection1 aACHARYA, R. M. tInternational Goat and Sheep Researchgv. 1 n. 3, p. 226-233, 1980.