Robustness of Selection Indices in Murrah Buffaloes

Gandhi, R. S.; Joshi, B. K.

doi:2004.17.2.159

Article

Animal Breeding and Genetics

Asian-Australasian Journal of Animal Sciences 2004;17(2): 159-163.
https://doi.org/10.5713/ajas.2004.159 Published online January 1, 2004.

Robustness of Selection Indices in Murrah Buffaloes

R. S. Gandhi, B. K. Joshi

Abstract

Data pertaining to first lactation records of 316 Murrah buffaloes, progeny of 47 sires, maintained at NDRI Farm for a period of 18 years were analysed to construct selection indices and to examine their robustness by changing the relative economic values of different economic traits. A total of 120 selection indices were constructed for three sets of relative economic values ( 40 for each set) considering different combinations of seven first lactation traits viz. age at first calving (AFC), first lactation 305 day or less milk yield (FLMY), first lactation length (FLL), first calving interval (FCI), milk yield per day of first lactation length (MY/FLL), milk yield per day of first calving interval (MY/FCI) and milk yield per day age at second calving (MY/ASC). The three sets of relative economic values were based on economic values of different traits, 1% standard deviation of different traits and regression of different traits on FLMY. The ''''optimum'''' indices for the first two sets had five traits each namely AFC, FLMY, FLL, FCI and MY/ASC giving improvement in aggregate genotype of Rupees 269.11 and Rs. 174.88, respectively. The accuracy of selection from both indices was 70.79 and 69.39%, respectively. The ''''best'''' selection index from the third set of data again had five traits (AFC, FLMY, FLL, FCI and MY/FLL) giving genetic gain of Rs. 124.16 and accuracy of selection of 71.81%. The critcal levels or break-even points for FLMY for varying levels of AFC and FCI estimated from the

Keywords: Accuracy of Selection; Aggregate Genotype; Break Even Points; Murrah Buffaloes; Relative Economic Values; Robustness of Selection Indices