Comparative analysis of various methods for estimating expected genetic gain of production and reproduction traits in Murrah buffaloes

The present study was conducted to assess the expected genetic gain for first lactation production and reproduction traits in Murrah buffaloes, in addition to optimization of progenies/sire. Data for period 1971-2020 were used from National Dairy Research Institute. Performance traits considered were 305 days milk yield (305DMY), average daily milk yield (ADMY), peak yield (PY), lactation length (LL), calving to first insemination interval (CFI), days open (DO), and calving interval (CI). Expected Delta G was estimated and compared by three different methods; method I involved heritability and selection differential; method II involved selection intensity, phenotypic standard deviation, and heritability; method III involved estimation of Delta G through four paths of inheritance. Initially, eleven progenies/sire were utilized for assessing expected Delta G by method III, and expected Delta G was found as 34.33, 0.12, 0.12 kg, 2.63, 1.51, 2.74, and 2.80 days/year for 305DMY, ADMY, PY, LL, CFI, DO, and CI, respectively. Additionally, there was a significant increase in expected Delta G on increasing progenies/sire from 6 to 11 while subsequent increase upto 16 had little effect on expected Delta G. These findings will be helpful in formulating breeding strategies worldwide in small buffalo herds to obtain sustainable Delta G in production and reproduction traits.