Usefulness of some components of the lactation curve for selection in Murrah buffaloes

Abstract

The study was based on 1156 lactation records of 545 Murrah buffaloes. Initial milk yield, peak yield, ascending phase milk yield and days to attain peak daily production, the means of which were 26·7 kg, 10·3 kg, 407 kg and 58·9 days respectively, were all affected by period, season and parity of calving. Heifers recorded the least initial milk yield and peak yield and took the longest time to reach peak production. Peak yield was the most important single factor (R2 = 0·41) in causing variation in 43-week milk yield. The heritability estimates for initial, peak and ascending phase milk yields and days to attain peak yield were 0·35, 0·51, 0·27 and 0·13 respectively, whilst that for 43-week milk yield was 0·18. Peak yield had the highest phenotypic (rP = 0·64) and genetic correlations (ra = 0·68 ± 0·19) with the 43-week milk yield. Other genetic correlations with the 43-week milk yield were low and non-significant. The results indicated that indirect selection for peak yield would be more effective than direct selection for improving the 43-week milk yield in buffaloes.