Genetic Analysis of Productive and Reproductive Performance of Frieswal Cattle at Mf Ambala

Abstract

A total number of 3005 lactation records of 1147 Frieswal cows, sired by 64 sires born and reared at Military Dairy Farm, Ambala, over a period of 15 years extending from 1993 to 2007 were used to study the average performance of production and reproduction traits, effect of genetic and non-genetic factors on production and reproduction traits and estimation of genetic and phenotypic parameters of production and reproduction traits. The least squares means of age at first calving, total lactation milk yield, 300 days milk yield, peak yield, lactation length, dry period, calving interval and service period were 980.41±8.22 days, 3299.35±136.21 kg, 3285.23±92.50, kg15.83±0.55 kg, 309.91±5.82 days,115.29±8.83 days, 423.05±12.24 days, and 148.24±12.66 days, respectively. The age at first calving differed significantly across the periods of calving. The AFC was shortest (925.54±12.16 days) in third period (1999-2001) and longest (1 064.38±19.51 days) in first period {1993-95). The effect of season and period of calving, lactation order and regression of age at first calving on total lactation milk yield, 300 days milk yield, peak yield, lactation length, dry period, calving interval and service period was highly significant.The sires was not found to have significant effect on any trait under study. Total lactation milk yield was highest in cows calved during summer season (3340.75±139.59 kg), 2nd period (3622.52±145.41 kg) and in fourth lactation (3442.80±143.42 kg). The average 300 days milk yield was highest in the cows calved in winter season (3359.16±96.76), 2nd period (3589.14±110.04 kg) and in sixth lactation (3579.26±214.40). The heritability estimates were low for almost all the traits under study. The heritability estimates for age at first calving, total lactation milk yield, 300 days milk yield, peak yield, lactation length, dry period, calving interval and service period was 0.15±0.06, 0.14±0.03, 0.13±0.04, 0.13±0.03, 0.074±0.028, 0.009±0.028,0.04±0.033 and 0.03±0.032 respectively. Total lactation milk yield had high genetic correlation with peak yield (0.93±0.045) low (0.359±0.199) with lactation length. Peak yield had low genetic correlation (0.297±0.227) with lactation length. The service period had high genetic correlation with dry period (0.161±1.246) and high calving interval (0.910±0.102).The dry period also found to have low genetic correlation (0.137±1.162) with calving interval in Frieswal cows. The phenotypic correlation of total lactation milk yield was high (0.726) with peak yield and low (0.425) with lactation length. The peak yield had very low phenotypic correlation (0.026) with lactation length. Service period had high phenotypic correlation (0.612) with dry period and very high (0.93) with calving interval. High phenotypic correlation (0.67) was also observed between dry period and calving interval.