Genetic analysis of productive and reproductive traits in farm bred nellore jodipi sheep

Abstract

The data collected on 5008 production records and 2965 breeding records of Nellore Jodipi sheep maintained at the Network Project on Sheep Improvement, Livestock Research Station Palamaner, Chittoor district was utilized in the present investigation to study the effect of various factors including inbreeding on productive and reproductive traits and also to predict and compare the breeding values by using Least Squares (LS), Best Linear Unbiased Prediction (BLUP) and Restricted Maximum Likelihood (REML) methods. newlineThe overall least squares means for BW (Birth Weight), 3M (3 Months), 6M (6 Months), 9M (9 Months) and 12 M (12 Months) body weights were 3.03 ± 0.01, 13.29 ± 0.07, 17.86 ± 0.10, 21.34 ± 0.12, 24.96 ± 0.15 kg, respectively. Period, season, sex and parity had significant influence (Plt0.01) on all the growth traits under study. The overall least square means for AGR i.e. from birth to 3, 3 to 6, 6 to 9, 9 to 12 and 3 to 12 months were 114.95 ± 0.76, 50.01 ± 0.65, 38.50 ± 0.64, 38.00 ± 0.72 and 40.19 ± 0.46 gms, respectively. Period and sex had significant influence on AGR for all age intervals. Both pre-weaning AGR and post-weaning AGR s were significantly (p lt 0.01) influenced by season of birth except post-weaning AGR 3-12 months. newlineThe overall least squares means for age at first lambing (AFL) in Nellore Jodipi sheep was 794.2 ± 6.9 days. Period of birth of ewe but not season of birth was found to be significant on AFL. The overall least squares means for lambing interval was 371.6 ± 11.9 days. Parity of ewe at lambing was found to be significant. The overall least squares mean lambing percentage (ewe covered) was 63.1 ± 2.30. Contemporary Group (CG) at breeding, but not parity of ewe at lambing had a highly significant influence on lambing percent newlineThe mean generation interval, inbreeding coefficient (F), proportion of population inbred, individual increase in inbreeding, equivalent number of generations (EqGi) and effective population size based on birth year were 3.37y, 0.97 %, 31 %, 0.48 %, 2.54 and 1