Environmental and Genetic Factors Influencing Performance Traits of Kajli Sheep in Pakistan

This study was conducted to estimate the genetic and environmental components or variation influencing various trails of economic importance in Kajli sheep. Data on 16,470 birth records from 5311 Kajli ewes kept at different livestock farms in Punjab province during 1977-1994 were utilized in the study. Mixed Model Least Square and Maximum Likelihood algorithms were applied to analyze the data using Harvey's statistical software. Birth, weaning and yearling weights in Kajli lambs averaged 3.7 +/- 0.01, 20.8+/-0.09 and 37.2+/-0.38 kg, respectively. The body weight averages were significantly (p<0.01) influenced by location, year and season, birth type environmental factors studied. Pre weaning and post weaning daily gains averaged 140.9+/-0.80 and 68.5+/-1.5 g, respectively. Paternal half-sib heritability estimates for birth, weaning and yearling body weight were 0.14+/-0.05, 0.13+/-0.02 and 0.08+/-0.05. respectively whereas the heritability estimates for pre and post-weaning daily weight gains were found to be 0.10+/-0.03 and 0.15+/-0.06, respectively. The heritability estimates for annual greasy fleece weight, weight at first service, age at first service and age at first lambing were 0.09+/-0.02, 0.12+/-0.04, 0.13+/-0.04 and 0.13+/-0.04 respectively. The study concluded that clue to low heritability estimates and significant environmental variation in different economic traits studied, the improvement in managemental practices can be used as the major tool for better performance.