Genetic and phenotypic trends for growth traits in Mecheri sheep

Data on growth of Mecheri sheep at Mecheri Sheep Research Station, Pottaneri, Tamil Nadu over a period of sixteen years from 1991 to 2006 were collected and analysed. Body weights for birth, 3, 6, 9 and 12 months of age were used to estimate the breeding values of sires by derivative-free maximum likelihood (DFREML) method. The genetic trends for birth, 3, 6, 9, and 12 months body weights of Mecheri lambs ranged from -0.15 to 0.23, -0.61 to 0.85, -1.12 to 0.91, -2.24 to 2.92 and -1.50 to 4.31 kg, respectively and their corresponding phenotypic trends varied from 2.02 to 2.72, 6.49 to 10.54, 9.94 to 14.33, 11.40 to 19.73 and 10.07 to 25.40 indicating an overall positive genetic change in growth traits.