Authors : Mostafa Lotfi Farokhad, Hedayatollah Roshanfekr, Saeed Amiri, Kourosh Mohammadi and Khalil Mirzadeh
Abstract: In this study, 6574 growth trait records of Arman sheep bred and reared in Abbas-Abad sheep breeding station, Mashhad, Iran during 1997-2007 were used to estimate the genetic trends for some of the growth traits using Animal model for lambs, rams and ewes. Genetic trends were estimated for Birth Weight (BW), Weaning Weight (WW) and 6 Months Weight (6 MW) traits. Appropriate models from single and three-trait analysis were applied for research of traits. Predicted breeding values averaged by year of birth from both the single and three-trait analysis for growth traits increased over time. Genetic trends of studied traits were estimated by regressing mean of breeding values on birth year. Direct genetic trends were positive and highly significant (p<0.01) for BW, WW and 6 MW and were 2, 7 and 8 g year-1, respectively. Also, maternal trends for BW and WW were positive and highly significant (p<0.01) and were 22 and 7 g year-1.
Mostafa Lotfi Farokhad, Hedayatollah Roshanfekr, Saeed Amiri, Kourosh Mohammadi and Khalil Mirzadeh, 2011. Genetic Trends Estimation for Some of the Growth Traits in Arman Sheep. Journal of Animal and Veterinary Advances, 10: 1801-1803.