Estimate of Variance Components with Different Methods for Growth Traits of Lambs and Reproductive Characters of Awassi and Red Karaman Ewes


Abstract: In this study, the effects of environmental factors on flock production characteristics of Awassi and Red Karaman ewes reared at the Research and Application Farm of the Agriculture Faculty were studied, and variance component estimates were made using different methods. Variance component estimates for both breeds for the number of pregnant ewes, ewes lambing, lambs born and lambs weaned per ewe mated, lambs born, lambs weaned, lambs surviving 120 and 210 days per ewe lambing, birth weight, weaning weight, daily weight gain until weaning, weight at the end of pasture and daily weight gain in pasture lambs were made using the Least Squares (LS), Minimum Variance Quadratic Unbiased Estimation (MIVQUE), Maximum Likelihood (ML) and Restricted Maximum Likelihood (REML) methods. The ML method gave the most accurate estimate in comparison with estimation of variance components obtained by LS, MIVQUE, ML and REML methods according to minimum error variance and Swallow and Monahan's criteria.

Keywords: Awassi, Red Karaman, Reproductive characters, Growth traits, Variance components

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