K. Mohammadi, M.T. Beigi Nassiri, A. Aghaei, K. Mirzadeh, H. Roshanfekr, Estimation of Genetic Trend for Body Weights at Post-Weaning in Zandi Sheep, Journal of Animal and Veterinary Advances, Volume 10,Issue 3, 2011, Pages 272-274, ISSN 1680-5593, javaa.2011.272.274, (https://makhillpublications.co/view-article.php?doi=javaa.2011.272.274) Abstract: Data from body weights at post-weaning were used to genetic trend for Zandi sheep reared in Khojir breeding station of Tehran-Iran over a 16 years period (1993-2008) using animal model for lambs, rams and ewes. Genetic trends were estimated for 6 Months Weight (6MW), 9 Months Weight (9MW) and Yearling Weight (YW) traits. For investigation of each trait appropriate models using 3-trait analysis were applied. Breeding values of animals were predicted by Best Linear Unbiased Prediction (BLUP) methodology under three-trait animal models. Genetic trends of studied traits were estimated by regressing mean of breeding values on birth year. The genetic trends were positive and significant for 6MW, 9MW and YW and were 21, 72 and 65 g year-1, respectively. Keywords: Zandi sheep;Iran;genetic trend;body weight;Animal model;post weaning