A Comparative Performance Study between Afec-Awassi Crossbred , Improved Awassi and Local Awassi Sheep Reared Intensively in Jordan

Abstract

A total of 246 performance and 257 prolificacy records belong to Afec-Awassi crossbred, improved and local Awassi sheep were collected through the years from 2007 to 2010. The sheep were kept under intensive production system at Al-Khanasry Research Station in the North of Jordan. The studied traits were: milk production, lactation, period, milk composition, birth weight and prolificacy of ewes of the three lines. The following environmental effects, parity of ewe, type of birth, sex of lambs and body weight of ewe at lambing were studied. The results showed that sex of lamb’s effect was significant in which males were heavier (P≤0.05) than females. Single born lambs were heavier (P ≤ 0.05) than other types of birth. Effect of ewe body weight at lambing on prolificacy was negatively significant (P≤ 0.01). Birth weight of Afec-Awassi crossbred lambs and the ewes' prolificacy were significantly higher than the lambs of other two lines. Year and ewe parity had significant effect on total milk production and lactation period. Total milk production was the highest (P < 0.05) in Improved Awassi ewes (134.1 ±15. 5 kg) with average lactation period of 106.2 ± 8 days, while the lowest lactation period was obtained by Afec Awassi ewes (83.3 ± 7 d). Fat and protein contents did not significantly differ between the studied lines. In conclusion, the fecundity gene that introduced into the Awassi sheep might have a remarkable positive effect on prolificacy, while it may contribute negatively in milk production.