The Effect of Urea Treated Straws and Urea-Molasses Feed Blocks (UMB) on Reproductive Performance of Libyan Barbary Sheep

Abstract

This experiment was conducted to evaluate the effect of urea treated straws and urea-molasses feed blocks (UMB) on reproductive performance of Libyan Barbary sheep. Total of 78 head of weaned females Barbary sheep were assigned randomly to four groups. Control group received untreated straws, group 1 received straws treated with urea, group 2 received untreated straws in addition to urea- molasses feed blocks (UMB),and group 3 received straws treated with urea plus UMB. The straws were treated with urea (4%). Blood samples were collected for the analysis of progesterone hormone to detect the ovarian activity. The average concentration of progesterone for the three months of age (the seventh, eighth and ninth) was signi cantly different (P≤0.05 ) between the control (1.47 ng/ml) and the rst group (1.76 ng/ml ), and between the second (1.24 ng/ml) and each of the control and rst groups and also between the rst and the third group (1.56 ng/ml), were it was not signi cant between the control and the third group. The results showed the percentage of animals reached puberty during the period of taking blood samples, where the female lambs in the rst group recorded highest percentage of puberty during the seventh and eighth month of age (33.3%) and (28.57%) respectively, followed by the third group (31.57%) and (26.33%). The study showed highest conception rate, lambing % and twining % in the rst group 33.3%, 38%, 4.7% followed by the third group 21, 21%, 0% respectively. The results also showed no signi cant differences (P≤0.05) in the birth weight of new born lambs between groups. The averages weights were 3.76, 3.63, 3.11 and 3.82 kg in the control, rst, second and third groups, respectively. It is clear that urea has no negative effect on the reproductive performance, and can be used safely to increase the nutritional value of the straws.