Effect of supplementary feed on productive and reproductive performance of sheep in grazing systems

Abstract

Introduction: This study was aimed to evaluate the effects of supplementary feeding on
productive and reproductive performance of Zel sheep breed, in mating, late pregnancy and
lactating periods.
Materials & Methods: For this purpose, 120 ewe Zel, 2-5 years old, average body weight
of 33.8±4.78 kg that had reproductive, were selected from the Zel flock of National research
station of Gavdashat Mazandaran province and divided to two same group. The treatments
contained; The first group (control); the ewes fed with basal diet + 100 gr concentrates in
late pregnancy and the first two months of lactating, The second group (Experimental
group); the ewes fed with basal diet + 200, 300 and 400 gr concentrates in mating, late
pregnancy and the first two months of lactating periods, respectively. Each group was
divided to two subgroups of 30 heads, and then entrance to a pen with a ram for 40 days.
Results: The results showed that, apparent fertility, prolificacy, ewe reproductive
performance, and ewe productive performance of control and experimental groups, were
85% and 90%, 111.8% and 114.8%, 95% and 103.3%, and 91.7% and 107.7%, respectively.
The live body weight of ewe after parturition, was not significant between control and
experimental groups. The lamb’s birth weight of experimental group (3.4 kg) was
significantly higher than control group (3.0 kg, (p<0.05), but the weaning weight of lambs
(13.5 and 14.7 kg, in control and experimental group respectively), did not affected by
supplementary feed.
Conclusion: In general, using supplementary dietary in concentrate form, in mating, late
pregnancy, and lactating periods, improves the reproduction performance, and ewe
production performance, and economical efficiency of sheep breeding units.