Feed supplementation improves estrus response and increases fertility of sheep induced to breed out of season.
To test the efficacy on reproductive performance of nutritional supplementation in an out-of-season mating system, 66 adult prolific Barbarine ewes were selected and induced to breed using "ram effect". The ewes were allocated to two homogeneous groups; each ewe received on a daily basis 700 g of hay and 500 g of barley grains starting 3 weeks before or 1 week after rams' introduction in group 1 and group 2, respectively. Supplementation ended 1 month after rams' introduction and mating lasted 60 days. Final live weight 30 days after introduction of rams was higher (P < 0.05) for ewes in group1 (39.45 vs. 36.72 kg). Seven days after introduction of rams, ewes in group 1 recorded higher plasma glucose levels than females in group 2 (4.12 and 3.9 S.E.M. 0.05 mmol l-1). Proportions of ewes which displayed estrus between days 16 and 26 were 48 and 38% in group 1 and group 2, respectively (P < 0.05), and those which had a normal induced cycle (16-17 days) were 25 and 11% in group 1 and group 2, respectively (P < 0.05). Fertilities were higher (P < 0.05) for ewes in group 1 than in group 2 (91.17 vs. 75.75% and 97.1 vs. 81.8% for fertility at induced estrus and total fertility, respectively). It is concluded that a timed supplementation starting 3 weeks before introduction of rams is effective in yielding high reproductive performance for the prolific strain of the Barbarine breed.
Department of Biology, Faculty of Sciences, Carthage University, Zarzouna, 7021, Bizerte, Tunisia.|Laboratory of Animal and Forage production, National Institute of Agricultural Research of Tunisia, Carthage University, Rue Hédi Karray, 2049, Ariana, Tunisia.
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Khlil
Laboratory of Animal and Forage production, National Institute of Agricultural Research of Tunisia, Carthage University, Rue Hédi Karray, 2049, Ariana, Tunisia.
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Khnissi
International Center for Agricultural Research in the Dry Areas (ICARDA), P.O. Box, 950764, Amman, 11195, Jordan.
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Rekik
Laboratory of Animal and Forage production, National Institute of Agricultural Research of Tunisia, Carthage University, Rue Hédi Karray, 2049, Ariana, Tunisia. lassoued.narjess@iresa.agrinet.tn.|Laboratoire de Production Animale et Fourragères, INRAT, 2049, Ariana, Tunisia. lassoued.narjess@iresa.agrinet.tn.
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Lassoued
D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001947:Breeding; D019587:Dietary Supplements; D004971:Estrus / Q000502:physiology*; D005260:Female; D008297:Male; D012621:Seasons; D012756:Sheep / Q000502:physiology*; D014329:Tropical Climate; D014416:Tunisia
Body condition score; Fertility management; Prolific sheep; Ram effect; Supplementation