THE ROLE OF CROSSBREEDING ROMANOV SHEEP WITH SUBTROPICAL RAHMANI BREED IN IMPROVING LAMB PRODUCTION EFFICIENCY | ||||
| Journal of Animal and Poultry Production | ||||
| Article 9, Volume 26, Issue 9, September 2001, Page 5335-5342 PDF (681.24 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jappmu.2001.257970 | ||||
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| Author | ||||
| H. R. Metawi, | ||||
| Animal Production Research Institute, Agricultural Research Center, Ministry of Agriculture, Egypt. | ||||
| Abstract | ||||
| The performance of pure Romanov (V), Rahmani (R) sheep, F1 crosses (V.R), back crosses to R (R.VR) and cross-bred sheep obtained by inter se mated (R.VR)’ was compared. Romanov ewes were mated once yearly, but R and V crosses were mated each 8 months. Romanov ewes gave birth to 2.31 lambs/ewe with conception rate averaging 79.7%,but their high lamb losses markedly reduced number of lambs weaned. Crossbred ewes had higher (P<0.01) fertility, greater (P<0.01) prolificacy and lower (P<0.01) lamb weaning weight than R ewes. Superiority of crossbred ewes over R ewes ranged from 6.63 to 9.36 % in fertility and from 0.22 to 0.43 lamb in prolificacy. Breed groups did not differ significantly in pre -weaning survival rates. The R.V ewes averaged 0.43 more lamb per litter than did R and 0.18 more lamb per litter than R.VR ewes. Inter -se mating of the R.VR did not affect the prolificacy of the produced ewes. The V.R ewes gave birth to 1.1 more lambs (3.9 vs. 2.8), weaned 0.9 more lamb (3.3 vs. 2.4) and 6 kilograms more of lamb (37.8 vs. 31.8) than did R ewes, over two year duration. While, R.VR ewes had 0.5 more lamb born and 0.3 more lamb weaned than did R ewes. On the other hand, R and R.VR ewes had similar weights of lambs weaned. The results indicated that V.R ewes were 15% more efficient than R.VR ewes and 22% more efficient than R ewes. | ||||
| Keywords | ||||
| Romanov; crossbreeding; lamb production; ewe efficiency | ||||
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