Diallel cross of three Moroccan breeds of sheep: I. Lamb growth and carcass traits.

A diallel cross involving three Moroccan breeds of sheep (D'man, Beni Guil, and Sardi) was conducted for two successive years at the Gharb Experiment Station in Morocco. Significant effects associated with breed of sire and breed of dam for live and carcass weights are consistent with differences in mature body size of the three breeds involved. Carcasses of lambs by Sardi sires or out of Sardi dams were the heaviest and those by D'man sires or out of D'man dams were the lightest. Lambs by D'man sires reached the prescribed stage of maturity for slaughter at a younger age than did lambs of Beni Guil sires, and lambs out of Beni Guil dams were younger at slaughter than lambs out of Sardi dams. Because of its genetic potential for high growth rate and carcass weight, the Sardi breed could be used in breeding programs to enhance meat production from sheep in Morocco. With the large and desirable maternal effects expressed by the Beni Guil breed on growth traits and carcass weight per 100 d of age, it could also be used in Morocco as a breed of dam.

Diallel cross of three Moroccan breeds of sheep: II. Reproductive performance and productivity of purebred ewes.

A diallel cross involving three Moroccan breeds of sheep (Sardi, Beni Guil, and D'man) was analyzed by least squares procedures. A total of 456 ewes were mated to 22 rams and this resulted in 528 lambs born from 412 ewes. D'man ewes had by far the highest general performance as measured by total weight of lamb weaned, even though the average live weight per lamb was the lowest for the three breeds; this resulted from the higher number of lambs weaned per ewe for the D'man. The least squares means for litter size at birth per ewe lambing were 2.04, 1.01, and 1.11 for D'man, Beni Guil, and Sardi ewes, respectively. The comparable figures for litter size at weaning were 1.55, .90, and .99, respectively, and the least squares means for total weight of lamb weaned were 20.7, 16.9, and 18.2 kg for D'man, Beni Guil, and Sardi ewes, respectively. The comparable figures for total weight of lamb weaned per 100 kg of ewe weight were 71.1, 44.3, and 41.1 kg/100 kg for D'man, Beni Guil, and Sardi ewes. Conversely, D'man rams had the poorest breeding performances of the rams of the three breeds, and Beni Guil rams had the lowest litter mortality. The breed of ram had only small and nonsignificant effects on all measures of fertility and ewe productivity. The least squares means for number born/ewe lambing were 1.36, 1.35, and 1.44, respectively, for D'man, Beni Guil, and Sardi rams; the comparable least squares means for number weaned per ewe lambing were 1.10, 1.18, and 1.16, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)