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Comparison of Bos Taurus-Bos Indicus Breed Crosses with Straightbred Bos Indicus Breeds of Cattle for Maternal and Individual Traits

1985; Oxford University Press; Volume: 60; Issue: 5 Linguagem: Inglês

10.2527/jas1985.6051181x

1544-7847

J. C. M. Trail, K. E. Gregory, H. J. S. Marples, J. Kakonge,

Rangeland Management and Livestock Ecology

Data were analyzed to compare crossbred females produced by crossing exotic Angus and Red Poll males to indigenous Ankole, Boran and Small East African Zebu (Zebu) females with straightbred females of the Ankole, Boran and Zebu breeds at the Ruhengere Field Station in the Ankole District of Southwestern Uganda. Progeny of the straightbred and crossbred dams were by Friesian, Brown Swiss and Simmental sires. Crossbred exotic × indigenous dams were favored over straightbred indigenous dams by 13.7% (P<.01) in calf birth weight and by 14.8% (P<.01) in calf weaning weight. Crossbred cows exceeded (P<.01) straightbred cows by 61.9% (48.5 kg) in calf weight weaned per cow exposed to breeding. Crossbred cows weighed 37, 46 and 42 kg more (P<.01) than straightbred cows at parturition, weaning and cow mean weight, respectively. Angus × Boran and Red Poll × Boran crossbred dams were compared specifically with straightbred Boran dams. Exotic (Angus, Red Poll) × Boran crossbred dams exceeded straightbred Boran dams by 27.0% (P<.05) in calf crop born, by 8.3% (P<.05) in progeny birth weight and by 14.7% (P<.01) in progeny weaning weight. Weight of calf weaned per cow exposed to breeding favored (P<.01) the Angus × Boran and Red Poll × Boran crossbred dams over the straightbred Boran dams by 50.5% (50 kg). Angus × Boran and Red Poll × Boran crossbred cows weighed an average of 24, 36 and 31 kg more (P<.01) than straightbred Boran cows at parturition and weaning and in cow mean weight, respectively. Results suggest that the ¾ exotic Bos taurus progeny of the Bos taurus × Bos indicus crossbred dams were not as well adapted to the climatic and nutritive environment to which they were subjected postweaning as the ½ exotic Bos taurus-½ indigenous Bos indicus progeny of the straightbred Bos indicus dams.