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Characterization of Biological Types of Cattle. VII. Milk Production in Young Cows and Transmitted and Maternal Effects on Preweaning Growth of Progeny

1978; Oxford University Press; Volume: 46; Issue: 4 Linguagem: Inglês

10.2527/jas1978.464908x

1544-7847

D. R. Notter, L. V. Cundiff, Gerald M. Smith, D. B. Laster, K. E. Gregory,

Effects of Environmental Stressors on Livestock

Preweaning growth and weight at 120 and 200 days were studied in the progeny of 564 2-year-old and 569 3-year-old crossbred cows produced by mating Hereford, Angus, Jersey, South Devon, Simmental, Limousin and Charolais bulls to Hereford and Angus cows. Two-year-olds produced calves by Hereford, Angus, Brahman, Devon and Holstein bulls and 3-year-olds produced calves by Hereford, Angus, Maine-Anjou, Chianina and Gelbvieh bulls. Progeny of Jersey and Simmental cross cows grew fastest (.785 and .790 kg/day, averaged over ages) and were heaviest at 120 (133 and 138 kg) and 200 (189 and 194 kg) days. Progeny of Hereford-Angus cross cows grew least rapidly (.715 kg/day) and were lightest at 120 (125 kg) and 200 (176 kg) days. In 2-year-olds, Brahman-sired calves grew significantly faster than Hereford- and Angus-sired calves (.77 vs .69 kg/day), and both Brahman-and Holstein-sired calves were significantly heavier at 200 days (190 and 174 vs 168 kg). In 3-year-olds, Chianina- and Gelbvieh-sired calves grew faster (P<.05) than Hereford- and Angus-sired calves (.81 vs .78 kg/day), and Hereford- and Angus-sired calves were lightest (P<.05) at 200 days. Fifty-nine 2-year-old and 125 3- and 4-year-old crossbred cows (plus purebred Hereford and Angus) were used to estimate milk production. Jersey and Simmental cross cows gave the most milk, whereas Limousin and Charolais cross cows and purebred Hereford and Angus cows gave the least. Heterosis for milk production declined as lactation progressed and averaged 15 percent.