Comparison of Three Mating Systems: II. Weights and Body Measurements of Heifers

Autor: J.W. Smith, R.E. Pearson, R.D. Plowman, R.H. Miller, M.E. Creegan, N.W. Hooven, L.A. Fulton
Rok vydání: 1977
Předmět:
Zdroj: Journal of Dairy Science. 60:1787-1798
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(77)84102-7
Popis: Body dimensions and weights of female progeny from three systems of mating were studied from birth to first calving. Heifers produced by outcrossing to Holstein sires in artificial insemination were largest up to first calving, at which time the average of heifers produced by crossbreeding (Ayrshire, Brown Swiss, and Holstein sires) exceeded the outcrosses in weight and body length from withers to pins. Heifers produced by mild inbreeding within a separate line were consistently smaller than outcrosses and crossbreds. Brown Swiss x Holstein heifers were largest of the six crosses; Ayrshire X Holstein crosses were smallest. Brown Swiss X Holstein crosses were also larger than both purebred Holstein groups. Heifers born in November and born of fourth parity dams were generally larger than heifers born in other seasons or of other parity dams, either in weight or in aspects of body dimension.
Databáze: OpenAIRE