Naslov
Maternal and direct genetic relationships between weaning weight and traits derived from the Brody growth curve in Angus cattle.

Autori
Kapš, Miroslav ; Herring, W. O. ; Lamberson, W. R.

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Journal Animal Science, 77 (Suppl. 1) / - , 1999

Skup
Presented at 1999 American Society of Animal Science National Annual Meeting, Indianapolis, Indiana.

Mjesto i datum
Sjedinjene Američke Države, 21.07.1999. - 23.07.1999

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
beef cattle; maternal genetic correlation; growth curve

Sažetak
Direct and maternal genetic and environmental variances and covariances and associated genetic parameters were estimated for weaning weight, and growth and maturing traits derived from the Brody growth curve. Data consisted of field records of weight measurements of 3, 044 Angus cows, and 29, 943 weaning weight records of both sexes. Growth traits included weights, and growth rates at 365- and 550-d, respectively. Maturing traits included the age of animals when they reach 65% of mature weight, and relative growth rates, and degrees of maturity at 365- and 550-d, respectively. Variance and covariance components were estimated by REML from a set of two-trait animal models including weaning weight paired with a growth or maturing trait. Weaning and cow contemporary groups were defined as fixed effects. Random effects for weaning weight included direct genetic, maternal genetic, and permanent environmental effects. For growth and maturing traits only direct genetic effects were defined as random effects. Heritability estimates for growth traits ranged from .46 to .52, and for maturing traits they ranged from .31 to .34. Direct genetic and maternal genetic correlation estimates were -.05 and .55 between weaning weight and degrees of maturity at 365- and 550-d, respectively. Direct genetic correlation estimates ranged from .04 to .06, and maternal-direct genetic correlation estimates ranged from -.50 to -.56 for weaning weight with the age when animals reached 65% of mature weight and relative growth rates. Since maternal genetic weaning weight reflects an animal's milk producing ability, these estimates indicate that higher genetic capacity for milk production was related to higher body mass and degrees of maturity between 365- and 550-d of age, but was negatively related to absolute and relative growth rates in that life stage.

Izvorni jezik
Engleski

Znanstvena područja
Poljoprivreda (agronomija)

POVEZANOST RADA