The first-lactation milk records of 20,850 artificially sired Holstein cows and their darns were analyzed by a sire-by-herd, variance components model to determine if unequal numbers of records in the filled subclasses had any effect on the paternal half-sib correlatiou or the daughter-dam regression. The variance components were estimated with the number per subclass held constant at 1, 2, 3, ...

Background data during the gestation period were obtained from 128 Wistar Hannover GALAS rats and 26 Crl:CD(SD) pregnant rats in the control groups of our previous toxicity studies. The body weights of dams in the Wistar Hannover GALAS rats were significantly lower throughout the gestation period than those in the Crl:CD(SD) rats. In contrast, the time-dependent change in the body weight gain (...

The somatotropic axis plays an important role in postnatal growth, development, and differentiation of skeletal muscle. The aim of this study was to examine the effect of sire breed and sire EPD for carcass weight (EPD(cwt)) on the expression of components of the somatotropic axis in LM of beef cattle at slaughter. Crossbred Aberdeen Angus (AA; n = 17) and Belgian Blue (BB; n = 16) steers born ...

Lifetime dairy production, reproduction and growth traits of 75 females sired by Holstein, Jersey or Brown Swiss bulls and Holstein-Friesian x Gir dams of 1/2 to 3/4 Holstein-Friesian fractions were compared. The animals were in a single herd under the same management. Milk, fat and protein yields, concentrates fed, reproduction, and weights were recorded throughout the lifetime of the cows. Th...

Selection practices in three synthetic lines of beef cattle were evaluated based on data collected over 12 to 13 years. Sires from the Jersey, Angus and Simmental breeds were mated to three lines of foundation crossbred dams to produce first generation progeny. Subsequent calves were produced mating crossbred parents of the same generation. Crossbred sires were selected based on an index that i...

The purpose of this study was to evaluate the effect of adjusting for heterogeneous variances across breed groups on prediction of breeding values (PBV) of selected sires and on breed of sire effects. Data on weights at birth (BWT), 200 d (WW), and 365 d (YW) of purebred and crossbred calves from matings of Angus (A), Hereford (H), Polled Hereford, Charolais, Shorthorn, Simmental, Limousin, Mai...

Postweaning growth, feed efficiency, and carcass traits were analyzed on 1,422 animals obtained by mating F1 cows to F1 (Belgian Blue x British breeds) or Charolais sires. Cows were obtained from mating Hereford, Angus, and MARC IIIHereford, 1/4 Angus, 1/4 Pinzgauer, and 1/4 Red Poll) dams to Hereford or Angus (British breeds), Tuli, Boran, Brahman, or Belgian Blue sires. Breed groups were fed ...

Genome-wide estimated breeding values can be computed from the simultaneous estimates of the effects of small intervals of DNA throughout the genome on a trait or traits of interest. Small intervals or segments of DNA can be created by the use of thousands of single nucleotide polymorphisms (SNP) available in panels of 10, 25 and 50 thousand SNP. A simulation study was conducted to compare fact...

Abstract Improved reproductive management allowed dairy cow pregnancies to be optimized for beef production. The objective of this sire-controlled study was characterize effects maternal genetics and the system on calf growth. Pregnancies were created with a 2 × factorial arrangement dam breed (Holstein or Jersey) mating type (artificial insemination implantation an in vitro produced embryo fro...