Growth and carcass characteristics of crossbred and straightbred Hereford steers. III. Post-weaning growth in seven environments in New South Wales

Abstract

Post-weaning growth, liveweight and body condition at slaughter were examined in 289 steers comprised of straightbred Hereford and first cross Brahman x Hereford, Simmental x Hereford and Friesian x Hereford. The steers were grown from weaning in seven environments throughout New South Wales. All steers were slaughtered when the average fat cover of the Herefords was in the range of 6-10 mm at the 12/13th rib. Brahman crossbreds were in similar body condition to Herefords at slaughter, which in turn were generally in better condition than both Simmental and Friesian crossbreds. Crossbred steers were heavier than Herefords at slaughter. Simmental crosses and Friesian crosses were 53 kg (12%) heavier on average over all environments, and Brahman crosses 41 kg (10%) and 83 kg (16%) heavier in inland and coastal environments respectively. Mean average daily gain (ADG) of the crossbred steers was always greater than that of the Hereford steers. There was a trend for ADG to be greater among the Brahman crosses earlier in the post-weaning period, but for the Simmental and Friesian crosses to grow faster later in the post-weaning period. Simmental crosses maintained a constant ADG advantage relative to Friesian crosses throughout the post-weaning period in environments where growth was favoured. Significant genotype x environment interactions occurred. Relative to Herefords, Simmental and Friesian crossbreds responded more to improved conditions, while Brahman crossbreds maintained a constant growth advantage regardless of environmental conditions. Bos taurus crosses grew faster than Brahman crosses, and Simmental crosses faster than Friesian crosses, only when environments were highly favourable.

Post-weaning growth of Hereford and first-cross heifers grazing three pasture systems

“…There were concomitant differences in measures of skeletal size, but when adjusted allometrically to a common live weight, pasture effects were removed, while differences between genotypes remained. At a common live weight F x H had the largest height, length and pelvic area, but shared the lowest body condition with S x H. Pelvic height was greatest among B x H heifers, but this cross had similar body length, condition and subcutaneous fat cover to H x H. The pattern of genotype x pasture interaction observed in this study was similar to that observed by Darnell, Hearnshaw & Barlow (1987) for growth rate among contemporary steers located in different environments.…”

“…Growth of cross-bred steers grew faster than straight-bred Here-calves to weaning, and of steers post-weaning, has been reported by Barlow & O'Neill (1978) and • Present address: P.M.B., Ramornie, N.S.W. 2461, Darnell et al (1987), respectively. A preliminary Australia.…”

Genetics of steer daily and residual feed intake in two tropical beef genotypes, and relationships among intake, body composition, growth and other post-weaning measures

“…Genotype · environment interactions commonly occur when breeds or breed-crosses are compared across variable environments (Thompson et al 1981;Darnell et al 1987;Arthur et al 1994), and in our study, they were indicated by the presence of significant genotype · cohort effects. The cohort mean level for a trait was taken as the measure of environment Estimates differed for Brahman and Tropical Composite; see Table 10 for genotype-specific estimates.…”

Comparison of the Brahman and Friesian breeds as sires for beef production in New Zealand

“…In comparisons made in each of seven environments in southern Australia, Darnell et at (1987) found no significant difference in liveweight at slaughter between Brahman-sired and Friesian-sired cattle. The 4.2% advantage in hot-carcass weight in Brahman-sired over Friesian-sired animals was not caused by differences in weights of fat depots carried by the Brahman-sired cattle (Table 7).…”