A comparison of breeds and their crosses for beef production. II. Growth and puberty of heifers

Morgan, Jhl

doi:10.1071/ar9810839

Cited by 7 publications

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“…The genotype differences observed on high pasture are consistent with the results of Laster et al (1976) for S x H v. H x H; Gregory et al (1979) for B x H v. Hereford-Angus cross; and Morgan (1981) for F x H v. H x H. However, Deland, Jakes & Giles (1974), and Morgan (1981) observed little difference in growth rate between B x H and H x H heifers in southern Australia. It is evident that B x H heifers grew relatively faster during the summer months, on poorer nutrition in Nebraska (Gregory et al 1979), and Deland et al (1983) observed a similar pattern of growth with steers in South Australia.…”

Section: Discussionsupporting

confidence: 82%

“…Genotype differences have been documented for weight at puberty: H x H, 274-290;S x H, 286;F x H, 263;and B x H, 332-336 kg (Laster et al 1976;Gregorys al. 1979;Morgan, 1981). For a high proportion of heifers (85 %) to be sexually mature, mean live weights need to be about 40 kg higher than these values (Laster et al 1976;Gregory et al 1979;Cohen, Garden & Langlands, 1980).…”

Section: Discussionmentioning

confidence: 99%

“…genetic variation among breeds of beef cattle for post-To obtain information on the performance of weaning growth. It may be possible to exploit these different genotypes over a range of conditions similar differences by judicious cross-breeding, but research to those encountered in New South Wales, Bos indicus in Australia has produced less consistent results, (Brahman), large European (Simmental), dairy suggesting that European and North American (Friesian) and British breed (Hereford and Poll findings cannot be simply transposed to an extensive Hereford) sires were mated to British breed (Hereford grazing industry (Morgan, 1981;Deland, Ponzoni & and Poll Hereford) females in each of 5 years and McNeil, 1983;Hodge, 1987). Further, Darnell et al their progeny were evaluated from weaning onwards (1987) found that while Bos taurus and Bos indicus on pastures of different nutritional value.…”

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confidence: 99%

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

Hearnshaw¹,

Darnell²,

Barlow³

et al. 1989

J. Agric. Sci.

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SummaryThe post-weaning growth, frame size and body condition of Hereford (H × H), Brahman × Hereford (B × H), Simmental × Hereford (S × H) and Friesian × Hereford (F × H) heifers were evaluated on three pasture systems in each of five years. One group of heifers was grown from weaning (at 8 months of age) to 18 months on the high-pasture system, which included supplementation with grain, while the other two groups were grown to 30 months on pastures of medium or low quality. Pasture effects were large compared with differences between years, with average daily gains between weaning and 18 months of 552, 275 and 97 g/day on high, medium and low pastures, respectively. Genotype had a significant effect on all measurements. Pasture × genotype interaction was significant in most instances. While crosses grew faster and were heavier than H × H on all pastures, S × H were heaviest by 18 months on high pasture, with B × H heaviest at all ages up to 30 months on both medium and low pastures. There was little difference in live weight between B × H and F × H on high pasture, or between S × H and F × H on medium pasture, whereas F × H was heavier than S × H on low pasture. 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 × H had the largest height, length and pelvic area, but shared the lowest body condition with S × H. Pelvic height was greatest among B × H heifers, but this cross had similar body length, condition and subcutaneous fat cover to H × H. The pattern of genotype × 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.

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Section: Discussionsupporting

confidence: 82%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

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

Hearnshaw¹,

Darnell²,

Barlow³

et al. 1989

J. Agric. Sci.

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“…Numerous studies have shown that age and weight at puberty differ among various cattle breeds (Reynolds et ai., 1963;Kennedy and Chirchir, 1971;Brown et al, 1972;Laster et al, 1972Laster et al, , 1976Swierstra et al, 1977;Young et al, 1978;Gregory et al, 1979Gregory et al, , 1982Morgan, 1981;Steffan et al, 1985); effects of nutrition on the growing heifer are well documented (Joubert, 1954;Crichton et al, 1959;Wiltbank et al, 1962Wiltbank et al, , 1965Wiltbank et al, , 1969Wiltbank et al, , 1985Bellows et al, 1965;Arije and Wiltbank, 1971;Short and Bellows, 1971;Vamer et al, 1977;Laster et al, 1979;Fleck et al, 1980;Lemanager et al, 1980;Ferrell, 1982). Interactions between genotypic groups and environmental variables, including breeds, breed crosses, and lines or strains within a bred that evolved in different environments, also have been reported (Cartwright, 1955;Rollins et al, 1963;Butts et al, 1971;Kress et al, 1971a,b;Burns et al, 1979;Koger et al, 1979).…”

Section: Lntroductlonmentioning

confidence: 99%

Evaluation of reproductive traits in Bos taurus and Bos indicus crossbred heifers: effects of postweaning energy manipulation.

Patterson

Corah

Brethour

et al. 1991

Journal of Animal Science

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Reproductive traits were evaluated in Bos taurus and Bos indicus crossbred heifers that were fed different diets during the postweaning period. The study was designed in a 2 x 2 x 2 factorial arrangement of treatments. Angus x Hereford (AH; n = 148) and Brahman x Hereford (BH; n = 148) heifers were sorted after weaning by body weight into light (LW) and heavy (HW) weight blocks. Heifers in each weight block were assigned to diets calculated to reach a target weight of 55% (LE) or 65% (HE) of their projected mature weights by the start of the breeding season. Puberty was determined after a 160-d observation period and characterized by the following criteria: 1) behavioral estrus, 2) presence of a palpable corpus luteum (d 6 to 10; estrus = d 0), and 3) rise in serum progesterone above 1 ng/ml (d 6 to 10). A higher (P = .01) proportion of AH heifers than of BH heifers reached puberty by the breeding season (93% vs 67%). Interactions of breed x weight block and energy level x weight block also contributed to this difference. Weight at puberty was heavier (P = .001) among HE than among LE heifers and greater for heifers in HW than for those in LW blocks (P = .02). Differences in prebreeding weight, body condition, average daily gain, hip height, and pelvic area were influenced selectively by breed, energy level, or weight block. Pregnancy rates were higher (P = .01) among AH than among BH heifers. Incidence and severity of dystocia was influenced by the breed x energy level interaction (P = .01). Brahman x Hereford heifers had less (P = .01) dystocia than AH heifers, HE heifers had less (P less than .02) dystocia than LE heifers, and HE-AH heifers had less (P less than .01) dystocia than LE-AH contemporaries. Subsequent duration of the postpartum interval to estrus was shorter (P = .002) among AH than among BH females. Pregnancy rates at the end of the 2nd yr were higher (P = .02) among LW than among HW females and weights were heavier (P = .001) at weaning among calves weaned from BH dams.

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“…Breed differences have been reported for the age and weight at puberty (Gregory et al 1991;Burns et al 1992;Martin et al 1992;Thallman et al 1999) and specifically, Bos indicus breeds (e.g. Brahmans) have been reported to be older at puberty than other breeds Morgan 1981;Bolton et al 1987;Hearnshaw et al 1994;Thallman et al 1999). Several studies have shown that the age at puberty was heritable in Bos taurus breeds of beef cattle (MacNeil et al 1984;Gregory et al 1995).…”

Section: Introductionmentioning

confidence: 99%

Genetics of heifer puberty in two tropical beef genotypes in northern Australia and associations with heifer- and steer-production traits

et al. 2009

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Abstract.A total of 2115 heifers from two tropical genotypes (1007 Brahman and 1108 Tropical Composite) raised in four locations in northern Australia were ovarian-scanned every 4-6 weeks to determine the age at the first-observed corpus luteum (CL) and this was used to define the age at puberty for each heifer. Other traits recorded at each time of ovarian scanning were liveweight, fat depths and body condition score. Reproductive tract size was measured close to the start of the first joining period. Results showed significant effects of location and birth month on the age at first CL and associated puberty traits. Genotypes did not differ significantly for the age or weight at first CL; however, Brahman were fatter at first CL and had a small reproductive tract size compared with that of Tropical Composite. Genetic analyses estimated the age at first CL to be moderately to highly heritable for Brahman (0.57) and Tropical Composite (0.52). The associated traits were also moderately heritable, except for reproductive tract size in Brahmans (0.03) and for Tropical Composite, the presence of an observed CL on the scanning day closest to the start of joining (0.07). Genetic correlations among puberty traits were mostly moderate to high and generally larger in magnitude for Brahman than for Tropical Composite. Genetic correlations between the age at CL and heifer-and steer-production traits showed important genotype differences. For Tropical Composite, the age at CL was negatively correlated with the heifer growth rate in their first postweaning wet season (-0.40) and carcass marbling score (-0.49), but was positively correlated with carcass P8 fat depth (0.43). For Brahman, the age at CL was moderately negatively genetically correlated with heifer measures of bodyweight, fatness, body condition score and IGF-I, in both their first postweaning wet and second dry seasons, but was positively correlated with the dry-season growth rate. For Brahman, genetic correlations between the age at CL and steer traits showed possible antagonisms with feedlot residual feed intake (-0.60) and meat colour (0.73). Selection can be used to change the heifer age at puberty in both genotypes, with few major antagonisms with steer-and heifer-production traits.

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A comparison of breeds and their crosses for beef production. II. Growth and puberty of heifers

Cited by 7 publications

References 0 publications

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

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

Evaluation of reproductive traits in Bos taurus and Bos indicus crossbred heifers: effects of postweaning energy manipulation.

Genetics of heifer puberty in two tropical beef genotypes in northern Australia and associations with heifer- and steer-production traits

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