Some factors related to calf crops of Brahman, Brahman crossbred and Hereford × Shorthorn cows in a stressful tropical environment

Frisch, J. E.; Munro, R. K.; O’Neill, C. J.

doi:10.1016/0378-4320(87)90002-9

Cited by 24 publications

(6 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…That the estrous events and conceptions occurred early in the breeding season rather than throughout the season (Table 2) supports evidence (Burris and Priode, 1958;Frisch et al, 1987;Cushman et al, 2013) of the more reproductive efficient female calving early rather than later in the calving season.…”

Section: Bullsupporting

confidence: 56%

“…Given the between and within breed variation in estrous intensity and duration, a quantitative genetic and genomic investigation of the two traits is warranted. Bos indicus cattle evolved in tropical regions and compared to B. taurus, have relatively lower reproductive rates (Frisch et al, 1987), inherently less estrous expression (Orihuela, 2000) and lower bull libido . Nevertheless, breeders of B. taurus beef cattle must also ensure that selection for production traits (e.g.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Using UHF proximity loggers to quantify male–female interactions: A scoping study of estrous activity in cattle

O’Neill

Bishop-Hurley

Williams³

et al. 2014

Animal Reproduction Science

View full text Add to dashboard Cite

Reproductive efficiency is an important determinant of profitable cattle breeding systems and the success of assisted reproductive techniques (ART) in wildlife conservation programs. Methods of estrous detection used in intensive beef and dairy cattle systems lack accuracy and remain the single biggest issue for improvement of reproductive rates and such methods are not practical for either large-scale extensive beef cattle enterprises or free-living mammalian species. Recent developments in UHF (ultra high frequency) proximity logger telemetry devices have been used to provide a continuous pair-wise measure of associations between individual animals for both livestock and wildlife. The objective of this study was to explore the potential of using UHF telemetry to identify the reproductive cycle phenotype in terms of intensity and duration of estrus. The study was conducted using Belmont Red (interbred Africander Brahman Hereford-Shorthorn) cattle grazing irrigated pasture on Belmont Research Station, northeastern Australia. The cow-bull associations from three groups of cows each with one bull were recorded over a 7-week breeding season and the stage of estrus was identified using ultrasonography. Telemetry data from bull and cows, collected over 4 8-day logger deployments, were log transformed and analyzed by ANOVA. Both the number and duration of bull-cow affiliations were significantly (P<0.001) greater in estrous cows compared to anestrus cows. These results support the development of the UHF technology as a hands-off and noninvasive means of gathering socio-sexual information on both wildlife and livestock for reproductive management.

show abstract

Section: Bullsupporting

confidence: 56%

Section: Introductionmentioning

confidence: 99%

Using UHF proximity loggers to quantify male–female interactions: A scoping study of estrous activity in cattle

O’Neill

Bishop-Hurley

Williams³

et al. 2014

Animal Reproduction Science

View full text Add to dashboard Cite

show abstract

“…In one long-term selection experiment in Central Queensland, heifer fertility (Frisch, 1981) and mature cow fertility (Frisch, Munro and O'Neill, 1987) increased as a result of selecting predominantly for pre-and post-weaning growth rate. However, this experiment was performed in a Hereford-Shorthorn cross that is unsuited to the prevailing environment.…”

Section: Growthmentioning

confidence: 98%

Correlated responses to selection for cow fertility in a tropical beef herd

et al. 1990

View full text Add to dashboard Cite

Correlated responses to selection in a tropical beef herd for high (H) and low (L) estimated breeding value for pregnancy rate were measured over three calf crops. The H line calves were proportionately 0-04 lighter at weaning but during the ensuing dry season they lost less weight than L line animals, so that between the ages of 12 and 18 months there were no significant line differences in live weight. It was concluded that selection for cow fertility had not directly altered the progeny's growth rate. Tick resistance and heat tolerance also did not differ between the lines. However, resistance to worms was lower (P < 0-05) in the H line indicating genetic antagonism between cow fertility and worm resistance. Scrotal circumference and scrotal circumference adjusted for live weight were significantly higher in H line bulls between 9 and 18 months of age. Pregnancy rates of heifers in the H line were 0-12 higher than in the L line despite similar average live weights at mating. It is suggested that accelerated sexual maturity in both heifers and bulls has occurred as a result of selection for lifelong cow fertility.

show abstract

“…Similar low reproductive rates for cows in northern Australia that were lactating at the time of mating have previously been reported by others (Frisch et al 1987;Burns et al 2010) with the main cause identified as prolonged periods of anoestrus following parturition (Entwistle 1983;Teleni et al 1988). A decreased number of mating opportunities during the mating period of interest is a consequence of an increased period of postpartum anoestrus and therefore, reducing the probability of pregnancy.…”

Section: Discussionmentioning

confidence: 51%

“…Consequently, it has been suggested that ecological studies conducted within the northern regions of northern Australia should continue for 6-8 years (Taylor and Tulloch 1985). The factors associated with the effect of season on fertility are suggested to include negative energy balance around the time of calving (Lalman et al 1997;Schatz and Hearnden 2008;Waldner and García Guerra 2013), body condition (Fordyce et al 1990;Vargas et al 1999;Blanc and Agabriel 2008), heat stress (Turner 1982) and potentially other unexplained nutritional parameters (Frisch et al 1987).…”

Section: Seasonal Variationmentioning

confidence: 99%

Risk factors affecting the reproductive outcome of beef breeding herds in North Australia

McCosker¹

View full text Add to dashboard Cite

Approximately half of Australia's beef breeding herds are located in northern Australia with reproductive performance being identified as having a significant impact on the profitability of these businesses. Although many of the risk factors affecting the reproductive performance of beef cattle have been previously identified, the relative contribution of major risk factors to key measures of performance, after partitioning the effects of other confounding variables, is lacking, particularly for extensive tropical rangeland systems typical of northern Australia.The overall objective of the research described in this thesis was to, i) describe the reproductive performance of commercial beef breeding cattle in northern Australia and, ii) determine, and quantify the effect of the major risk factors associated with three key measures of reproductive performance (lactating cows becoming pregnant within 4 months of calving, cows failing to become pregnant within an approximate 12 month reproductive cycle, and foetal/calf loss between confirmed pregnancy and weaning). It was hypothesised that the major risk factors determining the probability of lactating cows becoming pregnant within four months of calving are similar to those determining the probability of foetal/calf loss between confirmed pregnancy and weaning. To address these objectives, a prospective population-based epidemiological study was conducted between 2007 and 2011 involving 78 commercial beef properties located across northern Australia.Attainable and typical levels of reproductive performance for cow-age cohorts were described using a dataset containing 114,154 annual production cycles of performance data that represented approximately 78,000 heifers and cows managed in 142 breeding groups. Properties were assigned to one of four broad country types following a subjective assessment of the production potential of the grazing land and cross-referencing with pasture and vegetation descriptions reported by the herd owners/managers.The typical overall reproductive performance of cows in the Northern Forest (57 live calves at muster per 100 surviving mature cows), was considerably lower than that for the other country types (71-83 live calves at muster per 100 surviving mature cows). This was due to typically much lower percentage of cows becoming pregnant within 4 months of calving, higher foetal and calf loss and higher estimated mortality of pregnant cows in the Northern Forest compared to the other genotypes. These findings are consistent with the generally poorer quantity and quality of pasture, ii harsher environment and higher disease risk of cattle managed in the Northern Forest compared to the other country types.Country type and predicted calving period were top-order determinants of pregnancy within 4 months of calving while lactating. The effect of cow-age class cohort was dependent on country type with the expected occurrence of lactating cows pregnant within 4 months of calving estimated to be 23. 1-53.8, 38.1-61.6, 35.4-56.5 and 38.5...

show abstract

Some factors related to calf crops of Brahman, Brahman crossbred and Hereford × Shorthorn cows in a stressful tropical environment

Cited by 24 publications

References 24 publications

Using UHF proximity loggers to quantify male–female interactions: A scoping study of estrous activity in cattle

Using UHF proximity loggers to quantify male–female interactions: A scoping study of estrous activity in cattle

Correlated responses to selection for cow fertility in a tropical beef herd

Risk factors affecting the reproductive outcome of beef breeding herds in North Australia

Contact Info

Product

Resources

About