Factors Influencing Gestation Length, Birth Weight and Calf Survival of Angus, Zebu and Zebu Cross Beef Cattle

Reynolds, W. L.; DeRouen, T. M.; Moin, Saidi; Koonce, K. L.

doi:10.2527/jas1980.514860x

Cited by 72 publications

(63 citation statements)

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“…Estimates of variance components for sire, dam, and residual effects were computed using restricted maximum likelihood procedures (REML option in the MIXED procedure of SAS), and tested for difference from zero with a z-test. (Plasse et al 1968a, b;Reynolds et al 1980;Sacco et al 1990). Estrous synchronization combined with longer GL in cows with higher B percentage is likely to have contributed to their shorter TO than those cows with lower B fractions.…”

Section: Discussionmentioning

confidence: 94%

Association between cow reproduction and calf growth traits and ELISA scores for paratuberculosis in a multibreed herd of beef cattle

Elzo

Rae

Lanhart

et al. 2008

Trop Anim Health Prod

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The objective of this research was to assess the association between 4 cow reproductive and weight traits, and 2 preweaning calf traits and ELISA scores for paratuberculosis (0 = negative, 1 = suspect, 2 = weak-positive, and 3 = positive) in a multibreed herd of cows ranging from 100% Angus (A) to 100% Brahman (B). Cow data were 624 gestation lengths (GL), 358 records of time open (TO), 605 calving intervals (CI), and 1240 weight changes from November to weaning in September (WC) from 502 purebred and crossbred cows. Calf data consisted of 956 birth weights (BWT), and 923 weaning weights adjusted to 205 d of age (WW205) from 956 purebred and crossbred calves. Traits were analyzed individually using multibreed mixed models that assumed homogeneity of variances across breed groups. Covariances among random effects were assumed to be zero. Fixed effects were year, age of cow, sex of calf, year x age of cow interaction (except WC), age of cow x sex of calf interaction (only for WC), and covariates for B fraction of sire and cow, heterosis of cow and calf, and ELISA score. Random effects were sire (except for TO and CI), dam, and residual. Regression estimates of cow and calf traits on ELISA scores indicated that lower cow fertility (longer TO), lower ability of cows to maintain weight (negative WC), lower calf BWT, and lower calf WW205 were associated with higher cow ELISA scores. Further research on the effects of subclinical paratuberculosis in beef cattle at regional and national levels seems advisable considering the large potential economic cost of this disease.

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Section: Discussionmentioning

confidence: 94%

Association between cow reproduction and calf growth traits and ELISA scores for paratuberculosis in a multibreed herd of beef cattle

Elzo

Rae

Lanhart

et al. 2008

Trop Anim Health Prod

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“…Foetal/calf loss in cows tended to be 3-11 percentage points higher in the Northern Forest relative to the other country types. Typical levels of foetal/calf loss was 1-12 percentage points higher in heifers when compared to older cow-age class cohorts which is consistent with previous findings (Reynolds et al 1980;Entwistle 1983) The mechanism that cow-age class affects foetal and calf losses is uncertain however, it is speculated that due to learnt maternal instincts the…”

Section: Chapter 5 Reproductive Performance In a Selected Populationsupporting

confidence: 87%

“…Breed effects on calf survival have been reported previously (Reynolds et al 1980;Holroyd 1987;Prayaga 2004;Casas et al 2011;. The mechanism that breed affects calf survival is suggested to relate to factors associated with maternal instincts, risk of dystocia and calf viability .…”

Section: Class Of Animalmentioning

confidence: 94%

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

McCosker¹

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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...

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“…indicus cattle breeds are very popular in regions where tropical environmental challenges such as ticks, heat, drought and poor grazing exist. However, delayed age at puberty (Plasse et al, 1968;Cartwright, 1980), lower vigour of newborn calves (Reynolds et al, 1980), less intramuscular fat Whipple et al, 1990b) and less tender meat (Crouse et al, 1989;Wheeler et al, 1990;Shackelford et al, 1991) resulting from high percentage B. indicus (Brahman (BR)) seem to set the platform in countries such as South Africa, United States and Australia to consider other breeds to fulfil these challenges. The specific qualities of tropically adapted Sanga cattle breeds are well documented.…”

Section: Introductionmentioning

confidence: 99%

Variation in meat quality characteristics between Sanga (Bos taurus africanus) and Sanga-derived cattle breeds and between Sanga and Brahman (Bos indicus)

Strydom

Frylinck

Smith

2011

Animal

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Cattle breeds indigenous to Africa (Sanga) compare favourably to Bos indicus breeds with regard to adaptation to harsh environments. This study compared the meat quality of three Sanga breeds (Nguni, Tuli and Drakensberger), a Sanga-related breed (Bonsmara) and a B. indicus breed (Brahman) and supported these results with biochemical and histological measurements on the M. longissimus lumborum. Twelve young grain-fed steers of each breed were slaughtered and carcasses were electrically stimulated. All Sanga (and related) breeds, with the exception of the Tuli, had lower Warner-Bratzler shear force (SF) values at 2 and 21 days post mortem compared with the BR (P , 0.05). Measurements related to the calcium-dependent protease system and myofibrillar fragmentation explained the bulk of the variation among breeds, whereas variation in fibre type, sarcomere length and connective tissue properties gave less convincing support. With the exception of the Tuli, Sanga and Sanga-related breeds produced more tender (according to SF) meat than BR, mainly due to favourable calpain-to-calpastatin ratios. Small differences in colour, drip loss and cooking properties were found among breeds (P , 0.05).

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Factors Influencing Gestation Length, Birth Weight and Calf Survival of Angus, Zebu and Zebu Cross Beef Cattle

Cited by 72 publications

References 0 publications

Association between cow reproduction and calf growth traits and ELISA scores for paratuberculosis in a multibreed herd of beef cattle

Association between cow reproduction and calf growth traits and ELISA scores for paratuberculosis in a multibreed herd of beef cattle

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

Variation in meat quality characteristics between Sanga (Bos taurus africanus) and Sanga-derived cattle breeds and between Sanga and Brahman (Bos indicus)

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