Calving Date versus Calving Interval as a Reproductive Measure in Beef Cattle

Bourdon, R. M.; Brinks, J. S.

doi:10.2527/jas1983.5761412x

Cited by 64 publications

(60 citation statements)

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“…It has been generally observed that early breeding individuals in temperate zone habitats are few in number compared to the rest of the population, but have higher reproductive success compared to individuals that breed later (Perrins 1970;Bourdon and Brinks 1983;Olsson and Shine 1997;Dawson and Clark 2000). This observed pattern is consistent with patterns observed in the length of endogenous rhythms; that shorter rhythms are rare compared to longer rhythms while an intermediate rhythm length is most common (Helm and Visser 2010).…”

Section: Discussionsupporting

confidence: 77%

Early to rise, early to breed: a role for daily rhythms in seasonal reproduction

et al. 2017

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Vertebrates use environmental cues to time reproduction to optimal breeding conditions. Numerous laboratory studies have revealed that light experienced during a critical window of the circadian (daily) rhythm can influence reproductive physiology. However, whether these relationships observed in captivity hold true under natural conditions and how they relate to observed variation in timing of reproductive output remains largely unexplored. Here we test the hypothesis that individual variation in daily timing recorded in nature (i.e. chronotype) is linked with variation in timing of breeding. To address this hypothesis and its generality across species, we recorded incubation behavior data to identify individual patterns in daily onset of activity for 2 temperate-breeding songbird species, the dark-eyed junco (Junco hyemalis aikeni) and the great tit (Parus major). We found that females who first departed from their nest earlier in the morning (earlier chronotype) also initiated nests earlier in the year. Date of data collection and ambient temperature had no effect, but stage of incubation influenced daily onset of activity in great tits. Our findings suggest a role for daily rhythms as one mechanism underlying the observed variation in seasonal timing of breeding.

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Section: Discussionsupporting

confidence: 77%

Early to rise, early to breed: a role for daily rhythms in seasonal reproduction

et al. 2017

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“…No entanto, nas raças (Bourdon & Brinks, 1983), a correlação genética do IEP 1 com IEP foi negativa em todas as raças, apesar de suas correlações fenotípicas terem todas apresentado valores iguais a 1,00. A h 2 para o período de serviço (PS) foi, em geral, muito baixa nas quatro raças estudadas, principalmente na Jafarabadi que apresentou h 2 igual a 0,0 (Tabela 1).…”

Section: Resultsunclassified

Parâmetros genéticos das características produtivas e reprodutivas de búfalos na Amazônia brasileira

Cassiano

Mariante

McManus

et al. 2004

Pesq. agropec. bras.

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Resumo -O objetivo deste trabalho foi estimar componentes de variância e parâmetros genéticos, incluindo correlações genéticas, fenotípicas e herdabilidade das características produtivas e reprodutivas de búfalos na Amazônia brasileira. As estimativas de herdabilidade (h 2 ) das características variaram de 0,04 a 0,05 no primeiro intervalo entre partos, de 0,0 a 0,26 no intervalo entre partos, e de 0,0 a 0,25 no período de serviço, refletindo grande influência ambiental. Na idade ao primeiro parto, a herdabilidade variou de 0,12 a 0,38. Em relação ao peso ao nascer, a raça Murrah foi a que apresentou a mais alta h 2 (0,62). As correlações genéticas variaram de 1,00 a -1,00. Foram negativas as correlações genéticas entre idade ao primeiro parto e peso da fêmea adulta (-0,12 a -1,00 dependendo da raça), assim como as correlações entre período de serviço, peso ao nascer e peso da fêmea adulta (0,01 a -1,00). O efeito de ambiente permanente (c 2 ) variou de 0,000 a 0,155. Somente no intervalo entre partos para a raça Jafarabadi pode-se considerar que houve c 2 significativo (0,458). O efeito materno (m 2 ) no peso ao nascer variou de baixo a médio, nas raças Carabao, Jafarabadi, Mediterrâneo e Murrah (0,11, 0,17, 0,37, 0,04, respectivamente).Termos para indexação: correlações genéticas, herdabilidades, índices de produção e reprodução. Genetic parameters of production and reproduction traits of buffaloes in the Brazilian AmazonAbstract -The aim of this study was to estimate genetic parameters, including genetic and phenotypic correlations as well as heritabilities, for production and reproduction traits of buffaloes in the Brazilian Amazon. Heritability estimates varied from 0.04 to 0.05 for FCI (first calving interval), 0.0 to 0.26 for CI (calving interval) and 0.0 to 0.25 for SP (service period), reflecting high environmental variation for these traits. For AFC (age at first calving) the heritabilities varied from 0.12 to 0.38. The Murrah breed showed the highest heritabilitiy for BW (birth weight) (0.62). Genetic correlations varied between 1.00 and -1.00 depending on the traits. There were negative genetic correlations between AFC and MFW (mature female weight) (-0.12 to -1.00 depending on breed) as well as between SP, BW and MFW (0.01 to -1.00). Permanent environment effects of the traits were low (0.000 to 0.155) and only that for CI in the Jafarabadi breed could be considered significant (0.458). Maternal effects for birth weight were low to medium (0.11, 0.17, 0.37 and 0.04 for Carabao, Jaffarabadi, Mediterranean and Murrah, respectively).

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“…Several such components have been investigated as measures of female reproductive performance. In beef cattle, focus has been on calving date (Bourdon and Brinks, 1983;Buddenberg et al, 1990), or the related calving day (Ponzoni, 1992) or days to calving (Meyer et al, 1990;Johnston and Bunter, 1996;Donoghue et al, 2004a). Recently, heifer pregnancy status and the outcome of subsequent rebreeding have attracted interest (Evans et al, 1999;Doyle et al, 2000;Eler et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Genetic variability in calving success in Aberdeen Angus cows under extensive recording

Urioste

Chang

Naya

et al. 2007

Animal

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Data from 2032 Uruguayan Aberdeen Angus cows under extensive management and recording practices were analysed with Bayesian threshold-liability sire models, to assess genetic variability in calving success (CS), defined as a different binary trait for each of the second (CS2), third (CS3) and fourth (CS4) calving opportunities. Sire (herd) variances ranged from 0.08 to 0.11 (0.10 to 0.20) and heritability from 0.27 to 0.35, with large credibility intervals. Correlations between herd effects on CS at different calving opportunities were positive. Genetic correlation between CS2 and CS4 was positive (0.68), whereas those involving adjacent calving opportunities (CS2-CS3 and CS3-CS4) were negative, at 20.39 and 20.54, respectively. The residual correlation CS2-CS3 was negative (20.32). The extent of uncertainty associated with the posterior estimates of the parameters was further evaluated through simulation, assuming different true values (20.4, 20.2, 10.2 and 10.4) for the genetic correlations and changes in the degree of belief parameters of the inverse Wishart priors for the sire covariance matrix. Although inferences were not sharp enough, CS appears to be moderately heritable. The quality of data recording should be improved, in order to effect genetic improvement in female fertility.

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Calving Date versus Calving Interval as a Reproductive Measure in Beef Cattle

Cited by 64 publications

References 0 publications

Early to rise, early to breed: a role for daily rhythms in seasonal reproduction

Early to rise, early to breed: a role for daily rhythms in seasonal reproduction

Parâmetros genéticos das características produtivas e reprodutivas de búfalos na Amazônia brasileira

Genetic variability in calving success in Aberdeen Angus cows under extensive recording

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