Genetic parameters of reproductive traits in sheep

Rosati, A.; Mousa, E.; Vleck, L.D. Van; Young, L. D.

doi:10.1016/s0921-4488(01)00256-5

Cited by 72 publications

(57 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The estimates obtained for number of lambs born and weaned were generally low. The h² estimate for number of lambs born per ewe lambing (0.06) presented in Table 5 falls within the range of literature estimates (0.03 -0.12) (Brash et al, 1994b;Bromley et al, 2000;Rosati et al, 2002;Cloete et al, 2002a;b;. In the case of number of lambs weaned per ewe lambing, the estimate was 0.03.…”

Section: Resultssupporting

confidence: 79%

Revised models and genetic parameter estimates for production and reproduction traits in the Elsenburg Dormer sheep stud

Wyk¹,

Fair²,

Cloete³

2004

SA J. An. Sci.

View full text Add to dashboard Cite

Genetic parameters for production and reproduction traits in the Elsenburg Dormer sheep stud were estimated using records of 11743 lambs born between 1943 and 2002. An animal model with direct and maternal additive, maternal permanent and temporary environmental effects was fitted for traits considered traits of the lamb (birth and weaning weight and survival). Fixed effects were sex, birth status, year and age of dam. Weaning weights were pre-adjusted to a 100-day equivalent. For reproduction traits (considered as traits of the ewe), which included number and weight of lambs born and weaned, repeatability models were fitted. The random part consisted of direct additive and ewe and sire permanent environmental effects. Direct and maternal heritability estimates were 0.13 and 0.23 for birth weight and 0.07 and 0.09 for weaning weight. Corresponding proportions of total phenotypic variance due to maternal permanent and temporary environment were 0.09 and 0.28 and 0.06 and 0.22 respectively. The genetic correlation between animal effects was -0.23 in the case of birth weight. The results showed that temporary environment (full sibs within a year) generally has a major effect on all pre-weaning traits. The direct heritability estimate of survival was 0.02 while the temporary maternal environmental variance as a proportion of phenotypic variance was 0.10. The estimates obtained for number and weight of lambs born and weaned were generally low, ranging from 0.03 for number of lambs born to 0.11 for total weight at birth. The permanent environmental effect of the ewe accounted for 6-7% of the total phenotypic variance. Genetic correlations of total weight of lamb weaned with the other reproduction traits were generally high (0.64 to 0.92) with low standard errors. The corresponding phenotypic, environmental and ewe permanent environmental correlations were all medium to high and estimated with a fair deal of accuracy according to low standard errors. The genetic relationship between weaning weight of the ewe and her lifetime reproduction (accumulated over four lambing chances) ranged between 0.40 and 0.67. Correlations between number of lambs weaned per ewe and weight of lamb weaned per ewe were particularly high (0.8 -0.9). It was concluded that the maternal environmental effect should be partitioned into two components (permanent and temporary) when data sets involving multiple births over many generations are considered.

show abstract

Section: Resultssupporting

confidence: 79%

Revised models and genetic parameter estimates for production and reproduction traits in the Elsenburg Dormer sheep stud

Wyk¹,

Fair²,

Cloete³

2004

SA J. An. Sci.

View full text Add to dashboard Cite

show abstract

“…We combined information from different studies in sheep and cattle to form the covariance matrices needed for the procedure (Mavrogenis, 1996;Altarriba et al, 1998;Rauw et al, 1998;Rosati et al, 2002;Tsuruta et al, 2004). Parameters for milk yield were estimated in Latxa and Manchega (unpublished).…”

Section: Estimation Of Genetic Gainsmentioning

confidence: 99%

Economic weights of fertility, prolificacy, milk yield and longevity in dairy sheep

Legarra

Ramón

Ugarte

et al. 2007

Animal

View full text Add to dashboard Cite

Economic weights have been estimated in two breeds (Latxa and Manchega) using economic and technical data collected in 41 Latxa and 12 Manchega dairy sheep flocks. The traits considered were fertility (lambing per year), prolificacy (number of lambs), milk yield (litres) and longevity (as productive life, in years). A linear function was used, relating these traits to the different costs in the flock. The variable costs involved in the profit function were feed and labour. From this function, economic weights were obtained. Labour is considered in the Latxa breed to be a constraint. Moreover, farm profits are unusually high, which probably means that some costs were not included according to the economic theory. For that reason, a rescaling procedure was applied constraining total labour time at the farm. Genetic gains were estimated with the resulting economic weights to test if they give any practical difference. Milk yield only as selection criterion was also considered. The medians of the estimated economic weights for fertility, prolificacy, milk yield and longevity were 138.60 e per lambing, 40.00 e per lamb, 1.18 e per l, 1.66 e per year, and 137.66 e per lambing, 34.17 e per lamb, 0.73 e per l, 2.16 e per year under the linear approach in the Latxa and Manchega breeds respectively. Most differences between breeds can be related to differences in production systems. As for the genetic gains, they were very similar for all economic weights, except when only milk yield was considered, where a correlated decrease in fertility led to a strong decrease in profit. It is concluded that the estimates are robust for practical purposes and that breeding programmes should consider inclusion of fertility. More research is needed to include other traits such as somatic cell score, milk composition and udder traits.

show abstract

Section: Introductionunclassified

“…Determinada por fatores genéticos (Rosati et al, 2002) e ambientais (Lassoued et al, 2004), esta característica tem sido intensamente estudada, de forma a aumentar a oferta de cordeiros nascidos de parto múltiplo pode ser prejudicado, em parte devido à inabilidade dos cordeiros pequenos para ingerir o colostro nas primeiras horas de vida, mas, sobretudo, em virtude da menor ingestão individual de leite (Snowder e Glimp, 1991). Como consequência, estes animais podem permanecer mais tempo nos sistemas de terminação, consumindo maior quantidade de alimento.…”

Section: Introductionunclassified

“…Os resultados deste estudo indicam que, quando abatidos a um mesmo peso, cordeiros oriundos de parto simples possuem carcaças de melhor qualidade, em comparação a cordeiros nascidos de parto gemelar. (Rosati et al, 2002) e ambientais (Lassoued et al, 2004), esta característica tem sido intensamente estudada, de forma a aumentar a oferta de Recebido em 13 de junho de 2012 Aceito em 7 de novembro de 2013 E-mail: tatiana.wommer@ifms.edu.br cordeiros para abate e diluir os custos de produção.Cordeiros nascidos de partos gemelares, todavia, geralmente apresentam peso ao nascer inferior ao dos cordeiros provenientes de partos simples (Yilmaz et al, 2007), o que pode elevar sua taxa de mortalidade (Mukasa-Mugerwa et al, 2000). Além disso, o desempenho pós-natal de http://dx…”

unclassified

See 1 more Smart Citation

Características da carcaça e dos componentes não carcaça de cordeiros oriundos de parto simples ou duplo

Wommer

Pires

Galvani

et al. 2014

Arq. Bras. Med. Vet. Zootec.

View full text Add to dashboard Cite

RESUMOUm experimento foi conduzido com o objetivo de avaliar as características da carcaça e dos componentes não carcaça de cordeiros nascidos de parto simples ou duplo. Dezesseis cordeiros mestiços Texel × Ile de France, machos não castrados, foram desmamados aos 56 dias de idade e abatidos com aproximadamente 28kg de peso corporal. Imediatamente após o abate, cada componente corporal foi pesado separadamente, sendo as carcaças avaliadas após 24 horas de refrigeração a 2°C. Os cordeiros oriundos de parto simples apresentaram superioridade no peso e nos rendimentos da carcaça, além de maior área de olho de lombo. Por outro lado, proporcionalmente ao peso de corpo vazio, o rúmen é maior em cordeiros nascidos de parto duplo, o que resulta incremento da proporção de conteúdo gastrintestinal ao abate. Os resultados deste estudo indicam que, quando abatidos a um mesmo peso, cordeiros oriundos de parto simples possuem carcaças de melhor qualidade, em comparação a cordeiros nascidos de parto gemelar. (Rosati et al., 2002) e ambientais (Lassoued et al., 2004), esta característica tem sido intensamente estudada, de forma a aumentar a oferta de Recebido em 13 de junho de 2012 Aceito em 7 de novembro de 2013 E-mail: tatiana.wommer@ifms.edu.br cordeiros para abate e diluir os custos de produção.Cordeiros nascidos de partos gemelares, todavia, geralmente apresentam peso ao nascer inferior ao dos cordeiros provenientes de partos simples (Yilmaz et al., 2007), o que pode elevar sua taxa de mortalidade (Mukasa-Mugerwa et al., 2000). Além disso, o desempenho pós-natal de http://dx

show abstract

Genetic parameters of reproductive traits in sheep

Cited by 72 publications

References 11 publications

Revised models and genetic parameter estimates for production and reproduction traits in the Elsenburg Dormer sheep stud

Revised models and genetic parameter estimates for production and reproduction traits in the Elsenburg Dormer sheep stud

Economic weights of fertility, prolificacy, milk yield and longevity in dairy sheep

Características da carcaça e dos componentes não carcaça de cordeiros oriundos de parto simples ou duplo

Contact Info

Product

Resources

About