TAILIEUCHUNG - Báo cáo sinh học: " Heritability of longevity in Large White and Landrace sows using continuous time and grouped data models"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học quốc tế đề tài: Heritability of longevity in Large White and Landrace sows using continuous time and grouped data models | Mészáros et al. Genetics Selection Evolution 2010 42 13 http content 42 1 13 Ge n et i cs Selection Evolution RESEARCH Open Access Heritability of longevity in Large White and Landrace sows using continuous time and grouped data models Gábor Meszaros 1 Judit Pálos1 Vincent Ducrocq2 and Johann Solkner1 Abstract Background Using conventional measurements of lifetime it is not possible to differentiate between productive and non-productive days during a sow s lifetime and this can lead to estimated breeding values favoring less productive animals. By rescaling the time axis from continuous to several discrete classes grouped survival data discrete survival time models can be used instead. Methods The productive life length of 12319 Large White and 9833 Landrace sows was analyzed with continuous scale and grouped data models. Random effect of herd year fixed effects of interaction between parity and relative number of piglets age at first farrowing and annual herd size change were included in the analysis. The genetic component was estimated from sire sire-maternal grandsire sire-dam sire-maternal grandsire and animal models and the heritabilities computed for each model type in both breeds. Results If age at first farrowing was under 43 weeks or above 60 weeks the risk of culling sows increased. An interaction between parity and relative litter size was observed expressed by limited culling during first parity and severe risk increase of culling sows having small litters later in life. In the Landrace breed heritabilities ranged between and . for the continuous and between and . for the grouped data models and in the Large White breed they ranged between and . for the continuous and between and . for the grouped data models. Conclusions Heritabilities for length of productive life were similar with continuous time and grouped data models in both .

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