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- Lundgren, Helena, et al.
(författare)
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Genetic analysis of reproductive performance in Landrace sows and its correlation to piglet growth
- 2010
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Ingår i: Livestock Science. - : Elsevier BV. - 1871-1413 .- 1878-0490. ; 128, s. 173-178
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the reproductive performance of sows, including the interval from weaning to service after 1st litter and litter size in the following (2nd) parity, as well as the direct and maternal genetic effects of piglet growth on these reproduction traits. Data on 15 946 Norwegian Landrace sows' 1st and 2nd parity, and on 106,962 piglets born in 11,323 1st parity litters were included in the analyses, in total, five traits were analysed. Weaning-to-service interval was based on a 1- to 7-day interval (WS17) or a transformed 1- to 50-day interval (WS150). A third reproduction trait was total number of piglets born in 2nd parity (NBTnext). Piglet weight was included in the analyses, either as average piglet weight in the litter at 3 weeks of age (meanW3) or as individual piglet weight gain during the first 3 weeks of life (IWG03). Genetic parameters were estimated with animal models, including both direct and maternal effects for IWG03. Heritability estimates for WS17, WS150 and NBTnext were 0.08, 0.03 and 0.09 respectively. For meanW3. the heritability estimate was 0.21. For IWG03, the direct and maternal heritability estimates were 0.15 and 0.10 respectively. Negative and unfavourable genetic correlations were estimated between meanW3 and NBTnext (r(g) = -0.37), and between IWG03(maternal) and NBTnext (r(g) = -0.39). The ability to raise fast growing, heavy piglets seems to have an unfavorable effect on total number born in next litter but not on the weaning-to-service interval. (C) 2009 Elsevier B.V. All rights reserved.
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| 4. |
- Lundgren, Helena, et al.
(författare)
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Genetic parameters for feed intake, litter weight, body condition and rebreeding success in primiparous Norwegian Landrace sows
- 2014
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Ingår i: Animal. - 1751-7311 .- 1751-732X. ; 8, s. 175-183
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to estimate genetic parameters for feed intake recorded as farmers' perception of young sows' appetite for the first 3 weeks of lactation (APP) and feed intake recorded for one day in the 3rd week of lactation (FEED), litter weight (LW) at 3 weeks, sow body condition at weaning (BC) and the following five reproduction traits: weaning-to-service interval of 1 to 7 days (WSI7), weaning-to-service interval of 1 to 50 days (WSI50), delayed service or not (DELAYED), pregnant on first service or not (PREGNANT) and litter size in 2nd parity (NBT2). The analyses included data on 4606 Norwegian Landrace 1st-parity sows and their litters. The Gibbs sampling method was used. The traits DELAYED and PREGNANT were analysed as threshold traits and APP, FEED, LW, BC, WSI7, WSI50 and NBT2 were analysed as linear traits. The heritability estimates for APP and FEED were low (<0.1), whereas the estimates for DELAYED and PREGNANT were rather high (0.4 and 0.3). The heritability estimate for BC was 0.2. The genetic correlations confirmed the complexity of breeding for sow performance; selection for heavy 1st litters may lead to lower body condition at weaning, which in turn leads to lower reproductive performance and smaller litters in 2nd parity. Selection for higher sow feed intake would improve body condition, but the simple way of measuring feed intake tested in this study (APP and FEED) cannot be recommended because of the low heritability obtained for these traits.
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