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Selection for litter size in pigs. II. Efficiency of closed and open selection lines
- Source :
- Genetics Selection Evolution, Genetics Selection Evolution, BioMed Central, 2001, 33, pp.515-528, Genetics, Selection, Evolution : GSE, Genetics Selection Evolution, BioMed Central, 2001, 33 (5), pp.515-528. ⟨10.1051/gse:2001130⟩, Genetics Selection Evolution (33), 515-528. (2001), Genetics Selection Evolution, Vol 33, Iss 5, Pp 515-528 (2001), HAL
- Publication Year :
- 2001
- Publisher :
- HAL CCSD, 2001.
-
Abstract
- A selection experiment on litter size in the pig was carried on for seventeen generations in an Inra experimental herd. The founder population was made up of 10 males and 120 females from the Large White breed. Selection was first performed for ten generations in a closed line, compared to a control line derived from the same founder population. Selection was carried on within sire family on the total number of piglets born in the first two litters of the dam (TB1 + TB2). After ten generations, the selection criterion became dam TB1 only. The control line was then discontinued and a panel of frozen semen from the 11th generation boars was created for later comparisons. The selected line was opened to gilt daughters of hyperprolific boars and sows, at a rate of 1/8 per generation, and the same selection procedure was applied irrespective of the origin of the gilt. During the whole experiment, the number of ova shed (OS) and the number of live embryos (LE) at 30 days in the 3rd pregnancy were recorded. These two parts of the experiment were analysed using REML estimation of genetic parameters and a BLUP-Animal Model in order to estimate the responses to selection. Significant heritabilities for TB1, TB2, OS and LE were obtained, i.e. 0.10, 0.05, 0.43 and 0.19, respectively. Significant common environment variances and covariances were estimated for nearly all traits. Significantly positive BLUP responses per generation were observed from G0 to G17 for TB1 (+0.086), TB2 (+0.078), OS (+0.197) and LE (+0.157). However, the responses were 3- to 4-fold higher in the G12–G17 interval compared to G0–G11, and they were also in fair agreement with previous estimates based on standard least-squares procedures, using the control line and the control frozen semen panel. Since G11, the selection intensity was increased by nearly 80 p. cent compared to the previous generations, and the proportion of hyperprolific ancestry increased up to 65 p. cent in the sows of the last generation. The total genetic gain of about 1.4 piglets at birth per litter could be shared between a gain due to immigration, of about 0.8 piglets per litter, and a within-line selection gain of about 0.6 piglets. Thus by combining selection and immigration in the second part of the experiment, advantage could be taken from both the genetic superiority of the immigrants and the higher internal selection intensity made possible by immigration.
- Subjects :
- Litter (animal)
Male
Animal breeding
open line
lcsh:QH426-470
héritabilité
Litter Size
Swine
selection
Biology
Animal science
Control line
PERFORMANCE DE LA REPRODUCTION
GESTALIA
Pregnancy
méthode statistique
Genetics
Animals
porcin
Genetics(clinical)
Selection, Genetic
Selection (genetic algorithm)
Ecology, Evolution, Behavior and Systematics
lcsh:SF1-1100
amélioration génétique
[SDV.GEN]Life Sciences [q-bio]/Genetics
hyperprolificite
taille de la portee
Research
Sire
0402 animal and dairy science
pigs
04 agricultural and veterinary sciences
General Medicine
040201 dairy & animal science
Breed
lcsh:Genetics
[SDV.GEN.GA]Life Sciences [q-bio]/Genetics/Animal genetics
sélection animale
Genetic gain
040103 agronomy & agriculture
Herd
0401 agriculture, forestry, and fisheries
Female
Animal Science and Zoology
lcsh:Animal culture
immigration
Subjects
Details
- Language :
- English
- ISSN :
- 0999193X and 12979686
- Database :
- OpenAIRE
- Journal :
- Genetics Selection Evolution, Genetics Selection Evolution, BioMed Central, 2001, 33, pp.515-528, Genetics, Selection, Evolution : GSE, Genetics Selection Evolution, BioMed Central, 2001, 33 (5), pp.515-528. ⟨10.1051/gse:2001130⟩, Genetics Selection Evolution (33), 515-528. (2001), Genetics Selection Evolution, Vol 33, Iss 5, Pp 515-528 (2001), HAL
- Accession number :
- edsair.doi.dedup.....0aa177b865dd0e58e7e9be85f53d517c