Reproductive performance of Lithuanian White pigs in closed and open populations
2006
Razmaite, V., Lithuanian Veterinary Academy, Kaisiadorys (Lithuania). Inst. of Animal Science | Rekstys, V., Lithuanian Veterinary Academy, Kaunas (Lithuania)
The pig industry has usually competed on the basis of low cost per kilo of lean meat. The genetic objectives have, therefore, been to increase lean growth rate and pigs produced per sow per year. Sow productivity is one of the most important objectives for genetic improvement of pigs and profitability in pig production. The selection for improved reproductive performance has concentrated on traits such as litter size and litter weaning weight, however, low heritability for these traits and joint selection for growth and carcass traits have kept genetic improvement of prolificacy traits at a slow rate. Quinton et al. [4] have found that the relative importance of litter size for the finished pig market should decrease from 64% of the total breeding value when the average litter size is 9-8 pigs to 29% when the average litter size is 20 pigs. Lithuanian White pigs should be the breed used most often for producing dam lines and F1 females at the top of Lithuanian pig breeding structure. Therefore, the reproductive performance of Lithuanian White pigs will have a strong influence on reproductive performance in multiplying and commercial herds and wider use of Lithuanian White pigs. Since changing to a different a breed or line will always be a faster method of genetic improvement than selection [7], one solution adopted by the state pig breeding station has been to introduce 50% and more of Large White (Yorkshire) into Lithuanian White to give new improved composite commercial type of the Lithuanian White pigs. Another solution adopted by the Institute of Animal Science has been to conserve the remaining of original Lithuanian White pig breed in closed population. The objective of this study was to examine the reproductive performance on the sow level in nucleus herds of closed and open Lithuanian White populations.
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