Do ChangHee, Yang ChangBeom, Choi JaeGwan, Kim SiDong, Yang BoSeok, Park SooBong, Joo YoungGuk, Lee SeokHyun
National Institute of Animal Science, Rural Development Administration, Cheonan 31000, Korea .
Gyeongnam Research Center of Livestock Development, Sancheong 52263, Korea .
Asian-Australas J Anim Sci. 2015 Sep;28(9):1244-51. doi: 10.5713/ajas.14.0962.
A herd of Berkshire pigs was established in 2003 and subjected to selection without introduction of any genetic resources until 2007. The complete pedigree, including 410 boars and 916 sows, as well as the records from 5,845 pigs and 822 litters were used to investigate the results obtained from the selections. The index of selection for breeding values included days to 90 kg (D90kg), backfat thickness (BF) and number of piglets born alive (NBA). The average inbreeding coefficients of pigs were found to be 0.023, 0.008, 0.013, 0.025, 0.026, and 0.005 from 2003 to 2007, respectively. The genetic gains per year were 12.1 g, -0.04 mm, -3.13 days, and 0.181 head for average daily gain (ADG), BF, D90kg, and NBA, respectively. Breeding values of ADG, BF and D90kg were not significantly correlated with inbreeding coefficients of individuals, except for NBA (-0.21). The response per additional 1% of inbreeding was 0.0278 head reduction in NBA. The annual increase of inbreeding was 0.23% and the annual decrease in NBA due to inbreeding was 0.0064 head. This magnitude could be disregarded when compared with the annual gain in NBA (0.181 head). These results suggest that inbreeding and inbreeding depression on ordinary farms can be controlled with a proper breeding scheme and that breeding programs are economical and safe relative to the risks associated with importation of pigs.
一群伯克夏猪于2003年组建，在2007年之前未引入任何遗传资源的情况下进行选育。利用完整的系谱，包括410头公猪和916头母猪，以及5845头猪和822窝仔猪的记录来研究选育结果。育种值的选择指数包括达90千克体重日龄（D90kg）、背膘厚度（BF）和活产仔猪数（NBA）。从2003年到2007年，猪的平均近交系数分别为0.023、0.008、0.013、0.025、0.026和0.005。平均日增重（ADG）、BF、D90kg和NBA的年遗传进展分别为12.1克、-0.04毫米、-3.13天和0.181头。除NBA（-0.21）外，ADG、BF和D90kg的育种值与个体近交系数无显著相关性。近交每增加1%，NBA减少0.0278头。年近交增量为0.23%，因近交导致的NBA年减少量为0.0064头。与NBA的年遗传进展（0.181头）相比，这个幅度可以忽略不计。这些结果表明，通过适当的育种方案可以控制普通农场的近交和近交衰退，并且相对于与进口猪相关的风险而言，育种计划是经济且安全的。
