出生季节和胎次对美系、加系杜洛克纯种仔猪初生重的影响

The effect of birth season and parity on the birth weight of Duroc purebred piglets of American and Canadian origins

分析不同出生季节和出生胎次对美系、加系杜洛克仔猪初生重的影响,并比较不同胎次下两个品系的初生重间的差异。选取美系杜洛克种猪3992头和加系杜洛克种猪3945头。根据不同出生季节,按照春、夏、秋、冬分为4组,并按仔猪不同出生胎次分为1~7胎,对不同出生季节和出生胎次的美系、加系杜洛克繁殖性状的表型数据进行组间方差分析。结果:出生季节和胎次对美系、加系杜洛克纯种仔猪初生重有显著影响(P<0.05)。在美系杜洛克仔猪中,春季组初生重最大,夏季组最小,春季组的仔猪初生重显著高于夏季组仔猪初生重(P<0.05),但其他各组之间差异不显著;美系杜洛克初生重在1~3胎呈递增趋势,第3胎初生重最高,在3胎后呈递减趋势,但第2~7胎之间差异不显著。在加系杜洛克仔猪中,春季组初生重最小,夏季组最大,春季组的仔猪初生重显著低于夏季组仔猪初生重(P<0.05),但其他各组之间差异同样不显著;加系杜洛克初生重在第1胎最低,显著(P<0.05)或极显著(P<0.01)低于第2~7胎,在第2~6胎之间出生的加系仔猪,初生重差异不显著。研究结果表明,美系、加系杜洛克纯种仔猪最佳的出生季节在春季,秋冬季次之,且两种品系的仔猪在第2~6胎的初生重较高。此外,研究也表明品系对仔猪的初生重有重要影响,与美系相比,在相同胎次下,加系杜洛克仔猪初生重更大。

The purpose of this research was to study the effects of birth season and parity on the birth weight of Duroc purebred piglets of American and Canadian origins and to compare the differences in the birth weight of the pigs of the two origins under different parities.The animals used in this study were 3992 American-origin Duroc pigs and 3945 Canadian-origin Duroc pigs.To carry out this research,we classified Duroc piglets according to different birth seasons in which they were also divided into 1-7 parities.Inter-group analysis of variance was performed on the phenotypic data of the American and Canadian Duroc pigs’reproductive traits in different birth seasons and under different parities.The results were that birth season and parity had a significant effect on the birth weight of the Duroc purebred piglets of American and Canadian origins(P<0.05).In spring,the birth weight of the American Duroc piglets was significantly higher than that in summer(P<0.05);and of the four seasons,their birth weight in spring was the highest but that in summer the lowest.However,the difference in the other seasons was not significant.The birth weight of American Duroc piglets increased from the first to the third parity and then decreased after the third one.The differences between the second to seventh parities were not significant.On the other hand,the birth weight of the Canadian Duroc piglets in spring was significantly lower than that in summer(P<0.05),with spring being the lowest and summer the highest of the four seasons.Similarly,the difference between the other seasons was not significant,either.The Canadian Duroc piglets had the lowest birth weight at the first parity,which was significantly(P<0.05)or extremely significantly(P<0.01)lower than that at the 2nd to 7th parities,but there was no significant difference in the piglets’birth weight between the 2nd to 6th parities.The above results indicated that the best birth season for Duroc purebred piglets of American and Canadian origins was in spring,followed by autumn and winter.And the piglets of these two origins had a higher birth weight at the 2nd to 6th parities.In addition,the origin of the pigs also had an important effect on their birth weight;compared with the American origin,Duroc piglets of the Canadian origin had a greater birth weight at the same parities.