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Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/6/1998 Publication Date: N/A Citation: N/A Interpretive Summary: This study compared the reproductive performance of females that were either 1/4 Duroc, 1/4 Meishan, 1/4 Fengjing, or 1/4 Minzhu and the remainder 3/4 White Composite. Analyses indicate that crossbred gilts containing 1/4 Meishan, 1/4 Fengjing or 1/4 Minzhu will reach puberty earlier and have larger litters at first parity than gilts containing 1/4 Duroc. However, the Chinese crosses did not have an advantage in converting feed energy into litter weight gain or rebreeding after weaning. Litter size did not differ significantly amongst these breed types at second parity. Additional information is needed on litter size at later parities and on growth and carcass traits of progeny of females containing 1/4 Chinese breeding before recommendations can be made on the appropriate use of these Chinese breeds in commercial production. Technical Abstract: Data were analyzed from females that were either 1/4 Duroc, 1/4 Meishan, 1/4 Fengjing, or 1/4 Minzhu and the remainder 3/4 White Composite. A higher percentage of Fengjing crosses reached puberty compared to Duroc or Minzhu while Meishan crosses were intermediate and not significantly different from any of the other breed types. Breed types ranked Fengjing, Meishan, Minzhu, and Duroc in order from youngest to oldest at puberty wit approximately 14 d between adjacent breed types. Meishan and Fengjing crosses had a higher ovulation rate than Minzhu or Duroc crosses. With the exception of number of fetuses at 100 d and average fetal weight at 60 d, differences among breed types were not significant for litter or uterine traits measured on gilts slaughtered at 60 or 100 d of gestation. Total number of pigs born was higher for 1/4 Fengjing than 1/4 Duroc gilts. Breed type was not significant for gestation length, number born alive, number weaned, litter birth weight, or litter weaning weight for gilts. Duroc crosses were heavier than any of the Chinese crosses at d 1 and d 28 after farrowing, but the breed types did not differ significantly for backfat thickness at those times. Breed types did not differ for the ratio of litter gain from 0-28 d/total Mcal or any of the component traits in the ratio. Postweaning estrus activity, conception rate, and litter and uterine traits of sows bred for second parity were not affected significantly by breed type. These analyses indicate that crossbred gilts containing 1/4 Meishan, 1/4 Fengjing, or 1/4 Minzhu will reach puberty earlier, have larger litters, and weigh less at first parity than gilts containing 1/4 Duroc, but do not have any significant advantage in litter size at second parity. |
