Bagnato A, Oltenacu P A
Department of Animal Science, Cornell University, Ithaca, NY 14853-4810.
J Dairy Sci. 1994 Mar;77(3):874-82. doi: 10.3168/jds.S0022-0302(94)77022-3.
The effect of environmental factors on first service conception rate, days from calving to first service, weeks from calving to conception, days from first to second service, and number of services per conception and the relationship of production with reproductive performance were estimated using 1.42 million records. The production trait was 305-d mature equivalent milk production. Season and age affected fertility: reproductive performance was lowest for lactations initiated during warm months (May to July) and decreased with parity. The association of production and fertility was antagonistic. High producing cows had 12 d more from calving to first service, .15 lower first service conception rate, .32 more services per conception, and 4.8 wk more from calving to conception than low producing cows in the same herd. The negative effect of production on fertility was reduced by superior herd management associated with high production. The difference in reproductive performance of cows in high and low producing herds represented only about 35% of the difference in the performance of high and low producing cows within herds for all fertility traits. The negative effect of production on fertility for interval between first and second service was totally compensated for by better management.
利用142万条记录，估计了环境因素对首次配种受胎率、产犊至首次配种天数、产犊至受孕周数、首次至第二次配种天数、每次受孕配种次数的影响，以及生产性能与繁殖性能之间的关系。生产性状为305天成熟当量产奶量。季节和年龄影响繁殖力：在温暖月份（5月至7月）开始的泌乳期繁殖性能最低，且随胎次增加而下降。生产性能与繁殖力之间的关联是拮抗的。与同一牛群中的低产奶牛相比，高产奶牛产犊至首次配种的天数多12天，首次配种受胎率低0.15，每次受孕的配种次数多0.32，产犊至受孕的周数多4.8周。高产牛群的优质管理减少了生产性能对繁殖力的负面影响。高产和低产牛群中奶牛繁殖性能的差异仅占所有繁殖性状下牛群内高产和低产奶牛性能差异的约35%。生产性能对首次和第二次配种间隔的繁殖力的负面影响完全被更好的管理所弥补。
