Kirby J D, Tressler C J, Kirby Y K
Department of Poultry Science, Center of Excellence for Poultry Science, University of Arkansas, Fayetteville 72701, USA.
Poult Sci. 1998 Nov;77(11):1688-94. doi: 10.1093/ps/77.11.1688.
The ability to characterize the reproductive potential of male fowl can be affected by a number of factors, including age, type, insemination scheme, and number of sperm inseminated. Fertility is a complex interaction of traits involving two individuals of differing genetic composition: In modern broiler breeders, selected predominantly for growth and carcass characteristics, fertility problems may be exacerbated. In order to evaluate the male components of fertility, an experiment investigating the effects of male line on both average fertility and the duration of fertility was completed. Male chicks from five commercial broiler breeder male lines or sired by subfertile Delaware cross roosters were reared to adulthood. Between 30 and 60 wk of age, semen was collected from five males per line, extended and used to inseminate each of 10 to 12 hens from four broiler breeder female lines or Single Comb White Leghorn hens with 80 x 10(6) live sperm. Following a single insemination eggs were collected for 21 d and fertility determined by visual inspection following 4 d incubation. The percentages of live sperm and overall fertility data for the replicate trials were analyzed, following transformation, with a linear model and daily fertility data were analyzed by iterative least squares regression. Whereas there were large differences in fertility among individual males (durations from 3.4 to 14.5 d) within a line, there were no significant male line or replicate effects on overall fertility or the duration of fertility. However, there was a significant (P < 0.05) line-dependent reduction in the percentage of live sperm in broiler breeder males, with the subfertile Delaware cross males being intermediate. There were no significant female line or replicate effects on the duration of fertility; however, there were significant female line effects on overall fertility at both 7 and 21 d. These data suggest that although individual males varied widely, there were no male line effects on the duration of fertility in the lines of broiler breeders evaluated when analyzed by iterative least squares. Furthermore, these data suggest that although females may have significant affects on overall fertility, the duration of fertility appears to be a predominantly male characteristic. Therefore, iterative least squares regression may be a useful tool for identifying males with superior sperm fertilizing ability.
表征雄性家禽繁殖潜力的能力可能受到多种因素的影响，包括年龄、类型、授精方案以及授精的精子数量。繁殖力是涉及两个遗传组成不同个体的多种性状的复杂相互作用：在主要针对生长和胴体特征进行选育的现代肉种鸡中，繁殖力问题可能会加剧。为了评估繁殖力的雄性组成部分，完成了一项研究雄性品系对平均繁殖力和繁殖力持续时间影响的实验。来自五个商业肉种鸡雄性品系的雄性雏鸡或由繁殖力低下的特拉华杂交公鸡所生的雏鸡饲养至成年。在30至60周龄期间，从每个品系的五只雄性采集精液，进行稀释后用于给来自四个肉种鸡雌性品系的10至12只母鸡或单冠白来航母鸡输精，每只母鸡输入80×10⁶个活精子。单次输精后收集21天的种蛋，并在孵化4天后通过肉眼检查确定受精率。对重复试验的活精子百分比和总体繁殖力数据进行转换后，用线性模型进行分析，每日繁殖力数据通过迭代最小二乘法回归进行分析。尽管同一品系内个体雄性之间的繁殖力存在很大差异（持续时间从3.4天到14.5天不等），但雄性品系或重复对总体繁殖力或繁殖力持续时间没有显著影响。然而，肉种鸡雄性的活精子百分比存在显著的（P<0.05）品系依赖性降低（繁殖力低下的特拉华杂交雄性处于中间水平）。雌性品系或重复对繁殖力持续时间没有显著影响；然而，在第Ⅰ天和第21天，雌性品系对总体繁殖力有显著影响。这些数据表明，尽管个体雄性差异很大，但通过迭代最小二乘法分析时，在所评估的肉种鸡品系中，雄性品系对繁殖力持续时间没有影响。此外，这些数据表明，尽管雌性可能对总体繁殖力有显著影响，但繁殖力持续时间似乎主要是雄性特征。因此，迭代最小二乘法回归可能是识别具有优良精子受精能力雄性的有用工具。
