光照刺激对肉种鸡育成鸡性成熟的影响。

Effect of age at photostimulation on sexual maturation in broiler breeder pullets.

机构信息

Agriculture, Food and Nutritional Science Department, University of Alberta, Edmonton, Canada T6G 2P5.

出版信息

Poult Sci. 2014 May;93(5):1274-81. doi: 10.3382/ps.2012-02834.

DOI:10.3382/ps.2012-02834

Abstract

Genetic selection programs in broiler stocks have contributed to changes in the responsiveness of the broiler breeder female to nutritional factors. A study was conducted to investigate the effect of photostimulation (PS) age on sexual maturity traits in current broiler breeder pullets. Seven hundred twenty Ross 308 pullets with full access to feed to 1 or 3 wk of age were divided among 8 environmental rooms to 16 wk of age. At this time, 128 pullets (64 per initial feeding treatment) were randomly assigned to individual cages in 8 rooms with 16 pullets per room. Pullets were PS at 17 (PS17), 19 (PS19), 21 (PS21), or 23 (PS23) wk of age by increasing the day length from 8L:16D to 16L:8D (multiple steps). Each hen was dissected on the morning after first oviposition (sexual maturity). Data were analyzed by 2-way ANOVA with additional analysis of covariance analysis done using sexual maturity on BW as a covariate. Sexual maturation occurred later with later PS ages. Rate of sexual maturation was accelerated at later PS ages, although age at PS did not affect variation in age at sexual maturity. Despite a 42 d difference in PS age between the PS17 and PS23 groups, only a 25 d difference existed in mean age at sexual maturity among these groups. Initial egg weight, breast muscle weight, frame size, and abdominal fat pad weight at sexual maturity increased in birds with later PS ages. Covariate analysis indicated that these effects were influenced primarily by increased age and BW at sexual maturity in later PS birds. Pullets PS at 17 wk of age had 11.0 large white ovarian follicles, compared with 14.9 in PS23 birds. Comparison to previous studies demonstrates that the years of genetic selection for growth traits have not changed the interval between PS and sexual maturation. Previous research published on this theme likely had a confounding effect of mean BW on estimates of variation at various PS ages. Photostimulating later presented advantages with regard to development of the reproductive tract; these effects were BW dependent.

摘要

肉鸡种鸡的遗传选择计划导致了肉鸡种母鸡对营养因素反应的变化。本研究旨在探讨光照刺激（PS）年龄对当前肉鸡种母鸡性成熟特征的影响。720 只 Ross 308 母鸡在 1 至 3 周龄时可自由采食饲料，分至 8 个环境室，直至 16 周龄。此时，128 只母鸡（每个初始饲养处理 64 只）被随机分配到 8 个房间的单独笼子中，每个房间 16 只母鸡。母鸡在 17（PS17）、19（PS19）、21（PS21）或 23（PS23）周龄时通过将每天的光照时间从 8L:16D 增加到 16L:8D（分多个阶段）进行 PS。每只母鸡在第一次产卵后（性成熟）的早上进行解剖。数据通过双因素方差分析进行分析，并使用 BW 作为协变量进行协方差分析。PS 年龄较晚时，性成熟较晚。较晚的 PS 年龄加速了性成熟的速度，尽管 PS 年龄不影响性成熟的变异性。尽管 PS17 组和 PS23 组之间 PS 年龄相差 42 天，但这两组之间的性成熟平均年龄仅相差 25 天。性成熟时，PS 年龄较晚的母鸡的初始蛋重、胸肌重、骨架大小和腹部脂肪垫重增加。协变量分析表明，这些影响主要受后期 PS 鸟类性成熟时年龄和 BW 的影响。PS 于 17 周龄的母鸡有 11.0 个大白卵卵泡，而 PS 于 23 周龄的母鸡有 14.9 个大白卵卵泡。与之前的研究相比，这表明多年来对生长性状的遗传选择并没有改变 PS 与性成熟之间的间隔。之前关于这一主题的研究可能对不同 PS 年龄的估计存在 BW 均值的混杂效应。后期 PS 有生殖系统发育方面的优势；这些影响取决于 BW。