McCormick C C, Cunningham D L
Department of Poultry and Avian Sciences, Cornell University, Ithaca, New York 14853.
Poult Sci. 1987 Jun;66(6):1007-13. doi: 10.3382/ps.0661007.
Equal periods of fasting or high zinc feeding as a means of inducing a forced rest were examined. Single Comb White Leghorn hens (60 weeks of age) were fasted (F) or fed a layer diet containing 20,000 ppm zinc (Zn) for either 4 or 10 days in a 2 X 2 factorial arrangement of treatments. Feed intake was markedly depressed in the first day of high zinc feeding and averaged 10.7 and 6.1 g/hen-day during the 4 or 10 days of Zn feeding. Body weight losses of hens fasted or fed high dietary zinc were not significantly different. Egg production rate was highest for hens treated 10 days (both F and Zn) in the immediate weeks following the rest. However, over the entire 6-month experimental period, there were no significant differences among the four treatments. Ovary and oviduct regressed similarly in F and Zn hens. Tissue zinc concentration greatly increased during zinc feeding, especially in the pancreas, and rapidly returned to normal upon refeeding a normal layer diet. Fasting also caused a substantial increase in tissue zinc. The results show that the effectiveness of zinc as a forced-resting agent for hens is related to changes in feed intake.
研究了将禁食或高锌喂养作为诱导强制休息手段的等时长方案。选用单冠白来航蛋鸡（60周龄），按照2×2析因设计的处理方式，禁食（F）或饲喂含20000 ppm锌（Zn）的蛋鸡日粮4天或10天。高锌喂养第一天的采食量显著下降，在锌喂养的4天或10天期间，平均采食量为10.7克/只·天和6.1克/只·天。禁食或饲喂高锌日粮的母鸡体重损失没有显著差异。在休息后的几周内，接受10天处理（禁食和高锌处理）的母鸡产蛋率最高。然而，在整个6个月的实验期内，四种处理之间没有显著差异。禁食和高锌处理的母鸡卵巢和输卵管的退化情况相似。锌喂养期间组织锌浓度大幅增加，尤其是在胰腺中，重新饲喂正常蛋鸡日粮后迅速恢复正常。禁食也会导致组织锌大幅增加。结果表明，锌作为蛋鸡强制休息剂的有效性与采食量的变化有关。
