Reidy T R, Atkinson J L, Leeson S
Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
Poult Sci. 1998 May;77(5):639-43. doi: 10.1093/ps/77.5.639.
An experiment was designed to examine the effects of strain of turkey, size of egg, and stage of embryonic development on yolk and yolk sac utilization. Sixty eggs from Nicholas and British United Turkeys of America (BUTA) breeders were selected within each of the weight categories 70 to 76, 80 to 86, and 90 to 96 g. These eggs were incubated under commercial conditions, and eggs selected at 0 or 25 d incubation, at hatch, and 24 h posthatch and yolk and embryos were weighed and assayed for fat, protein, or fatty acids. Yolk weight declined from 23.7 g at setting to 4.66 g at hatch and subsequently to 2.87 g, 24 h posthatch. Yolk weight was affected by strain and egg weight and a number of significant (P < 0.05) interactions were observed. Nicholas strain birds yielded the largest yolks, with the strain difference being most pronounced for the largest egg weight category. Larger turkey eggs contained more water, such that at 24 h posthatch there was double the amount of residual water in the yolk sac. At 24 h posthatch, the Nicholas poults had more water available in the residual yolk. Egg weight had little effect on lipid reserve in the yolk or yolk sac after 25 d incubation. Fatty acid profile of yolk lipids changed little throughout incubation. A number of strain differences are seen in fatty acid profile in the yolk during utilization, although these are quite small and may not be of sufficient magnitude to account for any strain differences seen in early poult viability or growth. Data suggests that the poult and chick may be different in metabolism of various lipid fractions, although in general nutrient utilization by the poult follows a fairly well established sequence of events.
设计了一项实验，以研究火鸡品种、蛋的大小和胚胎发育阶段对卵黄和卵黄囊利用的影响。从尼古拉斯和美国联合火鸡公司（BUTA）种鸡所产的蛋中，在70至76克、80至86克和90至96克每个重量类别中各挑选60枚蛋。这些蛋在商业条件下孵化，并在孵化0天或25天、出雏时以及出雏后24小时挑选蛋，对卵黄和胚胎称重，并分析脂肪、蛋白质或脂肪酸含量。卵黄重量从入孵时的23.7克降至出雏时的4.66克，随后在出雏后24小时降至2.87克。卵黄重量受品种和蛋重影响，观察到一些显著（P < 0.05）的交互作用。尼古拉斯品种的鸡所产的卵黄最大，品种差异在最大蛋重类别中最为明显。较大的火鸡蛋含有更多水分，以至于在出雏后24小时，卵黄囊中残留的水分是原来的两倍。在出雏后24小时，尼古拉斯雏鸡的残留卵黄中有更多水分。孵化25天后，蛋重对卵黄或卵黄囊中脂质储备的影响很小。在整个孵化过程中，卵黄脂质的脂肪酸谱变化不大。在利用过程中，卵黄中的脂肪酸谱存在一些品种差异，尽管这些差异很小，可能不足以解释在雏鸡早期活力或生长中观察到的任何品种差异。数据表明，雏鸡和幼雏在各种脂质组分的代谢上可能有所不同，尽管一般来说，雏鸡的营养利用遵循相当既定的顺序。
