van der Hel W, Verstegen M W, Pijls L, van Kampen M
Department of Animal Husbandry, Agricultural University, Wageningen, The Netherlands.
Poult Sci. 1992 Dec;71(12):2014-21. doi: 10.3382/ps.0712014.
Newly hatched chicks were allotted to five different climatic treatment groups (28 to 32, 32 to 34, 34 to 35, 35 to 37, and 37 to 40 C) for 2 days after hatch during which feed and water were withheld. Their performance was measured for 2 wk and compared with control chicks kept under normal conditions. During the 2 days of climatic treatment, chicks lost weight of 5.3, 5.4, 6.7, 8.5, and 10.1 g, respectively, but control chicks grew 16.0 g. During 14 days of feed intake, chicks of the highest treatment group grew significantly less (217.5 g) than controls (267.7 g). Also, feed intake was significantly lower (292 versus 386 g). In the group exposed to 37 to 40 C, feed conversion decreased significantly from 1.43 to 1.37 g:g and mortality increased to more than 49%. Body composition of DM, protein, fat, and ash was also estimated. Chicks previously exposed to 37 to 40 C had significantly lower values for the gain in body components: DM (18.49 g), protein (7.13 g), fat (8.75 g), and ash (2.62 g) per chick at 2 wk. The ratios water:protein gain and fat:protein gain after posthatching heat exposure were decreased from 3.82 to 3.45 g:g and .76 to .67 g:g, respectively, whereas the ratio of gain in energy retention:weight gain was similar to that of controls.
刚孵出的雏鸡在孵化后被分配到五个不同的气候处理组（28至32℃、32至34℃、34至35℃、35至37℃和37至40℃），为期2天，在此期间不给它们喂食和饮水。对它们的生长性能进行了2周的测量，并与饲养在正常条件下的对照雏鸡进行比较。在气候处理的2天里，雏鸡体重分别减轻了5.3克、5.4克、6.7克、8.5克和10.1克，而对照雏鸡体重增加了16.0克。在14天的采食量期间，最高处理组的雏鸡生长明显低于对照组（217.5克对267.7克）。此外，采食量也显著降低（292克对386克）。在暴露于37至40℃的组中，饲料转化率从1.43克:克显著降至1.37克:克，死亡率增加到49%以上。还对雏鸡的干物质、蛋白质、脂肪和灰分的身体组成进行了评估。先前暴露于37至40℃的雏鸡在2周龄时，每只雏鸡的身体成分增加量显著较低：干物质（18.49克）、蛋白质（7.13克）、脂肪（8.75克）和灰分（2.62克）。孵化后热暴露后，水:蛋白质增加量和脂肪:蛋白质增加量的比例分别从3.82克:克降至3.45克:克和从0.76克:克降至0.67克:克，而能量保留增加量:体重增加量的比例与对照组相似。
