Stein H H, Trottier N L, Bellaver C, Easter R A
Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
J Anim Sci. 1999 May;77(5):1180-7. doi: 10.2527/1999.7751180x.
An experiment was conducted to investigate the effects of BW, feed intake, and the physiological condition of the animal on the loss and amino acid composition of endogenous protein in swine. Ten growing barrows and five multiparous sows were equipped with a T-cannula in the distal ileum for digesta collection. A protein-free diet was fed to all animals. The barrows were given free access to the experimental diet. The sows also were allowed to consume the diet on an ad libitum basis, and digesta were collected during lactation and in the following gestation period. In addition, digesta from the gravid sows were collected after restricting the sows to 2 kg of feed per day. For each animal group, the endogenous losses of protein and amino acids were calculated in relation to DMI, and the amino acid composition of endogenous protein was calculated. The total endogenous gut protein loss at the distal ileum of growing pigs, lactating sows, and gestating sows, given free access to feed, was 12.4, 9.4, and 11.2 g/kg DMI, respectively. These values were not different (P > .10). However, when gestating sows were fed only 2 kg/d, 17.8 g of endogenous protein was lost per kilogram of DMI, which was higher (P < .05) than for any of the other groups. This difference was mainly caused by higher (P < .05) losses of glycine, proline, and serine. There were no differences (P > .05) in amino acid composition of endogenous protein between growing pigs, lactating sows, and gestating sows given free access to feed, but restricted-fed gestating sows had an amino acid composition of endogenous protein that was significantly different from that of the other groups. The results from the experiment showed that age, BW, and the physiological condition of the animal have little or no effect on the amount of endogenous protein and amino acids lost at the distal ileum of hogs if calculated in relation to DMI. Likewise, the amino acid composition was not affected by the BW or physiological condition of the animal. However, DMI had a significant effect on endogenous protein losses in sows as well as on amino acid composition of endogenous protein.
进行了一项实验，以研究体重、采食量和动物生理状况对猪内源蛋白损失及氨基酸组成的影响。选用10头生长育肥公猪和5头经产母猪，在回肠末端安装T型瘘管以收集食糜。给所有动物饲喂无蛋白日粮。育肥公猪可自由采食实验日粮。母猪也可自由采食该日粮，并在泌乳期和随后的妊娠期收集食糜。此外，在将母猪的采食量限制为每天2千克后，收集妊娠母猪的食糜。对于每个动物组，根据干物质采食量（DMI）计算内源蛋白和氨基酸的损失，并计算内源蛋白的氨基酸组成。自由采食的生长猪、泌乳母猪和妊娠母猪在回肠末端的总内源肠道蛋白损失分别为12.4、9.4和11.2克/千克DMI。这些值没有差异（P>.10）。然而，当妊娠母猪每天仅饲喂2千克时，每千克DMI的内源蛋白损失为17.8克，这比其他任何组都高（P<.05）。这种差异主要是由于甘氨酸、脯氨酸和丝氨酸的损失较高（P<.05）。自由采食饲料的生长猪、泌乳母猪和妊娠母猪之间，内源蛋白的氨基酸组成没有差异（P>.05），但采食量受限的妊娠母猪的内源蛋白氨基酸组成与其他组有显著差异。实验结果表明，如果根据DMI计算，动物的年龄、体重和生理状况对猪回肠末端内源蛋白和氨基酸的损失量影响很小或没有影响。同样，氨基酸组成也不受动物体重或生理状况的影响。然而，DMI对母猪的内源蛋白损失以及内源蛋白的氨基酸组成有显著影响。
