Eklund M, Mosenthin R, Piepho H-P, Rademacher M
Institute of Animal Nutrition, University of Hohenheim, Stuttgart, Germany.
J Anim Physiol Anim Nutr (Berl). 2008 Oct;92(5):578-90. doi: 10.1111/j.1439-0396.2007.00751.x.
The study was carried out to estimate basal ileal endogenous crude protein and amino acid losses (IAAL(B)) and standardized ileal digestibilities (SID) of crude protein (CP) and amino acids (AA) originating from casein in newly weaned pigs from linear relationships between ileal recoveries and dietary intakes of graded levels of CP and AA. A total of 14 (12 + 2 for replacement) 3-week-old barrows weighing 5.7 kg was fitted with simple T cannulas at the distal ileum. At 28 days of age, the pigs were randomly allocated to the six experimental diets with two pigs per diet in four weekly repeated measurements. Corn starch-based diets, containing six graded levels of CP from casein (90, 155, 220, 285, 350, 415 g/kg CP as-fed basis respectively), were formulated. Titanium dioxide (TiO(2)) was included as a digestibility marker. Each experimental period consisted of 7 days. Ileal digesta were collected for a total of 24 h during day 6 and 8. Splitting the total range of 90 to 415 g/kg CP into smaller ranges, i.e. from 90 to 220, 220 to 350 or 285 to 415 g/kg CP, provides estimates for CP and AA recoveries which are not significantly different from zero. As a result, dietary CP and AA originating from casein are completely digested and absorbed until the end of the small intestine. In addition, the use of large ranges of dietary CP levels showed that IAAL(B) were affected (p < 0.050) by the dietary CP content. Accepting that ileal recoveries of CP and AA are exclusively of endogenous origin when purified corn starch casein-based diets are fed, IAAL(B) were estimated as a function of the dietary CP level. There were linear increases (p < 0.050) in IAAL(B) when the dietary CP content was increased from 90 to 415 g/kg. Average IAAL(B) expressed in g/kg dry matter intake (DMI) were 16.3, 0.7, 0.2, 0.9 and 0.2 for CP, lysine, methionine, threonine and tryptophan respectively. These values are in close agreement with IAAL(B) obtained in grower-finisher pigs.
本研究旨在通过回肠回收率与不同梯度水平粗蛋白（CP）和氨基酸（AA）日粮摄入量之间的线性关系，估计新断奶仔猪基础回肠内源粗蛋白和氨基酸损失（IAAL(B)）以及酪蛋白来源的粗蛋白（CP）和氨基酸（AA）的标准回肠消化率（SID）。总共14头（12头 + 2头用于替换）3周龄体重5.7 kg的公猪在回肠末端安装了简单的T型套管。在28日龄时，将猪随机分配到六种实验日粮中，每种日粮2头猪，进行四周重复测量。配制了以玉米淀粉为基础的日粮，其中含有六种梯度水平的酪蛋白CP（分别为90、155、220、285、350、415 g/kg CP，以饲喂基础计）。添加二氧化钛（TiO₂）作为消化率标记物。每个实验期为7天。在第6天和第8天总共收集24小时的回肠食糜。将90至415 g/kg CP的总范围分成较小范围，即90至220、220至350或285至415 g/kg CP，可得出CP和AA回收率的估计值，这些值与零无显著差异。因此，酪蛋白来源的日粮CP和AA在小肠末端之前完全被消化和吸收。此外，使用较大范围的日粮CP水平表明，IAAL(B)受日粮CP含量的影响（p < 0.050）。当饲喂纯化的玉米淀粉酪蛋白基础日粮时，假设CP和AA的回肠回收率完全来自内源，IAAL(B)被估计为日粮CP水平的函数。当日粮CP含量从90增加到415 g/kg时，IAAL(B)呈线性增加（p < 0.050）。以每千克干物质摄入量（DMI）表示的平均IAAL(B)，CP、赖氨酸、蛋氨酸、苏氨酸和色氨酸分别为16.3、0.7、0.2、0.9和0.2。这些值与生长育肥猪获得的IAAL(B)非常一致。
