摘要
Measurements of precaecal amino acid digestibility with digesta sampled from slaughtered animals may be affected by the chosen length of the sampled section. The length needs standardization, therefore, when digestibility is understood to be a measure of feedstuff potential. It was our objective to study the change in the net disappearance of amino acids from the lower small intestine of broiler chicken. The section between Meckel's diverticulum and 2 cm anterior of the ileo-caeco-colonic junction was cut into three subsections of equal length: proximal, medial, and terminal. The contents of each subsection were pooled within the birds of each pen (12 in Experiment 1 and 10 in Experiment 2). TiO2 was used as an indigestible marker. Prior to digesta sampling, broilers had been fed the experimental diets for seven days. In Experiment 1, two diets with either soybean meal or a mix of soybean meal and peas as the main protein sources were used. Each diet was allocated to eight pens and feeding commenced on day 14 of age. Net disappearance was significantly affected by diet only in regard to aspartic acid and methionine. No significant interaction between diet and subsection occurred. Net disappearance was significantly affected by subsection for all amino acids. It ranged from 74 – 92% for individual amino acids without significant differences in the medial and terminal subsections. Net disappearance was, however, between 3% and 9% lower in the proximal subsection. In Experiment 2, diets contained soybean meal as the main protein source and were given to 18 pens from day 22 of age. Again, the effect of subsection on net disappearance was significant for all amino acids. Net disappearance was significantly lower in the proximal than in the middle subsection, and differences ranged from 5 – 10%. Significant differences in the net disappearance were also found for most of the amino acids between the middle and the terminal subsection ranging from 2 – 4%. In conclusion, when precaecal amino acid digestibility should be used as a measure for a protein source's potential, digesta sampling should not consider the proximal third of the section between Meckel's diverticulum and the end of the ileum.
摘要译文
用屠宰动物取样的消化物测量前胆固醇氨基酸消化率可能受到取样切片长度的影响。长度需要标准化，因此，当消化率被理解为是一种饲料潜力的测量。我们的目标是研究肉鸡下部小肠中氨基酸净消失的变化。Meckel憩室与回肠 - 结肠连接处2 cm前部之间的切片被切成三段长度相等的部分：近端，内侧和末端。每个小节的内容汇集在每支笔的鸟类内（实验1中12个，实验2中10个）。 TiO 2被用作难消化的标记。在消化采样之前，肉鸡已经喂食实验饮食七天。在实验1中，使用两种豆粕或豆粕和豌豆混合物作为主要蛋白质来源的日粮。每种饮食分配给8支笔，并在14日龄开始喂食。净消失仅受天冬氨酸和甲硫氨酸的影响。饮食和分节之间没有发生显着的相互作用。对于所有氨基酸，净消失都受到分节的显着影响。对于单个氨基酸，其范围为74-92％，而在内侧和末端小节没有显着差异。然而，净失踪是，在近端部分下降3％至9％。在实验2中，日粮含有豆粕作为主要蛋白质来源，并从22日龄开始给予18支围栏。再次，对于所有氨基酸，子部分对净消失的影响是显着的。近端的净消失明显低于中段，差异范围在5 - 10％之间。大部分氨基酸在中间和末端小节之间的净消失率也有显着差异，从2％到4％不等。总之，当预处理氨基酸消化率应该被用作衡量蛋白质来源的潜力时，消化道取样不应考虑Meckel憩室与回肠末端之间的近端三分之一部分。
Holger Kluth [1];Katrin Mehlhorn [1];Prof. Dr Markus Rodehutscord [2]. Studies on the intestine section to be sampled in broiler studies on precaecal amino acid digestibility[J]. Archives of Animal Nutrition, 2005,59(4): 271-279