Sauer W C, Mosenthin R, Ozimek L
Dept. of Anim. Sci., University of Alberta, Edmonton, Canada.
J Anim Sci. 1988 Oct;66(10):2583-9. doi: 10.2527/jas1988.66102583x.
Studies were carried out with six growing barrows fitted with a simple T-cannula 5 to 10 cm anterior to the ileo-cecal sphincter. In Exp. 1, the digestibility of biotin was determined in three cornstarch-based diets formulated to contain 16% CP by supplementation with soybean meal (SBM), meat and bone meal (MBM) and canola meal (CM). In Exp. 2 the digestibility of biotin was determined in three diets that contained 96.8% barley, corn or wheat. Experiments 1 and 2 were conducted according to a replicated 3 X 3 latin square design. In Exp. 3 pigs were fed a cornstarch-based diet supplemented with 12% vitamin-free casein to determine the amount of endogenous biotin. In Exp. 4 the digestibility of supplemental biotin was determined. There was a small amount of endogenous biotin in ileal digesta, 11 micrograms/kg DMI. Digestibilities of biotin determined at the distal ileum (apparent digestibilities corrected for endogenous biotin) were 55.4, 2.7 and 3.9% in SBM, MBM and CM, respectively, and 4.8, 4.0 and 21.6% in barley, corn and wheat, respectively. The digestibility of supplemental biotin was 93.5%. There was a large increase in the level of biotin between digesta collected from the distal ileum and in feces, ranging from 138 to 324 micrograms/kg DMI. With the exception of the CM diet, this increase exceeded dietary biotin intake. Biotin in many feedstuffs was not available in the small intestine.
对六头生长中的公猪进行了研究，这些猪在回盲括约肌前方5至10厘米处安装了简单的T型套管。在实验1中，通过添加豆粕（SBM）、肉骨粉（MBM）和油菜籽粕（CM），在三种含16%粗蛋白的玉米淀粉基日粮中测定生物素的消化率。在实验2中，在三种分别含有96.8%大麦、玉米或小麦的日粮中测定生物素的消化率。实验1和2按照重复的3×3拉丁方设计进行。在实验3中，给猪饲喂添加12%无维生素酪蛋白的玉米淀粉基日粮，以确定内源性生物素的含量。在实验4中，测定补充生物素的消化率。回肠食糜中存在少量内源性生物素，为11微克/千克干物质摄入量。在回肠末端测定的生物素消化率（校正内源性生物素后的表观消化率）在SBM、MBM和CM中分别为55.4%、2.7%和3.9%，在大麦、玉米和小麦中分别为4.8%、4.0%和21.6%。补充生物素的消化率为93.5%。从回肠末端收集的食糜和粪便中的生物素水平有大幅增加，范围为138至324微克/千克干物质摄入量。除了CM日粮外，这种增加超过了日粮生物素摄入量。许多饲料中的生物素在小肠中无法利用。
