测定不同果皮、胚乳、胚芽含量人工玉米建立生长猪玉米氨基酸消化率预测方程

本试验选用18头初始体重为(24.7±2.5)kg、安装简单T型回肠瘘管的三元杂交(杜洛克×长白×大白)去势公猪,采用直接法测定15种不同果皮、胚乳和胚芽比例的人工玉米表观和标准回肠末端氨基酸消化率,以此为依据建立生长猪对玉米氨基酸消化率的预测方程。试验采用3个6×6拉丁方设计,分为6期,15种日粮,以无氮日粮法测定内源氮损失,以三氧化二铬为指示剂。每个试验期为7 d,前5 d为预试期,后2 d为食糜收集期。结果表明:营养成分含量不同的玉米各种氨基酸消化率存在显著差异(P<0.05)。试验中15种人工玉米赖氨酸的表观消化率范围是59.56%~80.82%,标准消化率则为70.94%~91.87%。通过对人工玉米营养成分和消化率的测定,可建立赖氨酸、蛋氨酸标准回肠消化率的线性回归方程。

Modeling of Amino Acid Ileal Digestibility in Growing Pigs Fed Simulated Corns Containing Different Portions of Pericarp, Endosperm, and Germ

The experiment was c onducted to model the amino acid ileal digestibility of corn in growing pigs fed the diets containing one of fifteen types of simulated corn,which was composed of pericarp part(hulls),endosperm part(grits,and meal),germ fraction(brans).Eighteen crossbred(Duroc×Landrace×Yorkshire) barrows(initial BW 24.7±2.5 kg) with a simple T-cannula were randomly assigned to one of the eighteen diets(fifteen corn diets and three nitrogen free diets,using chromic oxide as an exogenous indicator) in three 6 ×6 Latin square design with six 7-d periods,which comprised 5 d for adaption and 2 d for digesta collection.The results showed that significant differences in the amino acid ileal digestibility of fifteen simulated corns(P<0.05).The apparent ileal digestibility of lysine ranged from 59.56 to 80.82%,while the standardized ileal digestibility ranged from 70.94% to 91.87%.Several chemical parameters were identified to predict the standardized ileal digestibility of lysine and methionine.