饲粮粗蛋白质水平对断奶仔猪胃肠分泌及血清激素水平的影响

摘要

本文旨在研究饲喂不同粗蛋白质( CP)水平饲粮对断奶仔猪胃肠内环境变化及血清激素水平的影响. 选取28头35日龄平均体重为(10.0±1.0) kg的"杜×长×大"断奶阉公仔猪,随机分为4个组,每个组7个重复,每个重复1头猪. 各组分别饲喂无氮、低( 14% CP)、中( 17%CP)、高( 20% CP) 4种不同CP水平饲粮. 每头试验猪同时安装胃"T型"瘘管和颈动脉血管插管,术后恢复 5 d. 于正式试验第 6~8 天,每天餐前( 0 min ) ,自采食起 30、60、120、180 和300 min连续采取颈动脉血,并在第13~17天,胃食糜样每日每头猪采集1次( 0和300 min在同1 d进行) ,采样时间以随机顺序分别自采食起0、30、60、120、180和300 min不同时间点对试验猪进行胃食糜样采集,每头猪每天采集1个时间点,收集胃糜,分别检测血清激素指标、胃糜上清液pH和胃蛋白酶活性. 断奶仔猪为限制饲喂,每天450 g,自由饮水(收集胃糜期间除外) ,收集胃糜期间水料比为2:1. 结果表明:高、中、低3个CP水平饲粮对断奶仔猪平均日增重无显著影响(P>0.05),无氮饲粮组体重则呈负增长,且与其他组显著差异(P<0.05). 随着CP水平的降低,小肠长度减少( P>0.05) ,胃肠排空比率增加( P>0.05). 血清中胆囊收缩素、饥饿素、胃泌素、胃抑素、胃蛋白酶原Ⅰ和胃蛋白酶原Ⅱ水平不受CP水平和胃消化时间的显著影响( P>0.05). 本研究结果表明,在限制饲喂的情况下,与常规饲粮(粗蛋白质水平为20%)相比,断奶仔猪饲粮CP水平降低6%,不影响其胃pH、胃蛋白酶活性和血清激素水平.%The study was conducted to evaluate the effects of different dietary crude protein levels on gastroin-testinal internal environment change, gastrointestinal hormone levels of weaning piglets. Twenty-eight weaning piglets (Duroc×Large White×Landrace) with an initial body weight of (10.0±1.0) kg were randomly divided into four groups. Four diets containing 0 ( NFP) , 14% ( LP) , 17% ( MP) , and 20% ( HP) crude protein were fed, 7 replicates per treatment, 1 pig per replicate. Each piglet was placemented gastric fistula and carotid artery through surgical operation. And each pig was taken care for 5 d after surgery. Collecting arterial serum according to the time point before the meal (0 min), and 30, 60, 120, 180, and 300 min after fed from 6th to 8th days. And gastric chime was collected according to the same time point with serum from 13th to 17th days. Every pig was collected 1 time point every day except 0 and 300 min. Serum hormone levels, liquid su-pernatant of gastric chime, and pepsin activity were determined. All piglets were limited to feed, 450 g per day and were free to water except the time when collecting gastric chime. And the ratio of feed to water is 2 to 1 when collecting gastric chime. The results showed that the average daily gain ( ADG) had no significant differ-ence among HP, MP, and LP groups (P>0.05), piglets fed with NFP diet had a negative growth in ADG, and had significant difference with the other groups ( P<0.05) in the case of restricted feeding. With the de-crease of crude protein level, the length of small intestine was declined ( P>0.05) and the gastrointestinal evac-uation rate was accelerated ( P>0.05) . Serum levels of cholecystokinin ( CCK) , ghrelin, gastrin, gastric in-hibitory polypeptide ( GIP) , pepsinogen Ⅰ ( PG Ⅰ) , and pepsinogen Ⅱ ( PG Ⅱ) were not or little influ-enced by crude protein level and intake time ( P>0.05) . These results indicate that the 6% decrease of dietary crude protein level do not influence the pH, pepsin activity and serum hormone levels of weaning piglets com-pared with common diet ( crude protein is 20%) in the case of restricted feeding.