饲粮外源代谢葡萄糖水平对仔猪门静脉回流组织氨基酸利用的影响

本试验旨在研究饲粮外源代谢葡萄糖(MG)水平对断奶仔猪门静脉回流组织(PDV)氨基酸利用量的影响。选择20头健康状况良好、体重在7.74 kg左右的25日龄杜×长×大三元杂交断奶仔猪,分为4个处理组,每组5个重复,给每头猪的门静脉、颈动脉和肠系膜静脉安装血管插管,并安装"T"型回肠瘘管。待仔猪术后恢复正常后,4组分别饲喂MG水平为22.82%、26.59%、36.37%、42.41%的等能、等氮的玉米-豆粕型饲粮,每种饲粮添加0.1%的二氧化钛(TiO2)作外源指示剂。术后3 d,从肠系膜静脉持续灌注对氨基马尿酸(PAH),并从门静脉和颈动脉采血,并且在回肠段收集食糜。结果表明:仔猪PDV氨基酸利用量随着MG水平增加呈先上升后下降的趋势;PDV对17种氨基酸的利用量均在饲粮MG水平为26.59%时达到最大值;必需氨基酸、非必需氨基酸、生糖氨基酸、支链氨基酸也在饲粮MG水平为26.59%时达到最大值(P<0.05)。可见,饲粮适宜MG水平能够显著增加小肠氨基酸消失量和门静脉氨基酸净吸收量,从而显著提高仔猪PDV对饲粮蛋白质的利用效率。

Effects of Dietary Exogenous Glucose on Amino Acid Utilization in Piglet Portal Venous Reflux Tissue

The aim of this research was to study the effects of different exogenous metabolic glucose levels to the utilization of amino acids form weaned piglet's Portal-drained viscera. 20 hybrid weaned piglets(25-day-old and average body weight of 7.74 kg) were randomly divided into 4 treatment groups, with 5 replicates per treatment and 1 pig per replicate. The vascular fistulas was installed on the portal vein, carotid artery and mesenteric of each pig respectively,and the T-Cannula was implanted into the terminal ileum. After the piglets returned to normal, they were fed four diets that based on corn and soybean,with equal energy but different metabolic glucose(MG). 0.1% TiO2 was added as an external indicator to each dietary. The chyme was collected from the ileum, and PAH were continuously perfused from the mesenteric vein then blood was collected from the portal vein and carotid artery. The results showed that the amino acid utilization of piglet PDV tissue under the four dietary MG levels presented a trend of increasing first and then decreasing with the increase of MG levels. The maximum value of all 17 amino acids in PDV tissues was reached when the dietary MG level was 26.59%. Essential amino acids(EAA), non-essential amino acids(NEAA), raw sugar amino acids(GAA), and branched chain amino acids(BCAA)reached the maximum at 26.59 % in the dietary MG levels(P<0.05). The portal vein of histidine in the 4 treatment groups reached the maximum at 22.82% of the dietary MG level(P<0.05). In summary, dietary MG levels can significantly increase the disappearance amount of intestinal amino acid and the absorption amount of portal vein amino acid, thereby significantly improving the efficiency of dietary protein utilization in piglet PDV tissues.