本研究旨在通过测定低蛋白质饲粮中植物源血根碱替代色氨酸后仔猪门静脉血浆流率(PVPF)、氨基酸净吸收量及血清尿素氮净吸收量,探讨血根碱替代色氨酸对仔猪PVPF及门静脉氨基酸代谢的影响。试验选取12头20 kg左右的"杜×长×大"三元杂交公猪进行血液插管手术(颈动脉、门静脉和肠系膜静脉插管),随机分为4个处理,每个处理3头猪。4个处理分别为低蛋白质饲粮组(低蛋白质组)、低蛋白质不补充色氨酸饲粮组(缺色氨酸组)、低蛋白质不补充色氨酸添加血根碱饲粮组(血根碱组)和常规饲粮组。结果表明:1)猪PVPF会随着采食时间变化整体呈上升的趋势,在后期趋于稳定,缺色氨酸组6 h内平均PVPF比低蛋白质组、血根碱组和常规饲粮组均低,但差异不显著(P>0.05)。2)缺色氨酸组门静脉赖氨酸、色氨酸及精氨酸净吸收量显著低于蛋白质组、血根碱组和常规饲粮组(P<0.05),而低蛋白质组、血根碱组和常规饲粮组3组间门静脉赖氨酸、色氨酸及精氨酸净吸收量差异不显著(P>0.05)。缺色氨酸组门静脉必需氨基酸及总氨基酸净吸收量显著低于蛋白质组、血根碱组和常规饲粮组(P<0.05),而低蛋白质组和血根碱组间门静脉必需氨基酸及总氨基酸净吸收量差异不显著(P>0.05)。3)各组的血浆尿素氮的净吸收量相近,差异不显著(P>0.05)。由此可见,低蛋白质饲粮中不补充色氨酸,对PVPF和门静脉氨基酸净吸收量有一定影响;在不补充色氨酸添加血根碱后会相对提高PVPF,增加门静脉必需氨基酸和总氨基酸净吸收量,但不影响门静脉血浆尿素氮净吸收量。

This study aimed to investigate the effects of botanical sanguinarine replacing tryptophan of low protein diets on portal vein plasma flow rate and amino acids metabolism of piglets by testing portral vein plasma flow rate (PVPF), net absorptivity of amino acids and plasma urea nitrogen of piglets. Twelve growing pigs (body wight about 20 kg, Duroc×Landrace ×Large White) were used to install blood intubation (carotid artery, portal vein and mesenteric vein), randomly divided into 4 treatment, each treatment with 3 pigs. Low protein diet was the low-protein group, low protein diet without supplementary tryptophan was the lacking tryptophan group, low protein diet with tryptophan replacement by sanguinarine was the sanguinarine group, normal diet was normal diet group. The results showed as follows: 1) PVPF was on the rise until stabilization in the later period with the feeding time, portal vein blood flow rate within 6 h of the lacking tryptophan group was lower than that of other groups, but no significant difference was observed (P>0.05). 2) The portal vein net absorption levels of lysine, tryptophan and arginine of the lacking tryptophan group was significantly lower than that of other groups (P<0.05), but no significant difference was observed between low-protein group, sanguinarine group and normal diets group (P>0.05). The portal vein net absorption levels of essential amino acid and total amino acid of the lacking tryptophan group was significantly lower than that of other groups (P<0.05), but no significant difference was observed between low-protein group and sanguinarine group (P>0.05). 3) The net absorption of the plasma urea nitrogen were closed in all groups, and no significant difference was observed (P>0.05). In conclusion, the PVPF and net absorptivity of amino acids in portal vein of piglets are affected by feeding low protein diet without adding tryptophan; the PVPF, total amino acids in portal vein and net absorptivity of essential amino acids and total amino acids of piglets are increased by feeding low protein diet with sanguinarine but not trytophan, but the net absorptivity of plasma urea nitrogen is not affected.