基于猪体外仿生消化技术研究高粱与玉米养分降解效率的差异

Differences in Nutrient Degradation Efficiency between Sorghum and Corn Based on Bionic Digestion of Pigs in Vitro

本试验旨在解析高粱和玉米养分降解效率的差异,探究不同类型高粱替代玉米的潜力。以国产黄玉米、进口美国高粱、国产低单宁高粱和高单宁高粱为研究对象,通过体外仿生消化技术模拟高粱和玉米在猪前肠道中化学酶消化和后肠道中微生物发酵过程,解析高粱和玉米养分在猪前、后肠道的消化差异,每个处理分别设置5个重复和3个空白对照。结果表明:1)在胃蛋白酶作用下,国产低单宁高粱的养分消失率与国产黄玉米和进口美国高粱没有显著差异(P>0.05),而国产高单宁高粱的养分消失率显著低于国产黄玉米、进口美国高粱和国产低单宁高粱(P<0.05)。2)无论在胃蛋白酶-胰液素还是在胃蛋白酶-胰液素-微生物发酵作用下,国产低单宁高粱的养分消失率与进口美国高粱没有显著差异(P>0.05),但是显著低于国产黄玉米养分消失率(P<0.05),且显著高于国产高单宁高粱的养分消失率(P<0.05)。3)与其他处理相比,国产高单宁高粱的猪胃蛋白酶-胰液素酶解残渣的微生物发酵产气量在36和48 h显著降低(P<0.05),且发酵液中的总挥发性脂肪酸含量显著降低(P<0.05),pH显著升高(P<0.05)。综上所述,基于体外模拟猪的化学酶和微生物降解2种消化方式,国产低单宁高粱的养分消失率与进口美国高粱没有显著差异,而国产高单宁高粱的养分消失率较低。因此,尽管国产低单宁高粱比高单宁高粱更适合替代国产黄玉米用作猪能量饲料原料,但是仍不能忽略高粱养分消化率低的产业难题。

To compare the nutrient degradation efficiency between sorghum and corn and investigate the potential of different types of sorghum to replace domestic yellow corn,imported American sorghum,and domestic low tannin and high tannin sorghum were employed to analyze the differences between the digestion of sorghum and corn nutrients in porcine foregut and hindgut by simulating the process of chemical enzyme digestion in the foregut and microbial fermentation in the hindgut through in vitro bionic digestion technology,five replicates and three blank controls were set up for each treatment.These results showed as follows:1)disappearance rates of nutrient of domestic low tannin sorghum,domestic yellow corn and imported American sorghum showed no significant difference during the digestion of pepsin process(P>0.05),while which of domestic high tannin sorghum was significantly lower than that of domestic yellow corn,imported American sorghum and domestic low tannin sorghum(P<0.05).2)Under the digestion of pepsin-trypsin or the digestion of pepsin-trypsin and then fermentation of cecal microbiota,there was no significant difference in the nutrient disappearance rate between domestic low tannin sorghum and imported American sorghum(P>0.05).However,both domestic low tannin sorghum and imported American sorghum exhibited a lower nutrient disappearance rate than domestic yellow corn(P<0.05),and a higher nutrient disappearance rate than domestic high tannin sorghum(P<0.05).3)Compared with the other treatments,the total gas production of porcine pepsin-trypsin enzymatic residues of high tannin sorghum exhibited a significant decrease at 36 and 48 h(P<0.05)and the content of total volatile fatty acids in the fermentation broth was significantly decreased(P<0.05),and the pH was significantly increased(P<0.05).Based on the in vitro simulation of both chemical enzyme and microbial degradation digestion in porcine,the rate of nutrient disappearance of domestic low tannin sorghum showed no significant difference with that of imported American sorghum,whereas the rate of nutrient disappearance of domestic high tannin sorghum was lower.Therefore,although domestic low tannin sorghum is more suitable to corn as an energy feed ingredient than domestic high tannin sorghum,and the challenge of low nutrient digestibility of sorghum cannot be ignored.