Effects Of Xylooligosaccharides On Growth Performance, Meat Quality And PRKAG3 Gene Expression In Growing-Finishing Pig

Xylooligosaccharides (XOS) is one of the most active oligosaccharides which have beneficial effects on the growth of Bifidobacterium in vivo. It is hardly digested and absorbed by mono-gastric animals, hencing promoting multiplication of Bifidobacterium. Therefore, it is called non-digestible oligosaccharide. Xylooligosaccharides is widely existed in many plant fibers such as husklage, cotton seed hull. Studies on XOS started mainly on functional foods for humans in earlier years and extended to various field involving in animals, plants and microorganisms.Three experiments were conducted to investigate the effects of dietary XOS on performance, meat quality and the expression of gene-PRKAG3 in order to explore XOS effects and mechanism in growing-finishing pigs.In experiment one, one hundred and eighty healthy crossbred pigs (Duro×Yorkshine×Landrace, the average weight is about 50 kg) were randomly allotted to one of five treatments with different supplemental level of XOS (A, 50 XOS mg/kg; B, 90 XOS mg/kg; C,130 XOS mg/kg; D, contol group; E, 150 Avilamycin mg/kg) with six pens per treatment of six pigs in each pen. The feeding period lasted 68 days. As a result, dietary XOS supplementation significantly increased the average daily gain (ADG) in comparison to the control group (D), wih increasing by 16.1%, 16.1%, and 19.4% respectively for treatment A, B, and C(P<0.05). The ADG of treatment C was significantly higher than that of treatment E (P<0.05). However, there was no significant difference on ADG among the treatment A, B, and E. The feed efficiency (F/G) of treatment A, B, and C was greatly improved in comparison with treatment D, with improving by 9.4%, 10.7%, 13.1% and 7.8% respectively for treatment A, B, C and E(P<0.05). There was no significant difference on feed efficiency among the treatment A, B, C and D.In experiment two, three male and three female pigs from each treatment of one pig from each pen were sacrificed for slaughtering test. After slaughering, about 500 g dorsal longgissimus muscle was taken and quickly immerged into liquid nitrogen. The other carcass characteristics such as carcass length, backfat depth, pH, drip loss, and shear force, were also monitored. Dietary XOS supplementation had obvious effect on pH₂₄ and drip loss (P<0.05). Both treatment C and D had 2.2% higher pH₂₄ than treatment E(P<0.05). To compare with treatment D & E, drip loss decreased by 16.4% & 18.0%, 19.5% & 24.1%, and 21.1% & 22.6%, respectively. It indicates that XOS can increase water holding capacity. Dietary supplementation of XOS had no remarkable effect on carcass length and backfat depth (P>0.05). With the increasing of XOS in the diet, sensory index (pre-dealing the carcass then ripe it 24h after slaughtered) was improved (P>0.05). There was no significant difference on the other characteristices among 5 treatments(P>0.05).In experiment three, it was found that abundance of the PRKAG3RNA was increased with the increasing of dietary XOS (P>0.05). It suggests that dietary addition of XOS could not significantly influence expression of gene PRKAG3.