Effects Of Galacto-oligosaccharide On Growth Performance,Immune And Antioxidative Function In Weaned Piglets

The present experiment was conducted to investigate the effects of galacto-oligosaccharide(GOS)on growth performance,immune and antioxidative function in weaned piglets.Ninety 28-day-old weaned piglets were randomly allocated into 5 groups with 6 replicates(3 pens of males and 3 pens of females)per group and 3 piglets per replicate.These five diets were formulated by adding 0,500,1000,1500 and 2000 mg/kg GOS to the basal diet.The experiment lasted for 28 days,and feed and water were provided ad libitum.The results showed as follows:(1)With increased dietary supplementation of GOS,ADG(P=0.04)increased quadratically from d 14 to 28.Dietary supplementation of GOS linearly(P=0.01)or quadratically(P=0.02)increased the apparent digestibility of phosphorus during d 10-14.However,other apparent digestibility indexes were not affected.On d 28,with increasing GOS,the number of Lactobacillus markedly increased in a linear(P=0.01)or quadratic(P=0.04)dose-dependent manner,and the number of Bifidobacteria also had a linear(P<0.01)or quadratic(P<0.01)increase.But GOS decreased the number of Escherichia coli in a quadratic manner on d 14(P<0.01)and a linear manner on d 28(P=0.03).The appropriate adding dosage of GOS in diet was 1264 mg/kg.(2)Dietary supplementation of GOS improved serum IL-4 activity in a linear(P=0.01)or quadratic(P=0.04)dose-dependent manner,but GOS quadratically decreased serum TNF-α level(P=0.03).In addition,GOS increased serum concentration of soluble CD3(sCD3)in a linear or quadratic dose-dependent manner on d 14(P<0.01)and d 28(P<0.05).The appropriate adding dosage of GOS in diet was 974 mg/kg.(3)With increasing addition of GOS in diets,the level of CAT in serum of weaned piglets was increased quadratically(P=0.03)on d 14,and the level of CAT in serum was increased linearly(P<0.01)or quadratically(P<0.01)on d 28,the appropriate adding dosage of GOS in diet was 925-1100 mg/kg.In addition,MDA level showed a quadratic(P=0.02)decrease on d 28.The appropriate adding dosage of GOS in diet was 700 mg/kg.These results suggested that diet supplemented with 1000 mg/kg GOS exhibited the best effect on growth performance,immune and antioxidative function in weaned piglets.