Effect Of Epidermal Growth Factor On Growth Performance And Apparent Digestibility Of Weaning Piglets

The effects of high bio-activity epidermal growth factor expressed by Pichia pastoris on the weaning piglets were studied in this paper.The trails of the growth performance,apparent digestibility and serum physiological indexes were carried out to identity the function of epidermal growth factor in alleviating the weaning stress of piglets.The application protocol was confirmed in this study.This study was consisted of three experiments.The first trial was concentration gradient test.Two hundred weaned piglets were divided into 5 treatments.Each treatment contained 5 repeats and each repeat contained 8 piglets.The treatments were defined as follow,treatment A as the control group feeding with the basic diet,treatment B,C,D,E each feeding with 15μg/kg,30μg/kg,45μg/kg,60μg/kg EGF product in the basic diet.The second trial was mid-scale group test.Two hundred forty weaned piglets of 25 days old were divided into 2 treatments.Each treatment contained 5 repeats and each repeat contained 24 piglets.The treatments were defined as follow,treatment A as control group feeding with the basic diet and treatment B feeding with 30μg/kg EGF product in the basic diet.The apparent digestibility and serum physiological indexes were detected.The third trial was low protein diet test.One hundred fifty weaned piglets were randomly divided into 2 treatments.Each treatment contained 5 repeats and each repeat contained 15 piglets.The treatments were defined as follow,treatment A as the control group feeding with the basic diet of low protein and treatment B feeding with 30μg/kg EGF product in the basic diet.The results of the first trial showed that the treatment with 30μg/kg EGF had the best effects of significantly increasing the daily intake and the daily gain and reducing the F/C(P < 0.05)from weaning to day 70.The treatment with 30μg/kg,45μg/kg and 60μg/kg EGF could significantly reduce the diarrhea rate of weaned piglets(P < 0.01).The results of the second trail showed that the apparent digestibility of the treatment with 30μg/kg EGF was increased.The total energy and the apparent digestibility of crude protein in the EGF group were significantly higher than those of the control group(P < 0.05)in day7-11.The NDF and ADF were significantly higher than those of the control group(P<0.01).However,there were no significant difference in crude fiber,dry matter,calcium and phosphorus(P>0.05).The total energy,dry matter and crude protein were significantly higher than those of the control group(P<0.05)in day 27-31 and there was no significant difference in the apparent digestibility of NDF,ADF,calcium and phosphorus(P > 0.05).The TP of serum was significantly increased and BUN was significantly decreased at 11 d and 31 d.The results of the third trail showed that the growth performance and the average daily gain of the treatment with EGF were significantly improved(P<0.05),and the feed conversion ratio was significantly reduced by 2.99%(P < 0.01).Conclusion:Epidermal growth factor not only plays an important role in improving the performance of piglets,but also has a significant impact on improving the digestibility and protein utilization of animals.By adding different doses of epidermal growth factor to the diets of weaned piglets,the results showed that 30μg/kg was the best dosage,which could significantly increase the daily intake and the daily weight gain,reduce the feed conversion ratio,and significantly reduce the diarrhea rate of weaned piglets.