The survival rate of weaned pigs is one of the most important issues for ranch operators. People used to add antibiotics into fodder to anti diarrhea, increase food intake and keep weaned pig health. However, it's been reported that abuse of antibiotics may lead to bacterial resistance and may harmful to the human micro-biome. Many countries have restricted regulation to control antibiotics usage in the fodder. Thus, developing new product to replace antibiotics will be a great progress for traditional livestock raising.

Recently, researchers in Institute of Subtropical Agriculture, Chinese Academy of Sciences（ISA） has found that antimicrobial peptides (AMPs) could keep grice healthy and reduce diarrhea rate, which are benefit for pig growth performance and are also an enhancement to weaned pig survival rate.

AMPs include lactoferrin, cecropin, defensins, plectasin and other small peptide. It was reported to inhibit bacteria and fungus growth, but there is no quantify research to evaluate AMPs efficiency. In this study, Dr. XIONG Xia of ISA added different concentration of AMPs into routine diet as experiment group, use routine diet without any AMPs as control, and supply to five different ranches respectively, compare control group and experiment group, calculate their average daily gain(ADG), average daily feed intake (ADFI), and feed conversion rate (G:F) to check AMPs functions.

"AMPs could significantly improve weaned pig health condition, raise food intake and promote weight increase."Said XIONG. Compared with the control group, weaned pigs present higher G:F rate, indicating that dietary supplementation with AMPs could enhance grice growth.

This study showed weaned pig health also related with concentration of AMPs. Increases AMPs concentration could dramatically reduce weaned pig diarrhea rate, and enhance ADG rate.

In summary, this work found dietary with AMPs supply is benefit for weaned pig growth, reduce diarrhea rate and increases survival rate. Further study is going on to confirm AMPs function details, and evaluate different component efficiency.

This work was supported by the National Natural Science Foundation of China, National Science and Technology Support Program Funding, Nanjing Branch Academy of Chinese Academy of Sciences, Jiangxi Province Cooperation Project, Hunan Project and Guan- dong project.

Main findings are published on Livestock Science( http://www.sciencedirect.com/science/article/pii/S187114131400225X)