Porcine parvovirus (PPV) is one of the major agents causing swine reproductive failure. NS1protein is a non-structural protein of PPV and can be used as a reage
[1]Wu R X, Cui Z M, Pei T X, et al. Exploration of the optimum sowing time for dry-farming plastic-film corn in semi-arid area.North China Agriculture, 1999,14( S