Generation of a novel growth-enhanced and reduced environmental impact transgenic pig strain

Abstract

2In pig production, insufficient feed digestion causes excessive nutrients such as phosphorus and 3 nitrogen, which are then released to the environment. To address the issue of environmental 4 emissions, we have established transgenic pigs harboring a single-copy quad-cistronic transgene 5 and simultaneously expressing three microbial enzymes, β-glucanase, xylanase, and phytase in the 6 salivary glands. All the transgenic enzymes were successfully expressed, and the digestion of non-7 starch polysaccharides (NSPs) and phytate in the feedstuff was enhanced. Fecal nitrogen and 8 phosphate outputs were reduced by 23%-46%, and growth rate improved by 23.4% (gilts) and 9 24.4% (boars) when the pigs were fed on a corn and soybean-based diet and high-NSP diet. The 10 transgenic pigs showed a 11.5%-14.5% improvement in feed conversion rate compared to the 11 age-matched wild-type littermates. These findings indicate that transgenic pigs are promising 12 resources for improving feed efficiency and reducing nutrient emissions to the environment.