Transgenic Pigs that Digest Grains Better can Reduce Pork Industry's Carbon Footprint

A new research published in eLife presents transgenic pigs with the ability to digest more nutrients, which could possibly help reduce the pork industry's environmental impact.

A large amount of feed for pigs is wasted as they are unable to digest two of its key nutrients that cause environmental damage: nitrogen and phosphorus. Excessive amounts of these nutrients are subsequently released through the animals' manure into the environment, where they can pollute both air and water. Pigs release harmful amounts of these nutrients as they lack the microbial enzymes that break down phytate - the main source of nitrogen and phosphorus - and types of fiber called non-starch polysaccharides. The enzymes are β-glucanase, xylanase, and phytase.

The group led by Xianwei Zhang, postdoctoral researcher at the South China Agricultural University delivered the three enzymes into the genome of pigs. The enzymes were optimized to adapt to the pigs' digestive system. They were expressed specifically in the pigs' salivary gland, allowing the digestion of phytate and non-starch polysaccharides to begin in the mouth. The feeding trials showed that the pigs were able to digest these and other key nutrients, lowering their emissions as a result. The team also found that the animals' increased nutrient uptake led to a faster growth rate, and that no negative side effected were reported.

For more details, read the paper in eLife.