Barenbrug New Zealand Limited Smart Ideas funded projects

Legumes provide nitrogen to pastures and are high-protein feed for ruminants. However, protein degradation in the rumen results in inefficient utilization and increases susceptibility to bloat. Condensed tannins (CTs) protect proteins from ruminal degradation, allow passage to the ruminant digestive system thus improving animal nutrition efficiency, leading to increased animal productivity (milk, wool, and meat). Protein-CT binding in the rumen reduces nitrogen losses, bloat (less ruminal gas  foam), methane and nitrous oxide production, and internal parasites. CTs also protect plants against pests and diseases.White clover only produces CTs in flowers and trichomes. Decades of clover breeding has failed to increase CTs in foliage to effective levels, but recent GM manipulation has demonstrated increased CT foliage levels. Here we provide a non-GM route to achieving that goal.Barenbrug NZ has bred a novel white clover. Our analyses have revealed an altered transcription factor that is inducing overexpression of a secondary metabolite pathway. We hypothesize that by knocking out a gene in this pathway it will be possible to increase the CT content in white clover.The resulting clover would provide a non-GM pasture legume that could significantly mitigate livestock waste (methane and nitrogen), through CT binding plant proteins in the rumen and passing proteins to the digestive system, where they are efficiently utilized by the animal. This would improve: nutrient use efficiency of livestock, animal health, and reduce environmental footprint of ruminants.

Barenbrug has identified an unusual distantly related ryegrass ecotype that exhibits a unique property that may improve livestock gain efficiency and pasture resilience. Over the past 16 years, this character has been bred into elite New Zealand germplasm resulting in plant lines with known genetic structure and a diverse range of this trait in the field. Using state-of-the-art metabolomic and genomic tools, the aim of this project is to identify the chemicals and genetic tags responsible for this character. This knowledge will facilitate the breeding of ryegrass cultivars that will substantially improve livestock gain through improved pasture utilisation. Improved ryegrass utilization will help maintain legumes, herb species, and other more resilient grasses in mixed pastures. The anticipated outcomes include promotion of biological nitrogen fixation, mitigation against nitrogen leaching, and improved management and maintenance of diverse, resilient, productive pastures in alignment with regenerative farming goals.