Sheep grazing Trigonella balansae had productivity, health and meat quality similar to sheep grazing subterranean clover or French serradella

Context. An accession of the annual legume Trigonella balansae Boiss. & Reuter. has been selected for commercial release in Australia. Aims. As part of a duty-of-care assessment, we tested the hypothesis that sheep grazing the trigonella accession will have liveweight, condition scores and wool production similar to those of sheep grazing two widely adopted annual legumes, subterranean clover (subclover, Trifolium subterraneum L. cv. Dalkeith) and French serradella (Ornithopus sativus Brot. cv. Erica). We also hypothesised that sheep grazing the three legumes will have similar meat quality and health, as indicated by blood plasma panel analysis. Methods. Wethers (n = 6) grazed plots (n = 4) of three pasture species. Liveweight, condition scores and wool growth were measured, and a subset of animals were subject to blood sampling to assess health. Consumer sensory taste analysis was used to assess meat eating quality from two sheep per plot. Forage biomass, dry-matter digestibility, crude protein, fibre, mineral content and isoflavones were measured across the plant's lifecycle. Key results. There were no significant differences in liveweight, wool growth, wool yield or condition score that were associated with pasture species during the grazing period. There were differences in dry matter digestibility, minerals and crude protein content of the pastures over time. As trigonella matured, it did not meet the minimum sulfur, phosphorus, manganese, molybdenum and copper requirements for mature sheep. We found some differences in indications of animal health; however, there were no significant systematic detrimental differences between sheep grazing trigonella and the other two species. In total, 2 of 24 individual sheep grazing trigonella had more than two plasma indicators of liver damage. There were no differences in meat tenderness, juiciness, flavour and overall consumer acceptability. Conclusions. The data supported the hypotheses. Under the conditions of this experiment, the pasture legumes had the same relative feeding value. Some care must be taken in interpreting the outcome as the trigonellacomprised only 18% of the dry matter on offer at the termination of grazing. Implications. Results of this study will be considered during the commercialisation process for T. balansae.

Automated summary

This study compared the feeding value and animal health effects of a new pasture legume, Trigonella balansae, with two widely adopted legumes. The results showed no significant differences in weight, wool growth, or condition score of sheep grazing different pastures. However, the digestibility, minerals, and crude protein content of the pastures varied over time. Sheep grazing Trigonella balansae had some health issues due to the insufficient intake of certain minerals. Nevertheless, there were no significant differences in meat quality among the three legumes based on sensory analysis.