L.LSM.0026 - A novel amino acid approach to lamb survival

Summary

This project developed novel methods to improve lamb survival, particularly twins/multiples between conception and weaning. Twin-bearing ewes sustain higher nutritional demands during gestation with nutritional recommendations focused on meeting higher energy requirements. Amino acids including glutamine, glutamate, arginine, histidine and leucine have been identified as limiting in twin fetuses development. These amino acids are important for fetal growth and contribute significantly to hormone production required for fetal development. The first experiment in this project aimed to determine the role of non-essential (glutamine and glutamate) and essential (arginine, histidine and leucine) amino acid supply in twin-bearing ewes on foetal development and lamb vigour under controlled animal trial conditions. The results indicated that twin lambs born from ewes supplemented with rumen protected glutamine during late gestation had similar growth rates to single-born lambs at weaning, although there was no statistical significance between treatments. Based on these findings several nutrition companies demonstrated interest in exploring opportunity to develop a rumen protected glutamine product that could be utilised to achieve the remaining project objectives and improve lamb vigour and survival metrics. Unfortunately a consistent supply of rumen protected glutamine could not be sourced for the remaining trails as the method for developing the product is not commercially available and requires further R&D development. Discussions with one commercial global nutrition company have shown promise although reaching a definitive agreement may take time, the company remains optimistic about potential collaboration and its positive impact for the sheep and red meat industry.

Objectives

The current project aims to:
1) Determine the role of Non-Essential (glutamine and glutamate) and Essential (arginine, histidine and leucine) amino acid supply in twin-bearing ewes on foetal development and lamb vigour.
2) Determine if oxygen is required in combination with amino acid supplementation to optimise amino acid metabolism.
3) Determine the timing of amino acids supplementation during pregnancy of twin-bearing ewes based on cost-effectiveness.
4) Evaluate the cost-effectiveness and practicalities of supplementing amino acids on-farm under two different feeding regimes to evaluate foetal loss, lamb survival at birth and weaning.

Key findings

• Twin lambs born from ewes supplemented with glutamine during late gestation were able to grow at a similar rate as single-born lambs by weaning, showing similar liveweights (25.2, 27.6 and 18.5 kg, respectively for glutamine, single and twin control groups). It demonstrates the potential benefit in using maternal amino acid supplementation to reduce mortality rate of twin lambs.

• The combination of amino acids with sildenafil citrate did not provide any beneficial effect on the progeny at birth and weaning.

• Natural substances could be a cost-effective way to prevent partial microbial degradation of glutamine in the rumen. However, further investigation is needed to determine if these substances are effective in increasing glutamine levels in the small intestine and bloodstream of ruminants for metabolism.

Benefits to industry

This project aimed to improve lamb survival which would have had significant benefits to industry in producing twin-born lambs at the same weaning weight as single-born lambs. If this can be replicated commercially, with an advantageous cost-benefit analysis showcasing value of supplementing twin bearing ewes to producers this could drive improvements in lamb survival on a national scale.

MLA action

MLA continues to be supportive of the principles of this project however given the minimal improvement in lamb survival and challenges sourcing a product for remaining trials the project faced further delays and project was terminated. The research team were encouraged to find a commercial partner and reapply via MDC funding pathway.

Future research

In order to further enhance our efforts in facilitating the adoption of rumen-protected glutamine, it is also imperative to conduct additional research to evaluate the bioavailability of the cost-effective rumen-protected glutamine developed by our research group.

Simultaneously, future engage with a nutritional company to ensure the commercial availability of rumen-protected glutamine in the future. Once the availability of rumen-protected glutamine is determined it becomes crucial to conduct an evaluation of the optimal timing for its supplementation and the potential outcomes that can be expected from this practice. This assessment will provide valuable insights into the most effective strategies for incorporating rumen-protected glutamine into nutritional protocols, thereby maximising its benefits. This comprehensive approach will contribute significantly to its successful adoption within the industry.