Development of a vaccine to enhance muscle yield in beef cattle – A feasibility study

Summary

Myostatin is the protein that negatively controls muscle growth, however breeding programs focused on selecting for Myostatin mutations in cattle to increase muscle mass and carcase value can be challenging. Immune-stimulation against myostatin is an alternative approach and has been successfully used in mice resulting in hyper-muscularity.

This study evaluated both immunological and physiological responses to 4 different peptide-conjugated candidate vaccines in non-HGP treated feedlot heifers with known Estimating Breeding Values (EBVs).

Objectives

The objectives of this project were to:

• investigate the best approach for the development of a candidate vaccine against myostatin that have the highest probability to an induce immune response in cattle
• identify and develop the best candidate vaccines
• measure immune response, muscle growth response and caracse attributes in treated young cattle.

Key findings

• Four vaccines designed to regulate the action of the myostatin protein had no significant effect on live animal or standard carcass measurements (except for MSA marbling score).
• Immune response was variable and in most instances did not strongly correlate with phenotypic responses.
• The trend to positive fat EBVs in bulls can potentially result in a higher incidence of non-compliance.

Benefits to industry

This approach has potential to be cost effective for adoption by the beef industry. The vaccine formulations used in the current project was considered low cost (approximately $15/head for 2 doses).

Assuming production under industrial scale can considerably reduce costs, it is feasible that that if further development can improve vaccine effectiveness without impacting significantly on manufacturing costs than a positive benefit cost ratio can be achieved.

Future research

Given the regulatory complexity of developing novel products for livestock destined for human consumption and the difficulty in obtaining objective information from regulatory bodies, it is thought that if further work is to be carried out a specialised consultant should be engaged from the early stages.

If the vaccine is further developed and the results are favourable for commercialisation, the impact on eating quality should then be extensively tested in the MSA model.