BCRC 3 - The biology of marbling and fat distribution in relation with production systems

Summary

​The experimental design and methods for this study were approved by the Beef CRC's 2008 Annual Scientific and Industry Review, Underpinning Science Committee, and Management Committees, and by NSW DPI Animal Care and Use Committee. The experiment is focused on strategic nutritional supplementation post-weaning to enhance intramuscular fat cell development and subsequent expression of marbling during feedlotting, and on understanding the biology of marbling. The experiment is applying strategic nutritional supplementation post-weaning across divergent genotypes for marbling and fat distribution to determine if there are nutrition x genotype interactions for development of marbling and other fat depots. The experiment will allow for detailed biological and metabolic studies of fat depot development using strategic post-weaning nutritional treatment and the divergent genotypes. The strategic post-weaning nutritional treatment aims to enhance adipocyte development prior to the major period of lipid filling of fat cells during feedlotting. These studies also aim to identify differential metabolism and expression of genes in fat depots, including those within muscles, at various developmental time points to allow fine-tuning of nutrition to maximise marbling, and with a view to assisting with future identification of early biological markers of marbling and potential gene markers. The study also aims to understand the influence of marbling in altering eating quality of cuts such as the 'outside' or biceps femoris muscle which has been shown to have unusually high eating quality in MSA experiments using Japanese Black (Wagyu) cattle. In addition, this experiment is providing resources and data to enhance development of the BeefSpecs phenotypic prediction models in Project 1.2.1, and to enhance the accuracy and validate ultrasound scanning of highly marbled cattle by AGBU staff. The methodologies for the study have been established or are being refined. This study addresses important industry and scientific issues that impact on capacity of producers to meet market specifications and the efficiency with which specifications are met, particularly given competition for resources such as grain for feedlot cattle. Given that this project commenced in February 2009, it is too early to draw conclusions from the limited results of the study that are available to date. Progress with the experiment was presented to the Beef CRC's 2009 Annual Scientific and Industry Review in May. It is recommended that the experiment continue as planned.​