Effect of lupin supplementation and phenotypic characteristics on the performance of pastoral cattle grazing tagasaste

Within the Western Australian beef industry there is a negative perception of the capabilities of pastoral cattle to be finished in agricultural regions, especially those that have dominant Bos indicus characteristics. In order to address this perception, the performance, temperament and muscle glycogen levels of pastoral cattle grown in the agricultural region were investigated. Sixty steers were divided into phenotypic groups types, as either B. indicus (n = 30) or B. taurus (n = 30), and were randomly allocated to 2 treatments, each with 2 replicates. They were grazed on tagasaste (Chamaecytisus proliferus) and supplemented for 8 months with lupin grain 3 times per week at an equivalent of 1.5 or 3 kg/animal. day. There was no significant (P > 0.05) difference in weight gain between the B. indicus and B. taurus type steers on either supplement level with both gaining weight at an average of 0.6 kg/day. Muscle biopsies from the M. semimembranosus (SM, topside) and M. semitendinosis (ST, eye round) were analysed for glycogen concentration, as an indicator of potential meat quality. Muscle glycogen concentration was not significantly (P > 0.05) different between nutritional treatments or type of cattle. All steers had sufficient glycogen in the sampled muscles (1.3% in the SM and 1.0% in the ST) to produce meat with a desirable pH (< 5.7). Flight speed, as an indicator of temperament, was recorded to detect any differences between the 2 types of cattle. Flight time was not significantly (P > 0.05) different between the B. indicus or B. taurus steers, suggesting that there was no difference in temperament. The results illustrate that selection of pastoral cattle based on phenotypic characteristics alone is not substantiated, and that decisions should be made on the basis of genetic and past management information. If proper management strategies are put in place, pastoral cattle can perform adequately in the agricultural regions, which presents an opportunity for further integration between northern pastoral regions and southern agricultural regions to enhance overall beef productivity of the state.