Reducing feedlot costs by pre-boosting: A tool to improve the health & adaptability of feedlot cattle

Summary

Some 200 male beef calves (Angus x Hereford and Hereford) were separated from their mothers at 7-9 months of age and allocated to one of three main weaning treatment groups. The groups were matched for liveweight and any negative disease history. The treatments were (1) yard weaning with hay or silage (2) yard weaning with hay or silage plus a novel handling procedure to train the animals to be able to find a grain ration in a trough, (3) paddock weaning without supplement or handling according to common industry practice. Experimental vaccines against the major BRD pathogens were given to half of each group 1-2 months prior to entry into a large commercial feedlot. Performance in the feedlot was monitored up to slaughter after approximately 90 days on feed with extensive serology to monitor disease transmission and detailed clinical and postmortem examination.

This experiment was repeated over three production cycles in order, to refine the treatments which, collectively, were known as pre-boosting. The yard-weaned and yard-trained cattle had a significantly higher weight gain in the first month and over the 90-day feeding period than the paddock-weaned control groups. There was no difference between the groups in pre-feedlot weight gain. The yard-trained groups were not significantly different from yard-weaned. The vaccination treatment also significantly improved the weight gain in the first month and over 90 days.

The combination of yard weaning and vaccination produced the highest weight gains overall. There was consistently lower morbidity in the yard- weaned groups compared to paddock-weaned controls. The morbidity in yard-trained groups was more variable, but overall it was intermediate compared with these two. Mortalities did not occur in pre-boosted cattle in phases 1 and 3, but during an acute IBR episode after 11 weeks on feed in phase 2, the pre-boosting treatments were less effective. A method of weaning in small yards, coupled with the appropriate use of effective BRD vaccines 1-2 months before feedlot entry (i.e. pre-boosting) are recommended for feeder steers to minimise sickness and improve productivity in the feedlot. Associated benefits are reduced risks of antibiotic residues or animal welfare problems. This procedure was clearly cost-effective there being an increase in gross margin of up to $33 per head while costs increased by $5-15 per head. Benefits to the beef industry were estimated to be $8 million by 2001.

MLA is committed to investing in top quality scientific research, performed by suitably qualified, experienced and registered researchers and organisations. In experiments that involve livestock, MLA acknowledges that such research needs to be done under the auspices of a recognised Animal Care and Ethics Committee (AEC). The responsibility for obtaining AEC approval lies with the researcher. MLA has in the past not specifically asked for evidence that such AEC approval had indeed been obtained.