Milk quotas have resulted in a reduction in dairy cow numbers between 1983 and 1987 which represents a loss of almost 250,000 calves for beef rearing. Increasing slaughter weights is one way to make up for some of the consequent shortfall in beef production. However slaughter weights will not increase unless it is profitable to the producer.

MLC investigations are showing that differences in performance within a group of finishing cattle means that there is extra profit in keeping faster growers longer than average. Table 1 shows slaughter weights of a group of Charolais cross male suckled calves at different ranges of daily gain. Optimised slaughter weights for each sub-group and the extra gross margin after interest which should have accrued if they had been sold at the optimised weights are also given. Within the group the fastest growing bulls should have been kept longest and would have shown the biggest increase in margins.