Weaning weight vs age at finishing Light (24-27kg) Medium (28-31kg) Heavy (32-35kg) 21 weeks 29 weeks 38 weeks
Wt gain - three weaning wt and ages
Feed intake - three weaning wt and ages
FCR - three weaning wt and ages
FCR – sex at 3 ages
What does it mean for industry Most efficient lambs put on 1kg live weight for every 3 kg of feed consumed. – Cost to finish $6.39 Least efficient lambs eat 15+kg of feed, for every 1kg of live weight gain. – Cost to finish in the order of $30.00 (in feed costs alone) Variation between sire groups for FCR ranged from 5.17 to 8.81, average for all lambs, 7.09:1 ITS WORTH DOING SOMETHING ABOUT IT!!!!!
How can we capture benefits? Correlations of 0.8 and 0.4 – genomic breeding values vs milk yield and vs feed efficiency traits. We know what pigs and poultry have achieved. If feeding lambs at home, there are tools.
Industry implications Restricted growth through to weaning does not compromise the efficiency of lambs when it comes time to finish them. – Lambs that are light at weaning can still be finished in a cost effective manner, HOWEVER if carrying lambs over, beware of lambs that were already heavy. Lambs that are light at weaning do have a bigger window for finishing – still efficient at older ages. Inefficiency driven by two things – poor weight gains and they still consume a heap of feed (lambs that are heavy at weaning, but hung onto too long!) Feeding lambs at the right stage of maturity appears to be critical to profitable outcomes – dont try and turn them into something they shouldnt be! We love our lamb!
Pre-weaning restriction Live weight Age Pre-weaning Grow-out Finishing some compensation during backgrounding similar feedlot growth performance calves dont catch up in weight no adverse effect on composition kg - 40kg - 35kg 30 mths
Low birth weight Live weight Age Pre-weaning Grow-out Finishing slower growth to weaning no compensation during backgrounding reduced feedlot performance calves don t catch up in weight no adverse effect on composition - 25kg - 40kg - 55kg - 10kg Birth 30 mths