Summary
The two objectives of achieving good cattle growth rates during the summer/autumn period on kikuyu pastures and maintaining pasture control, conflict with each other. Generally beef finishers want to grow young cattle as fast as possible. However, there are times when some lines of cattle can be held back for pasture control purposes with little consequence due to having time to recoup the foregone weight gain during a later season. Running leader/follower grazing systems, where
one group of cattle grazes ahead of another, is one approach to allocating different feeding levels while still maintaining good levels of pasture control. This approach was examined on kikuyu based pastures over two different seasons.
Leader/follower grazing resulted in good levels of kikuyu control during summer/autumn with no compromise in the growth rates of the leader cattle. Leader cattle were offered pasture with higher ME, higher proportions of green leaf and clover, and lower proportions of kikuyu stolon and dead material than follower cattle. In both studies, leader cattle put on 58 kg more liveweight gain (LWG) than follower cattle over the duration of the study. The cost of the compromised follower cattle
will depend on the ability of those cattle to regain their foregone LWG.
Leader/Follower grazing systems are an effective approach to prioritising feed in order to achieve different LWG for different mobs while maintaining pasture control.
Targeting different LWG for different lines of cattle
Beef finishers will often have a number of cattle classes within a farm system. These cattle classes will usually have different targeted LWG targets and timing of slaughter and carcass weights, or as with breeding stock, liveweight and condition score targets.
An example of two different targeted growth paths within one age class of cattle would be where a beef finisher targets to slaughter a proportion of cattle prior to the second winter, while the remainder are targeted for slaughter in the late spring. In this example one approach would be to split the cattle based on weight and target a faster growth path for the heavier line in order to achieve adequate weights by the earlier slaughter date.
Accomplishing this might require reducing the feed allocated to the lighter line of cattle and ‘finishing’ them with good feeding during spring instead. Providing more feed to one stock class over another may be achieved by allocating different classes of land, having different stocking rates, different grazing rotation lengths, having one mob grazing if front of another, or a combination of these factors.
