This winter has been hard on yearlings. Wet paddocks mean less pasture grown on the young stock block as well as the milking platform. Less Nitrogen has gone on and it has been difficult to feed and utilise supplements for the yearlings. We all know this, but do you know how much this has affected your yearlings? 
 
The only way you can conclusively know this is to weigh them and look at their winter weight gain. How many yearlings have dropped behind target weight? Are they going to make it to 60% of mature live weight at planned start of mating (PSM)? We know for certain that heifers that are not at 60% of mature live weight at PSM are less likely to get pregnant early in the mating period, and then will calve later as heifers. This does not set them up for a long-life in the herd, it means you will be constantly playing catch up with these lighter heifers. 
 
The best time to get them back on track is NOW! 
 
Last season one of the herds we work with identified that there was a definite tail in the yearling mob when weighed in winter. Action was taken immediately and the yearlings were split into two mobs based on weights and previous weight gain i.e. all the heifers that had dropped behind since the previous weighing were put into one mob. The mobs were made equal size to make management easier. The lighter ‘at risk’ mob was then fed a mix of PKE and Soyahulls in a PKE trailer (3-4kg/animals/day) for the 30-40 days up until PSM. The light group gained 1kg live weight per yearling per day over the time on supplement whereas the ‘better mob’ that was well fed on all grass grew only at 0.6kg per day. 
 
This meant the lighter heifers had caught up leading into mating, which was the plan. 
 
Take the time to ensure that your replacement stock have adequate mineral supplementation to optimise their growth rates and chance of getting in calf early. Now is the time to check with your grazier.