Calving Growth Target
In order to perform well, young stock need to reach their target weights on schedule. Beef cattle that get to their target weight on time can usually be sold for a better price than those that lag behind. Dairy cows that are raised well as heifers are more likely to have good reproductive performance than heifers that have been slow to develop. They are also more likely to reach their milk production potential.
Setting target weights is important. For male beef calves, the target should be based on your desired sell date: work back from there to determine checkpoint targets. Heifer calves that are going to be mated at 15 months should be 30% of their mature liveweight at weaning, and 60-65% at mating. Given that an LIC study conducted in 2012 found that 53% of heifers were more than 5% below their 6-month weight target, it’s clear that we have room for improvement.*
Once you have set target weights, you need to monitor stock progress. While it’s easy just to guess or go on age, it’s not very accurate. It’s worth investing in a set of scales and weighing calves on a regular basis to see if they are on track. The DairyNZ website contains targets for young stock at 3, 6, 9, 15 and 22 months.
A set of scales will also help to ensure you don’t wean calves when they are too light. Friesian calves on restricted milk and adlib meal can be weaned after they reach 63 kg; calves on a high-milk system need to be 75-80 kg at weaning.
To keep your calves on track, aim for steady growth; an adequate supply of suitable feed is an obvious essential, but keeping stress to a minimum is also important. One stressor that’s easily overlooked is, in fact, the feed. Abrupt changes to the feeding regime can cause growth checks, as calves take time to adapt to new feeds.
You can reduce the impact of new feeds by introducing them gradually, slowly reducing the proportion of the old feed and increasing the proportion of the new one. Minimise the number of changes at each step in the transition, e.g. if changing from muesli to pellets, choose pellets that smell and taste the same as the muesli. That way, the calves only have to get used to the new texture.
To make sure that calves wean successfully, focus on getting their rumens well developed. Feeding a quality calf starter containing 20% crude protein will help. Once they are on pasture, continue feeding them, gradually decreasing the meal allowance. Monitor stock growth to ensure they are meeting their targets and if weight gain is not on track, consider altering either the type of feed or the quantity allowed.
*McNaughton & Lopdell, 2012