Weighing and setting targets provides valuable information on how your calves are performing and allows you to benchmark against other years and other farmers and to know if you will reach your mature cow LW targets. Targets will vary depending on your end objective. For example with bull beef it may be the lowest cost rearing to achieve 100 kg by 12 weeks. For replacement heifers it is likely to be maximising liveweight at mating to ensure best performance in the milking herd. To achieve this in heifers, recommendations are based around percent of expected mature weight (6-8 year old cow) at various ages. Often growth rates in excess of 600 g/day are needed to reach mating LW targets . You need to know the targets for your farm and be able to track how you are progressing.
Having targets can also alert you to problems – with animal health or with feed. Having a set target for weaning means the decision is objective. If you rely on “how they look” you will invariably feed a lot more milk than those who are using scales.