As the next generation of milking cows. it is important that we do not lose focus on achieving replacement heifer target weights over the autumn.
Hitting target weights at this point of the year is crucial to ensure replacement heifers are on course to achieve the main goal of being 60% of their mature weight when bred at 15 months. Over the next few months, optimal average daily gain may be difficult to maintain as grass growth and quality declines and grazing conditions become more challenging in late autumn. Therefore, it is important to consider where your replacement heifers are in relation to targets (% of mature weight) currently.
Target Weights
By weighing now, compared to weighing at the point of housing, this allows the opportunity to identify heifers that are not on target, group accordingly and make alternative plans for those heifers under target weights. The threshold figure for 2022 spring born weanling heifers is approximately 190 kg in mid-September (approximately 33% of an assumed mature weight of 570 kg). Heifers that are lighter than this should be separated and given priority access our highest quality grass and concentrates depending on their weight relative to the herds target.
Supplementation
Higher weight gains can be achieved from grass rather than from winter/silage diets and a good response to autumn supplementation can be achieved. If grass is in short supply or quality/conditions are deteriorating, under-target replacement heifers should be fed a supplement until housing time to maintain or increase growth rates. 1-2 kg of concentrate/head/day should be sufficient.
Research shows that youngstock at grass in summer can achieve a weight gain of 0.85 kg/day on grass alone. While in the autumn where 1 kg of concentrate plus high-quality grass are offered, average daily gains of 1 kg/head/day can be achieved.
For More Information:
Contact your local Agritech Sales Advisor.