In Ireland, as dairy farms approach weaning season, Teagasc — the Agriculture and Food Development Authority — offers vital guidance on optimal weaning targets for heifer calves. With most calves now between 8 to 12 weeks old, managing stress and ensuring proper rumen development is key to future productivity.
Teagasc, Ireland’s national body for agriculture and food development, has released essential recommendations for dairy farmers as heifer calves across the country reach the 8 to 12-week weaning threshold.
According to Teagasc, calves should only be fully weaned once they are consuming at least 1kg of starter concentrates per day for several days consistently. The organisation warns against premature weaning, which could result in digestive stress, illness like pneumonia, and growth setbacks.
Weaning is advised around week 8 or 9, but flexibility is key, especially as calving season started slightly later than usual this year. Heifers still under target at 8 weeks may require continued once-a-day (OAD) milk feeding for an additional two to three weeks.
Teagasc emphasizes that calves transition from monogastric to ruminant animals during this period, requiring a careful balance of milk and solid food. Rumen development is best supported with high-quality concentrates, fresh straw or hay, and access to clean water—approximately 4-5L of water is needed per 1kg of concentrate consumed.
Target weaning weights are also based on the genetic maintenance sub-index of future dairy cows. For instance, a heifer with a €0 maintenance index should weigh around 94kg at weaning, while those with €10 and €20 indexes should weigh 88kg and 82kg respectively. These estimates align with reaching 15% of predicted mature body weight before weaning.
Weighing calves prior to weaning is recommended, though many farmers use concentrate intake and visual assessments. Still, Teagasc insists that catching underperforming calves early with a brief extension in milk feeding is far more cost-effective than trying to recover growth in yearlings or maiden heifers.
Heifer rearing remains one of the most significant costs in a dairy enterprise. As such, Teagasc’s targeted weaning guidance helps ensure long-term productivity and cost-efficiency across Irish dairy farms.
