Guidelines for managing heifers and cows before calving
Careful management of female cattle in the build-up to calving pays dividends at calving time. Calf loss will be minimised and calving supervision can be kept to a minimum. Calving difficulties will be reduced by maintaining cow condition scores between 2.5 and 3.5; and minimum heifer liveweight at three, six and nine months post-conception are as specified for the various breeds and crosses.
If females go outside these guidelines:
• Increase or decrease pasture available and/or pasture quality before calving to ensure condition score of cows or liveweight of weaner heifers remains within the guidelines. As a guide, manage British breed heifers to gain an average weight of 0.5 kg/day to a joining liveweight of 280kg, condition score 3 at 15 months.
• Consider supplementary feeding of a high quality diet to cows when condition score is below 2.0.
• Consider supplementary feeding of heifers, including the use of a protein source rich in rumen non-degradable protein, particularly if pasture is readily available but quality is low. This ensures weaner heifers gain weight at 0.5 kg/day to reach target weights at three, six and nine months post-conception.
• Assess animal health status, particularly for internal parasites (worms and fluke tend to be a greater problem in younger animals) and correct if there is a problem.
• There is a balance required between:
– Overfeeding (heifers in particular) in the last three months of pregnancy, as this will also increase birth weight of the calf; and
– Underfeeding in the last month of pregnancy, as this will predispose to metabolic disorders like ketosis.
Poor nutritional management of heifers and cows before calving can lead to a number of significant problems:
• Dystocia in heifers, due to inadequate pelvic size for the foetus; and in mature cows, due to over-fatness and uterine inertia;
• Difficulties during the birth process may lead to still-born calves, inability of the mother to go back in calf, inability of the live calves to thrive, a reduced ability of resulting heifer calves to reach target weights at mating and possibly reduced mature weights as cows.
• Predisposition to various metabolic disorders, including milk fever (hypocalcaemia) and ketosis/pregnancy toxaemia, due to over and underfeeding of cows before calving.
What to measure and when
• Condition score of cows every 2 weeks from 12 weeks before calving;
• Weight and growth of heifers at three, six and nine months of pregnancy
