Growing calves to weaning

With calving underway, now is the time to focus on calf-rearing fundamentals to ensure robust, healthy calves are weaned.

For optimal colostrum management, calves require gold-quality colostrum of greater than 22 brix units with up to four litres given in the first 12 to 24 hours of life. This is likely to provide passive transfer of antibodies which gives the newborn calf initial immune protection. 

Warm calves are more likely to thrive, so be sure to dry calves if they come into the shed wet and implement best practice of feeding warmed colostrum, aiming for 38 to 40 degrees Celsius. As they progress onto milk feeds, whether calf milk replacer (CMR) or whole milk, it is best to continue warming milk to within this temperature band.

Young calves have limited body reserves. In sheds, they need to be sheltered from wind and rain. The rule of thumb is having the shed twice as long as it is wide and allowing two square metres per calf. Calf pens should ideally have solid divisions between them as this reduces draught and disease transfer. Invest in calf covers to keep calves warm if temperatures are cold. When calves are noticeably shivering, the energy they get from drinking milk will be put into keeping warm rather than growth.

At birth, a calf rumen is not functioning. Develop the rumen efficiently by feeding a commercially available meal of either muesli or pellet that contains 20 percent protein, good starch levels and a coccidiostat. Also, offer hay to minimise calves chewing on bedding and rails. A non-negotiable is having fresh clean water on offer at all times as there is not enough liquid in their diet despite being fed milk. Offer water in troughs, not in calf feeders. 

Have electrolytes on hand in case calves become unwell. Remember that electrolytes containing sodium bicarbonate cannot be fed within two hours of a milk feed as they interfere with milk clotting. Probiotic pastes support gut health when calves are recovering from scours. Keep shed hygiene at the top of the list, aiming to isolate any illness so it cannot spread through the shed.

Calf vaccinations are also important to reduce the risk of clostridial diseases. Two vaccinations are required. If using a 5-in-1 vaccine given four to six weeks apart, deliver the first dose pre- weaning and the second dose post-weaning.

Learn more about the various calf milk replacers, meals and vaccines available from your local PGG Wrightson store.