Why wean early??

With Tom Little



Photo credit; https://www.farmweekly.com.au/story/5774792/quality-yarding-for-boyanup-weaner-sale/

Early weaning is a logical option for many cattle producers experiencing dry conditions, so they can reduce total feed requirements by allowing more feed to be allocated to growing stock, rather than for milk production. The main objective of early weaning is to run more cows and achieve higher reproductive performance from them, or to ease the pressure on feed resources while maintaining the body condition score of the herd. The ideal weight to wean calves early in dry conditions is around 100kg – 130kg.

Economically early weaning stacks up, with a cow and calf unit requiring more megajoules of metabolised energy per day (MJ ME/day) compared to a cow and weaned calf. A cow weighing 550kg has a maintenance requirement of 60 MJ ME/day. A calf weighing 150kg with the assumption of achieving a moderate growth rate requires 36 MJ ME/day. If this 36 MJ ME/day was to be provided entirely by the cow in the form of milk (equating to 7 litres of milk/day), it would require an additional 95 MJ ME/day. This takes into consideration the amount of MJ ME/day a cow needs to produce milk and the reduced efficiency from the calf utilising the milk as an energy source.

Energy requirement for unweaned cow/calf unit

60 + 95 = 155 MJ ME/day

Total energy requirement for cow and weaned calf

60 + 36 = 96 MJ ME/day

As shown in the above calculations, an unweaned cow/calf unit requires an additional 59 MJ ME/day compared to a cow and weaned calf. In a production system where 100 unweaned cow and calf units are grazing in a high energy density pasture of 10 MJ ME/kg of dry matter, they will require an additional 590 kg of pasture dry matter per day. Therefore, early weaning increases the energy efficiency of feed resources, converting available feed energy into saleable beef by increasing growth rates of young stock while also maintaining body condition scores in breeding herds.

It is critical when deciding to wean early that it is planned and prepared several weeks before being implemented. This includes being prepared for nutritional management, disease management, having the correct infrastructure and allocating time towards handling stock. The most effective system to manage calves when early weaning, is through yard weaning. Yard weaning is where calves are held in confinement, typically in a set of yards, where nutritional requirements are provided through feeding high quality forage, grain, protein meals or a combination of these. High quality hay or silage, in combination with a cereal grain, will generally meet the nutritional requirements to optimise weight gain in weaners. It is also vital that weaning stock are always provided with an adequate clean water supply.

If you would like more information about early weaning, contact myself via admin@dalbyruralsupplies.com.au, call our Merchandise Team on (07) 4660 0400, or pop in and see us in store. A special mention to the team at Zoetis for contributing their knowledge and materials for reference in this article.