When dealing with feed & water shortages early weaning is a strategy worth considering.
1. Maintain herd fertility – Cows down in condition are more likely to cycle and conceive sooner after calving, if the calves are weaned prior to joining.
2. Reduced cost of supplementary feed – Early weaning will enable you to better allocate supplements to different classes of animals. By weaning the calf off the cow early, the cow returns to maintenance requirement energy levels. This separation can provide a 30% saving in energy across the farm. High energy and protein feeds can be fed to young growing stock, and lower quality feeds (poorer quality hay) to the dry cows. This will reduce the overall cost of supplements during the drought.
3. Reduced water usage – Early weaning can reduce water requirements of cows by up to 60%. Lactating cows require 100L/day and even though a calf’s water intake doubles when it is no longer getting milk, there is a significant net saving in water.
4. Reduced stock numbers – Early weaning will allow sale of older and cull cows.
AGE OF WEANING:
- Ideally wait and wean calves at 12 weeks old or around 100-120kg.
- Calves can be weaned onto high quality dry rations at 5 weeks or around 50Kg.
- If cow survival is of concern calves can be weaned earlier but a milk replacer will be required if calves aren’t going to be sold as bobby calves.
- NUTRITION, NUTRITION, NUTRITION!!!
- Introduce concentrates (grains) slowly
- Rumen microbial populations require up to 2 wks to completely adapt to a new diet.
- Expose calves to the post-weaning supplement while they are still on the cow. This can be done by feeding the cow-calf mobs or slowly via creep-feeding 2 weeks before weaning.
- Avoid combining stressful procedures like castration and dehorning.
- Weaning in containment areas is recommended so that they rest and feed.
- Allow 4 square metres/calf as minimum or 6-8 square metres for larger 150kg calves.
- Provide high quality hay, such as Lucerne hay, and clean water troughs.
- High quality rations will increase the risk of pulpy kidney so vaccination for clostridial diseases (5 in 1 or 7 in 1) is very important and can be done from 6 weeks of age.
- The younger the weaning age the higher the energy and protein levels need to be.
- Unless the feed has adequate energy density, feed intake and animal performance may be restricted by small rumen capacity. Much of the pasture hay and silage made in Australia is by itself unsuitable for early-weaned calves.
- e.g. 100kg calf, growth rate 0.5kg/day, Max daily intake 3kg/day, Metabolisable energy (ME) requirement 29MJ/day, Minimum ME concentration of diet 9.7MJ, Crude protein 16%
- Supplementary Vitamin A is usually necessary – injection of A,D,E recommended.
- Six weeks after weaning, draft off tail-enders into separate management group.