Pre-rut weaning is when calves and hinds are separated before the rut, usually in February-March, when the calves are 3-4 months of age.
The advantages of pre-rut weaning are that it allows-
- optimisation and prioritisation of feeding management for different stock classes well before the onset of winter;
- pre-winter accustomisation of calves to desired grazing systems;
- simplification and implemention of a targeted health management regimen for calves (e.g. anthelmintic treatments);
- simplification of mating management of hinds (especially for setting up single-sire mating programmes); and
- terminatation of lactation to allow hinds to improve BCS before mating (i.e. improve mating success).
Disadvantages of pre-rut weaning may include the following things:
- stress on young calves due to physical separation from dams; growth rates can be checked for several weeks;
- compromisation of feed planning for newly weaned calves in dry conditions; and.
- physical injury of young calves if there has been no prior habituation to yarding/handling.
Post-rut weaning (May-June) is when calves and hinds are separated after the rut, usually in May-June, when the calves are 6-7 months of age.
The advantages of post-rut weaning include:
- reduced workload on farm prior to rut;
- less stress on calves ; and
- much lower risk of severe pre-winter growth checks in calves.
Disadvantages of post-rut weaning may include:
- compromisation of hind BCS may be by lactation leading into the rut, leading to negative impacts on pregnancy rate and/or conception date;
- calf removal at the start of winter being complicated by bad weather;
- limited opportunities to habituate calves to winter management regimens;
- pre-weaning health treatment of calves being complicated by the presence of hinds; and
- sorting of hinds into mating groups being complicated by the presence of calves.
Natural weaning is when hinds and calves are left to their own devices. Most calves will be naturally weaned between August-September, when they are 9-10 months of age.
The advantages of the natural weaning approach are:
- minimal social disruption and minimal stress on offspring;
- that simplicity of farm design (e.g. minimal paddock subdivision) doesn’t suit early calf separation; and
- that it suits a very “hands-off” farming style.
However, natural weaning systems have the following major disadvantages :
- very limited flexibility around feed management to optimise both reproductive performance of hind and growth performance of calves;
- affords limited opportunities to habituate young stock to handling and to conduct health treatments; and
- sub-optimal tameness of calves (could be important when sending young stock for slaughter).