Weaning and weaning management are the most effective tools to manipulate important factors in beef cattle management. These factors include the breeding efficiency and fertility of the cow herd, feed utilisation, animal behaviour, future carcase merits of steers and future breeding efficiency of heifer weaners.
The weaning of calves instantly reduces the stresses on the cow.
Weaning allows the cow to transfer nutrition, previously going into milk production, to her own normal body functions including improving her own condition and preparing herself for the next calving.
The important aspects of herd fertility - calving percentage, calving pattern and calving span - are strongly affected by cow condition.
The better the condition of a cow at calving, the better her milk supply and the sooner she will show oestrus after calving.
Weaning of calves at 6-7 months, from two-year-old heifers, light condition and later calving cows, allows the cows to improve in condition, calve in better condition and show oestrus earlier. This should condense the calving time of the herd.
In a severe drought calves can be weaned as early as six weeks if they are placed on a high protein (18 per cent) concentrate diet and carefully managed. Weaning at this stage will conserve the body condition of the cows, stimulate oestrus activity, ovulation and ensure reasonable conception rates at joining.
Generally, the longer calves remain on the cow without drawing down her body condition the better. Calves four months old are much easier to feed and manage in a drought situation. (See the Primefact Feeding calves in drought)
Calves are generally weaned between 8-10 months of age. The actual age depends on several factors:
In good seasons, when calves are fattening quickly, wean heifer calves intended for replacements at 5-6 months. Grow them out steadily to acceptable joining weight and condition. Alternatively, draft cows with heifer calves from cows with steer calves. Put the cows with heifer calves on lower quality feed.
Growth in cattle is determined genetically and influenced by their nutrition and maturity pattern.
Recent research by NSW Agriculture and Beef Co-operative Research Centre, Armidale, has highlighted the effects of feed restrictions on the calf’s future fattening pattern and carcase.
The pre and post-weaning management can have a significant affect on performance of the calves.
There are several commonly used methods of weaning - yard weaning, abrupt separation, gradual separation and creep weaning. The method chosen will depend on the facilities, time available, training needs of the weaners and possible markets.
It should be made as stress-free as possible for the calves.
Yard weaning requires more labour and may be more expensive than some other methods. However, it has several benefits:
Yard weaning is seen as an essential part of the overall education and management process on more extensively managed properties where Brahman and Bos indicus cross cattle are run.
The weaning and training program may last up to 10-14 days and includes feeding, drafting, working through the race and yarding from adjoining paddocks.
Animals that do not settle down can be marked for future culling. Temperamental animals are not suitable for feedlot or intensive fattening systems.
Yard weaned calves should be fed good quality hay or silage and have ample water.
Abrupt separation is a common weaning practice. The calves are drafted from the cows and moved as far away as possible. The cows and calves are difficult to move to their respective paddocks and both take longer to settle down. It is more stressful than other methods for both the cow and calf. The more determined animals often break through fences to get back to each other or, alternatively, walk the fences.
The cows and calves are put in adjoining paddocks on either side of a secure fence. The cows will move to water and graze away for extended periods while the calves will group together on the fence. After 4-5 days the cows are moved to a more distant paddock.
It is important that the calves find the water. A few older animals in the mob may help settle the calves and teach them the run of the paddock.
Creep weaning is a gradual "self weaning" process. It causes minimal stress to the calves but requires more preparation and supervision.
As the calves approach weaning age, give them access to a good quality pasture, or supplement crop in an adjoining paddock. A specially constructed "creep gate" or opening in the fence line or gateway allows the calves to pass through but not the cows (see Agfact A2.5.4 - Creep feeding calves). The openings in the creep should be 400-450mm wide.
The calves become accustomed to grazing away from the cows in the adjoining paddock. Close the creep gate off at weaning time, leaving all the calves on one side of the fence, cows on the other. After a few days move the cows away.
Research carried out by NSW Agriculture at the Beef CRC compared weaning methods and subsequent feedlot performance. It showed clearly that yard weaning, compared to typical paddock weaning, resulted in better weight gain and reduced incidence of respiratory disease when these cattle were subsequently lot fed.
Researchers said that these benefits followed when the following specific conditions applied. The first four conditions are essential.
Weaning is a suitable time to further develop the Herd Health Preventative Program. Practices include:
A well planned internal parasite program is important for weaner calves as they are very susceptible to worms - particularly Ostertagia.
The drench program should be coordinated with the development of a "clean safe" weaning paddock. The purpose of a clean safe paddock is to reduce the number of worms on pasture. The worms in the cattle are readily controlled by the use of efficient drenches. The safe pasture is developed in autumn/winter by preventing pasture contamination with worm eggs.
The pasture can be prepared in several ways:
The weaners are drenched and then placed on the safe pasture.
The steers and heifers are separated at the end of weaning. A preliminary cull of heifers may be done at this stage. The replacement heifers and the cull heifers placed on different feeding regimes, one for growing, the other for fattening.
The nutrition required by replacement heifers depends on age at joining. Those heifers, which are calved at two years of age, have about six months from weaning to reach target joining weights.
Steer weaners should be managed so they will meet the production target.
What and how weaners are fed will depend on the production targets the livestock manager has set for the beef herd. For example, a production target may be:
Once the target is defined for the herd, practices can be adopted to achieve the target in the most cost effective manner.