2 - Wean as early as possible, without compromising overall calf growth rate

Deciding what size, or age, to wean at requires balancing the economics of the costs of infrastructure, feeding and management against the benefits of reducing breeder mortality and time taken to get back into calf.

Factors to consider in planning and implementing your weaning strategy inlcude:

• type of country
• seasonal conditions and time of year
• ages of breeders
• mating system
• target markets.

Type of country

Weaning calves at a younger age will help keep breeders in better body condition. This applies on all land types and land condition classes but on country in good condition, cows are also generally in better condition and therefore some weight loss may be acceptable. On poor country where cows are generally lighter, managing body condition is much more important.

Seasonal conditions

Flexibility in weaning times is critical for managing poor seasonal conditions (eg. periods of no rain, lack of annual plant growth and/or low perennial growth). Earlier weaning will allow cows to maintain better body condition in these conditions.

Duration of joining period

This determines the spread of weaner weights and a longer calving period usually means a greater number of lighter calves at weaning. It is important to only wean the number, and types, of weaners that can be adequately managed. Continuous mating, as practiced in the arid zone, usually results in calves of mixed sizes.

Guidelines to determining the best calf weaning age

As a principle, the sooner calves are weaned the greater the potential turnoff of young cattle. Earlier weaning is the single most important way to increase weaner throughput as this allows better allocation of feed to reproduction and turnoff.

The keys to maximising the benefits of weaning age to throughput and productivity are to:

• identify the time when the efficiency of pasture use will be greater for the calf alone than for the cow and calf together. This is normally around six months into lactation when the higher quality pasture required to maintain cows and produce a relatively small amount of milk is better consumed directly by the weaned calf.
• implement a weaning strategy that ensures no setbacks to calf/weaner growth occur.

Use higher quality weaner pastures for consistent growth

Weaning age and projected liveweight gains post-weaning depend on pasture availability and quality.

Ideally, weaning needs to take place when pasture height and availability are best for maximum intake by the weaned calf and the pasture has a nutritional quality of more than 11.5MJ per kilogram of dry matter (MJ ME/kg DM) and at least 15% crude protein. 

Native pastures do not consistently achieve that level of nutritional quality, so it is important to be aware of the overall nutritional value of the pasture in your paddocks, and place weaners on the best nutrition available.

In general, use the combination of age and weight of calves, and condition score of cows, as the basis for a decision to wean calves early. This is particularly important in the arid zone when there is a limited quantity of high quality pasture available.

As a general rule, the earlier the age of weaning, the better the nutrition, in terms of energy and protein, required for the weaners. In most instances, reliance on the native pasture alone will not be adequate and a high quality supplement will be required.

Early weaning

Early weaning is a useful management strategy in the arid zone as it allows much better allocation of a limited feed resource and can be implemented to improve throughput of sale. 

It has been reported that early weaned cow-calf pairs were 43% more efficient in converting digestible nutrients into calf weight gain than were conventionally weaned cow-calf pairs.

Early weaning of calves also provides substantial benefits to the cows through reduced weight loss during lactation, higher body conditions scores and significantly shorter calving intervals.

Weaning should involve a period of at least one week in the yards. Calves that are not yarded can be difficult to manage later and may suffer more stress if finished in a feedlot, or at sale or slaughter.

Weaning management involves planning for the muster, the yards, cow-proof fencing, stocks of hay and other supplements, the weaner paddocks and transport.

Questions to consider include:

• What is the condition of the weaner paddocks?
• Are the facilities and equipment in good order (yards, gates and fences, water supplies, troughs for water and feed supplement, hay racks in place)?
• Are there sufficient stocks of good-quality hay and supplements?
• Are there stocks of current animal health products?
• What animal husbandry practices will also be carried out at time of weaning?

Reducing stress

Both mother and calf are stressed when they are separated; the cows are going to call for their calves and try to return. While the calves are locked in a sturdy and secure yard, the cows may try to break the fence of their paddock so it is best to move to an area from which they cannot hear their calves.

Key factors in managing stress at weaning include:

• providing the right nutrition
• segregating weaners based on size
• regular and calm handling
• monitoring every day for a couple of weeks
• vaccinating against relevant diseases.

Calves can be weaned successfully at 100 days of age and from weights as low as 100kg as long as they are provided high quality feed. The feed offered to early weaned calves must be of high nutritional quality. This is particularly important for weaners which are dehorned, castrated, branded and/or ear marked.

Table 4: Energy and protein requirements/day.

Live weight Steers/heifers	Growth Rate	Intake Max	ME MJ/day requirement	Minimum ME required	Crude protein %
200	0 0.5 1.0	5.5	26 44 59	4.8 8 10.7	8 12 13
300	0 0.5 1.0	7.6	35 57 76	4.6 7.5 10	8 10 13
400	0 0.5 1.0	9.4	45 71 93	4.8 7.6 9.9	8 9 13

The likely benefits of early weaning and good weaner management on the breeder herd include:

• better overall breeder condition
• higher conception rates
• fewer mortalities
• lower cost of supplements for breeders
• more females for sale
• more concentrated calving in continuously-mated herds
• more maiden heifers heavy enough to mate.

Extra costs will include:

• more expensive supplementary feed
• more labour for tending small weaners
• increased infrastructure for yarding and feeding weaners.

What to measure and when

• Estimates of age and weight of calves at 100 days from when the last calf was born.
• Any harmful effect on cow health and udder damage to high milk yield cows.
• Quality and quantity of pasture available for weaned calves is adequate.

Guidelines to yard weaning calves

Yard weaning is a simple and effective procedure that has good implications for lifting weaner productivity.

Use dedicated yards to wean calves

Cattle that are yard-weaned are more familiar with stock yards, water troughs, feeding routines and people. By exploiting the fact that weaning is a critical learning time, young cattle can be well prepared for a productive future. Yard-weaned groups of cattle also have the major advantage of having stronger social bonds between individuals. While training cattle during yard weaning, their individual temperament (confidence) can be assessed and flighty (shy) cattle can be identified for removal or special treatment.

Weaning is an important learning phase for cattle

The benefits of yard weaning are fully realised if cattle later go on to feedlots. In the feedlot, a healthy and productive feeder steer has to:

• accept confinement and go on to concentrate feed and water quickly
• adapt easily to the initial social/psychological and metabolic stress involved
• achieve high feed conversion rates and weight gain through good adaptation individually and as a feeding group
• have strong resistance to respiratory disease, partly as a result of social compliance and group cohesion
• accept the presence of people, vehicles and horses at close quarters.

The following requirements must be met to implement yard weaning as a management tool:

• well built, weaner-proof yards with solid opaque pen sides (rubber belting 1.2m wide is ideal)
• a reasonably sloped, well drained, non-bog surface
• pen stocking density of 4m²/head for 180–260kg calves; and 2.5m²/head for 100–170kg early-weaned calves
• weaners kept in the yards for 5–10 days, with the aim to have the majority back onto quality pastures as quickly as possible
• good quality drinking water supplied in a trough
• shy feeders removed and managed as a separate group to prevent rapid and excessive weight loss
• routine human contact each day, for example walking quietly through the yard at least two or three times each day
• in general, keep dogs away from the weaning yard.

Further information on yard weaning

• Tips & Tools: Yard weaning methods for preparing feeder cattle

Handling at weaning

Positive contact between humans and weaners minimises management problems down the track

Weaned calves should be encouraged to approach humans with a memory of positive associations. Grouping calves in a small area at weaning with regular handling boosts socialisation between animals and with humans, and reduces subsequent stress associated with handling and transport. Well-behaved stock will generally create fewer management and occupational health and safety problems.

Negative or insufficient positive contact between humans and calves at weaning can result in the animals remaining frightened of human activity. This can cause increased stress during handling and transport, high pH and dark-cutting meat. Insufficient contact with humans can also lead to cattle not adapting well to more intensive feeding such as in droughts or feedlots.

Weaner pastures

High quality feed produces rapid liveweight gains in weaner cattle

Depending on the seasonal conditions at weaning, the liveweight of weaner cattle may be maintained until feed conditions improve or they can be weaned onto high quality pasture for rapid growth rate. As a guide for best pastures liveweight gains in weaners should be of a nutritional quality of at least 11.5 MJ ME/kg DM and 15% crude protein. If high quality pastures are not available at weaning and weight gain is desired, consider providing a feed supplement to boost the nutritional quality of the pasture, but ensure that the cost of a supplementary feeding option does not exceed the benefits.

What to measure and when

• Monitor pastures at least weekly, and more often if seasonal conditions are deteriorating. See Module 3: Managing your Natural Resources for information on the assessment and monitoring of land condition and pasture quantity/quality.

Impact of weaner growth on meat quality

Saleyard and abattoir prices now favour good weight-for-age cattle; the best prices are for milk and two-tooth cattle at domestic and export slaughter weights. Meat tenderness is affected by animals repeatedly losing and gaining weight, and is detected through the assessment of carcase ossification (a measure of carcase maturity) during MSA grading. Abattoirs with Meat Standards Australia (MSA) grading will pay a bonus for cattle that satisfy MSA requirements.

Good weaner management is the key to producing an animal with the potential to meet MSA grading. Weaners need to be grown as fast as economically possible. Weaners that grow poorly in their first year or are under about 220kg liveweight at 12 months of age have little chance of grading to MSA specifications later.

Pre-weaning nutrition is generally less important although calves with low weaning weights may take too long to reach market specifications and possibly attract premium prices.

Pastoral producers should focus on turning off the animal without it putting on too much weight as that pasture could be used to raise another calf/animal instead. Backgrounders and/or feedlotters are going to be interested in getting lighter weight animals with good frames because that way they get more compensatory gain once the animal is fed a high quality diet.

For slaughter animals, the age of turn-off can also be critical to meet dentition and ossification specifications in additional to target turn-off weights.