Weaning Considerations: Reduce Stress to Minimise Shrink09 September 2014
A lot of pressure goes on an animal as it is weaned and marketed, resulting in weight-loss or shrink, which cannot be avoided entirely but can be minimized.
Preconditioning could be a route to this, according to a Kansas State University Extension specialist.
Adding beef is especially worthwhile during current times of record high beef values, said Justin Waggoner in September's Beef Tips publication.
"One of the factors often overlooked in our conversations about marketing a calf crop is shrink," he added.
"On many operations, the opportunity to weigh calves prior to shipment is limited and thus the amount of weight change between the operation and the sale is unknown."
Mr Waggoner writes that shrink is essentially the loss of bodyweight associated with gathering, transporting, limiting access to feed and water, and marketing cattle.
The loss of bodyweight associated with these events is inevitable and affects both buyers and the sellers. Shrink is primarily composed of losses in gastrointestinal fill (rumen contents, faeces and urine) and tissue shrink (cellular fluid loss).
"Shrink is essentially unavoidable, but can be managed by limiting the amount of stress placed on newly weaned calves prior to sale delivery."
Losses associated with gastrointestinal fill can be recovered in a few hours. However, tissue losses may require several days to recover. A number of factors ultimately influence shrink including diet, ambient temperature, length of transport, hauling conditions, and handling method.
Today, there are many different weaning methods used by producers to reduce the stressors associated with weaning.
However, regardless of the weaning method used, maternal separation, acclimation to a new environment, feedstuffs, and transportation are all stressors that newly weaned calves have to overcome as they move on to the next production phase.
Shrink of newly weaned calves is highly variable and will typically range from 2 per cent to 8 per cent of initial bodyweight. In some situations, shrink of newly weaned calves may be even greater as high stress calves may exhibit limited interest in both feed and water.
An Oklahoma State study evaluated shrink of calves weaned 22 days prior to a simulated sale event, weaned and overnighted at the sale facility, and weaned the day of the simulated sale.
Calves weaned 22 days prior to the simulated sale shrank 2.3 per cent , calves weaned and overnighted prior shrank 4.9 per cent and those weaned and delivered on the day of the simulated sale shrank 3.4 per cent .
The results of this study indicate that weaning calves for a period of days prior to sale delivery is better than weaning on the day of the sale, and weaning on day of delivery is preferred to weaning and standing calves overnight prior to a sale.
Although the calves backgrounded for 22 days exhibited the lowest shrink, research suggests that preconditioning programs in general have a limited impact on calf shrink.
Preconditioning or back-grounding calves prior to sale may not impact shrink, but could potentially result in a premium and a potentially greater sale weight.
It is important to remember that a preconditioning or back-grounding phase must be long enough to gain back any weight lost during the weaning phase and gain enough additional weight to offset the cost of the program.
Shrink is essentially unavoidable, but can be managed by limiting the amount of stress placed on newly weaned calves prior to sale delivery.
Reducing shrink losses is beneficial for both the seller and buyer. The seller ultimately markets more pounds of calf resulting in greater calf revenue and the buyer purchases calves that will regain fill losses quickly, are more likely to remain healthy, and ultimately be more successful in the next production phase.