Stress and the Immune response

The negative effect of stress on people’s health is well known, but graziers too are beginning to appreciate that it has the same effect on their herds. Poor nutrition due to weaning stress contributes to health problems in young cattle.

The conventional approach of abruptly separating cows from calves at weaning is very different to the slow and gradual weaning process that would occur naturally. Yard weaned calves show a higher tendency to stress related diseases, while their mothers also lose condition.

Medical research has proved that stress releases hormones into the system, which in quantities too large for the animal to absorb, cause cattle to become prone to physical illness. These stress hormones cause a decreased uptake of nutrition and poor immune response resulting in runny noses, colds and weight loss. It also leads to a general reduction in the ability to absorb vitamins and minerals which in turn makes reconditioning a more costly and time consuming process.

Dr Brian Sheahan of Samford Valley Veterinary Hospital in Brisbane says: “Abruptly taking calves from their mothers at weaning and locking them in a yard is an interruption to their routine but up until recently has been the only option. It can lead to increased worm burdens, weight loss and other diseases associated with stress. It is preferable to allow the calves and mothers to remain together and go through a more natural gradual weaning process, if management procedures can handle it.”

Martine Traill from Tuwingi, Quirindi said that they have found a stress free, cost effective and successful method of weaning their cattle with the use of noserings. The noserings are attached to the calf’s septum so that it has difficulty suckling. With the calf being unable to suckle, lactation in the cow ceases and her focus can return to her own nutrition. Without separating the calf and cow, the effects of stress are greatly reduced for a smoother weaning period.

“We initially wanted to use weaner rings to keep the cows and calves in one mob, to increase the length of recovery for pastures. After we used them, we realised the other benefits of weaner rings. No more busted fences or escapee weaners. More importantly we noticed a reduction in weight loss, pink eye, scourers and respiratory infections often associated with yard weaning,” she explained.

According to the New South Wales Department of Primary Industries, for the cow, weaning means being able to transfer nutrition that was previously dedicated to milk production to her own body functions, allowing for the improvement in her condition for the next calving.

Mrs Traill comments that in dry years where nutrition is limited it is often harder to get a cow in calf the second time because she is still run down from feeding her first calf.

It is important then, that her stress levels remain low enough so that her immune response and nutrition absorption are ideal to maintain her peak condition. A reduction in weaning stress leads to better condition of a cow at calving, improved milk supply and faster recovery for the next joining.

Weaning with a weaning device such as an EasyWean nosering may offer a viable alternative for some cattle producers. Particularly those who retain their own calves for feeding or breeding stock as they stand the best chance of realising the potential long term benefits that low-stress weaning offers.