Calves are particularly susceptible to stress but by taking steps to keep your youngstock calm and comfortable – and feeding a high-quality milk replacer – you can limit the impact of any stressful events on youngstock productivity.

As Volac expert Peter Smith advises: “It’s important to minimise stresses on calves, especially during the first 90 days of life when the die is set for future productivity. Keeping young calves healthy, happy and meeting target growth rates with sound nutrition should be your goal.” 

Mr Smith explains that stressful events trigger a cascade of hormonal changes that can lead to serious consequences, such as reduced feed conversion, greater production of manure and even infectious calf scours. He adds that exposing calves to overly stressful situations can also hamper well-intentioned husbandry efforts.

“Calves have good memories and learn to associate certain events or environments with stress. For example, if medication was injected or an ear tag administered while a calf is drinking from a trough or using an automatic feeder, a calf may be nervous and resistant to those ‘events’ in future.”

Mr Smith says that learning to pick up on cues in calves can help farm staff to mitigate stress and prevent any negative health or performance consequences.

“For example, stressed calves often have a reduced feed intake, an elevated heart or breathing rate and/or may lack vigour. Calves may also stand with their head down and ears lowered – or even look excessively fatigued or display signs of fear. All these signs point to calves in a potentially stressed state.”

Important stress triggers

Two of the most significant stress triggers in calves come from the housing environment and weaning. But the list of specific triggers also includes excessive cold or heat, transportation, overcrowding, handling, tagging, administering vaccinations, feed competition, weighing and de-horning.

“Calves don’t tolerate change well, so when it comes to mitigating housing stressors, comfort and consistency is key. Calves also like a quiet environment and should be checked regularly,” says Mr Smith.

“Calves are most comfortable when housing ambient temperature is between 10-20C (humidity 65-75%). If the temperature falls below 10C consider the use of calf jackets to keep youngstock warm and dry.

“Good ventilation is important too. Aim to locate your calf housing upwind of other cattle housing facilities and at right angles to the prevailing wind direction. Good ventilation is all about encouraging fresh air to circulate (to remove airborne pathogens) without exposing calves to draughts.”

Peter adds that it’s important to avoid overcrowding as well – allowing 1.1sq m of space for calves up to four weeks of age, increasing to 1.8sq m for 12-week-old youngstock. “Keep the age range of your groups as close as possible too.”

To keep calves comfortable, clean, dry bedding is a must. “Carry out the ‘kneel’ test regularly. This means getting on your knees in the calf shed and if your knees get damp, so will your calves and eventually become stressed!”

When it’s time to wean calves, the process should be smooth and gradual. Abrupt weaning is far too stressful, leaving little or no time for a calf to adjust to a forage-based diet.

“It’s good practice to begin offering chopped straw and creep feed while they are milk-fed to give the rumen ample opportunity to adapt. This more considered approach to weaning will lead to increased weaning weight, reduced growth checks and more efficient feed conversion.

And just like humans, calves like to play too. “Many calf rearers are now embracing the idea of enrichment activities to alleviate boredom amongst calves. Providing brushes, swinging punch bags and padded posts also helps mitigate stress and keeps animals happy, healthy and performing well.”

Volac recently launched a new 100% dairy protein milk formula to help calf rearers improve the nutrition of digestively challenged calves.

New Imunogard has been formulated specifically for under-performing stressed calves or to meet the unique needs of calf units wrestling with a stubborn scour problem that can’t be overcome by an improvement in environmental hygiene. 

“This new 23% crude protein calf milk formula is vegetable protein-free, which means it is more easily digested by calves under stress,” says Mr Smith.

He adds that the product also contains a slightly higher fat content to allow for more energy to be metabolised for growth. It also benefits from the inclusion of other beneficial health supplements.