As winter drags on in many places of the world, it is important to keep your calves nice and warm. Calves are much more sensitive to cold temperatures than adult cattle. As the calf ages and increases its energy intake, it generates more heat to keep itself warm.
Calves are much more sensitive to cold temperatures than adult cattle. As the calf ages and increases its energy intake, it generates more heat to keep itself warm. Older calves also develop thicker skin and more subcutaneous fat, which act as insulation. Despite this, all calves still need special attention in colder temperatures.
All animals have a thermoneutral zone, which is a temperature range where the animal is not too hot or too cold, and does not need to use energy to keep itself comfortable (such as panting when hot or shivering when cold). Calves under three weeks of age are comfortable at environmental temperatures between 15 and 25°C. When the temperature is above or below this range, calves will start to adjust their behaviour to keep warm or cool off. When temperatures fall below 15°C, energy will be used by the calves to keep warm, leading to cold stress. This means if producers do not offer calves more feed (energy), the feed calves are given will be used to keep warm instead of for growing or protecting against disease. Calves not given enough feed in cold weather will not grow and may even go backward and lose weight.
Newborn calves are particularly susceptible to cold stress for the following reasons:
Wet hair cannot insulate the calf. Newborn calves or calves that are wet for any reason need to be dried off. As water on a calf evaporates, it takes heat with it. This process of evaporative cooling is important for older animals during periods of heat stress, but takes a lot of energy from young calves in the winter.
Make sure calves are dry before putting calf jackets on.
Newborn calves have only 1.5 per cent brown adipose tissue (BAT), a type of fat present at birth for the purpose of generating heat during cold stress. Without colostrum, BAT stores are depleted in 18 hours.
Colostrum IgG absorption is reduced with cold stress.
Newborn calves have only three per cent body fat, leaving them heavily dependent on nutritional energy sources for heat production.
Ensuring calves are dried off immediately after birth and are fed plenty of high quality colostrum, followed by ample amounts milk or milk replacer will help calves born in the winter thrive.
Calves older than three weeks of age begin to experience cold stress at 5°C. For all unweaned calves, increasing the amount of milk or milk replacer fed will ensure the calf has enough energy to keep warm, grow, and stay healthy.
The best way to raise healthy and productive calves in the winter is to feed them plenty of good quality feed. For more feeding and calf housing tips and to read the rest of this article, click HERE