Calves are less tolerant to cold temperatures than cattle.
When temperatures decrease and approach freezing, the maintenance energy needs of the calf increases. As a result, the calf will be using so much energy and body reserves to keep warm, subsequently decreasing growth rates. Furthermore, the stress of using body tissue to maintain energy levels causes the immune system to be depressed and less responsive to disease/health challenges.
Housing, bedding and other measures can help, but if cold weather cattle feed management is not executed, energy resources will be diverted from growth and immune function, therefore calves will not gain weight, and will be more susceptible to disease.
NUTRITION: To maintain growth rates in cold weather, feed more energy:
Calves under 3 wks. will have little or no rumen function, so the extra energy will have to come from the milk source.
This can be achieved by either feeding an extra feed or keeping the same number of feeds but feeding at a higher concentration.
REMEMBER: Feed milk at body temperature (39 ̊C)
EXTRA FEED: Feeding an extra meal can allow you to feed a higher concentration without predisposing the calf to a digestive upset.
It would be beneficial, to feed an extra meal at night, when temperatures are at their lowest.
The warmth and energy from milk will have the greatest benefit when it is most needed.
If too labour intensive, only feed calves which need an extra meal
(Under 3 wks.)
CONCENTRATION: As a general rule of thumb, for every 1°C below 15°C, an extra 11g of milk replacer is required.
Visit this link: www.calfnotes.com/downloads/AddedCMR.xls to calculate your own calf rearing situation, with regards to calf weight, temperature and age of calf.
REMEMBER: Allow nutritional changes to be made gradually to minimise stress & digestive upsets. Monitor calves throughout the changes; some calves may struggle with extra calories.
Crediton Milling in Devon are producers and suppliers of lamb and sheep feed and offer carefully researched sheep feed advice.