Cold Winter Calf Feeding
Feeding calves during the cold weather season can be a big challenge for any calf raiser. Producers need to be sure that calves housed outside during the cold weather are meeting their nutritional needs. Research suggests that calves raised in outside hutches during cold weather benefit from extra energy during the first month of life.
Calves have been successfully raised in calf hutches to prevent respiratory disease and avoid problems with humidity and spread of pathogenic organisms. Dairy producers in areas of cold winters have expressed concern about growth and survival of young calves. Newborn calves have small amounts of body fat plus relatively high energy requirement in relation to body weight.
The effects of housing and season on calf growth were observed from birth to 7 days of age. Significantly lower average daily gain was shown by calves housed in hutches during the winter compared with calves raised in a conventionally heated barn and fed the same ration. Cold temperature alters digestive processes and therefore the nutrient requirements of domestic animals. Cold stress and feeding animals is especially important because the digestive function in younger, smaller animals may be more influenced by environmental temperature than that of older larger animals. Weight gains are usually lowest during times of low temperatures (-10°C) and highest during times of warmer temperatures (-20°C). The additional energy from dry starters is superior to low fat milk replacers for total weight gains and efficiency of feed conversion. It has been shown that calves housed at -4°C require 32% more energy for maintenance than calves housed at 10°C.
In another study, it was also shown that calves raised in cold environments benefit from supplemental dietary fat. Holstein calves were fed three levels of dietary fat (10%, 17.5%, or 25%) in milk replacers at two environmentally controlled temperatures (-4°C or 10°C). The 17.5% fat diet supplied 8.2% more metabolizable energy per kilogram of DM and the 25% diet supplied 17.5% more metabolizable energy per kilogram of DM than the recommendation for milk replacer. Average daily gains for the 10%, 17.5%, and 25% fat diets were as follows: 10% - -.04 at -4°C and .15 at 10°C; 17.5% - .02 at -4°C and .22 at 10°C; 25% - .09 at -4°C and .20 at 10°C. Calves housed at the lower temperature either lost weight or gained less weight than did those at higher temperature. However, in this study no starter was fed! Results do relate to increased energy requirement at cold temperatures, but not the fat level in milk replacer when a starter is fed.
The fat content of dry whole milk is approximately 30%, however, the fat fraction supplies 45% of dietary energy and protein and lactose supply the remaining 55%. The fat content of MR should be between 10 and 25%. The quantity of fat needed or supplied in a MR depends on its digestibility, the rate of growth desired, environmental conditions, and cost of fat and milk protein substitutes and palatability/ intake of starter -- which is also related to water availability. A minimum of 10% fat in MR is recommended when the temperature-wind index is above 5°C, and a minimum of 20% fat is needed when the temperature-wind index is below 5°C (again dependent on starter).
Let it be noted again, that an effective way to increase energy is to encourage drier starter intake. This is best accomplished by:
- Providing small amounts of fresh Calf Startena daily
- Provide free choice water or feed water 3-4 times daily during periods of freezing weather conditions
- As a guide, wean calves when starter intake averages 1 1/2-2 lb per calf per day
Source: E.H. Jaster, G.C. McCoy, and R.L. Fernando. 1989. Dietary fat in milk or milk replacers for dairy calves raised in hutches during the winter. J. Dairy Sci. 73:1843 E.H. Jaster, G.C. McCoy, and N. Spanski. 1992. Effect of extra energy as fat or milk replacer solids in diets of young dairy calves on growth during cold weather. J. Dairy Sci