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Dairy Pipeline: November 2004
Robert E. James
Extension, Dairy Scientist,
Dairy Nutrition
(540) 231-4770 email: jamesre@vt.edu
At this time of year many homeowners are getting ready for colder weather by installing more insulation, adding storm windows, or putting more fuel in the tank for the furnace. It's time to do the same for your calves! Young calves, by nature of their size, lose heat more rapidly than older, larger animals. Cold weather can present serious challenges to the young calf. What can the calf raiser do to ensure healthy calves through the winter? Fine tune those dry cow feeding programs. Ensure that rations have adequate energy, protein, minerals and vitamins. An energy deficiency will result in thin cows giving birth to calves with little reserves of body fat. A prolonged cold snap or low intake of milk or milk replacer can be deadly for the calf. Excellent colostrum management encourages efficient absorption of antibody-rich colostrum. Quality (older cows and first milking), quantity (one gallon during the 1st 12 hours of life), and timing (feed at least 2 quarts within the first 6 hours of life) are essential for effective colostrum management. Earlier colostrum feeding is even better. Consider increasing the nutrient content or quantity of milk or milk replacer fed to the calf during the winter. The influence of season and liquid diet on calf growth is shown in the following table which represents expected growth of a 125 lb. calf fed either whole milk, a 20% protein:20% fat, or a 28% protein:20% fat milk replacer at different feeding rates and different environmental temperatures.
| 68°F | 32°F | ||||
|---|---|---|---|---|---|
| Liquid | Lb./day | Energy allowable gain | Protein allowable gain | Energy allowable gain | Protein allowable gain |
| Whole milk | 8.6 lb. | .47 lb. | .76 lb. | Weight loss | Weight loss |
| 20 lb. | 2.46 lb. | 2.18 lb. | 1.88 lb. | 2.18 lb. | |
| 20:20 milk replacer | 8 lb. @ 12.5% DM | .10 lb. | .48 lb. | Weight loss | Weight loss |
| 28:20 milk replacer | 14.7 lb. @ 17% DM | 1.4 lb. | 1.77 lb. | .72 lb. | 1.77 lb. |
Traditionally, calves are fed about a gallon of liquid a day, regardless of the source of nutrition. The table shows that feeding a gallon of whole milk (3.2% protein, 3.85% fat) provides only enough energy for about a half pound of gain/day. However, when the temperature drops to freezing the calf will lose weight. A 20% protein: 20% fat milk replacer fed at about a gallon/day will result in only a tenth of a lb. of gain per day when it's 68°F. When it drops to freezing, the calf loses weight. Higher protein milk replacers have increased in popularity. These "intensive" milk replacers are also fed at higher feeding rates. This table shows that even at lower temperatures the calf will continue to grow when fed the intensive replacer. Higher feeding rates of whole milk also encourage healthier gains during cold weather, although at considerably greater expense. In addition to higher body weight gain with higher feeding rates, these faster growing calves are usually healthier, resulting in lower treatment costs. Benefits of liberal feeding programs are more pronounced with smaller, younger calves that lose body heat more readily. When temperatures drop, keep the dilution the same and feed more liquid to the calves. Consider trying the "intensive" milk replacers during the winter. In addition to dietary management changes, more liberal bedding of calf hutches or calf stalls and the use calf blankets reduces body heat loss as well. Keep those calves warm this winter!