Below freezing weather provides good calf growing conditions.
Heat stress is absent. Pathogen survival and growth in freezing conditions is poor. In cold weather conditions calves have a great opportunity to grow without these stresses.
In this article different ways of feeding more energy in cold weather are described.
Below freezing weather provides good calf growing conditions. Heat stress is absent. Pathogen survival and growth in freezing conditions is poor. In cold weather conditions calves have a great opportunity to grow without these stresses. And, they are eager to eat every day. Year after year I had my best rates of gain in winter weather.
Calves are basically cold weather creatures. The temperature at which they use no energy either to warm or to cool themselves is called “thermoneutral.”
For newborns that temperature is about 60°. At one month of age this thermoneutral value drops to about 30°. Thus, as they mature through the preweaned weeks they become more comfortable with freezing weather.
The Need for Energy
The limiting conditions for wintertime growth are adequate energy and water. Seventy percent of new growth for a calf is water. As she begins to eat starter grain in addition to milk or milk replacer, more water than that provided by milk is essential for efficient growth.
Energy is the other major limiting factor. Energy used for keeping the calf alive increases as body size increases and as temperatures go down. In an accompanying chart, the blue bars show the amount of maintenance energy needed for an eighty-pound calf (on the left) and a one hundred-pound calf (on the right).
The reason for three bars for each size calf is to show the influence of emperature on the amount of energy needed for maintenance. Looking at the ighty pound calf on the left, note how the blue bar goes up as the housing emperature goes down from 50 to 30 to 10 degrees F (10 to -1 to -12 degrees).
The solid black line that runs from left to right at 4 quarts of 20-20 milk replacer daily shows the energy available from that feeding rate. Only at 10° does the blue bar go above this solid black line. The weather has to get very cold to put an eighty pound calf into a negative energy balance for maintenance. Of course, this assumes that this size calf eats all four quarts daily.
But, notice that when we combine both the blue and purple parts, the tops of all bars are above the solid 4 quarts per day line. If we want these calves to gain one pound per day, they will have to eat more than the amount provided in 4 quarts of 20-20 milk replacer a day.
Look at the bars for the one hundred-pound calf. As soon as freezing temperature arrives, she lacks enough energy from the 4 quarts a day feeding to even meet maintenance needs.
That means she will start losing weight as she robs her body tissue to keep warm. And, note that this assumes that she is dry and housed in a draft free place.
The amount needed for this larger calf to grow a pound a day in addition to maintenance is shown in the purple part of the three bars on the right. Even at 50° when fed just 4 quarts of 20-20 milk replacer daily this one hundred pound calf isn’t going to gain even close to one pound a day.
In rough winter weather, this is one of the calves that is likely to lose a lot of eight and have pneumonia. These calves respond poorly to antibiotic treatment for respiratory illness because they have no body reserves to combine with the medicine to mount a defense against the bacteria.
The bars in the graph tell us the plain facts about cold weather feeding and gains. Feed too little and calves not only won’t gain, they will have trouble surviving. Feed enough and calves will thrive like no other season of the year.
Five different ways to feed more energy in cold weather.
Calves grow very well in cold weather. Naturally, they need a good start with plenty of good quality colostrum as soon as possible after birth. Calves body reserves at birth are very limited.
Thus, the first feeding of colostrum provides essential energy for survival. Several feedings of colostrum or high fat transition milk are very desirable in freezing weather.
Our challenge as calf raisers is to work out some plan on our farms that will get extra cold weather energy into calves.
If we want calves to grow and build strong immunity, they must have plenty of energy for growth as well as that needed for maintenance. When freezing weather conditions absorb a lot of energy calves often fall short of the nutrients needed for healthy growth.
How can we increase the amount of energy fed? If you have access to transition milk that is an excellent feed because it is about 16 to 18 percent dry matter. Whenever it was available, I used to feed it to the calves under a week old. Especially in freezing weather, they thrived on it because of all the extra energy.
If you have whole milk available, replace all or some milk replacer with milk. Holstein milk has about twenty-five percent more energy than 20-20 milk replacer. Jersey milk is higher, fifty percent.
Please be careful about using waste milk, however. If fed immediately after milking, it could have an acceptable level of coliform bacteria for calves. If it is held without refrigeration for more than two hours it could have high levels of coliform bacteria leading to unacceptable rates of scours and respiratory illness, reduced rates of gain and even death.
Keep in mind also that unpasteurized waste milk, depending on your herd’s health situation, could be the route for infecting calves with salmonella, mycoplasma or Johnes.
Feed more of the same
Another practical way to increase energy levels is to stay with the same milk replacer but just feed more of it. In my experience when 20-20 milk replacer is mixed according to tag instructions it can be fed in winter conditions up to three or three and one-half quarts per feeding twice a day.
Calves will make more efficient use of this feed and begin eating starter sooner if free choice water is offered at least once a day. “Yes”, that says to offer water even when the weather is below freezing.
More and more farms are working out schedules to feed water in wintertime. Lots of them fill water pails once a day and, before it freezes solid, dump pails once a day.
Add more milk replacer powder
Some farms that feed free choice water all year round choose to increase the dry matter content of their milk replacer in freezing weather. Without free choice water I never had much success increasing dry matter content of milk replacer.
As you mix in more powder for the same amount of water it is possible to offer mixes up to 15 and 18 percent dry matter. For example, using ten ounces of powder per calf per feeding rather than eight increases the energy level by twenty-five percent.
These mixes contain a lot more energy per quart. This method works well for young calves (that have free choice water daily).
Add an extra feeding
For several years, when the labor situation was just right, in the winter I added a mid-day feeding for all the calves less than two weeks old. This is a relatively small proportion of the total calves on milk so it was workable.
We were already working with all the calves at that hour feeding them water. So, the extra milk was not much extra work. I fed by size: one extra quart to average size calves and two quarts to the largest ones (100# and up). I had no problems with scours. And, it reduced my problems with respiratory illness in this age group.
Add extra fat
Some farms don’t want to change their feeding procedures between summer and winter. These folks may wish to increase the fat content of their ration. One way to do this is to purchase a special “winter” formula milk replacer such as a 20-27. This provides the extra energy as fat without having to add it as a separate step. In situations where feeding has to be limited to two or two and one-half quarts of milk replacer per feeding, this has worked well.
The other method is to add fat separately. The product that I have worked with directly is Merrick’s Super Calf Kit. There are others available. Ask your milk replacer supplier.
It works well to increase energy. However, it is an extra step at milk replacer mixing time. Only a small amount is used per calf at each feeding. Therefore, I recommend purchasing a sturdy garbage pail to store a product like this in order to maintain product quality once a bag has been opened.
By: Sam Leadley, Calf & Heifer Management Specialist, Attica cows, www.atticacows.com