Dr. Pete Erickson, extension dairy specialist, University of New Hampshire, says the most important thing for any newborn calf is to ingest colostrum as soon as possible.
“We mainly think about colostrum in terms of disease protection (temporary immunity provided by the antibodies it contains), but the other important ingredient is fat,” he says.
This is especially important in cold weather to give the newborn calf energy and calories to help keep warm.
“Baby calves have a low critical temperature of about 55 degrees (if the outside temperature is below that, they become chilled and stressed). Dairy calves are less hardy than beef calves and need more attention in cold weather. A newborn calf has only about 18 hours of internal fat stores. It is important to get colostrum into that calf,” he says.
“We dry the calf, dip the navel — everything you’d normally do regardless of the time of year — but the more colostrum you give the calf, the healthier it will be. We need to provide at least a gallon. Some people give it all at once, some give two-thirds of it at birth and one-third a little later, but it needs to be provided before the calf is 12 hours old.”
Gut closure begins immediately after birth. It’s a race against time, and also a race between the antibodies in the colostrum and pathogens the calf encounters. It’s crucial to get the optimum amount of colostrum into the calf as soon as possible.
This is especially important in situations where there’s stress, since stress also hastens gut closure. Calves may not be able to absorb enough antibodies if they are already cold and stressed. A difficult birth is also a stress. The calf needs colostrum immediately, and at least a gallon.
“Ideally, colostrum should be tested with a colostrometer or refractometer. The fat content of colostrum varies. I’ve seen fat content in Holsteins as low as 4.5% and up to around 7%,” Erickson says.
The fat and antibody levels are a bit lower in Holsteins just because of the large volume of fluid.
“The colored breeds have better quality colostrum from an antibody standpoint and fat (less total volume, and more concentrated solids) but sometimes we run into problems, especially with Jerseys, since they often don’t produce much colostrum in the winter,” says Erickson.
“We are doing a research study, evaluating this issue. My first experience with this problem was with a 250-cow Jersey herd in Maine. The dairy wasn’t sure what was happening; some people thought it was genetic, or diet; they’d just put in new corn silage. An interesting study was done at the veterinary school at Washington State University, and a dairy in Texas. They looked at colostrum production in Jerseys throughout the year, and found it varied with the seasons. During winter, the aged cows produced a lot less colostrum. In December, 48% of those cows produced no colostrum. Those researchers think it has to do with photoperiod and less daylight.
“Here in New Hampshire we are close to 45 degrees latitude (45th parallel, halfway between the equator and North Pole), so days are short during December. We have two dairy herds at UNH and our Jersey herd stops producing colostrum about November. The problem with that herd is that it’s an organic herd, and up until this past year there was no organic colostrum replacer on the market. We store frozen colostrum, for use in winter.”
The lack of colostrum in winter is an interesting phenomenon with Jerseys.
“We have a graduate student doing three studies. The first study is looking at the pre-fresh diet, and the second study will look at photoperiod. We’ll put one group of cows in a barn and give them 16 hours of light daily,” Erickson says.
This is similar to putting mares under lights starting in November to influence the body to think it is spring so the mares will start cycling earlier for earlier breeding.
“The other group of cows will only get eight hours of light each day to see if there is an impact on colostrum production. There is data from Maryland and Illinois on lactating cows showing positive response to more daylight hours. We want to see if it has an effect on colostrum production,” says Erickson.
The third study will involve collaboration with several dairy farms in New England.
“One of the members of this graduate student’s committee is on the faculty at Utah State University, so she may also go to Utah, and maybe also to some Jersey herds in Idaho, to collect data, as well,” he says.