Just how important are the first 12 hours of a calf's life? Extremely, says Dave Smith, University of Nebraska-Lincoln Extension veterinarian. "Those first 12 hours set them up for success or failure all the way through their life," he says.
Calves that die within this 12-hour period are considered stillborn, and it's still a major problem impacting ranchers. National Animal Health Monitoring System (NAHMS) data from 1997 indicates stillbirths and neonatal-calf deaths accounted for 4.3% of the 1996 calf crop. If calves don't make it through this period, the buck literally stops here.
Producers need to understand that when a calf is born, it has an immune system that's not armed to fight infections. The only antibody disease protection that calf will have for the first few weeks of life comes from the passive immunity passed to it in its mother's colostrum, explains Glenn Selk, Oklahoma State University Extension animal reproduction specialist. Without that vitally important milk, calves have what is called "failure of passive transfer."
U.S. Meat Animal Research Center (USMARC) data found that when compared to calves with adequate passive immunity, calves with inadequate levels had:
- 5.4 times greater risk of pre-weaning death,
- 6.4 times greater risk of sickness in the first 28 days of life,
- 3.2 times greater risk of sickness prior to weaning, and
- 3 times greater risk of being sick in the feedlot.
Health begins with the first meal. Mother's first milk, or colostrum, is full of immunoglobulins -- or antibodies. The calf's ability to absorb antibodies, which are very large proteins, is dependent upon intestinal closure. From the moment a calf is born, the clock is ticking on its ability to absorb larger proteins due to sloughing of cells within the calf's lower gut. The gradual loss of these cells occurs over 1-2 days (Table 1.)
"At six hours of age, we're down to absorbing something in the neighborhood of two-thirds of what they could have absorbed at birth," Selk says. "So getting that first milk into the calf is extremely important -- the sooner, the better."
Selk cautions, however, that a producer's good intentions can speed the rate of intestinal closure. One way is feeding whole milk (without antibodies) to the calf for its first feeding, followed by a bottle of colostrum 6-12 hours later.
"That calf's ability to absorb the immunoglobulins out of the colostrum in the second feeding is greatly reduced from what it would have been if he hadn't gotten the whole milk to start with," Selk says.
"It's extremely important that the calf's first meal contain immunoglobulins. While each subsequent meal also would contain some immunoglobulins, that calf's ability to absorb them declines with each meal," he adds.
The volume of antibodies in colostrum can vary by cow. While a beef cow produces less milk volume than a dairy cow, for instance, the concentration of immunoglobulins is generally higher, Selk points out. In most cases, mature cows produce more antibodies in their colostrum than heifers.
Supplementing milk. Ranchers must intervene in cases where calves don't nurse on their own. Natural colostrum is superior to colostrum supplements and replacements, Smith says. While these artificial products can raise calves' antibody levels, their performance pales in comparison to that of real colostrum because there are fewer immunoglobulins and they are not matched to the pathogens in the herd. "The technology is still behind Mother Nature," Selk adds.
Acquiring, storing and thawing natural colostrum, however, does present management challenges.
Natural colostrum isn't as readily available as when local dairies were more abundant. Then, producers could work out a deal with dairy producers to capture some colostrum from the first milking of postpartum dairy cows (which isn't allowed in the milk line).
But "free" colostrum is hard to find today. Nonetheless, Selk and Smith caution producers seeking dairy colostrum to check out the dairy's health status. "In particular, I'd like to know if the dairy has had any Johne's disease incidence because it can be transferred via colostrum," Selk says.
A better source is stored colostrum from your own herd. Selk recommends obtaining colostrum only from cows that can be handled safely in such a personal way.
In fact, the challenges associated with acquiring, freezing and thawing colostrum (see "Some Tips For Storing And Thawing Colostrum," elsewhere in this newsletter) is why producers generally turn to colostral substitutes, which can be as convenient as mixing a powder into a warm liquid and feeding it to the calf. Such supplements are readily available at livestock supply stores.
At a minimum, Selk recommends beef producers supplement a normal-sized beef calf (80 lbs.) with two quarts of natural colostrum/feeding, and again 12 hours later.
"If the calf can take another half or three-quarters of a quart, more power to him -- the more the merrier," Selk says.
For colostral supplements, producers should follow directions closely, and never split a bag between two calves. "You'll under-nourish both calves rather than take good care of one," Selk says.
Other factors include difficult birth, weather and equipment.
Difficult birth. Calves undergoing a difficult birth are subjected to uterine contractions and asphyxiation when the umbilical cord "shuts off," Selk explains. Known as respiratory acidosis, the body builds up carbon dioxide (a result of lack of oxygen) and lactic acid. Such calves are unlikely to get up and nurse on their own.
"An acidotic calf's gut has an impaired ability to absorb antibodies, even if they're available to him," Selk says. While the calf may be saved, its state of limited immunity makes it vulnerable to disease. His advice is "get colostrum into the calf, as much as it can absorb."
Weather. As soon as a calf hits the ground, weather is often its first adversary. Because they're unable to regulate their body temperatures, calves are susceptible to extreme cold and heat.
In temperatures less than 20°F, calves face frostbite and hypothermia. Research also indicates that calves that are hypothermic or extremely cold-stressed absorb antibodies more poorly.
Meanwhile, temperatures in the upper 80s and 90s can lead to an over-warmed calf that gets dehydrated.
Clean equipment. "Obstetrical equipment needs hot, soapy water because all the organic material must be washed off," Smith says. "Topical disinfectants won't do the job."
On tube feeders, mucus and saliva that coat the tube must be physically washed off, as does the milk and colostrum inside it. Smith uses a brush in tough-to-reach areas of feeders. Don't forget to air-dry the feeder between feedings.
Diluted liquid bleach is a great disinfectant, but can harm clothes. Chemical disinfectants like Nolvasan and Roccal do an effective job with less risk to clothes, but the water must be hot and soapy, Smith says.
|Time of feeding |
(hours after birth)
|Plasma concentration |
(mg/ml) 24 hours