Importance of Colostrum
The passive immunity transfer window may be shorter than you think.
Newborn calves need colostrum to protect them from diseases during the first weeks of life. Unlike human babies who obtain their mother’s antibodies via her bloodstream and placenta, ruminants are born with a naïve immune system. Travis White, veterinarian and director of veterinary services at Saskatoon Colostrum Co. Ltd., explains that the type of placenta in the dam prevents any pass-through of antibodies from her blood. Newborn calves require colostrum consumed orally.
The sooner the calf ingests colostrum, the better.
“It’s a race against time. Years ago people thought calves had 24 hours in which to obtain the antibodies, but studies have shown the highest absorption of IgG (immunoglobulins) [to be] within the first two hours. By about six hours, calves have lost about half the absorptive capacity of the gut,” he says. Gut closure (preventing large molecules from passing through into the blood and lymph systems) begins soon after birth.
A 12-hour-old calf’s absorptive capacity has dropped to about 15%. But, it’s more than a race against the clock, it’s also a race between antibodies and pathogens. If the calf nuzzles a dirty flank, he may ingest pathogens before he nurses colostrum. If he gets too cold or can’t get onto a teat, this delay can make him vulnerable to disease.
The consequences of a calf that doesn’t receive adequate colostrum, or receive it soon enough, can have effects on future health and performance.
“Numerous studies have looked at this,” says White. “If the calf didn’t get adequate colostrum (failure of passive transfer), he is 3.5 to 9.5 times more likely to become sick prior to weaning with scours or pneumonia. These calves are 5.5 times more likely to die prior to weaning than calves that get adequate colostrum.”
Negative consequences go even further.
“Calves with failure of passive transfer have lower daily gains,” White says. “Their average daily gain is reduced by about one-third. They gain at about two-thirds the rate of their healthier cohorts, and feed efficiency can be reduced as much as 50%.”
Age at first service is extended about 30 days, he adds. “We have to feed them 30 days longer to get to breeding weight.”
If the calf hasn’t nursed by the time he’s 2 hours old, White says, it’s time to consider giving colostrum. If it’s difficult to help the calf suckle or milk out the dam and administer the colostrum, producers can use a colostrum replacer product.
“Typically, we’d start with a product that provides 100 grams of IgG,” says White. “Then about six to eight hours later we’d want to see that calf up and nursing the dam. If he’s not, he needs a second dose.”
An orphan calf is another situation in which to give replacement colostrum. A calf may be orphaned for one of several reasons. The cow may die, or the calf may have to be removed for some reason, such as if the cow had twins and doesn’t have enough colostrum for both. A calf without a mom needs two doses of colostrum as a full replacement. If you leave a set of twins with the cow, supplement both with colostrum to make sure they each get enough, White advises.
Studies have shown that 70% of calves with inadequate passive transfer come from first-calf heifers. |
“Stress decreases the newborn calf’s ability to absorb antibodies from colostrum,” says White. “If it was a difficult birth, extremely cold weather or any other severe stress, ability to absorb colostrum drops by about 35%. Those calves need additional colostrum.”
Calves from first-calf heifers may also benefit from a supplement. According to White, studies have shown that on average, about 33% of beef calves fail passive transfer due to cows having poor-quality colostrum, not enough colostrum, a weather event or a bad udder.
“About 70% of calves with inadequate passive transfer are from first-calf heifers,” he says. “They may have lower quantity and maybe not as many antibodies. Supplementing calves from first-calf heifers can make a big difference in their weight gain and health status.”
Editor’s note: Heather Smith Thomas is a freelance writer and cattlewoman from Salmon, Idaho. [Lead photo by Shauna Hermel.]
