Colostrum is key to prolonged calf health to establish immunity and provide nutrition
The key to getting newborn calves off to a good start is making sure they receive adequate colostrum.
“Eighty-five percent of the calves dying from infectious disease have received inadequate passive transfer of colostrum,” according to University of Nebraska Extension Veterinarian Richard Randle.
“In an ideal situation, we want cows to give birth to healthy, vigorous calves with little or no calving difficulty,” he continued. “We want those calves to remain healthy and grow efficiently.”
Colostrum provides immunoglobulins and other components that help the calf fight pathogens and develop an immune response.
“Colostrum also provides nutrients such as lactose, fats and protein,” he added.
Randle said ideally, the calf needs five to six percent of its body weight in colostrum within the first six hours of birth and an additional five to six percent of its body weight by 12 hours after birth. For an 80-pound calf, two to 2.5 quarts per feeding would be required.
Why do they need it?
“When a calf is born, its intestine has the ability to absorb intact immunoglobulins into the bloodstream,” Randle explained. “The intestine rapidly changes over the next several hours after birth. By six to 12 hours, absorption is significantly reduced, and by 24 hours, intact immunoglobulins can no longer pass. That is why it is critical that calves receive colostrum as soon after birth as possible.”
Passive transfer can be determined in the calf. To see if it has received adequate colostrum, producers can measure the level of IgG, an immunoglobulin, at 24 to 48 hours of age.
Randle said if the serum IgG concentration is greater than 10 grams per liter, the calf has adequate passive transfer, but if it is below that, the calf is considered at higher risk of disease.
“The calf’s immune system is competent at birth, meaning it does have the ability to respond to disease agents, but it is immature, so it doesn’t respond the same as an adult,” he explained. “They are also naïve when they are born because there is no passage of immunoglobulins across the placenta during pregnancy.”
If the calf doesn’t stand and nurse soon after birth, or fails to repeatedly nurse during the first six to 12 hours, it is at high risk of having inadequate levels of IgG to protect itself from disease. In these cases, the producer may need to intervene, Randle said.
Calves suffering from cold stress, born after calving difficulties, dystocia or hypoxia or from cows that lack mothering ability may also require producer intervention, he added.
Where to get colostrum
Ideally, producers should collect colostrum from the dam and feed it to the calf. If that isn’t possible, he suggests collecting it from a mature cow in the same herd and feeding it to the calf.
“Heifer colostrum is inferior compared to mature cows in both quality and quantity,” Randle explained.
Producers can also give the calf colostrum from outside sources, such as a dairy, but he recommends using caution since several disease sources can be transmitted through colostrum.
Supplements and replacers
If producers use a commercial product, Randle says they should determine whether the product is a colostrum supplement or a colostrum replacer.
Supplements are very similar to replacers, but the key difference is a colostrum supplement is designed to boost the quality of the natural colostrum. It provides less than 100 grams of IgG per dose.
A colostrum replacer is designed to be fed as the calf’s only source of colostrum in the event that no high quality colostrum is available. It should contain more than 100 grams of IgG per dose, in addition to digestible proteins, vitamins and minerals.
Colostrum replacer can be made from colostrum that is dried and heat-treated to eliminate harmful agents or made from blood serum collected and dried from packinghouses.
When purchasing these products, Randle encouraged producers to determine if the product is a colostrum replacer or supplement, if it is made from bovine colostrum or blood serum and if it is labeled with a claim for bovine IgG or just globulin proteins.
He said producers should also make sure the product is licensed by the USDA as a replacer.