DURHAM, N.H. – Recent research shows that 73 percent of cows at their first calving and 61 percent of multiparous cows do not produce enough colostrum to feed their calves. Farmers and researchers have long understood the importance of colostrum for the health and survival of newborn calves, making the lack of colostrum production (CP) a critical challenge.

Peter Erickson, a professor and extension dairy specialist at the University of New Hampshire, said he has noticed a lack of CP at dairy farms in the last few years. Erickson and his colleagues reviewed published research about colostrum yield in dairy cattle, and the review was published in the academic journal Applied Animal Science.

The key results of the review found that low or no colostrum yield can be attributed to various factors, including nutrition, genetics, environment, the mammary system and farm management.

Erickson said that one of the key factors with the greatest impact on CP is dry period length. Research shows that cows with shorter dry periods produce significantly less colostrum than those with longer dry periods. A minimum dry period of 60 days is recommended for optimal CP.

“Dry period length seems to be the main driver in the amount of colostrum produced. For instance, the data would say that in the summer, spring and fall, if you have a longer dry period, you will tend to have more colostrum production,” he said. “Of interest, the opposite thing happens in the winter, at least in the northern environments.”

Some research shows that increasing dry period length in winter has little impact on CP, pointing toward an environmental influence. Erickson’s hypothesis is that CP is highly influenced by temperature.

“(New Hampshire University) has two research dairies. We have a conventional Holstein tie stall barn, and we have an organic Jersey barn. (Low colostrum production) is not really an issue with our Holsteins, but it is an issue with our Jerseys in our organic barn,” he said. “Well, organic cows need to have access to the outside, and it gets cold. This is just my hypothesis, but I think that the reduction of colostrum has to do with environmental temperature. When it gets cold, it seems like the production of colostrum shuts down.”

Cold stress may reduce levels of prolactin, a hormone critical to produce milk and colostrum, Erickson added. Still, more research is needed to confirm the impacts of temperature on CP.

Research regarding nutrition is not conclusive, Erickson said. Some studies show that feeding a pre-fresh diet containing more sugar in the weeks leading up to calving tends to increase colostrum yield. Choline supplementation and lipid supplementation using sunflower seeds have also shown the potential to increase colostrum yield, although more research is needed.

Protein intake had no significant effect on colostrum yield, though high-protein diets may enhance IgG uptake in calves. Nicotinic acid, or vitamin B3, has also been associated with an increase in IgG concentration but does not significantly impact CP. Studies using probiotic supplementation also demonstrated no impact on colostrum yield or IgG concentration.

Other factors that influence CP are mastitis, which decreases yield; calf size, with larger calves and male calves linked to higher yield; and genetic components, with one study demonstrating that low CP in dairy cows had a 3.9 percent inbreeding coefficient, and other studies finding specific sections of genes related to CP. Erickson noted that new research from across the globe suggests that perhaps colostrum is present but isn’t liquid enough to be released from the gland.

Increasing CP will likely require a multifactorial solution.

“I think that if we calve inside and not in a cold environment, less than 41°F, that would be one thing that would increase colostrum yield,” Erickson said. “If you’re running into a problem with (colostrum) production, try increasing your dry period length by ten or 20 days, not in the winter but in other times of the year.”