Low Colostrum Yield in Dairy Cows

By Victor Malacco

Have you ever noticed that cows produce less colostrum during the fall and winter months? The deficiency in colostrum production is sometimes reported as no colostrum production at all. Despite these observations, little is known about its causes.

Colostrum is essential for the newborn calf. Because the placenta of cows completely separates the dam and fetal blood, no antibody or immunoglobulin transfer occurs during gestation. Therefore, the newborn’s immune protection relies primarily on colostrum immunoglobulins absorbed in the intestine during the first 24 hours after birth. In addition to antibodies, colostrum is a good source of several nutrients and bioactive compounds. It provides growth factors important to the developing calf, peptides with anti-microbial activity and, when fed fresh, can transfer immune cells to calves. The success of transferring the immunoglobulins to the calf depends on the timing that it will receive the colostrum and the colostrum quality, cleanness and quantity. The quantity can be a challenge during the fall and winter months when the cows start to drop the colostrum synthesis.

It is well known that nutrition, dry period length, milk production history and the number of calvings affect colostrum immunoglobulin concentration and its nutrient composition. However, the risk factors that result in low colostrum production remain unclear. Gavin and colleagues conducted a year-long study in Texas dairy herd where they evaluated the colostrum production and quality of 2,988 Jersey dairy cows to assess possible effects of photoperiod, temperature and cow factors on colostrum production. They observed an average colostrum production of 9.4 lbs. in a range of 0 to 58.4 lbs. Interestingly, they noted a considerable variation during the year, with average colostrum production of 10.6 lbs. in May, 14.5 lbs. in June and 5.5 in December. They also observed that cows with more than one lactation had a more significant decline in colostrum production from June to December, on average, compared to first-lactation heifers, with 35% of them producing no colostrum in December compared to 1% of the first lactation heifers. The primary factor identified by the authors affecting colostrum production was the photoperiod. They observed that longer sunlight duration 21 days before and at calving day strongly correlated with greater colostrum yield. They also highlighted that genetics could influence colostrum production, with the yield varying between sire lines within the Jersey breed.

Similarly, a study by Soufleri and colleagues conducted in Europe evaluated 1,017 healthy Holstein cows from 10 farms observed effects of the number of calvings, milk production in the previous lactation, and season of calving on colostrum yield with lower colostrum production observed in fall and winter months (13 lbs. on average) and greater on spring and summer (16 lbs. on average). Furthermore, during an evaluation of nine Holstein dairy herds in New York, Westhoff and co-authors observed the lowest colostrum yield in October for first-calving cows and in February for multiparous cows. They also reported that the risk of a cow not producing colostrum was more than three times higher in December (9.5%) compared to June (2.9%).

A recent study led by Rossi and co-authors conducted at three commercial Michigan dairy farms observed the lowest colostrum yield during winter (4.5 quarts) by cows milked within 6 hours after calving when compared to the other seasons (5.7, 6.2, 5.7 quarts of colostrum during spring, summer and fall, respectively). Interestingly, regardless of the season, only 40% of cows produced sufficient first-milked colostrum to support the second meal of colostrum to calves (6 liters total yield).

To date, the relationship between photoperiod and colostrum yield is an association, with a cause-effect relationship yet to be determined. The speculation around the reduction in colostrum production and photoperiod length is related to the variation of hormones like melatonin and prolactin. The light incidence in the cows’ eyes controls melatonin secretion by the pineal gland, with long days resulting in low melatonin concentrations. On days with a short photoperiod, melatonin concentrations are high and could inhibit the release of the hormone prolactin and IGF-1. These hormones are essential for the induction and maintenance of lactation and their lower concentrations could explain the low colostrum synthesis in cows exposed to reduced photoperiod. However, more studies are necessary to confirm this theory.

While the decrease in colostrum production is commonly associated with the late fall and winter months, characterized by lower temperatures, there is currently no substantial evidence linking colder temperatures to an elevated nutrient requirement in cows that could lead to reduced colostrum production. Although the precise lower critical temperature at which dairy cattle begin expending energy to maintain their body temperature remains uncertain, it is generally observed that temperatures above 20 degrees Fahrenheit would not have detrimental effects on cow productivity.

Nutritional strategies have been a focal point in the efforts to enhance colostrum production in dairy cows. However, in well-managed herds where cows are adequately fed, only a few prepartum dietary components have been associated with colostrum production. Several studies have investigated different protein levels in prepartum diets, however, colostrum yield is not reported in most of the studies and there is no evidence supporting that increasing crude protein or metabolizable protein in the close-up diet would enhance colostrum production (Farahani et al., 2019; Hare et al. 2023). This is consistent with the findings of Westhoff and colleagues, who observed greater colostrum yield in multiparous cows with prepartum diets containing CP levels of 13.6% to 15.5% of DM and ≤13.5% of DM for first lactating cows. The role of energy levels influencing colostrum production has also been explored, with studies suggesting that altering diet energy four weeks before parturition does not significantly affect colostrum yield in dairy cows.

Recent advances in research have unveiled nutritional strategies that could be potentially used to improve colostrum production in dairy cows. For instance, supplementing 13 to 20 grams of choline ions in a rumen-protected form resulted in cows producing more colostrum compared to non-supplemented cows (Swartz et al., 2022; Holdorf et al., 2023). Moreover, research presented during the American Dairy Association meeting this year indicated that cows supplemented with rumen-protected arginine produced an additional 5.5 lbs. of colostrum compared to their non-supplemented counterparts. However, it is essential to approach these promising results with caution, as they were not specifically designed to account for seasonal effects.

The reduction in colostrum yield seems to be a seasonal variation, with dry cow management and cow factors playing only a minor role in this phenomenon. Since providing extra daylight is not possible for many farms, the potential adverse effects of the colostrum shortage on calf health must be addressed through well-planned banking of high-quality colostrum and the use of colostrum replacement strategies when necessary.

Another strategy already adopted for farms that have a low prevalence of failure of transfer of passive immunity and recommended by Michigan State University Extension is the second feeding of 2 to 3 quarts of colostrum 6 to 12 hours after the first feeding. Calves that received a second colostrum feeding were less likely to develop morbidity, had better growth rates in the pre-weaning phase and tended to produce more milk in the first lactation, as Rossi and colleagues reported.