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We’ve all heard at one time about the importance of feeding colostrum to calves and that the ingestion and absorption of high quantities of antibodies or IgG is vital to the health of the newborn calf. We also all know that colostrum from cows and heifers can vary widely in solids, fat, and IgG concentration. Many of you are aware that we can estimate the overall quality of colostrum by estimating the solids concentration using a Brix refractometer. (Yes, the same tool syrup producers use to measure sugar content when boiling sap.) We generally assume that colostrum greater than 50 grams of IgG per liter or 22% on a Brix refractometer is “good” quality colostrum and suitable for passive transfer of immunity if 4L is given to the calf in a timely enough fashion. But what happens when we find the colostrum may be too low in IgG concentration to feed the calf to achieve successful passive transfer of immunity?


One obvious approach is to supplement or boost the existing maternal colostrum with a dried colostrum replacement product. A recent study out of Guelph in 2022 did exactly that. The study grouped calves into 5 groups. The in the first 3 groups, calves were fed 3.8L of poor ( 30 grams IgG/L), medium ( 60 grams IgG/L) and high (90 grams IgG/L) quality colostrum. In the last two groups, they looked at supplementing low quality colostrum (30 grams of IgG/L) with 551 grams of colostrum replacer to achieve medium quality colostrum (60 grams of IgG/L) and supplementing  medium quality colostrum (60 grams IgG/L) with 620 grams of colostrum replacer to achieve high quality colostrum (90 grams IgG/L). Colostrum replacer was 27% IgG on a dry matter basis similar to Head Start Powder available commercially. 

Results were interesting when measuring IgG levels in blood from the groups of calves. As one would expect calves fed low, medium, and high-quality natural colostrum resulted in increasing serum IgG levels. Based on the design of the study, one would expect serum IgG results to be similar for medium quality natural colostrum and poor-quality colostrum supplemented with colostrum replacer to achieve medium quality, as well as high quality natural colostrum and medium quality colostrum supplemented with colostrum replacer to achieve high quality colostrum. Supplemented low quality colostrum did achieve higher blood concentrations of IgG than natural low-quality colostrum alone, however it was somewhat lower than natural medium quality colostrum. Supplementing this poor-quality colostrum improved serum IgG, but it was not quite to the level of natural colostrum. When high quality natural colostrum was compared to supplemented medium quality colostrum however there was a large difference with serum IgG in calves fed natural high-quality colostrum much higher. Additionally, there was very little difference between natural medium quality colostrum and the supplemented medium quality colostrum.


The study would suggest that you can make poor quality colostrum better, but you can’t make good quality colostrum better. So, while it is possible to supplement maternal colostrum with colostrum replacer, but it appears that the best results will occur when poor quality colostrum is supplemented. Of course, knowing which colostrum is poor, medium or high to start with is the only way to know which maternal colostrum could and should be supplemented with colostrum replacer powder. Talk to your herd vet about testing your colostrum with a Brix refractometer as part of your calf health program. 


Sticking with the theme of feeding new born calves, another recent study from Michigan State University looked at the effects of transition milk and milk replacer supplemented with colostrum replacer on growth and health of dairy calves. Transition milk is often defined as the second through fourth milkings after calving. Although not as high in IgG as colostrum, transition milk does supply additional fat, protein and immunoglobulins to the calf compared to commercial milk replacers. The study compared growth rate and overall health of calves after 9 feedings day 2 through 4 of life of three different diets, milk replacer, transition milk, or a 50:50 blend of milk replacer and colostrum replacer (Alta HiCal Colostrum Replacer) at a rate of 1.9L 3 times per day for 3 days. After the initial diets ended at day 4, all calves were fed and managed similarly.

Results demonstrated that from birth through weaning, calves fed transition milk and milk replacer/colostrum replacer blend gained 3 kg more total body weight than those fed milk replacer alone. Health scores did not differ between the treatment groups, although the study was designed that all calves received IgG enriched colostrum replacer for the first two feedings after birth and achieved successful transfer of passive immunity based on measured serum IgG values. Therefore, proving that feeding high quality Colostrum is critical in raising health calves. Compared with milk replacer alone, feeding transition milk or milk replacer with colostrum replacer for 3 days increased growth rate of calves throughout the preweaning period.

We would expect that improved health outcomes would be obtained if this program was given to calves that didn’t get adequate colostrum at birth but doesn’t replace good colostrum management at birth.

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