Growing Beef Newsletter
February 2025, Volume 15, Issue 8
Retrospective serum total protein analysis on beef calves born in October 2022 to December of 2023 and its effects on morbidity and mortality
Dr. Megan Hindman, clinical assistant professor, CVM Veterinary Field Services
Calves are born agammaglobinemia, or without immunity due to the nature of their placenta (cotyledenary synepitheilochorial). Therefore, colostrum is their sole source of not only nutrition but immunity for calves when they are born. Besides its immune properties, colostrum provides key nutrients to the calves such as important carbohydrates, enzymes, enzyme inhibitors, proteins, nucleotides, growth factors, cytokines, vitamins, fats, pre-biotics, and minerals. All of these are difficult to replicate as a complete supplement without providing “cow-made” colostrum. In previous history the required amount of IgG from colostrum a calf needs to have a successful passive transfer and immune system was 50g of IgG, however, today that number has grown to a minimum of 200g of IgG and some authors suggesting 300g of IgG to receive adequate immunity.1 Due to rapid gut closure, all of this needs to be consumed by the calf no later than 24 hours from birth but ideally within the first 12 hours. There are several studies published mostly on dairy calves, but few have been on beef calves due to the nature of how they are reared. This is why the need to look at data of total proteins in beef calves alone is important to the industry. The objective of this study was to look at baseline parameters of calves and determine if there was a correlation between calves that received adequate passive transfer and those that did not and if there was a difference in average daily gain, treatments, and mortality between them. The hypothesis is calves that failed from a passive transfer status were more likely to die than those that did not.
Methods and Materials
Data was retrospectively collected from a beef embryo recipient farm that was routinely collecting the information gathered prior to this. Cows were greater than three years of age and of mixed beef genetics. Cows were vaccinated with a commercially available modified live vaccine pre-breeding, and a scour vaccine prior to calving. Cows were also fed a totally mixed ration once a day with free choice water. Once cows calved in a large close-up staging pen, pairs were separated and moved to a pairing pen for at least 48 hours. A composite colostrum sample was taken from all four quarters, teats were scored, and noted if there were nonfunctioning teats present. A brix refractometer was used to determine a brix reading on the composite colostrum sample and calves were supplemented with a commercially available colostrum if a brix score was less than 22. Blood was collected via jugular vein from the calf, blood was centrifuged down, and a serum total protein was run at 24 hours of age. Calves' identification, gender, type of embryo, and birthweight were collected. Pairs were moved into pens with an age spread of no more than 10 days between calves. During the time on farm, 60-day weight, average daily gain at 60 days, treatments, and mortality were all recorded. Calves were vaccinated with commercially available modified live vaccines throughout the growing period. A commercially available statistical program (R) was used to determine if there was a significant difference between average daily gain at 60 days of age and mortality with respect to birth weight, total serum protein, colostrum brix recording, and treatment.
Results and Discussion
The preliminary data was comprised of 659 calves born from October of 2022 to December of 2023 (Table 1).
There were no statistical differences between gender of the calf and the parameters analyzed. Of the 659 calves, 557 were in-vitro fertilized embryos. Finally, calves that had a serum total protein of 5.5 or higher had at least twice the chance of living than a calf with a serum total protein of 5.5 or less. To put into economic perspective, a quality colostrum replacer will cost $70-90 per full replacement. When looking at a calf with colostrum having a 2:1 odds of surviving compared to one that had a failing serum total protein likely because it did not receive adequate colostrum, we are still talking a profit of $1,800 per calf assuming a conservative $2.80/lb price minus the cost of a replacement. That is not assuming any production weight differences between those that did not receive enough vs those that did. Overall, the results indicate a positive and economically important benefit of calves receiving enough colostrum within the first 24 hours of life.
1Godden SM, Lombard JE, Woolums AR. Colostrum Management for Dairy Calves. Veterinary Clinics of North America: Food Animal Practice 2019;35:535-556.
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