Colostral volume and immunoglobulin G and M determinations in mares.

This research paper looks at the volume of colostrum (the first form of milk produced by the mammary glands of mares after foaling), and the concentration of Immunoglobulin G (IgG) and Immunoglobulin M (IgM) in this colostrum. Measurements were taken right after birth and every two hours up to 20 hours postbirth. The study found no significant correlation between the initial levels of IgG and IgM in the mare’s serum and the volume of colostrum or total IgG and IgM values.

Details of Research

• The study was conducted on 6 multiparous mares – that is mares that had previously given birth. Measurements of colostrum volume and concentrations of immunoglobulin G (IgG) and M (IgM) were taken at birth and then again at 2-hour intervals for a total of 20 hours.
• The rate of colostrum production (also called mammary secretion rate) was observed to be around 292 milliliters per hour. This rate varied from 202 to 389 milliliters per hour.
• The total volume of colostrum produced was around 5.1 liters, with a range of 3.2 to 7.0 liters.
• The three important constituents of colostrum being studied – IgG and IgM – had total content values of 440g and 3.1g respectively. These values also varied greatly, with the range for IgG being 199 to 855g and for IgM it was 0.7 to 7.1g.

Research Findings

• Upon investigating the relationship between the immunoglobulins in the mare’s serum and in the colostrum, researchers found no significant correlation between serum and initial colostral IgG and IgM concentration or between serum and total colostral IgG or IgM values.
• A significant positive correlation, however, was observed between the concentrations of IgG and IgM at birth and the total IgG and IgM contents in the colostrum. This finding signifies that the initial amounts of these immunoglobulins in the colostrum at birth can be indicative of their total amounts in the colostrum over time.
• The research also gave insights into the importance of initial colostrum ingestion for the newborn foals. The initial 250 milliliters of colostrum contained 10% of the total IgG and 6% of the total IgM. Doubling the amount to 500 milliliters, increased these amounts to 20% and 14% respectively. These findings highlight the substantial immunity boost that a newborn foal can receive from initial colostrum intake immediately after birth.