Good colostrum management is key to the health of newborn calves. Good management includes harvesting and feeding enough good-quality colostrum in a timely manner so that the antibody level in the calf will provide protection against the range of disease-causing microbes that the calf will encounter in its first few days and weeks of life.
Good colostrum-management starts with harvesting excellent quality colostrum — colostrum that contains large concentrations of protective antibodies (and not many contaminating bacteria). Quality is so important that many suggest testing colostrum with a BRIX refractometer to make sure the colostrum is indeed good quality.
If colostrum quality can be quite variable, then it pays to understand things that we can do to help make sure that we harvest colostrum in a way so it will provide good protection. It has been known for a while that delaying stripping out colostrum will reduce the concentration of antibody in the colostrum. It is assumed that this occurs because colostrum gets diluted as the udder switches from colostrum production to milk production.
Recently, researchers looked to see if what happens to the cow as colostrum is harvested can affect either the amount or the quality of colostrum. They wanted to see if having the cow’s calf present when colostrum was being harvested or giving oxytocin had an impact on colostrum. The idea was that oxytocin is the natural hormone that promotes milk let-down, so providing additional oxytocin may be beneficial. They decided to test the impact of the presence of the calf with an idea that any calming affect of having the calf in front of the cow might lead to a natural release of oxytocin. They were also able to look at several other things that could impact colostrum like when the cow calved during the day and what day of the week she calved.
Giving oxytocin or having the calf in front of the cow did not have any impact on the quantity of colostrum but both did improve the quality. Quality was measured by looking at the amount of antibody in the colostrum and comparing it to colostrum from control cows that had neither oxytocin nor the calf present.
The time of day when the calf was born had an impact on colostrum quality too. Colostrum from cows that calved at night was better than from cows that calved in the morning or afternoon. Interestingly, colostrum quality was also different depending on what day of the week the calf was born. Cows that freshened on Sunday gave better colostrum. Both of these findings were surprising. The researchers proposed that the differences might be because night time and Sunday could be quieter times on the dairy farm. It could also be that there were some differences in the care provided at night or on Sunday. Maybe the farm workers were less rushed. Less bustle might mean that fresh cows were calmer and more likely to release natural oxytocin. The researchers did not measure any cow’s oxytocin, though.
This research did confirm that some controllable aspects of the cow’s environment could affect the quality of colostrum. That could be useful in some situations. They did caution that the trial was done at one large dairy. It is possible that the findings might not be the same at all dairies.
Dr. Rob Tremblay is a veterinarian for Boehringer-Ingelheim and lives near Guelph. Follow his blog at http://bovinehealth.ca.