14 October 2014

2 minute read

It may be the case that colostrum is far more than a signal of protection against disease through antibody protection, the 2014 Dairy Production Conference heard earlier this year. 

Speaking at the conference, a Cornell Professor described the variety of molecules present in milk when comparing mature milk to colostrum.

Dr Mike Van Amburgh said that colostrum has an 18:1 ratio for prolactin, 65:1 ratio for insulin, 155:1 ratio for IGF-1 and 7:1 ratio for IGF-2 alongside mature milk.

How these hormones and growth factors totally affect the calf is not known, writes dairy adviser Mary Sowerby for the University of Florida quarterly newsletter.

But, it is known glucose (the sugar used for energy) absorption is enhanced in colostrum-fed calves versus milk-replacer fed calves and that in piglets there is an increased rate of protein synthesis in skeletal and intestinal tissues of colostrum-fed versus mature milk feeding.

In cattle, there is significant mammary development prior to weaning which does not occur after weaning, which added protein from milk has been shown to enhance, writes Mrs Sowerby.

Dr. Van Amburgh cited numerous studies which have shown benefits ranging from 1000 to 3000 additional pounds of milk produced by first lactation cows who received increased liquid nutrient intake prior to weaning (either by approximately doubling normal milk replacer feeding rates (two pounds per day instead of only one) or adding supplemental protein to whole milk).

At Cornell researchers found the strongest relationship associated with first lactation milk production was growth rate prior to weaning. For every one pound of average daily gain prior to weaning (or at least 42 to 56 days of age) the heifers produced approximately 937 pounds more milk.

Dr. Van Amburgh suggested a minimum goal of doubling birth weight by 56 days. For instance a calf weighing 85 pounds at birth should be 170 pounds at 56-days-old. Some Jersey herds have achieved three times the birth weight in 60 days. In addition he recommended keeping calf mortality less than 5 per cent and morbidity (sickness requiring treatment) less than 10 per cent.

Why?

1. To capture feed efficiency in early life.
2. To achieve optimal breeding weight at an earlier age and therefore an earlier calving age.
3. Potentially increase milk yield and herd life.