Colostrum, otherwise known as ‘beestings’, is the most important feed a calf will get in its entire lifetime – as it contains vital antibodies to protect the calf against infections; many of which occur in early life.
This is according to Leonal Leal – ruminant researcher at Trouw Nutrition research and development in the Netherlands – who gave an interesting presentation on the topic of colostrum at the CAFRE, Dairy UK and the Ulster Farmers’ Union conference, on November 19, 2019.
In a study – which compared the level of immunoglobulins in blood and the mortality rate of calves pre-weaning – Leonal found that calves which contained less than 800IgG/L in blood (after 24 hours) had a pre-weaning mortality rate of 27%.
This was under the exact same feeding and rearing protocols, Leonal stated.
In calves which contained between 800lgG and 1,200IgG in their blood, this figure dropped to below 10%. Then, in those which contained immunoglobulins greater than 1,200IgG, the mortality rate dropped to 3%.
Immunoglobins is another word for antibodies. These enter the blood after the calf has been fed colostrum.
However, the amount of immunoglobins in blood is influenced by: the amount of colostrum fed; the quality of colostrum fed; and the amount of time after birth the colostrum is fed.
Continuing, Leonal referred to another study where they compared a group of calves fed 2L of colostrum at birth with another group of calves fed 4L at birth.
The two most obvious differences seen here was, number one, only 75% of the calves fed 2L survived their first two lactations – versus 87% for those fed 4L – and number two, those fed 2L had an average daily gain (ADG) of 0.8kg versus an ADG of 1kg.
Milk yield was also impacted, with those receiving 4L yielding 10,000kg of milk more during their second lactation.
In another study, a comparison was made between colostrum feeding with a stomach tube versus feeding with a bottle – to see would there be any difference in immunoglobulin levels in blood.Also Read: Comparison: Bottle feeding vs. stomach tubing colostrum
The immunoglobulins in the blood were exactly the same for both feeding methods.
The delayed feeding of colostrum or the hours after birth the colostrum is first fed, was another aspect assessed.
He found that the calves that were fed within an hour after birth had much faster amounts of immunoglobulins in the blood and, in total, had higher levels of immunoglobulins in blood – than those fed six or eight hours after birth.
However, he explained what is most interesting was that even by feeding calves for six and 12 hours they eventually reached almost the same concentration.
Finally, Leonal mentioned another study whereby they gave a second feeding of colostrum 12 hours after birth.
“The level of immunoglobulins in their blood increased slightly from this second feed. So there is still an opportunity to give an extra boost to the calf,” he said.
To conclude, Leonal gave the following advice to farmers on colostrum feeding:
- Maintain a high level of cleanliness;
- Feed within one hour of birth – or as soon as possible after birth;
- Feed at a temperature of 40°;
- Only feed colostrum which is greater than 22% on the BRIX Refractometer;
- Feed 4L/calf or 8.5% of the calf’s birth weight.
It is strongly advisable for farmers to test the quality of the beestings produced by their cows and this can be measured through the use of a Brix Refractometer.