How Much Milk Should We Expect Calves to Drink?
As part of a study looking at the effects of ad libitum consumption of milk by calves, milk intakes were recorded daily for days one through thirty-five.
What did they find?
Not surprisingly, intakes go up the first week in life. Average intakes for Holstein calves peaked a little over 9 quarts (8.5L) daily at six to seven days of age. There was considerable variation among calves with some calves peaking at 8.5 quarts (8L) and others going up to 10.5 quarts (10L).
Not so anticipated was the uniform decline in milk consumption from day seven through thirteen. The average intakes dropped from a peak of 9 quarts (8.5L) to 6.5 quarts (6.2L) over those six days. The lowest-intake calves dropped just below 6 quarts (5.7L) daily.
The research dairy environment has a history of cryptosporidia exposure for calves. One might speculate that a mild case of cyptosporidiosis may have contributed to some degree of gastrointestinal upset that was associated with a reduction in appetite.
After day thirteen the trend was up and up and up. Most calves reached peak intake around twenty-three to twenty-five days. Again, lots of variation among calves. A few peaked as high as 12.5 quarts (11.9L) while a few others peaked well below that at 10.5 quarts (10L).
When expressed as a percentage of live weight, naturally the percentages go down as the calves grow. While the intakes started out at an average of about twenty-one percent of live weight (days four-seven) they declined steadily to an average of fourteen percent (days twenty-two through twenty-eight).
Bottom line: One, when milk availability is not restricted we should expect calves to drink large amounts of milk. Two, lots of differences of intakes among calves is normal biological variation, not necessarily some aspect of mismanagement on our part.
For graphs showing intakes by age click HERE
Reference: J. Jasper and D.M. Weary "Effects of ad libitum milk intake on dairy calves." Journal of Dairy Science 85:3054-3058.