Negative energy balance in newborn calves?

Yes! We’re all aware of negative energy balance in fresh cows, and its devastation to health and fertility, but unheard of, well, at least never discussed, in the first week of the calf’s life. While the calf is in its mother’s uterus it is served a perfect ration of energy and protein via the maternal blood supply, as a priority: often at the mother’s expense when her diet is deficient in energy and protein. A subject we’ve written much on.

There are two causes to this problem, which is well documented in live-weight losses in the first week of life. The two contributors to negative energy balance in new born calves are, firstly, inadequate fatty acids in milk fed to these calves. It is known fat and protein content of cows’milk decreases significantly after one week post-calving.

The second is ambient temperatures. In cold winters, let alone wind, the calf requires considerably more energy to sustain body temperature. Research at Iowa State University highlighted weight loss in week one of calves lives at both 4.5c and 15.5c ambient temperatures. Blood samples revealled high levels of fat and low levels of glucose (hallmarks of negative energy status) indicating mobilisation of body fat to meet energy deficiency from either low fat milk and/or cold stress. In cows we call this ketosis. In another experiement calves were fed for energy needs and the reverse of these two blood tests occurred (low fat/high glucose), and restored weight gain.

How do we combat this problem without turning the dairy into a logistical nightmare. As above, there is a significant decrease in solids content of milk after seven days post calving, about 21% less. Bucket cows are no fun in the middle of intensive calving; however, the calf milk needed is known by the number of calves being fed, so if fresh cow colostrum milk does not meet this need, then the possibility of leaving cows on the bucket a couple of days longer to meet the milk required will aleviate this negative energy balance in first week calves. It just might improve your milk quality as a bonus. For large herds who run a fresh cow herd this is not a problem, provided it is only a “fresh cow” herd and not a “hospital herd” with antibiotic cows in it too.

Negative energy balance in newborn calves runs a close second to water intake as a significant threat. Both are critical, apart from colostrum Ig passive transfer, in calf survival, but more so, a calf that ‘stumbles’ in the first week often never reaches her genetic production/fertility potential. High fertility herds select replacement heifers after a few weeks of life when these issues are known. The calf that passes through the first few weeks without weight loss/scours or any other lifetime-limiting incidents are the ones they keep. This is the first cull decision criteria.