“Teat surgery” is a common practice on many dairy farms and calf-rearing operations. But it is not a surgery performed on cows.  And Neil Anderson, veterinarian with the Ontario Ministry of Agriculture, says it’s also not advisable.

Anderson is referring to the enlargement of calf nursing nipples, usually with a pocket knife. While it makes less work for nursing calves, it also may endanger their health. 

The most serious risk is aspiration pneumonia. Calves’ swallowing rate cannot keep up with the volume of milk expressed from the nipple, and thus some of the liquid escapes the esophagus and enters the respiratory tract instead. A telltale sign is the presence of fat globules in the lung tissue of necropsied calves. Newborn calves consuming their first feeding of colostrum are particularly vulnerable to the problem.

Rather than mechanically enlarging the nipple holes, Anderson advises breaking in new nipples by using them to feed preweaned calves for several days, and then using those (thoroughly sanitized) nipples for newborn calves.