Calves being raised for bob veal or heavy veal should not be fed milk from cows that have had drugs infused into their udders or that have been injected. Drugs leave residues in the veal. Milk from treated cows should only be fed to calves being kept as herd replacements or being kept for a period of at least eight to twelve weeks after the last feeding of such milk. Mastitic milk should be fed only to individually housed calves that will not come into direct contact with other calves for at least one hour after feeding. Calves that suck each other immediately after drinking mastitic milk may actually innoculate the immature teats and eventually cause heifer mastitis.
Bloody milk is usually safe to feed to calves.
However, bloody milk from a cow with an elevated temperature or a cow that is off feed can contain harmful bacteria or toxins. Milk replacers should meet recommended standards and should be fed according to label instructions. A manufacturer's reputation is often a good indicator of the quality of ingredients in a milk replacer. Calves may be started on a milk replacer when four to six days old, but the switch from whole milk to milk replacer should be gradual. Table 13 shows recommended composition and ingredients for milk replacers.