We have black cows with a red tinge to their hair coat, newborn calves that are knuckled over at birth, reduced reproductive rates, and increased morbidity rate. What are nutritional influences that can be involved with these symptoms?

The calf morbidity and reduced reproductive rate could be nutrition on the cow side, and calf morbidity could be lower immunoglobulin G in the colostrum, but this doesn’t fit with red hair and knuckled over at birth. Some additional thoughts that would be compatible with the signs you describe are that copper deficiency can cause faded coat color in cattle. Red coats turn yellow, and black coats turn brown. There can be “spectacles” of faded hair around the eyes. Neonatal ataxia, stiff gait, improper bone development, infertility, and anestrous among other signs have been associated with low copper. Elevated dietary Mo, Ca, Fe, Mn, P, Se, and Zn can lower availability of Cu in the diet. Mn deficiency has been associated with silent heat, reduced conception, paralysis, and skeletal damage in calves. Ca, Fe, P, and Zn will interfere with Mn absorption. Se deficiency has also been associated with the clinical signs you described.

Micromineral deficiencies can be difficult to diagnose and usually involve cooperation between a nutritionist and your veterinarian. There are several diagnostic approaches and treatments depending on particular deficiency.

There could be additional possibilities, but these should be investigated first.