Effects of Complete Vitamin and Mineral Supplementation in Full Potential All-milk Diets on Growth and Health of Holstein Bull Calves

and Implications Pre-ruminant Holstein bull calves were fed two diets of pasteurized whole milk (PWM) in amounts that either limited intake or that maximized intake according to common commercial practice. Diets then were either supplemented or not supplemented with a full complement of vitamins and trace minerals (VTM) that met or exceeded NRC requirements. The objective of the study was to quantify the effects of the four feeding strategies on growth of calves, vitamin and mineral statuses in blood, and magnitude of acute phase inflammatory protein expression in response to lipopolysaccharide (LPS) exposure. Calves were assigned randomly to one of four treatment groups (LM-, low milk, not VTM supplemented; LM+, low milk, TMV supplemented; HM-, high milk, not VTM supplemented; HM+, high milk, TMV supplemented) for 15 days. The HM strategy increased average daily gain in calves, but VTM supplementation did not improve growth during the first two weeks of life. Calves fed more milk had greater magnesium and copper concentrations in blood plasma, but treatment groups did not differ in acute phase protein expression. Introduction Calves on dairy farms throughout the United States are fed pasteurized whole milk (PWM) to recover productive losses from mastitis. Proponents of PWM diets claim that bovine milk is an optimal diet for bovine offspring, but conventional feeding approaches often limit milk intake to encourage dry starter-grain intake. Grain is normally fortified with vitamins and trace minerals (VTM), and PWM is not commonly VTM fortified. Both caloric and VTM malnutrition may occur early in life before grain intake is optimized. To avoid malnutrition in calves, " full potential " dietary programs have been implemented that maximize dry matter intake from milk or milk replacer, but contributions of full-potential PWM diets to vitamin and mineral requirements of the calf remain largely unexplored, as do the effects of caloric and VTM malnourishment on intestinal immune functions in the humorally naïve neonate. Given that the first several weeks of the calf's life represent