Evaluation of starter diet crude protein level and feeding regimen for calves weaned at 26 days of age.

The objectives of this study were to evaluate two levels of CP in starter diets offered to calves weaned on d 26 and to compare postweaning intake of starter diets and performance of calves weaned at 26 or 42 d. Forty Holstein calves were housed in individual outdoor hutches and assigned to one of four treatments. Treatments consisted of weaning on d 26 after offering a 20% CP starter diet from d 1, or d 21, or after offering a 25% CP starter diet from d 21, or weaning on d 42 after offering a 20% CP starter diet from d 1 (control). Between d 42 and 84, calves were commingled in outdoor group pens. On d 42, BW of control calves was heavier than that of early weaned calves. On d 84, BW did not differ among treatments. Consumption of starter diet was not affected by the age at which it was first offered. Weaned calves consumed more starter diet than controls from d 29 to 42. Postweaning performance was not affected by increasing CP in the starter diet. Weaning treatment did not affect the incidence of scours. Comparison of CP intakes with current NRC recommendations suggests that CP requirements for young milk-fed calves are adequate.