UC Davis

Objective: Our objective was to determine whether preweaned steer and heifer calves given a phytogenic starter supplement (either one containing caraway, licorice, oak bark, and vanilla that was soluble in milk, PM, or one containing caraway, licorice, oak bark, and vanilla, PC) or no phytogenic supplement, control (CTR), at a commercial calf ranch would have increased starter intake, weight gain, or rumen development. Materials and Methods: Holstein calves (124) were randomly assigned to 1 of 3 treatments, CTR, PM, or PC, at 2 d of age. Supplements PM or PC were added to individual feed buckets at each feeding at the rate of 0.25 g/kg of starter at a.m. and p.m. feedings. Calves were weighed at enrollment and at weaning, and blood samples were collected from a subset of 13 calves per treatment to assess rumen development. Weekly average DMI, milk intake, Glu, and BHB were analyzed using the Mixed procedure of SAS (v. 9.4; SAS Institute Inc., Cary, NC) Results and Discussion: Weekly average DMI (P < 0.01), BHB (P < 0.01), and Glu (P < 0.01) were different by week but not by treatment. Product PC group was numerically greater in total DMI, gain, and ADG and had faster rumen development indicated by overall greater BHB values but were not different among treatments. Implications and Applications: Addition of PM or PC to starter feed did not increase DMI, rumen development, or BW gain. But, the dose may have been too small or not fed long enough to elicit a response during the preweaning period.