Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Dairy Science

First Advisor

David Casper


calf, essential oils, yeast cell wall


Stay Strong (SS, Ralco Inc., Marshall, MN) is a blend of essential oils (EO) and prebiotic fiber technologies designed to promote immunity and stimulate appetite, helping to diminish health challenges and stresses experienced by newborn calves. Current feeding inclusion rates are unknown to achieve optimal performance in the first 8 weeks of life. The study objectives were to determine the optimal feeding inclusion rate of SS when added to milk replacer (MR) to achieve optimal performance when compared to a yeast cell wall (YCW). One hundred Holstein calves were blocked by birth date and randomly assigned to 1 of 5 treatments. Treatments were: Control (C): a 24:20 MR, EO mixed into 24:20 MR at a rate of 1.25 g/feeding (EO-0.5), 2.5 g/feeding (EO-1.0) or 3.75 g/feeding (EO-1.5), or 24:20 MR with an inclusion of YCW at a rate of 2 g/calf/feeding. Calves were sourced from a commercial dairy farm where they were fed colostrum for the first 2 d and then were transported to South Dakota State University (SDSU). The 24:20 MR was fed via bucket 2 x/d at a rate of 0.28 kg/calf/d for 14 d, increased to 0.43 kg/calf until 35 d and were reduced to 1 x/d at 36 d to facilitate weaning at 42 d. Decoquinate was added to MR at 37.8 g/ton for coccidiosis control. Calves were housed in individual Calf-Tel hutches bedded with straw with ad libitum access to a 20% CP calf starter (CS) and water. It was hypothesized that calves supplemented with the medium dose (EO-1.0) of the commercial EO would be most optimal, and in general calves supplemented with commercial EO would have improved growth, health, and immunity compared to calves not supplemented. All data was analyzed using PROC MIXED in SAS as a completely random design. Calves fed EO-0.5 demonstrated greater ADG (0.65, 0.71, 0.64, 0.64, and 0.63 kg/d for C, EO-0.5, EO-1.0, EO-1.5, and YCW, respectively) through 56 d compared to calves fed EO-1.0 and YCW, and tended to be greater for C and EO-1.5. Total body weight gains (36.8, 39.9, 35.5, 35.8, and 35.4) were greater for calves fed C and EO-1.5 compared to calves fed EO-1.0 and YCW. Body length gains were greater for calves fed EO-0.5 compared to calves fed other treatments. Hip width gains were similar among treatments. Wither height gains were greater for calves fed EO-0.5 compared to calves fed the remaining treatments. Hip height gains were also increased for calves fed EO-0.5 compared to calves fed C, EO-1.0, and EO-1.5, while being similar for calves fed YCW. These results demonstrate that supplementing EO-0.5 (1.25 g/calf/d) in a 24:20 MR may be optimal to enhance growth rates compared to calves fed a 24:20 MR and a 24:20 MR containing YCW technology or other inclusion rates of EO.

Library of Congress Subject Headings

Calves -- Feeding and feeds

Dairy cattle -- Feeding and feeds

Essences and essential oils


Immunity -- Nutritional aspects


Includes bibliographical references (pages 51-57)



Number of Pages



South Dakota State University

Included in

Dairy Science Commons



Rights Statement

In Copyright