Evaluation of a Starter Ration on Growth and Performance of White-Tailed Deer Fawns

Until recently, there was not a ration available to the Texas white-tailed deer (Odocoileus virginianus) industry that was designed specifically for fawns. Common practice for pen-raised white-tailed deer breeders is to provide fawns with a ration that is formulated for mature deer. The objective of this study was to evaluate growth and performance of fawns on a new starter ration and to evaluate a dietary supplement designed to enhance the immune system of young fawns. To achieve this, 44 white-tailed deer fawns (26 female, 18 male; 14 d of age) from an established herd (3-S Ranch, Bedias, TX) were randomly assigned to one of two diets. Twenty-two fawns received the control diet (16% CP, 71.6 % TDN, 2.12 % Ca, 0.96 % P, and 0.47 % Mg), which was a pelleted feed formulated for mature deer when limited forbs and browse are available, and 22 fawns received the treatment diet (22% CP, 79.5 % TDN, 1.90 % Ca, 0.63 % P, and 0.31 % Mg), which was also a pelleted feed, but one specifically formulated for young, growing fawns. The treatment diet also contained a proprietary supplement designed to enhance immunity. All fawns in the study were removed from their dams shortly after birth and were bottle-fed using a milk replacer for white-tailed deer according to ranch protocol. Feed was first offered when fawns were 14 d of age and feed intake was recorded daily through 140 d of age. Growth measurements including cannon length, leg length, body length, heart girth circumference, and BW were recorded every 2 wk from d 0 to 140. Data were analyzed using the PROC MIXED procedure of SAS for the effects of diet and day and the diet x day interaction. Male fawns consuming the treatment ration had a greater ADG (P<0.05) than male fawns on the control diet. However, there was no effect of diet on cannon length, leg length, body length, heart girth circumference, or body weight for female or male fawns. Additionally, there was no difference in morbidity, mortality, or the number of days treated for illness between the fawns on the different diets. These data reveal that there is an inconsequential difference in growth and performance of fawns consuming the two different rations; however, fawns required a greater daily intake of the less nutrient dense ration formulated for mature deer to achieve the same level of performance observed in the fawns consuming the starter ration. In addition, these data indicate that white-tailed deer fawns may rely on metabolic signals to regulate feed intake.