Prediction of Protein Intake in White-Tailed Deer in South Texas

Abstract

The relationships between blood urea nitrogen (BUN), creatinine, glucose, cholesterol, total serum protein (TSP), packed cell volume (PCV), and recent nitrogen intake (NI) of white-tailed deer (Odocoileus virginianus) were investigated. Five isocaloric diets containing 11.4, 15.2, 17.3, 22.2, and 23.8% crude protein were evaluated. The diets were fed to groups of four to eight deer in 30-day feeding trials with subsequent evaluation of the blood characteristics. Differences in NI significantly (P < 0.001) affected only BUN values with the relationship estimated by the equation: NI = 12.719 + 0.782(BUN mg %) (r2 = 0.606). In a collateral study, 97 free-ranging deer were collected over a 1-year period to estimate their dietary NI and digestible energy intake from rumen contents analysis. The relationship between estimated dietary NI derived in this manner and the condition of the deer as indicated by body weight and kidney fat index compared to the BUN prediction equation indicated only marginal usefulness of the latter technique for evaluation of the nutritional plane of wild deer. J. WILDL. MANAGE. 48(2):518-526 The search for a method to directly assess nutritional condition of deer and indirectly assess the quality of their habitat has included physical measurements of fat deposits (Harris 1945, Cheatum 1949, Riney 1955, Ransom 1965, Anderson et al. 1972b, Ratcliffe 1980, Finger et al. 1981), organ size (Ozoga and Verme 1978), postmortem analyses of rumen material (Klein 1962, Briiggemann et al. 1968, Kie 1977), and blood characteristics (Rosen and Bischoff 1952, Browman and Sears 1955). The latter work led to subsequent studies of a wide range of blood characteristics in white-tailed deer (Johnson et al. 1968, White and Cook 1974, Coblentz 1975, Hoff and Trainer 1975, Seal et al. 1978a), mule deer (0. hemionus) (Anderson et al. 1972a), elk (Cervus elaphus) (Herin 1968, Pedersen and Pedersen 1975), pronghorn (Antilocapra americana) (Barrett and Chalmers 1977a,b; Seal and Hoskinson 1978), moose (Alces alces) (Franzmann and LeResche 1978), mountain sheep (Ovis canadensis) (Franzmann 1972), and reindeer (Rangifer tarandus) (Timisjairvi et al. 1981). These studies have proved promising, but quantification of deviations in blood characteristics caused by nutrition requires the determination of responses under controlled conditions. Responses of blood characteristics to different levels of dietary protein and/or energy were investigated in white-tailed deer fawns (Teeri et al. 1958, Ullrey et al. 1967, Kirkpatrick et al. 1975, Seal et al. 1978b), pregnant or lactating female white-tailed deer (Youatt et al. 1965, Seal et al. 1972, Hartsook et al. 1975, Bahnak et al. 1979), and mule deer fawns and does (deCalesta et al. 1975, 1977). The objectives of our study were to evaluate responses of specific blood characteristics to different levels of dietary protein under controlled conditions and to test the predictive value of a derived equation on free-ranging deer. We thank R. L. Bingham for assistance with the statistical analysis and A. J. Kay for help in diet formulation. This project 'Present address: Department of Fisheries and Wildlife Science, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061. 518 J. Wildl. Manage. 48(2):1984 This content downloaded from 157.55.39.51 on Sat, 18 Jun 2016 05:50:14 UTC All use subject to http://about.jstor.org/terms PREDICTING PROTEIN INTAKE IN DEER * Kopf et al. 519 Table 1. Ration formulas and analyses of diets used in nitrogen balance and feeding trials with white-tailed deer in south Texas.