R. L. Kirkpatrick

Energy and Protein Influences on Blood Urea Nitrogen of White-Tailed Deer Fawns

Nineteen female white-tailed deer fawns (Odocoileus virginianus) were used in a 2 X 2 factorial experiment to determine the effect of 2 levels of energy and 2 levels of protein on food consumption, weight gains, and blood urea nitrogen over a 20-week period beginning when the animals were 3.5 months of age. The 2 levels of ration-digestible energy averaged 2,498 and 3,064 kcal/kg. The 2 levels of protein averaged 9.6 and 18.2 percent. Food consumption tended to be greater in animals on low energy diets but decreased in all treatment groups from November through February. Weight gains were significantly greater (P < 0.05) in animals on high protein diets, but no significant difference was found due to energy. Weight gains decreased significantly (P < 0.01) from the 8th through the 20th week of the experiment. Blood urea nitrogen (BUN) was significantly greater (P < 0.01) in fawns receiving high protein diets than in those receiving low protein. Conversely, fawns on high energy intakes had significantly lower (P < 0.01) BUN than those on low energy intakes. J. WILDL. MANAGE. 39(4):692-698 For several years wildlife biologists have sought indices which would correlate well with the recent nutritional status of deer (Odocoileus spp.) and thus would be useful for evaluating trends in habitat conditions. Bone marrow fat, antler development, rumen content analysis, abomasal parasite counts, and many different hematological characteristics have been examined by various authors. None has proven entirely satisfactory, and it is anticipated that as deer management becomes more intensive the need for good indices of deer and habitat conditions will increase. Recent work on BUN in both domestic and wild species has indicated that this easily-measured characteristic might be of use as an index of recent nutritional status. Torell et al. (1974) and Blowey et al. (1973) have shown that BUN levels can be used as indicators of protein intake in domestic sheep and cattle, respectively. Seal et al. (1972b) suggested that BUN levels also might be useful as an index of recent nutritional status of pregnant white-tailed deer and presented limited data to substantiate this. Further, work by Seal et al. (1972a) on white-tailed deer and Franzmann (1972) on bighorn sheep (Ovis canadensis) has shown that BUN levels are not readily affected by the excitement of restraint or immobilization with certain drugs. The present study was conducted to investigate further the possible use of BUN as an indicator of recent nutritional status of deer. More specifically, the study was to determine the effect of known levels of energy and protein intake on BUN concentration 692 J. Wildl. Manage. 39(4):1975 This content downloaded from 157.55.39.179 on Tue, 12 Apr 2016 10:12:35 UTC All use subject to http://about.jstor.org/terms BLOOD UREA NITROGEN OF DEER FAWNS ? Kirkpatrick et al. 693 Table 1. Ingredient composition of pelleted experimental

Energetic Cost of Lactation in Microtus pinetorum

Captive lactating pine voles ( Microtus pinetorum ) were monitored for total metabolizable energy intake (MEI). Metabolic energy requirements increased throughout the 21 days of lactation. Lactating females exhibited positive relationships between MEI and litter size (one to three young) and MEI and litter weight. The average litter size was 2.2 ± 0.1 (SE). The average neonate weighed 2.0 ± 0.1 (SE) g at birth. Tissue production by young was estimated at 1.76 kcal/g of live weight gain. The amount of energy deposited as suckling growth was related to both litter size and day of lactation. The average female had an MEI of 418.9 ± 21.2 (SE) kcal for the 21 days of lactation, an estimated 134.7 ± 9.4 (SE) kcal beyond the maintenance requirement for the nonbreeding female. The average litter incorporated an estimated 35.1 ± 1.8 (SE) kcal of energy into tissue production, which was 26.0% of the metabolizable energy above nonbreeding female requirements. The metabolic cost of supporting a litter increased with each day of lactation. The average lactating female and her litter had a 47.5% increase in metabolizable energy requirement above that for the nonbreeding female.

Plasma Progestins and Puberty in Fawns as Influenced by Energy and Protein

Twenty-four captive female white-tailed deer fawns (Odocoileus virginianus) were weaned at 3.5 months of age and randomly assigned to 1 of the following 4 treatments in a 2 X 2 factorial experiment: high energy-high protein, high energy-low protein, low energy-high protein, and low energy-low protein. High and low energy diets averaged 3,064 and 2,498 kcal/kg, respectively. High and low protein diets averaged 18.2 and 9.6 percent, respectively. High energy diets caused a significant (P < 0.05) increase in progestin concentrations over low energy diets (0.75 vs. 0.32 ng/ml) when taken over the entire experiment. Nine of 11 animals on high energy diets and 0 of 8 on low energy diets had progestin levels of at least 1.00 ng/ml during the experimental period. This was interpreted as indicating a higher incidence of ovulation and puberty in animals on high energy diets. Protein level had no apparent effect on progestin concentrations or attainment of puberty. J. WILDL. MANAGE. 40(3):442-446 There is presently very little quantitative information available concerning the effects of specific nutritive components on the attainment of puberty in the white-tailed deer even though the age at which the female deer reaches puberty seems quite important in terms of the productivity of the entire herd. Fawns in the northeastern states produced almost as many fetuses as 5-year-old does and more than does older than 5 years (R. D. McDowell 1959, paper presented at 11th N.E. Wildl. Conf.). Quality of range in New York affected the proportion of fawns attaining puberty in different regions (Cheatum and Severinghaus 1950). Trainer (1962:341) found that 75 percent of captive fawns raised on good diets produced young. Haugen and Trauger (1962:234) found that 83.6 percent of Iowa white-tailed fawns collected in December had reached puberty and 75 percent of those collected in January were pregnant. On 3 different ranges in Manitoba, Ransom (1967:117) found that 25, 33, and 0 percent of the fawns had conceived on areas of decreasing habitat quality. It seems that the attainment of puberty by an animal is directly related to the plane of nutrition and the entire growth process of that animal. As Sadleir (1969:23) pointed out, the attainment of puberty by fawns seems to be definitely related to the level of nutrition available to them during the summer and fall seasons of their first year. Information on which aspect of nutrition is important in influencing the attainment of puberty is needed for the more intensive management of deer areas. This study was conducted to determine the effects of known levels of dietary energy and protein on plasma progestin levels in captive female deer. Since the major source of plasma progestins is corpora lutea of ovulation, inference was then to be made on the influence of energy and protein intake on the incidence of ovulation and the attainment

HEMATOLOGIC COMPARISONS OF SHOT AND LIVE TRAPPED COTTONTAIL RABBITS1

Comparisons were made between hematologic measurements of shot and box-trapped cottontail rabbits (Sylvilagus floridanus). Trapped rabbits had significantly (P < 0.001) higher serum corticoid levels and segmented neutrophil percentages and significantly (P < 0.001) lower lymphocyte percentages than did shot rabbits. Trapped rabbits also had significantly (P < 0.05) higher packed cell volumes and blood urea nitrogen values than did shot rabbits.

A MODIFIED BLOW-GUN SYRINGE FOR REMOTE INJECTION OF CAPTIVE WILDLIFE

A modified syringe capable of automatic injection and suitable for use with a blow-gun is described. The syringe has been used successfully with white-tailed deer (Odocoileus virginianus) under confined conditions. Desirable characteristics for blow-gun syringes are discussed.

ECTOPIC FETUSES IN TWO COTTONTAIL RABBITS1

Mummified fetuses were discovered in the abdominal cavities of two cottontail rabbits (Sylvilagus floridanus) collected during separate years from the same geographical location in Virginia. One of these rabbits had a patent opening through the vaginal wall to the abdominal cavity. The uterus and vagina of the second rabbit appeared normal.