F.M. Whiting

Secretion of DDT in milk by fresh cows

Environmental contamination of animal feed by pesticides applied onto nearby crops is considered to be the major source of pesticide residues found in milk. However, examination of the pesticide input from these sources frequently does not account for the level of pesticide residue found in the corresponding milk. Attempts to explain the discrepancy between the amount of pesticide residue found in milk and the amount which one can predict should be found based on many feeding studies (i, 2, 3, 4) has led many persons to suggest that there may be a relationship between these unexplainably high pesticide residues in milk and the stage of lactation in the cow, i.e. that cows which have just come fresh secrete more pesticide in their milk fat than during later stages of lactation. The rationale which

Some aspects of the nutritional biology of the collared peccary

C. L. SHIVELY, Department of Animal Sciences, University of Arizona, Tucson, AZ 85721 F. M. WHITING, Department of Animal Sciences, University of Arizona, Tucson, AZ 85721 R. S. SWINGLE, Department of Animal Sciences, University of Arizona, Tucson, AZ 85721 W. H. BROWN, Department of Animal Sciences, University of Arizona, Tucson, AZ 85721 L. K. SOWLS, Arizona Cooperative Wildlife Research Unit, University of Arizona, Tucson, AZ 85721

A Gate System for Feeding Captive Ungulates

The Calan Feeding Control System (Am. Calan, Inc., Northwood, N.H.) is used to obtain data on forage selection by livestock. We modified the dimensions of the system and tested it with 2 adult male desert bighorn sheep (Ovis canadensis mexicana); modifications were adequate for bighorn sheep. The animals required 7 days to adjust to the feeding frame and 9 days to learn how to use the controlled-access feeding system. Consumption by bighorn sheep of a daily ration decreased about 50% during the learning phase but returned to maintenance levels within 14 days. Controlled-access feeding serves as an alternative to traditional techniques for quantifying diets. J. WILDL. MANAGE. 52(4):613-615 Diets have been quantified using fecal (Gill et al. 1983) and rumen analyses (Wydeven and Dahlgren 1983), esophageal fistulation (Mautz and Fair 1980), estimates inferred from habitat use (Oldemeyer 1983), observation of restrained animals (Schwartz et al. 1988), and bite-count observations (Collins and Urness 1983). Difficulties with identification of plant fragments in fecal samples and contamination of pellets have been discussed by Gill et al. (1983). Limited sample size for rumen analyses (Wydeven and Dahlgren 1983), surgery and healing times associated with fistulae (Mautz and Fair 1980), and reliance on locating individuals for bitecount observation are problems related to diet studies of wild species. Economic limitations also are inherent in studies of large herbivores. We determined if a feeding gate system used in dairy research could be modified for desert bighorn sheep and examined the systems acceptability by bighorn sheep. We acknowledge W. W. Brown and C. B. Theurer for their assistance in obtaining the Calan system. We thank M. C. Wallace and R. C. Etchberger for assisting with animal care and maintenance of the Calan system between feeding trials. We thank the students and staff in the wildlife and fisheries program at the University of Arizona for assistance in vegetation collection. This study was funded by the Agricultural Experiment Station, University of Arizona and The Estes Company, Tucson.

Metabolism of toxaphene by the isolated perfused bovine liver

The metabolic fate of toxaphene was studied by perfusion experiments with isolated bovine livers. Metabolic patterns were elucidated by examining toxaphene components and toxaphene derived products in perfusate and liver tissue using gas liquid chromatography/electron capture detection. These patterns revealed that the bovine liver is capable of a very rapid uptake of toxaphene components from the blood followed by a rapid rate of dechlorination. The liver also accumulates partially dechlorinated products with a subsequentslow rate of further degradation.

Grapefruit seed oil sterols

Grapefruit seed oil sterols separated from other lipids by Florisil column chromatography were characterized by gas liquid chromatography. The presence of stigmasterol, campesterol and β-sitosterol is indicated. Expressed in terms of peak area, the three sterols are present in proportions of 2.5%, 7.4% and 90.1% of the total, respectively.