Effects of the Horn Fly (Diptera: Muscidae) on Physiological and Nutritional Responses of Beef Steers: Continuous Fly Population Levels
Authors: PRESLEY, S. M.; KNAPP, F. W.; BOLlNG, J. A.; BURG, J. G.
Source: Journal of Economic Entomology, Volume 89, Number 1, February 1996 , pp. 138-143(6)
Publisher: Entomological Society of America
Abstract:Twenty-four Hereford-Angus crossbred beef steers were exposed to 0, 75, 150, and 225 horn flies, Haematobia irritans (L.), per head under controlled environmental conditions. The physiological and nutritional indices of all steers were recorded during a 14-d infestation period. Overall rectal temperature increased in steers exposed to 225 H. irritans per head. Feed intake and nitrogen consumption by steers exposed to 225 H. irritans was lower than uninfested steers during the first 4 d. Overall serum cortisol was lower in steers exposed to 150 or 225 H. irritans per head compared with unexposed steers. Compared with unexposed steers, packed cell volume (percentage) was lower in steers exposed to 150 H. irritans on days 4, 7, and 14, lower in steers exposed to 225 H. irritans on days 7 and 14, and lower in steers exposed to 75 H. irritans on day 14. Blood urea nitrogen (BUN) was higher on day 1 in steers exposed to 75 H. irritans per head compared with uninfested steers, whereas BUN was lower in 225 H. irritans-exposed steers on days 7, 10, and 14 when compared with uninfested steers. Our data, in conjunction with previously published data, suggest that rectal temperature increases in beef steers exposed to > 150H. irritans per head, and water consumption and urine production increases at infestation levels >225 H. irritans per head. Our data were unable to resolve H. irritans effects on steer heart rate, respiration rate, urinary nitrogen excreted, nitrogen retained, and serum cortisol levels.
Document Type: Research Article
Publication date: February 1, 1996
- Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.
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