Response of northern bobwhites fed single doses of gossypol

Abstract

ABSTRACTCottonseed products have been used as a feed supplement for ruminant livestock and white‐tailed deer (Odocoileus virginianus). Gossypol, a secondary plant metabolite found in cotton (Gossypium spp.), is known to be toxic to a variety of animals, specifically monogastric mammals and birds. However, there are no published data regarding the effects of gossypol in northern bobwhites (Colinus virginianus). Our goal was to determine whether ingestion of gossypol presents a threat to northern bobwhite survival and reproduction. We performed this study at Tarleton State University Northern Bobwhite Research Center (Stephenville, TX, USA) during March and April 2016, using the Environmental Protection Agency's 850.2100 Guideline: Avian Acute Oral Toxicity Test. We administered one‐time doses of refined gossypol to northern bobwhites at 20 mg/kg, 200 mg/kg, 262 mg/kg, 342 mg/kg, 447 mg/kg, 585 mg/kg, 765 mg/kg, and 1,000 mg/kg body weight (BW) and observed them daily throughout a 14‐day period. We measured feed consumption daily and body mass weekly. Birds receiving larger doses (447–1,000 mg/kg BW) consumed less total feed postdosing (55.46 ± 56.46 g, n = 39) and had greater, negative postdosing percent change in mass (−23.02 ± 13.04%, n = 85) compared with control birds and those receiving lower doses (20–342 mg/kg BW). We also examined laying performance and egg quality of birds dosed with 20 mg/kg and 200 mg/kg BW (n = 30 pairs) and the growth rate and percent mortality of second‐generation young produced from these pairs. There was no difference in laying performance, egg quality, the percentage of chicks that hatched, and the growth rate and percent mortality of chicks between the dosing rates. Our results suggest that gossypol can have adverse effects on feed consumption and body mass in northern bobwhites at sufficient doses; however, a one‐time acute dose of gossypol up to 200 mg/kg BW does not pose any negative reproductive effects. © 2018 The Wildlife Society.