The Effects of 22,25-Diazacholesterol Dihydrochloride on the Pigeon Testis and on Reproductive Behaviour

Abstract

In recent years, attention has been focused on the potential of reproduction inhibitors for the possible control of harmful birds (Davis, 1961(Davis, , 1962 Elder, 1964;Becker, 1966). Elder, in his search for an effective avian oral contraceptive, found that the best results were obtained with a hypocholesterolemic agent, 22,25-diazacholesterol dihydrochloride (compound SC-12937, Searle & Co., Chicago). When this constituted 0\m=.\1% of the diet of pigeons for 10 days, ovulation was inhibited for 3 months and impaired for a further 3 to 9 months. The present study was designed to investigate the effects of compound SC-12937 on the pre-incubatory behaviour of Columba livia and to assess the action of the drug on normal testis cytology.Males and females in two groups, each of three pairs, and a third group of six pairs, were laparotomized, their gonads measured and seen to be in breeding condition. The individuals were kept in separate cages for a 3-day post-operative recovery period. The members of each pair were then allowed access to each other for 15 min to ensure that the males would all give the initial bowing display. Group 1 was then dosed with 30 mg SC-12937, administered in gelatin capsules, for 5 consecutive days during the 1st week and for 5 days more during the 2nd week. Group 2 birds similarly received five doses of 60 mg/bird in the 1st week, but at this point two birds (one male, one female) died from the effects of the drug and the remaining two pairs were given only two further doses during the 2nd week. The total dose/bird for each group was, therefore, 300 and 420 mg, respectively. Group 3 (six pairs) served as controls and were given only empty gelatin capsules. Observations on the behaviour of all birds began at the start of the 2nd week and continued for a week after dosing had ceased. The method used was that adopted by Fabricius & Jansson (1963), based on the techniques of Carpenter (1933) and Beach (1951), in which the birds were housed in individual cages and were only paired for \ hr daily. During this time a record was kept of certain activities and displays occurring in each 2-min period throughout the \ hr and also the frequency with which particular displays followed each other. However, on Days 6 and 7 the birds 145

Radioimmunoassay of Plasma Estradiol During the Breeding Cycle of Ring Doves (Streptopelia risoria)1,2

“…However, several investigators have attributed nest soliciting in male doves and pigeons to estrogen secretion. Lofts et al (22) were among the first to suggest such a relationship. They noted that when male pigeons were treated with 22,25-diazacholesterol dihydrochloride, an avian antifertility agent, moderate doses that damaged the Sertoli cells produced a decrement in nest soliciting (these authors used the term "nest demonstration") while Leydig cells and bowing displays were unaffected.…”

Male animal sterilization: history, current practices, and potential methods for replacing castration

“…The compound was given the trademark DiazaCon™ and was marketed first as Ornitrol to control bird populations ( 260 , 262 ). However, at higher doses, there were non-reproductive health effects and, in one study, caused the death of two birds ( 259 ). It has also been used in the control of other mammalian wildlife, including the prairie dog ( 263 , 264 ) and grey squirrels ( 265–267 ).…”

Review of issues concerning the use of reproductive inhibitors, with particular emphasis on resolving human‐wildlife conflicts in North America

“…Although the drug was effective in reducing egg laying and egg hatchability (Woulfe 1968), the pigeon is a year-round breeder and long-term use of the compound became expensive. In addition, long-term ingestion of this product at high levels might have undesirable health effects on the birds (Lofts et al 1968) because cholesterol is necessary for a range of key processes within the body as well as the production of reproductive hormones. In recent tests, the compound was found to be effective in reducing egg laying, egg fertility and egg hatchability for 2-4 months in coturnix quail Coturnix coturnix (Linnaeus, 1758) after feeding it for 10-14 days (Yoder 2000;Yoder et al 2004).…”