Effects of an In Ovo Injection of an Anti-Androgen on Embryonic and Posthatching Growth of Broiler Chicks

Abstract

Experiments were conducted to determine whether in ovo injection of Flutamide, a non-steroidal anti-androgen, would affect posthatching growth of broiler chickens. Before doing these studies it was necessary to develop a bioassay to demonstrate that Flutamide had anti-androgenic actions when injected in ovo. In ovo injection of 0.06 to 1.74 mumol of testosterone propionate (TP) per egg on the 8th d of incubation caused a dose-related decrease in weight of the bursa of Fabricius of newly hatched chicks. In subsequent experiments, 1.74 mumol of Flutamide significantly decreased the bursal regression produced by 0.58 mumol of TP when both substances were injected on Day 8 of incubation and bursal weights were taken on the day of hatch. Having established that Flutamide could block the effects of high doses of exogenous TP, it was reasoned that it could block the action of much lower endogenous levels. In two of the three experiments, injection of Flutamide on the 8th d of incubation resulted in a dose-related decrease in 21- and 49-d BW of male broiler chickens. The material had no effect on BW of males in one experiment and had no effect on BW of females at any age in any of the experiments. The data suggest that interference with the actions of endogenous androgens during embryonic life suppresses the posthatching growth of male broilers.

Effects of Androgen Disruption by DDE on the Development and Functioning of the Immune System in Japanese Quail

“…study using the antiandrogenic chemical flutamide. (26) Although the histology from this study showed obvious differences in the appearance of the crosssections of the DDE-treated and control bursas, finding measurements to quantify these differences was challenging. Since B cells mature in the follicles, we assumed that disruption in the development of these structures would impact B cell maturation.…”

Maternally derived yolk testosterone enhances the development of the hatching muscle in the red-winged blackbirdAgelaius phoeniceus

“…In £utamide-treated clutches, ¢rst-laid eggs were injected controls and last-laid eggs were injected with £uta-mide, an anti-androgenic compound that blocks androgen receptor activation, in vehicle. The dose used (0.08 m mol) has anti-androgenic e¡ects on the development of the domestic fowl (Burke 1996). Injections were made on the day each egg was laid using the same procedure as described above for the collection of yolk samples.…”

Sex-specific effects of yolk testosterone on survival, begging and growth of zebra finches

“…Maternal androgens markedly affect offspring behaviour after hatching-they enhance offspring begging (Schwabl 1996;Eising & Groothuis 2003) and increase or reduce offspring growth and survival (Sockman & Schwabl 2000;Eising et al 2001;Eising & Groothuis 2003). Sex-specific effects of yolk androgens have hardly been studied, but they differentially affected sons and daughters in some studies (Burke 1996;Henry & Burke 1999) and not in others (Lipar & Ketterson 2000).…”