Evaluation of corn furan fatty acid putative endocrine disruptors on reproductive performance in adult female chickens.

Based on evidence from rodent models, it was hypothesized that furan fatty acids found in corn would inhibit reproduction in the laying hen. An isomeric mixture of furan fatty acids [9, (12)-oxy-10,13-dihydroxystearic acid and 10, (13)-oxy-9,12-dihydroxystearic acid] was administered for a period of 3 wk via the diet (1 and 3 ppm) at levels greater than those in corn to 20-wk-old pullets. There were no overt indications of acute or chronic toxicity (no effects on mortality, feed intake, or average daily gain). Similarly, there was no dose-dependent effect on reproductive parameters [egg production, egg weight, shell thickness, ovarian weight, number or weight of large yolky preovulatory follicles, and number of small yellow follicles (4-8 mm in diameter)]. The present data do not suggest that furan fatty acids are a cause of concern to the poultry industry.

Lack of estrogenic or antiestrogenic actions of soy isoflavones in an avian model: the Japanese quail.

Isoflavones are soy compounds that possess weak estrogenic and antiestrogenic activities. In addition, phytochemicals, including isoflavones, may play a role in regulating seasonal reproductive cycles. As soy is a common constituent in poultry diets, the effect of these compounds on the reproductive system of production birds may be of concern. The present study examined the putative effects of soy isoflavones supplemented into the diet at 1 and 5% using endpoints of growth and reproduction in the Japanese quail. Isoflavones did not exert an effect on growth, feed intake, growth:feed, or the weight of the estrogen-sensitive immature oviduct in female quail. Furthermore, isoflavones did not influence the growth of the oviduct stimulated by exogenous estradiol. Similarly, isoflavones did not influence growth, feed intake, or growth:feed in male quail. However, isoflavones at 1%, but not 5%, in the diet reduced photoperiod-induced testis development 40% vs. control. In contrast, isoflavones did not influence testis regression stimulated by exogenous estradiol in sexually maturing male quail. The present results suggest that isoflavones may exert modest endocrine disruptor-like effects on reproduction in male, but not female, quail.

Lack of effects of atrazine on estrogen-responsive organs and circulating hormone concentrations in sexually immature female Japanese quail (Coturnix coturnix japonica).

The widely used herbicide, atrazine, has been reported to exhibit reproductive toxicity in rats and amphibians. The present studies investigate toxicity of atrazine in Japanese quail and its ability to influence reproduction in sexually immature females. Atrazine was administered in the diet at concentrations from 0.001 to 1000 ppm (approximately 109 mg kg-1 per day) or systemically via daily subcutaneous injections (1 and 10 mg kg-1) or Silastic implants. Atrazine did not cause overt toxicity in sexually immature female quail (no effects on change in body weight, feed intake, mortality or on circulating concentrations of the stress hormone, corticosterone). It was hypothesized that if atrazine were to have estrogenic activity or to enhance endogenous estrogen production, there would be marked increases in the weights of estrogen sensitive tissues including the oviduct, the liver and the ovary together with changes in gonadotropin secretion. However, atrazine had no effect on either liver or ovary weights. Atrazine in the diet increased oviduct weights at 0.1 and 1 ppm in some studies. These effects were not consistently observed and were not significant when data from studies were combined. Systemic administration of atrazine had no effect on oviduct weights. Dietary (concentrations from 0.001 to 1000 ppm) and systemically administered atrazine had no effect on circulating concentrations of luteinizing hormone (LH). The present studies provide evidence for a lack of general or reproductive toxicity of atrazine in birds.

In ovo exposure to a triazine herbicide: effects of atrazine on circulating reproductive hormones and gonadal histology in young Japanese quail.

The triazine herbicide, atrazine, has come under scrutiny for its reported feminizing effects in amphibians. To date, there is little information concerning the effects of atrazine on reproduction in avian species. The current study examined the putative reproductive toxicity of atrazine after exposure in ovo. Atrazine at 504, 246, and 123 microg/kg was administered to Japanese quail eggs before incubation. The eggs were hatched and the birds raised to 14 days of age. Indices of hatchability, sex ratios, and growth were determined. Furthermore, circulating concentrations of reproductive hormones (estradiol, progesterone, and testosterone) and gonadal histology were examined. Atrazine at 504 microg/kg decreased 14-day hatchling weight by 13.1% versus controls. However, no detrimental effects on hatchability or sex ratios were observed. In female birds, atrazine at 504 microg/kg decreased ovarian weights and circulating concentrations of progesterone to 48.3% and 73.3%, respectively, versus control. However, concentrations of estradiol and testosterone did not differ from controls. In male quail, at all doses tested, atrazine had no effect on gonadal weights or circulating concentrations of estradiol, testosterone, or progesterone. Moreover, no incidences of left ovotestis formation were observed. In contrast, 10 ng/kg ethinylestradiol (a positive control) induced the formation of a left ovotestis in four of eight birds analyzed. The current results may suggest that exposure to atrazine in ovo at concentrations above ecologic relevance exerts effects on the reproductive system of young Japanese quail. However, no evidence is presented that atrazine induces feminization of the testis in male quail.

Effects of Lactobacilli and lactose on Salmonella typhimurium colonisation and microbial fermentation in the crop of the young turkey.

1. Three experiments were performed to examine the effects of Lactobacilli and lactose on microbial fermentation and Salmonella enterica serovar Typhimurium colonisation in the crop of the young turkey. 2. The following carboxylic acids were detected in the crop ingesta: formic, acetic, butyric, lactic, valeric, caproic, oxalic, phenyl acetic, succinic and fumaric; propionic, isobutyric and isovaleric acids were not detectable. 3. At the beginning of the night, there were considerable quantities of ingesta in the crop of young turkeys. During the scotophase, there were progressive reductions in the contents and pH. Moreover, there were linear increases in the concentration of lactic, valeric and caproic acids (by approximately 7-fold over 8 h). Much smaller changes in crop pH were observed in the study where dietary treatments of Lactobacilli were not included. 4. Chronic addition of lactose or Lactobacilli to the diet exerted modest effects on the carboxylic acid concentration in the crop contents but did not consistently influence colonisation of the crop by Salmonella enterica serovar Typhimurium. 5. Young turkeys confine eating to the hours of illumination (photophase) with a peak in consumption prior to the subjective dusk.