No abstract

The use of soy-based products in the diet of infants has raised concerns regarding the reproductive toxicity of genistein and daidzein, the predominant isoflavones in soybeans with estrogenic activity. Time-bred Long-Evans dams were fed diets containing 0, 5, 50, 500, or 1000 ppm of soy isoflavones from gestational d 12 until weaning at d 21 postpartum. Male rats in all groups were fed soy-free diets from postnatal d 21 until 90 d of age. The mean +/- SD concentration of unconjugated (i.e. biologically active) genistein and daidzein in serum from the group of dams maintained on the diet containing the highest amount of isoflavones (1000 ppm) were 17 +/- 27 and 56 +/- 30 nM, respectively, at d 21 postpartum. The concentrations were considerably greater in male offspring (genistein: 73 +/- 46 nM; daidzein: 106 +/- 53 nM). Although steroidogenesis was decreased in individual Leydig cells, male rats from the highest exposure group (1000 ppm diet) exhibited elevated serum levels of the sex steroid hormones androsterone at 21 d (control: 15 +/- 1.5 vs.28 +/- 3.5 ng/ml; P < 0.05) and testosterone at 90 d of age (control: 7.5 +/- 1 vs.17 +/- 2 ng/ml; P < 0.05). Testosterone secretion by immature Leydig cells, isolated from 35-d-old male rats, decreased on exposure to 0.1 nm genistein in vitro (control: 175 +/- 5 vs. 117 +/- 3 ng/10(6) cells per 24 h; P < 0.05), indicative of direct phytoestrogen action. Thus, phytoestrogens have the ability to regulate Leydig cells, and additional studies to assess potential adverse effects of dietary soy-based products on reproductive tract development in neonates are warranted.

No abstract

The objective of this study was to examine possible interactions between drinking water contaminants and suboptimal nutritional status for performance and immune function in male broiler chickens. Experimental drinking water contained a mixture of arsenic, benzene, cadmium, lead, and trichloroethylene (TCE) at low concentrations (0.80, 1.3, 5.0, 6.7, and 0.65 ppm) and high concentrations (8.6, 13, 50, 67, and 6.5 ppm). These chemicals were selected because they are among the most common contaminants found in ground water near hazardous waste sites. The experimental diets included feed containing 50% added vitamins and minerals (V&M) and feed without added V&M. Increasing levels of drinking water contaminants and decreasing levels of V&M in diet resulted in significantly (P < or = 0.05) decreased water and feed intake, decreased weight gain, and suppression of natural, humoral, and cell-mediated immune response. In a paired-water study, feed consumption, body weight, and immune function were decreased in chickens provided low and high concentrations of the chemical mixture in drinking water compared with chickens given control drinking water equal to the volumes consumed by the chickens given the low and high concentration of mixture, respectively. A deficiency of dietary V&M caused increased sensitivity to adverse effects of drinking water contaminants.

. W. 2010. Effect of dietary citric acid, flavomycin and their combination on the performance, tibia ash and immune status of broiler. Can. J. Anim. Sci. 90: 57Á63. The goal of this research was to investigate the effect of citric acid (CA), the antibiotic growth promoter flavomycin (FL) and their combination on the growth performance, tibia ash and immune status of broilers. One hundred and sixty straight run day-old broiler chicks (Hubbard Classic) were randomly distributed into four dietary groups, with four replicate cages having 10 birds in each. Standard cornÁsoybean-based basal starter diet was given to control birds. Diets for other groups were further fortified by 0.5% CA, 0.001% FL and their combination (0.5% CA plus 0.001% FL). On day 35, CA and its combination (CA'FL) group had 17 and 12% increase in live weight compared with control, respectively (PB0.05). Total live weight on day 35 was 1141, 1337, 1169, and 1275 g bird Á1 in different groups, respectively (PB0.05). Cumulative feed intake was higher (P B0.05) in CA and its combination (CA'FL) compared with the control and FL groups on day 28. Supplementation with CA improved (P0.05) feed conversion ratio [FCR; feed intake (kg):weight gain (kg)] compared with FL and its combination (CA'FL). Carcass yield was increased (P0.05) due to the addition of CA and its combination (CA'FL). Tibia ash content in the CA group (59.0) was higher (PB0.05) than in the control (53.6%), FL (53.1%) and their combination (57.1%). The lymphocyte cells associated with immunity in the lymphoid organs (caecal tonsil, bursa Fabricius and ileum) were more densely populated, suggesting an increased level of innate immunity in the CA group. Overall mortality was low (1.25%), and there were no treatment-related effects on mortality. Citric acid reduced the pH of formulated feeds, but mild reduction was found in the pH of the faeces. Dietary supplementation of 0.5% CA increase weight gain, feed intake, tibia ash deposition and non-specific immunity (PB0.05) as well as feed efficiency and carcass yield (P0.05) of broilers. Citric acid has potential as a growth promoter to replace the antibiotic growth promoter FL. . Les oiseaux du groupe AC avaient plus (PB0,05) de cendres dans le tibia (59,0%) que ceux du groupe te´moin (53,6%), du groupe FL (53,1%) et du groupe prenant le me´lange (57,1%). Les organes lymphoı¨des (gros intestin, amygdales, bourses de Fabricius et ile´on) renfermaient plus de lymphocytes associe´s au pouvoir immunitaire, ce qui laisse croire que les oiseaux du groupe CA jouissaient d'une meilleure immunite´inne´e. Dans l'ensemble, le taux de mortalite´e´tait faible (1,25 %) et les traitements n'ont eu aucune incidence sur la mortalite´. L'acide citrique re´duit le pH de la ration, mais celui des fe`ces ne connaıˆt qu'une le´ge`re baisse. L'addition de 0,5 % d'AC aux aliments