RESUMEN
The present study is an attempt to shed more light on the role of epinephrine (EP) and norepinephrine (NE) in regulating ovarian follicular development, folliculogenesis and ovulation in laying hens. Sixty Egyptian local cross females (Mandarah), 50 weeks old, were individually housed and equally divided into three treatments: control (saline, 0.9% NaCl), EP (0.15 mg epinephrine/hen/day) and NE (0.75 mg norepinephrine/hen/day) (n=20). Animals were injected intramuscularly once a day for 15 successive days. At the end of the experimental period, 10 females from each treatment were randomly chosen, weighed and killed by decapitation. Ovaries and oviducts and ovarian follicles were examined. Plasma concentrations of estradiol-17beta, progesterone, zinc and triglyceride were determined. Results indicated that the ovaries of NE- and EP-treated hens were more developed than those of control hens being heavier and containing more yellow yolk-filled follicles. EP or NE significantly increased the ovulation rate and plasma concentrations of estradiol-17beta, progesterone, zinc and triglyceride compared with control treatment. It could be concluded that catecholamines may have a part in promoting ovarian follicular development and in stimulating ovulation in laying hens at the end of their reproductive lives.
Asunto(s)
Catecolaminas/farmacología , Pollos/fisiología , Estradiol/sangre , Ovario/efectos de los fármacos , Ovulación/efectos de los fármacos , Progesterona/sangre , Triglicéridos/sangre , Zinc/sangre , Animales , Animales Domésticos , Eficiencia/efectos de los fármacos , Femenino , Tamaño de los Órganos/efectos de los fármacos , Ovario/anatomía & histología , Ovario/crecimiento & desarrollo , Ovulación/fisiologíaRESUMEN
Furazolidone (FZ) was administered to 42-day-old female Japanese quails as a feed additive at doses of 0, 200, 400, 600 and 800 ppm for a period of 28 days. Dose-dependent effects were observed. High levels of FZ (600 and 800 ppm) significantly altered growth, decreased feed consumption, caused marked atrophy of the ovaries and oviducts leading to cessation of egg laying, and resulted in higher mortality. Hepatotoxicity was evidenced by an increase in serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase and a decrease in serum total protein, in addition to degenerative changes of the hepatocytes in FZ-treated birds. A rise in serum urea was also observed. Symptoms leading to death included a loss of appetite causing emaciation followed by nervous disturbances (compulsive movements and circling). No signs of cardiomyopathy were observed. Japanese quails did not tolerate FZ at a concentration (400 ppm) recommended for the prevention of salmonellosis in poultry.