Ameliorative effects of betaine and ascorbic acid on endocrine and erythrocytic parameters of sexually-maturing female Japanese quails during the dry season.

Abstract

This study investigated the ameliorative effects of betaine and ascorbic acid on some endocrine and erythrocytic parameters in female Japanese quails (Coturnix coturnix japonica) reared during the dry season. A total of 372 fourteen- day-old female quails sourced commercially was kept in cages for 56 days. After seven days acclimation, all birds were weighed and allotted by complete random design to four groups with 3 replicates per group. Every group having 93 quails, comprised of 31 birds per replicate. Experimental groups were birds fed: Control (basal); ascorbic acid (AA), at 200mg/Kg; betaine (BET) at 2g/kg and combination of AA (200mg/Kg)+BET (2g/kg) of diets. Daily dry-bulb temperature (DBT), relative humidity (RH) and temperature-humidity index (THI) measured at 08:00h, 13:00h and 17:00h fluctuated widely and exceeded the zone of thermal comfort for Japanese quails. Serum levels of catalase (CAT), reduced glutathione (GSH), cortisol, sex hormones (luteinizing hormone, LH and estradiol) and erythrocyte parameters (packed cell volume, PCV; red blood count, RBC; haemoglobin concentration, Hb; mean corpuscular volume (MCV), hemoglobin (MCH) were obtained at 28, 49 and 70 days of age. In female quails, AA±BET increased (P<0.05) CAT and GSH, but decreased (P<0.05) cortisol levels when compared with control values at varying ages. There were higher (P<0.05) values of LH in quails fed dietary AA+BET (28 and 49 day-old) and estradiol in those which consumed either BET or AA+BET (28, 49 and 70 day-old) and AA (at 70 day-old). At 49 day-old, either BET or AA+BET increased (P<0.05) RBC count, but lowered (P<0.05) MCV and MCH. In conclusion, betaine and ascorbic acid supplementation improved activities of serum sex and stress hormones, and erythrocytic parameters of Japanese quails during the dry season.