Asian Journal of Microbiology, Biotechnology & Environmental Sciences Paper

INFLUENCE OF AGE, SEX AND REARING SYSTEMS ON SERUM CORTICOSTERONE AND HETEROPHIL TO LYMPHOCYTE RATIO AS A STRESS PROFILE IN PEARL GUINEA FOWL

CHONGTHAM SONIA, M.NORJIT SINGH, BLESSA SAILO, CHONGTHAM TANIA, A. ROMILA , CH. PREMABATI AND MENALSH LAISHRAM

Abstract

The present study was designed to evaluate the effect of age, sex and rearing system on serum corticosterone and hetyerophil to lymphocyte ratio in pearl guinea fowl. Twenty four Pearl Guinea fowls each were placed in cage and on floor and the birds were maintained under standard managemental conditions. Once every four weeks from the fourth week onwards blood was collected from these birds up to 16 weeks of age. Two milliliters of blood was collected from all 48 birds using a 3ml syringe. Drop of blood was used for smear preparation and staining with Modified Leishman- Giemsa stain for the differential count to obtain heterophil to lymphocyte ratio and the remaining blood was kept undisturbed for two hours for separation of serum for performing ELISA test for serum corticosterone estimation. The heterophil to lymphocyte ratio was significantly (P<0.01) affected by age and rearing system of guinea fowl. Older birds of 12 and 16 weeks of age had a higher heterophil lymphocyte ratio of 1.4 ± 0.16 and 1.38 ± 0.19 respectively. Caged reared birds had a significantly (P<0.01) higher heterophil to lymphocyte ratio. All the interactions except rearing system × sex × age were highly significant (P<0.01). Other than rearing system, neither age nor sex had influenced the serum corticosterone level in pearl guinea fowl. Birds reared on floor had higher corticosterone levels of 1.12 ± 0.03 ng/ml than those raised in cages (1.00 ± 0.15) ng/ml and this was highly significant (P<0.01). The result of the present study revealed that a higher heterophil to lymphocyte ratio identified in older birds (12-16 week) to be more stressed than the younger (4-8week) guinea fowls. Guinea fowls reared on floor had higher serum corticosterone levels than those reared on cages while heterophil to lymphocyte ratio was higher in cage reared birds.