Effects of repeated eastward and westward synchronizer phase-shifts on growth, blood morphology and biochemical variables in male domestic fowls.

ABSTRACT

The effects of repeated synchronizer phase-shifts on growth (increment in body weight), blood morphology and growth related biochemical variables in 3-day-old juvenile male chicks were evaluated till they become 20 weeks old. The control birds were kept under a fixed LD 1212 light schedule throughout, while the LD 1212 regimen of experimental birds was shifted weekly either by delaying (westward shift) or by advancing (eastward shift) the time of light onset by 8 hr. The rate of growth was more in fowls which were exposed to repeated advancement of synchronizer schedule than the controls and those exposed to westward shifts of the synchronizer schedule. Hematological indices, viz., hemoglobin concentration, number of circulating erythrocytes, hematocrit and biochemical variables, such as concentration of glucose and protein in plasma; glycogen, protein and lipid in liver; and muscle tissues were significantly more in chicks exposed to repeated eastward shifts, when compared with the control birds (LD 1212). It is suggested that the eastward shift of the synchronizer may be beneficial for the poultry birds.