Petar Kraljević

Body weight and enzymes activities in blood plasma of chickens hatched from eggs irradiated with low level gamma rays before incubation.

An attempt was made to determine the effect of eggs irradiation by low dose gamma radiation upon body weight (BW), body weight gain (BWG), feed consumption (FC) and feed conversion ratio (FCR) of chickens hatched from irradiated eggs. Our aim was also to investigate the activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT), acid phosphatase (ACP) and alkaline phosphatase (ALP) in the blood plasma of those chickens. The eggs of heavy breed chickens were irradiated with a dose of 0.15 Gy gamma radiation (60Co) before incubation. Along with the chickens which were hatched from irradiated eggs, there was a control group of chickens hatched from nonirradiated eggs. All other conditions were the same for both groups of chickens. BW of chickens was measured by a single weighting of chickens on the 1st and 42nd day of the fattening period. An average BWG was calculated from the obtained results during the whole fattening period (i.e. from the 1st until the 42nd day). FC was measured each day during the fattening time and total feed consumption was calculated. On the basis of FC and BW, FCR was calculated (FC/BWG). Blood samples were taken from the right jugular vein on the 1st and 3rd day, or from the wing vein on days 5, 7, 10, 20, 30 and 42. The activity of all enzymes was determined spectrophotometrically by using reagents according to recommendations of the International Federation of Clinical Chemistry and Laboratory Medicine. BW of chickens hatched from irradiated eggs was statistically significant higher than in the controls during the fattening period ; on day 42 of fattening, BW of the experimental chickens was 90 g (i.e. 4.8 %) higher than in the controls (P<0.05). FC during the fattening period did not essentially differ in the experimental and the control group. The AST activity was significantly increased in blood plasma of chickens hatched from irradiated eggs on days 3 and 10 (P<0.05), ALT activity was increased in the same chickens only on the 10th day (P<0.05). The activity of ACP in the blood plasma of the same chickens was increased on day 42 (P<0.001) and the activity of ALP in the blood plasma of chickens hatched from irradiated eggs was decreased on day 42 (P<0.001). The obtained results indicate that low doses of gamma radiation have a stimulative effect upon metabolic processes in chickens hatched from eggs irradiated before incubation, which is proved by increase of BWG and BW, as well as by increase of AST, ALT and ACP activities in blood plasma.