CHANGES IN HEMATOLOGICAL AND BIOCHEMICAL CHARACTERISTICS OF BLOOD OF BROILERS DURING FATTENING

The paper presents the results of hematological and some biochemical examinations of broiler chicks during fattening. A total of 312 clinically healthy chicks of the HYBRO broiler hybrid were examined: 96 birds at the age of 21 days, 96 birds at the age of 35 days and 120 birds at the age of 49 days. Tabs. I - III summarize the results of hematological and biochemical examinations including statistical data. The results have indicated numerous changes in the values of hematological and biochemical characteristics during fattening, that means with the growing age of chicks. In older chicks, hemoglobin content was decreasing significantly (P less-than-or-equal-to 0.01) from 86.51 to 82.54 g/l, mean corpuscular hemoglobin (MCH) from 38.78 to 33.61 pg (p less-than-or-equal-to 0.01), mean corpuscular hemoglobin concentration (MCHC) from 29.32 to 28.56 % (P less-than-or-equal-to 0.01) and mean corpuscular volume (MCV) from 133.21 to 118.33 fl (P less-than-or-equal-to 0.01). There were minimum changes in hematocrit value, the mean values ranged from 0.295 to 0.290 l/l. A highly significant rise of total erythrocyte counts was observed: from 2.29 to 2.51 T/l (P less-than-or-equal-to 0.0 1). T o k o s o v a and P I e v a (1988) reported on similar changes in the red component of the blood picture. Significant fluctuations were demonstrated in total counts of leukocytes; first, there was a significant drop (P less-than-or-equal-to 0.05) from 16.21 G/l (day 2 1) to 11.64 G/l (day 35), secondly, a highly significant increase (P less-than-or-equal-to 0.01) in leukocytes counts to 15.60 followed (day 49). These changes were accompanied during fattening by a significant drop (P less-than-or-equal-to 0.05) of eosinophil concentration from 4.13 to 3.14 % and by a highly significant drop (P less-than-or-equal-to 0.01), of lymphocytes from 61.15 (day 21) to 53.59 % (day 35). On the other hand, basophil concentrations rose significantly (P less-than-or-equal-to 0.01) from 1.82 to 3.06 %, heterophil concentrations rose from 27.66 (day 21) to 32.84 % (day 35). Minimum fluctuations were observed in monocyte concentrations which ranged from 5.97 to 5.09 %. The described changes in leucocyte counts can be explained from stress conditions of chick fattening. This conclusion can be confirmed by current references (M a x w e l l et al., 1990a, b, 1992; M c F a r l a n e, C u r t i s , 1989a, b; G r o s s , 1989, and others). Similarly like in hematological characteristics, certain changes were recorded in biochemical characteristics in the blood plasma of broilers during fattening; e.g. cholesterol level decreased from 3.56 to 3.01 mmol/l (P less-than-or-equal-to 0.01), urea level from 0.80 to 0.43 mmol/l (P less-than-or-equal-to 0.01) and AST activity dropped from 1.16 to 0.92 mukat/l (P less-than-or-equal-to 0.01). On the contrary, ALT activity increased from 0.061 to 0.093 mukat/l (P less-than-or-equal-to 0.01). Minimum changes in the blood plasma of broilers during fattening were determined in total protein content, its average values ranged from 37.42 to 38.07 g/l. Our conclusions of the biochemical studies am m agreement with the conclusions drawn by some authors (e.g. A l e t o r , 1989; G a d o et al., 1989).