Differences between metabolic profiles of egg-type and meat-type hybrid hens

The main objective of this study was to compare the metabolic profile (i.e. selected haematological and biochemical parameters in blood plasma) of production egg-type hybrid hens (E, MORAVIA BSL) with that of meat-type hybrid hens (M, COBB 500), and to evaluate dynamic changes occurring during the laying period from the 25th to 50th week of age. The study was prompted by both poultry farmers and veterinary practitioners since parameters defining the health of layers are absent. Selected parameters of the metabolic profile of layers were monitored regularly in 5-week intervals during egg laying. Samples of blood for haematological and biochemical examination were obtained by puncture of the vena basilica and stabilized by heparin. The study has revealed that monitored parameters of the metabolic profile significantly vary with factors such as production type, nutrition, and egg-laying intensity. Enhanced metabolism in egg-type hens was reflected in erythropoiesis which increased (in comparison with meat-type hens) highly significantly (P ≤ 0.01), particularly for erythrocyte count 2.36 T/l (2.14 T/l), haematocrit level 0.32 l/l (0.30 l/l), content of haemoglobin 94.48 g/l (84.18 g/l) and leukocyte count 17.06 G/l (13.22 G/l). Similarly, enhanced metabolism in egg-type hens also led to a highly significant increase (P ≤ 0.01) in the levels of biochemical parameters in blood plasma, particularly the total level of protein was 57.62 g/l (50.98) g/l), glucose 14.03 mmol/l (13.36 mmol/l), cholesterol 5.34 mmol/l (3.73 mmol/l) and calcium 6.52 mmol/l (5.52 mmol/l). ) In the case of the plasma level of phosphorus, no significant difference was found between egg-type hens (1.58 mmol/l) and meat-type hens (1.59 mmol/l). The reported results are based on the total of 180 haematological and biochemical analyses performed during the laying period. The results are crucial not only for future development of avian haematology and biochemistry, but also in respect to veterinary practice.