Changes in plasma lipaemia, glycaemia and uremia caused by the negative interaction of the genotype and environment during the laying period of hens of initial lines of laying hybrids*

Abstract. During the laying period the changes in concentrations of plasma total lipids, cholesterol, glucose and urea were studied in the RIW laying line selected for the number of eggs laid during the eight month laying period. The feed mixtures were changed qualitatively causing both changes in plasma lipaemia, glycaemia and uremia and time-limited reduction in the body weight and laying intensity. Average concentrations of the individual blood indicators of the entire group of hens during the laying period ranged as follows: total lipids 5.06 ± 0.63 g.l⁻¹ to 21.51 ± 5.28 g.l⁻¹, cholesterol 1.99 ± 0.45 mmol. l⁻¹ to 4.73 ± 1.54 mmol. l⁻¹, glucose 4.43 ± 0.51 mmol .l⁻¹ to 19.02 ± 5.25 mmol.l⁻¹ and urea 3.53 ± 0.98 mmol.l⁻¹ to 6.29 ± 2.51mmol.l⁻¹.

The concentrations of the given biochemical indicators were also studied to contrast at the age of 25 weeks in other lines of hens originating from the RIW and BPR lines. The average values of all the studied indicators were different in lines of different laying intensity and earliness (fed the same feed mixture in the same hall), i.e. total lipids 25.00 ±7.51 to 45.85 ± 11.98 g.l⁻¹, cholesterol 3.25 ± 0.85 to 4.83 ± 0.81 mmol.l⁻¹, glucose 11.91 ±2.69 to 15.15 ± 1.98 mmol.⁻¹ and urea 3.08 ± 0.53 to 6.90 ± 1.61 mmol.l⁻¹.

We can say that during the laying period important changes in plasma lipaemia, glycaemia and uremia of the hens occur in dependence on changes in the feed mixture or in its quality too. These criteria monitor the level of interaction between the genotype and the environment on the level of pre-clinical response of the organism.