THE POSSIBILITY OF THE FLATTENING THE EGG WEIGHT DEVELOPMENT CURVE OF LAYING HENS BY LIGHTING AND FEEDING METHODS

The objective of this experiment is to find out the possibility of the flattening of egg weight development curve on laying hens by lighting and feeding methods. The 456 laying hens (LSL), placed in individually cages in two separated windowless houses, were used for the experiment. The factorial analysis has been used in this experiment with pullets and laying hens lighting and also feeding as a factor unit. The pullet lighting were differenciated in early and late stimulation. The laying hens lighting consisted of control (14 L, 10 D) and treatments with symmetric intermittent lighting [6(1.5 L, 2.5 D)] unit 50 weeks of age was applied and afterwards asymmetric intermittent lighting [2(1.5 L, 2.5 D) 6 L, 10 D] was also applied. The feeding consisted of control and phase feeding. The phase feeding was in three diets with different on linoloic acid and methionine content (R1 from 23 to 40 weeks of age, R2 from 41 to 60 weeks of age, R3 from 61 to 80 weeks of age). The experiment took 15 laying months (a 28 days). Egg weight, egg production and egg quality were selected for further statistic analysis. The two pullet lighting programs lead to different egg weights. Pullet with late lighting stimulation especially in the beginning of the lay period showed an increase in egg weight and a decrease in egg production. Pullet lighting program indicated that there was no influence on egg weight development curve. Symmetric intermittent lighting increased egg weight, decreased egg production and lead to better eggshell stability and higher per cent in yolk. After the changing of lighting program (after 50 weeks of age) egg weight went down quickly to the same level of control. The means, the egg weight development curve was flatted. Through high linoleic acid and methionine within late lighting stimulation, egg weight increased slightly. In contrast, decreasing linoleic acid and methionine content in diets in the end of laying period lead to decrease egg weight. This means an attempt to flattening the egg weight development curve can be further achieved. The results indicated that the attempt to flattening the egg weight development curve by a combination of lighting and feeding methods was possible.