IMPROVEMENT OF THE MORPHO-PRODUCTIVE INDEXES AT THE ROSS-308 BROILER BREEDERS, THROUGH INCREASED PHOTOSTIMULATION

The researches focused on the eggs yield improvement at the „Ross 308" hens breeders, through the optimisation of the lighting schedule. The groups method, mixed with the periods one, was applied. Two groups have been established (Lc and Lexp), comprising each 5260 hens and the required roosters; the fowl have been observed during 20-60 weeks age period. Both groups received the standard phostostimulation schedule, as specified by the producer. However, the Lexp group received 1 supplemental hour of lightning/week and 10 lux higher lighting intensity. The live weight was found within the standard curve in both groups and the hens in the experimental group were 0.15-3.60g heavier than those in the control group. Although the mortality percentage was close between groups (9.85% in Lc and 9.29% in Lexp), the culling generated by prolapses was 0.59% lower in Lexp. Eggs yield reached 183.65 pieces in Lexp compared to just 178.25 pieces in Lc, leading thus to an improved feed conversion ratio, meaning 3.11% better at the experimental group. The main conclusion of the study states that the usage of an increased photostimulation schedule on the "Ross 308" broiler breeders provides an appropriate correlation between the sexual maturity onset and the reaching moment of the optimal live weight, generating thus higher morpho-productive indexes, compared to those achieved within the classical photostimulation version.