Phenotypic variation between two egg-type chicken strains for residual feed consumption and cell-mediated immunity

الملخص EN

An experiment was conducted to estimate the residual feed consumption (RFC), cell mediated immunity and their relationship in Hy-line (commercial) and Norfa (synthetic Egyptian) strains.

Sixty laying hens (30 each) were randomly chosen and individually housed in cages from 46 to 54 weeks of age.

The present results revealed that the Hy-line had significantly higher egg mass and better feed conversion ratio compared to Norfa one.

Opposite trend was observed for eggshell quality.

With respect to cutaneous basophil hypersensitivity (CBH) response, the Norfa was hyper responder to Phytohemagglutinin-P (PHA-P) injection compared to Hy-line.

The observed feed consumption values were somewhat close to their expected values in Hy-line.

Swelling measured at 24hrs post PHA-P injection was significantly negatively correlated with RFC in Hy-line.

Similar trend was noticed between swelling measured at 48hrs post PHA-P injection and RFC in Norfa .

It could be concluded that the Hy-line strain had better egg production traits and RFC ; however, the Norfa had better eggshell quality and was a higher responder to PHA-P injection.