Influence of protein rearing regimens and age on egg quality characteristics of Saudi Arabian baladi hens

Eggs used in this study were obtained from 465 Saudi Arabian Baladi Hens. The birds were subjected to four different protein rearing regimens: conventional (C), reverse protein (RP) 12% CP from 1 to 6 wks, followed by 15% CP up to 14 wks and 18% CP diet from 14-20 wks of age, single stage low protein (551) 15% CP and (552) 12% CP diets from 1-20 wks of age. All the experimental groups received a conventional 18% CP diet during the first week of age and were offered a commercial layer ration during<br>the laying period. A total of 120 eggs, whenever possible, of each experimental group was collected over the three consecutive days of each month for a production period of twelve months. The eggs were examined for weight, Haugh units, shell thickness, shape index, incidence of blood and meat spots and yolk pigmentation. The results indicated a significant protein rearing regimen (P~ .01) effect upon egg weight, Haugh units and shell thickness. Egg weight was adversely affected by RP, SS) and SS, while Haugh units were similarly influenced by SS) and 552, RP and SS, also appeared to have a detrimental effect on shell thickness. Shape index, incidence of blood and meat spots and yolk pigmentation were not significantly affected by the protein rearing regimens. Overall hen day egg production, feed intake/bird and feed consumed/dozen eggs also did not differ significantly among any treatment. However, the C group had significantly (P~ .05) lower livability than the SS) group. Age had a significant (P~ .01) effect upon all studied egg quality traits. Egg weight increased while Haugh units and shell thickness decreased with increasing age. Shape index decreased during the first four months of lay then started to increase in the fifth month of the laying period. Blood spots increased with age, while meat spots and yolk pigmentation varied greatly from one age period to another