ACID-BASE HOMEOSTASIS AND QUALITY OF EGG-SHELL IN 2 WHITE LEGHORN GENOTYPES

Thirteen White Leghorn layers 7 of which were from an experimental sto ck carriers of the naked neck gene (Na) and 6 common layers (L12) of 4 2 weeks of age were used with the aim of determining the acid base bal ance and egg shell quality. The hens were allocated in individual cage s according to a completely randomized design and were offered a basal diet composed of wheat, soy bean meal and torula yeast with 16% CP an d 11.7 MJ/kg ME. Feed and water were offered ad libitum. The experimen t was carried out during the summer. The maximum and minimum mean temp eratures for the month were 33 and 27 degrees C, respectively and the relative humidity, 80%. Differences were not found between the normal hens and those of NaNa For the acid base indicators studied; pH: 7.37 and 7.37; PCO2 38.45 and 40.94 mm Hg and HCO3: 22.34 and 23.49 meq/lit ers, respectively. The egg shell quality measures showed breaking resi stence values of 3.09 and 3.29 kg/cm, shell weight percentage 1 was of 9.00 and 9.28% and the specific gravity of 1.086 and 1.988 g/cm for c ommon and naked neck hens, respectively There was no relation between the acid base indicators and the measures of the eggshell quality. Res ults showed that under the conditions studied both hen lines have a si milar performance in homeostatic regulation and egg shell quality.