INFLUENCE OF PRODUCTION SEASONS ON EGG QUALITY CHARACTERISTICS OF LAYERS IN SEMI-ARID SOKOTO, NORTH-WESTERN NIGERIA

Résumé

An experiment was conducted to assess the influence of production seasons (Rainy and Cold Seasons) on the egg quality performance of laying pullets in semi-arid Sokoto environment. Using Completely Randomised Design (CRD), a total of 240 day-old chicks were raised to point of lay (POL) both in battery cage (BC) and on deep litter (DL) housing systems under the rainy and the cold seasons serving as treatments. For each of the seasons, 240 POL birds were divided into 6 replications with 20 birds per replicate and allocated to the BC and DL houses, under the same roof for each season. All management recommendations were observed. At 20 weeks in lay, 72 egg samples were randomly collected, 36 from each housing system and 6 eggs from each of the 6 replications for each season. The sampled eggs were studied for external and internal egg quality traits. From these records, other egg indices were calculated. Reported values are therefore, composite means of the two housing systems under each season. Instruments used were sensitive electronic balance, vernier calliper, micrometer screw gauge, meter rule, flat trays, tissue paper etc, for egg analysis. Results showed that environmental factors that constitute the production seasons have varied effects on external (egg weight (EW)(g), egg length (EL)(cm), egg width (EWd)(cm), egg shell surface (ESS)(cm) and egg surface index (ESI)) and internal egg quality traits (Albumen height (AH)(cm), Albumen width (AW)(cm), Albumen weight (AWt)(g), Albumen index (AI), Yolk height (YH)(cm), Yolk width (YW)(cm), Yolk weight (YWt)(g), Yolk index (YI), Yolk colour (YC), Shell weight (SW)(g), Shell thickness (ST)(mm) and the Haugh Unit (HU) (%) of eggs produced by commercial layers. These traits were more significantly (P>0.05) favoured during the cold season production than in the rainy season. HU, being the overall score of EQ was significant under the seasons in favour of the cold season. It was thus concluded that the cold season is the best production season when EQ is attained at its best, thus recommended to farmers in the study area to obtain the highest EQ and price for their
table eggs.