Comparison of husbandry and egg quality of conventional and free range commercial layers -

Abstract

The thesis is divided into two parts namely, studies A and B. The objective of study A was to present the degree of compliance of Lebanese intensive system (IS) and free range chicken layers (FRCL) farms to the EU standards, targeting the welfare of chicken and the improvement in its egg quality. A questionnaire was implemented to uncover the adopted husbandry system on IS and FRCL. The improvement in egg quality included also an experiment that was conducted to asses quality parameters, and heavy metal content of eggs produced by IS versus FRCL. Five IS and five FRCL farms were selected and 5 eggs were randomly collected from each farm. The percentage of compliance of farms in both systems with EU regulations ranged between 0 and 66.7 percent namely, for the parameters of housing management, feeding, watering, vaccines, medication, packaging and egg quality. The egg quality parameters were not significantly different between the two systems, in relation to egg weight, porosity, shell thickness, density, yolk percent, albumenpercent, shellpercent and percentage of eggs with AA quality. However, the IS eggs had significantly higher Haugh unit scores and yolk color index compared to the FRCL eggs. Copper was the only metal that was significantly higher in yolk of the FRCL as compared to that of the IS eggs. The objective of study B was to evaluate the growth promotion in broilers by two natural essential oil preparations (Mentofin and modified Mentofin) versus synthetic Maxiban in the period from d1 till d21(growth promotion period), under controlled temperature versus open system. Another objective was to study the protection and performance of broilers, 7 days following an eight Eimeria spp. cocktail challenge at 21 days of age. Eighty birds were equally distributed into 8 groups of 10 each. Birds of group 1-5 were reared under a controlled environment and were challenged with the Eimeria cocktail. Birds of groups 6-8 were reared in an open system and left without Eimeria challenge. Feed conversion during growth promotion in the period