The effect of deshelled and shell-reduced mussel meal on egg quality parameters of organic laying hens under commercial conditions

Effects of Dietary Supplementation of Salvia officinalis L. in Organic Laying Hens on Egg Quality, Yolk Oxidative Stability and Eggshell Microbiological Counts

Aromatic plants of Labiatae family are used in poultry diets because of their antimicrobial and antioxidant activity. The notion is that hens raised in organic systems face several health and environmental challenges. Hence, the objective here was to assess hens' performances and the quality of their eggs in such systems following a dietary supplementation of Salvia officinalis L. in powder form. The experiments were conducted over two successive years (1 and 2). They lasted 16 weeks each and involved 198 laying hens aged 40 weeks old randomly assigned to three groups: Con (control diet), Sal-0.5%, and Sal-1.0% (diets supplemented with Salvia officinalis L. at 0.5% or 1.0%, respectively). The malondialdehyde (MDA) levels in egg yolks in year 2 were lower in both Sal-0.5% and Sal-1.0% compared to the Con (p < 0.05). The total number of Enterobacteriaceae in eggshells were lower in Sal-1.0% compared to the Con (p < 0.05) in both years. The results suggest that a dietary supplementation of Salvia officinalis L. at 1.0% improves the antioxidant status and reduces the microbial load of eggs produced in organic systems.

Dual-Purpose Poultry in Organic Egg Production and Effects on Egg Quality Parameters

Egg laying genotypes have been selected for generations due to their high yield and egg quality, resulting in efficient feed utilization and low body weight; hence, they are not suitable for meat production. This imposes an issue for the male layer chicks, which are killed at one day old. Because of ethical and food waste concerns, the search for suitable dual-purpose genotypes in order to avoid euthanasia of male day-old chicks has intensified. The aim of the present study is to evaluate potential dual-purpose genotypes for their egg quality compared to a representative egg laying genotype. Two dual-purpose genotypes with divergent characteristics were evaluated: genotype A represented an experimental crossbreed based on a broiler type male and an egg layer female, and genotype C was a crossbreed of a layer type. These were compared to a rustic genotype B and a control genotype D, which was an egg layer. Eggs were collected six times during the period of 21–54 weeks of hen age, i.e., a total of 990 shell eggs were analyzed. Examined parameters were weights of egg, shell, yolk, and albumen, by calculating their relative proportions. Shell quality was assessed by shell strength, shell stiffness, and shell thickness. Yolk quality was determined as yolk color and inclusions of blood and meat spots, and albumen quality was evaluated in terms of pH and dry matter (DM) content. The egg layer genotype produced the smallest eggs with least blood and meat spot inclusions compared to that produced by the three dual-purpose genotypes. Shell quality was superior for the layer genotype. However, the experimental genotype A laid eggs of comparable shell quality, albumen DM, and yolk weight, but also with the darkest and most red-yellow colored yolk. The two other dual-purpose genotypes produced eggs of low-medium quality. In conclusion, the genotype A could serve as dual-purpose genotype from an egg quality perspective.