Guinea fowl (Numida meleagris) eggs and free-range housing: a convenient alternative to laying hens' eggs in terms of food safety?

Evaluation of the Quality of Guinea Fowl (Numida meleagris) Eggs from Free-Range Farming Depending on the Storage Period and Age of Laying Hens

The aim of the study was to determine the changes occurring in the eggs of helmeted guinea fowl (Numida meleagris) from free-range farming in relation to the laying season and storage time. The experimental material consisted of 360 guinea fowl eggs, collected in the first, second and third laying seasons and stored for 7, 14 and 21 days. After each period, physical and physicochemical characteristics of the eggs were determined, as well as the basic chemical composition and mineral content of the albumen and yolk and the yolk fatty acid profile. The age of the guinea fowls affected certain physical parameters of the eggs. The egg weight, shape index and shell thickness increased with the age of the laying hens; however, a decrease in the proportion of shell in the egg was demonstrated. Storage time had a significant effect on egg weight, weight loss during storage and air cell height. Significant differences were found in the chemical composition of guinea fowl eggs depending on the age of the laying hens. Eggs obtained from older laying hens were characterized by higher yolk fat content and lower ash content, while the albumen contained higher water content and lower ash content. During the three-year laying period, changes were observed in the mineral composition of the eggs. The fatty acid profile underwent significant changes; however, no important differences were observed in the total content of SFA, MUFA, PUFA and n-6 fatty acids. Conversely, significant differences were found for n-3 acids and the n-6/n-3 ratio. Eggs in the first and second laying seasons exhibited the most favorable composition. The slow dynamics of changes occurring in successive laying seasons and egg storage time indicated that the raw material studied was safe and could be used by consumers.

Changes in Fatty Acids Profile, Health Indices, and Physical Characteristics of Organic Eggs from Laying Hens at the Beginning of the First and Second Laying Cycles

The present study compared the fatty acid profile and some physical parameters of eggs from hens reared according to the organic system at the beginning of the first and second laying cycle. A total of 1080 eggs were analysed at the beginning of the first (from the 28th to 30th week of age) and the second (from the 78th to 80th week of age) laying cycle. It was found that the hen ages influenced the egg weight, egg surface area, yolk proportion, and eggshell colour. Albumen and eggshell proportion, albumen, yolk index, Haugh unit score, and eggshell strength were lower in eggs from older hens compared with those produced from younger layers. Monounsaturated fatty acids were found in higher amounts than saturated fatty acids and polyunsaturated fatty acids in egg yolks of eggs from layers only at the beginning of the second laying cycle. The PUFAn-6/n-3 ratio, saturation, atherogenic, and thrombogenic indices were significantly lower in the egg yolks from older hens compared to younger layers. These findings (regarding the eggs from the older ones) prove that it is practical to utilize them in the organic farming system during a period of two years.

Quality of free-range and commercial eggs subjected to different storage periods and temperatures

Abstract The objective was to evaluate the internal quality of eggs from commercial laying hens and free-range hens subjected to different storage periods and temperatures. For the experiment, 280 eggs were randomly distributed into different treatments, adopting a completely randomized design, in a 2 x 7 factorial arrangement of two temperatures, seven storage periods, totaling 14 treatments with 10 replications. The treatments consisted of two storage conditions: under refrigeration (6 ± 1.0ºC) and at room temperature (26.6 ± 1.0ºC). Eggs were analyzed for 30 days, with evaluations in different storage periods (0, 5, 10, 15, 20, 25 and 30 days). For each storage condition, 140 eggs were separated, 70 commercial eggs and 70 free-range eggs. There was a linear increase in egg weight loss, yolk weight, albumen pH, yolk pH, length and width of albumen and yolk of commercial and free-range eggs, as the storage period increased. There was a linear reduction in weight, height and albumen index and in the yolk index of commercial and free-range eggs as the storage period increased, with more pronounced responses for eggs stored at room temperature (P<0.05). Albumen percentage was linearly reduced only for commercial eggs (P<0.05). Eggs kept at room temperature reduce their quality after 15 days of storage, and the storage under refrigeration for 30 days is recommended to preserve the shelf life of the egg for consumption.

Do the differences in egg contamination, penetration, and resistance against microorganisms among the hen genotypes exist?

The aim of this study was to evaluate and compare the impact of genotype and storage conditions (temperature and time) on microbiological contamination and eggshell quality. There were four genotypes of laying hens used, Czech golden spotted (CGS), Greenleg Partridge (GP), White Leghorn (WL) and commercial hybrid (CH) hens were included. After collection, the eggs were divided equally into five groups regarding the storage time (0, 14, 28 days) and temperature (5 and 20 °C). The microbiological analysis included counting of colonies forming units (CFU) of Escherichia coli (EC), Enterococcus (ENT) and total number of microorganisms (TNM) on eggshell surface, eggshell membranes and in thin albumen. The analysis of eggshell quality included the determination of eggshell proportion (SP), thickness (ST), strength (SST), index (SI) and surface (SS). Moreover, egg weight (EW) and egg weight loss (EWL) were determined. The significant effect of genotype was found in contamination of eggshell by EC, ENT and TNM, eggshell membranes by TNM and albumen by EC (all P ≤ 0.05). The significantly lowest contamination of eggshell from EC was in eggs from the WL hens (4.42 log CFU/eggshell), while from ENT was in eggs from the CGS hens (1.22 log CFU/eggshell) and from the WL hens (1.40 log CFU/eggshell). The lowest incidence of TNM was also detected in eggs from the WL hens (5.03 log CFU/eggshell). Statistically the lowest contamination of eggshell membranes by TNM was found in eggs from the WL (0.12 log CFU/eggshell membranes) and CH hens (0.15 log CFU/eggshell membranes). Regarding the effect of genotype, the GP (not detected) and WL (not detected) hens was in eggs with statistically the lowest occurrence of EC bacteria in albumen. Regarding the EW and eggshell quality, all the parameters were significantly affected by the genotype (P ≤ 0.0001). Also EWL was significantly (P ≤ 0.05) affected by genotype (after 14, 21 and 28 days of storage). There were found to be significant differences of microbial contamination of egg surface among observed hen genotypes. The penetration of selected microorganisms was also significant in contamination of eggshell membranes by TNM and in contamination of albumen by EC.

Modulation of Morphology and Glycan Composition of Mucins in Farmed Guinea Fowl (Numida meleagris) Intestine by the Multi-Strain Probiotic Slab51®

Probiotics have become highly recognized as supplements for poultry.Since gut health can be considered synonymous withanimal health, the effects of probiotic Slab51® on the morphology and the glycan composition of guineafowlintestine were examined. The probiotics were added in drinking water (2 × 1011 UFC/L) throughout the grow-out cycle.Birds were individually weighed andslaughtered after four months. Samples from the duodenum, ileum and caecum were collected and processed for morphological, morphometric, conventional and lectin glycohistochemical studies.The results were analyzed for statistical significance by Student's t test. Compared with control samples, probiotic group revealed (1) significant increase in villus height (p < 0.001 in duodenum and ileum; p < 0.05 in caecum), crypt depth (p < 0.001 in duodenum and caecum; p < 0.05 in ileum) and goblet cells (GCs) per villus (p < 0.001) in all investigated tracts; (2) increase in galactoseβl,3N-acetylgalacyosamine(Galβl,3GalNAc)terminating O-glycans and αl,2-fucosylated glycans secretory GCs in the duodenum; (3) increase in α2,6-sialoglycans and high-mannose N-linked glycans secretory GCs but reduction in GCs-secreting sulfoglycans in the ileum; (4) increase in Galβl,3GalNAc and high-mannose N-linked glycans secretory GCs and decrease in GCs-producing sulfomucins in the caecum; (5) increase in the numbers of crypt cells containing sulfate and non-sulfated acidic glycans. Overall, dietary Slab51® induces morphological and region-specific changes in glycoprotein composition of guinea fowl intestine, promoting gut health.