In this study, the eggs produced in uncontrolled village conditions were compared to free-range, organic and cage-system in two seasons, in autumn and spring, in terms of external and internal quality traits. In the autumn and spring period, 110 eggs were collected from the village eggs and 50 eggs from other production systems. In order to determine the fertility in the village eggs, 60 eggs were placed in a laboratory type incubator in both seasons and fertility control was made at the 18th day. All data of egg quality traits were performed by taking the average of the two seasons. Egg shape index, shell ratio, shell thickness, shell cleanness, shell defects, albumen and yolk traits differed significantly among production systems (P < 0.05). The lowest shape index, shell thickness and shell cleanness were found in village eggs. Higher shell rates were determined from eggs in cage and organic production compared to others (P < 0.05). The yolk height and yolk index were the lowest and the yolk colors were the darkest in the white cage eggs (P < 0.05). Brown cage eggs showed the better results in the majority of their quality traits. However, they had a higher meat and blood-spot level than other systems. In addition, the presence of cockerels in the village flocks caused the fertile eggs and approximately 85% fertility was obtained. Our results showed that it has become obvious that the village hen and free range hen eggs which can be marketed in high prices compared to the commercial eggs, have no superiority in terms of the traits they are considered. Besides, as they are significantly fertile, especially in hot summer months, according to storage duration and conditions, the probability of embryo development for these eggs has turned to be of high importance for consumption.

The aim of this study was to investigate the effects of organic copper supplementation (0, 5, 10 and 20 mg/kg) in the commercial diet on performance, egg quality and haematological parameters in laying quails. In this 10-week trial, a total of 80 laying quails, aged 22 weeks, were randomly distributed among four experimental groups. Each experimental group contained four replicates of five female birds each. The addition of organic copper to the diets did not statistically affect egg production, egg weight, egg mass, feed conversion ratio, damaged eggs, egg shape index, Haugh unit, and blood parameters except neutrophils and mean corpuscular haemoglobin. Compared to other groups, body weight change was decreased by the addition of 20 mg/kg organic copper, and feed intake was decreased by the addition of 10 mg/kg copper in the quails. The addition of 20 mg/kg of organic copper to the quail diets significantly decreased the eggshell breaking strength and eggshell weight, while it significantly increased the eggshell thickness compared with the control group. The neutrophil and mean corpuscular haemoglobin were increased by the addition of 10 and 20 mg/kg organic copper, respectively, with compare to other groups. It can be said that up to 10 mg / kg of organic copper can be added to commercial quail diets, but its addition at 20 mg/kg negatively effects on some blood parameters as neutrophil and mean corpuscular haemoglobin in quails.

In this study, the performance, egg quality, egg yolk colour and fatty acids profile of quails fed on diets containing different fat sources were determined. During 8 weeks trial, a total of 75, 10-weeks-old laying quails were used. Three diets were formulated to contain soybean oil (SBO), sunflower oil (SFO) and hempseed oil (HSO), respectively. The performance parameters were not significantly influenced by the dietary different oil sources. Eggshell ratio, eggshell thickness, eggshell breaking strength, egg shape index, egg yolk index, albumen index and egg yolk colour values (except a*) were not influenced by the different dietary oil sources. The a* value was significantly affected and the highest a* value was the HSO of group. The different oil sources supplementation to the diets was effective on fatty acid composition of the egg yolk. The highest value in terms of α-linolenic acid, total polyunsaturated fatty acids and total n-3 fatty acids were found in the diet fed group with HSO added. As a result; supplementation of different sources of oil to quail diets without negatively affecting performance and egg quality can be used to change the egg yolk fatty acid composition. Hempseed oil may increase the amount of total polyunsaturated fatty acids and total n-3 fatty acid content of egg yolk.

This study compared egg quality parameters in layers under free-range system with prefabricated pens and backyard while emphasizing hen age. A total of 300 eggs collected from prefabricated pens and backyard farming families in the Çamardı District of Niğde Province were used as study materials. The assessed external and internal egg quality characteristics included egg weight, shape index, shell thickness, shell breaking strength, albumen index, Haugh unit, yolk index, and yolk colour. The effect of production system on albumen index, Haugh unit, and yolk colour score was found statistically significant. There was a significant effect of age on shape index, shell thickness, shell breaking strength, albumen index, Haugh Unit, yolk index, and yolk colour score. The effect of interaction between age and production system was statistically significant for shape index, shell thickness, yolk index, Haugh Unit, and yolk colour score. It was determined that the egg`s meat and blood spots percentages from the free-range and backyard systems were 10.6% and 15.3%, respectively. It was concluded that while eggs produced from free-range system are superior in terms of egg weight, shape index, and Haugh unit those obtained from backyard hens are higher in eggshell thickness, eggshell breaking strength, and egg yolk colour.

Most poultry farmers in Nigeria feed their laying birds twice a day with one bag of 25 kg to 200 layers which translate to 125g/bird/day, while very few feed once or thrice a day and there has been little or no documentation on how many times laying hens should be fed in a day to optimize profit. Thus, this study was designed to investigate the performance and egg qualities of Isa-Brown layers fed different quantities of feed at varying feeding frequencies. Three hundred and sixty (360) 16-weeks in-lay Isa-Brown layers were used in this trial. The treatment consisted of 95g, 105g, 115g, and 125g of feed per day at varying frequencies of once, twice and thrice per day. The birds were housed in California type cages, 3 birds per cage unit, 5 cage units per replicate, and 6 replicates per treatment. A completely randomized experimental design with a 4x3 factorial was adopted. Results at the end of the trial showed that bird fed 115g of feed twice per day had the highest percentage hen-day production (85.24%), highest egg mass (56.69g) and best feed conversion ratio (1.96) while lowest percentage hen-day production (62.02%) and lowest egg mass (39.22g) were observed in hen fed 95g of feed thrice per day and worst feed conversion ratio (2.50) was recorded in bird fed 125g of feed thrice per day. The bird fed 115g twice per day had the highest net profit (N637.63) while the lowest net profit (N199.33) was recorded in bird fed 125g thrice per day. It could be concluded that for optimum laying performance and to save time and labour expended in feeding birds thrice per day, feeding laying Isa-Brown birds the required feed quantity (115g) twice per day would be most economical.

Eggs were coated with propolis in order to determine its effect on egg quality and total bacterial count. Effect of storage time prior to propolis coating was also studied. Eggs were obtained from a local farm, coated with 0, 3, 6 or 9% of propolis and stored at 4 ºC with a humidity of 75% for 30 days. A total of 18 eggs were used for egg quality traits and 6 eggs were chosen for microbial activity for each group. Bacteria were recovered with sterile cotton swabs from egg surfaces. Colonies with different morphology and color were detected. 11 bacterial species were determined following the characterization of 14 isolates. Elevated levels of bacterial counts were detected for daily eggs, which were significantly higher than those stored for 30 days. The quality traits of the daily eggs have also been found higher compared with the other groups. It was observed that coating the eggs with varying concentrations of propolis lead to significant differences in the total bacterial counts of the eggshells. Moreover, the egg quality traits which decreased with the increase in storage time have not been further affected with propolis coating.

ATAK-S is a newly developed native hybrid layer. Although the laying performance of this hybrid has been studied and determined, the performance response of the hybrid to different environmental temperature conditions is not known. This study was therefore undertaken to determine the effect of cold and heat stress on egg quality traits. Hens were divided into three different groups; control (20°C), low (12°C) and high (32°C). A total of 360 hens, with 120 in each of the groups, were used in the study. Hens were held in three tier battery cages in an environmentally controlled poultry house. The study lasted for 3 weeks. No differences were found among different groups in terms of shape index, albumen height and Haugh unit of the egg quality traits. It was found that the differences among the heat groups in terms of egg shell breaking strength, egg weight, shell thickness and yolk colour were significant and the value of these traits decreased under the heat stress conditions, whereas they were not affected from the cold stress.

An experiment was conducted to determine the effect of different combination calcium sources and particle size on performance and egg shell quality in layer hens. In the experiment, 198 brown laying hens at 44 week of age were randomly assigned into 11 treatments groups. The experimental diets consisted of different calcium sources (Fine limestone, large limestone, large oyster shell and large egg shell) and their different combination. The experimental unit consisted of a groups of three hens, thus each treatment was replicated six times. Different calcium sources and particle size addition to the laying hens diet had no significantly effect on body weight gain, egg production, egg mass, feed intake, feed conversion ratio, egg specific gravity, egg shell weight, egg shell thickness and egg shell breaking strength but egg weight had significantly affected by the treatments. The significantly highest egg weight was found in laying hens fed with 50 % fine limestone and 50 % large limestone. Dietary different Ca sources had a significant effect on Ca, P and Mg as mineral contents of eggshell and tibia. In the present study, when dietary large calcium sources (limestone, oyster shell and egg shell) had no effect on performance and eggshell quality parameters in laying hens. However, dietary containing at least 50 % large calcium sources had positive effect on mineral contents of tibia.

To improve hen welfare, several studies have investigated various environmental enrichments that suit different laying hen production systems. The positive results of these studies can enable such environmental enrichments to be utilized in commercial laying hen production. This paper reviewed the effects of environmental enrichments in different laying hen production systems on hen welfare and egg quality. The successfully proven environmental enrichments in free-range production system include forage, shelterbelt, and artificial shade in outdoor area and novel objects and H-shaped perching structures in indoor. These are associated with increased range use that positively affects hen welfare. In aviary system, perches, and litter materials (e.g., straw, sand) as environmental enrichments are linked to improved behavioral expression, reduced stress, and enhanced immune system. Under the litter system, environmental enrichment with substrates (e.g., pecking stones, alfalfa blocks, silage, straw, barley) has been found to increase the foraging behavior of laying hens. This reduces severe feather pecking thus, improving the plumage condition of hens. Although the effects of environmental enrichments on hen welfare have been assessed and scientifically proven in the reviewed studies, significant progress of their impact on egg quality traits has not been reported. The studies have shown that environmental enrichments have no significant effect on egg quality traits. Also, appropriate pasture or plant species as environmental enrichments in free-range production system in relation to hen welfare and egg quality have not been identified. Therefore, it is important to continue studies on environmental enrichments while emphasizing their influence on egg quality since it is a major performance trait in the egg industry. In addition, there is a need for studies to identify ideal pasture or plant species for free-range production system that positively affects hen welfare and egg quality.

In this study, it was investigated the effect of clove oil supplementation at increasing levels into laying hens’ diets on performance, egg quality traits, some blood parameters and yolk TBARS (Thiobarbituric Acid Reagent) values. For this purpose 96 Lohman white laying hens, 28 weeks of age, were divided into four treatment groups. Control group was fed with basal diet (C) and treatment groups were fed with diets formed by addition of clove oil at 50 ppm (CO1), 100 ppm (CO2) and 150 ppm (CO3), respectively. During the trial, feed and water were given as ad-libitum, and poultry house was illuminated for 17 hours. Experiment lasted for 13 weeks. Addition clove oil at increasing rates into diet did not affect the live weight. The data analysed as polynomial showed that supplementation of clove oil into layer diet linearly improved feed conversion ratio and increased the egg production. But, daily feed consumption, egg weight, damaged egg ratio and egg quality parameters were not affected by treatments. Serum parameters such as triglyceride, glucose, aspartate aminotransferase, alanine aminotransferase and calcium were not affected by the clove oil supplementation. TBARS values in C, CO1, and CO2 were found higher than the CO3 group fed with diet including 150 ppm clove oil. In conclusion, clove oil at 150 ppm level in diets of laying hens could be used due to extend the egg shelf life and to decline serum cholesterol content.