Quality of poultry products, especially eggs, is a very important issue for the consumers and for the processing industry. The aim of the present study was to examine the interaction between the storage time and age of laying hens and their effect on the quality of table eggs. Eggs from 34 and 59- wk-old Bovans Brown hens were sampled and stored in the refrigerator for 1, 2, and 3 weeks. Significant effect of hen age (P<0.01) was found on egg weight, shell strength, albumen height and Haugh units (HU). Eggs from older hens had 2.58% higher mass compared to the eggs of young hens. Eggs from 59-weeks old hens had significantly lower shell strength (3.63 kg vs. 4.31 kg). Albumen height and HU were lower in eggs from the older hens compared to the young ones (5.7 mm vs. 7.11 mm for albumen height; 70.35 vs. 81.77 for HU). Significant negative effect of storage time was found on egg weight, albumen height, HU and yolk colour (P<0.01). The results indicated that egg quality characteristics monitored in this study decrease by hen age and during storage. The interaction effects between storage time and age of hens were significant only for yolk colour (P<0.05).

The objective of this study was to establish the effects of chestnut tannin extract or vitamin E added to linseed oil-enriched diets on growth performance, meat quality, and intestinal morphology of broiler chickens. A total of 240 day-old Ross 308 male broiler chicks were included in trial. 5% of cold-pressed linseed oil was included in finisher diets (21–40 days), and three feeding treatments with four replicates were formed: finisher without additives; finisher + 200 IU vitamin E/kg; finisher + 500 mg/kg of chestnut wood tannin extract. No significant influence of treatments was established on body weight or feed conversion ratio. A negative effect on feed intake (p < 0.05) was found in the vitamin E group. The addition of vitamin E increased the dressing percentage (p < 0.05) and increased the breast meat yield (p < 0.01) compared to the control group. No significant effects were found on the water holding capacity or pH of breast meat. The highest level of AST (p < 0.01) and ALT (p < 0.05) was recorded in vitamin E group. The addition of chestnut tannin extract in feed increased villus height, villus height: crypt depth ratio, and villus area compared to the other two groups (p < 0.05). It can be concluded that vitamin E supplementation improves carcass percentage and breast meat yield, while chestnut tannins improve the intestinal morphology of broiler chickens when added to oil-enriched diets.

Апстракт The aim of this research was to determine some exterior and interior quality traits of Japanese quail eggs. A total of 60 Japanese quail eggs were collected from two different farms near Novi Sad, and the eggs quality traits were tested in the laboratory of poultry science at the Department of Animal Science of the Faculty of Agriculture in Novi Sad. The egg weight, albumen weight, yolk weight, shell weight, shell breaking force, shell thickness, albumen height and egg yolk colour were determined. The external and internal egg quality traits of quail eggs from two farms in Serbia do not differ from the results of quality traits from other countries.

In broiler breeder production, up to 2% of hatching eggs are rejected because of cracked or broken shells. Eggs with cracks give a reduced hatchability and a lower chick quality and cause economic loss. The main goal of this study was to determine the effect of sealing eggshell cracks with surgical tape on hatching parameters. A total of 3,000 eggs from a 34 weeks old Cobb 500 broiler breeder flock was used in the experiment. Six hundred intact eggs represented a positive control. Other eggs were artificially cracked by the operator either on the first day of storage (1,200 eggs) or on the fourth day of storage (1,200 eggs). In both groups, cracks on 600 eggs were sealed by the adhesive surgical tape while the other 600 eggs remained untreated and were used as a negative control. Within each experimental group, eggs were assigned randomly to 4 setter trays representing 4 replicates of 150 eggs. The egg weight loss during incubation was the highest (P < 0.01) in groups of nonsealed cracked eggs. The egg weight loss in sealed groups was higher compared to the control group (P < 0.01). Percentage of egg contamination was not different between groups. Embryonic mortality was higher in non-sealed groups in all stages of embryonic development (P < 0.01) compared to groups of sealed cracked eggs and the control group. Hatching percentage was significantly lower in non-sealed groups (P < 0.01) compared to sealed groups and positive control. No significant difference in hatching parameters was observed between sealed groups and positive control, indicating that surgical tape can be used for sealing cracks on the eggshell to support embryonic survival.