The food of animal origin that is the most consumed is the table egg, but laying hens treated with antibiotics can produce eggs contaminated with antibiotic residues. Residues of antibiotics may present a risk for consumer health. Keeping in mind that laying hens almost always suffer from Mycoplasma (Mycoplasma synoviae), for which they are treated with antibiotics, high-quality egg production is even harder. Our research aimed to investigate the influence of three different antibiotics compared to the tea tree (Melaleuca alternifolia) essential oil administered to naturally infected laying hens with M. synoviae, on antibiotic residues in eggs as well as the egg nutritive and sensory qualities. A total of 20,000 laying hens, housed in one facility and divided into four lines each consisting of 5000 hens naturally infected with M. synoviae, was used. For the antimicrobial therapy, tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC) were used, respectively. As a control, tea tree essential oil (TT) was used. Based on the gained results all tetracyclines treatment residue values were significantly (p < 0.05) higher compared to the control treatment (TT), but without any significant differences (p > 0.05) between themselves. The results showed no differences in the nutritive and the sensory qualities of eggs between the control and the experimental treatments (p > 0.05). Keeping in mind the obtained results from this study, it can be concluded that tea tree essential oil could be successfully used as a natural antibiotic in the treatment of M. synoviae, without any adverse effects on table egg quality.
The experiment was conducted to evaluate the influence of strain and age on some egg quality parameters (egg weight and egg shell strength) of commercial laying hens. Layers of lines ISA Brown and DeKalb White were examined in period of nine months. Both lines were at same age (28 weeks) and were confined in common facility in battery cages. Laying hens were reared and fed according to standard breeding technology. Once a month 25 eggs of each line were taken to be examined for eggshell strength and egg weight, or in other words, total 450 table eggs were tested. Analises were done in Laboratory for testing egg quality by gaudges Egg Multi Tester EMT 5200 and Egg shell Gauge (Robotmation Co. Ltd., Tokyo, Japan) which have computerised equipment to examine quality and physical characteristics of eggs. Statistic analyses on results were done by computer sub-programme ANOVA and Fisher's LSD test to determine the level of statistical significant difference between examined factors. Egg weight was under significant impact of age (P ? 0,05), but not under the influence of strain, although eggs of ISA Brown line were insignificantly heavier than eggs of DeKalb White line. Eggs were heaviest at layers with older age, while they were lightest at younger birds. The results have shown significant differences (P ? 0,05) in eggshell strength compared to line influence (genotype) and months of age. Eggs from ISA Brown laying hens had much better and eggshell strength than those eggs from DeKalb White. Correlations between eggshell strength and egg weight were with significant (R < 0,05) negative value, which indicating that with increasing egg weight decreases of eggshell strength.
The effects of ambient temperatures and hen's age were investigated on poultry farm on the south of R.Macedonia, where annually average temperature was higher then other regions. In nine-month period of testing were included summer, autumn and winter season. Two groups of hens (ISA-BROWN) were used; the first one was younger (to 45-week age) and second was older (above 45-weeks). Once a month, about 100 eggs were examined, so the final number of tested eggs was 877. Average shape index was 75.19% for all eggs. High significance (p<0.01) showed both factors: age and season. Eggs from younger hens had index value of 76.16%, which is pointed on eggs with rounded shape, while older hen's eggs had index 74.20% with elongated shape. In summer and autumn season, most of eggs were with elongated shape, while rounded shape had eggs in winter season.
Abstract:In this work quantity of abdominal fat (weight and portion) was examined in broilers of two genotypes in the fifth, sixth and seventh week of their growth. The examination was carried out in production conditions, in the facility for commercial fattening of broilers chickens, so all technical recommendations related to intensive rearing of chickens were provided. Broilers Cobb 500 and Hubbard Classic which were housed in separate boxes (8 boxes for each genotype) were used as a material. Forty male chickens and forty female chickens at the 5, 6 and 7 weeks of age were selected for slaughtering by random selection, so 240 all together sacrificed chickens were prepared for further treatment. By cutting of the carcasses, abdominal fat was removed and measured, and it was put in proportion to the body mass before slaughtering and in this way the share of abdominal fat was obtained. All data was statistically processed by the subprogram Basic Statistic and Anova. The chickens of the genotype Hubbard had significantly higher share (0,96%) and insignificantly higher weight (19,47g) of abdominal fat than Cobb 500 (0,83% and 17,16g). Female chickens of both genotypes in the examination had significantly higher weight (19,84g) and share (0,96%) of abdominal fat in carcass then male broilers. Chickens at the age of 49 days had statistically significantlly higher abdominal fat than the chick at the age of 42 and 35 days in absolute (25,35g) and relative values (1,06%). This confirms the importance of the examined factors on the amount of abdominal fat in carcass of broiler chickens.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.