The Effects of Supplementation of Bergamot Oil (Citrus bergamia) on Egg Production, Egg Quality, Fatty Acid Composition of Egg yolk in Laying Hens

The impact of dietary oregano essential oil supplementation on fatty acid composition and lipid stability in eggs stored at room temperature

*1. In many countries, eggs are not refrigerated and must be stored at room temperature. The objective of this study was to explore the effects of dietary oregano oil (275 mg/ kg; ORE) versus an unsupplemented control diet (CON) on laying hens on the shelf life and fatty acid profile of eggs.2. Treatments were randomly distributed into 10 pens containing 27 birds each. A total of 200 eggs were collected from both groups on the same day and were stored for either 0, 10, 21 and 35 d. At each storage time, egg yolks were analysed for fatty acid profile and lipid peroxidation.3. The main indicator of lipid peroxidation, malondialdehyde (MDA), was significantly lower in ORE eggs compared to CON eggs (p = 0.001). Storage time had a significant impact on MDA concentrations (p = 0.023), with the highest found after 35 d. Significant differences were found for individual fatty acids, saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA). Palmitic acid, stearic acid, oleic acid, linoleic acid and arachidonic acid were significantly lower in ORE eggs compared to CON eggs (p < 0.05). Palmitoleic acid (p = 0.002), linolenic acid (p = 0.001) and docosahexaenoic acid (DHA, p = 0.001) were significantly higher in ORE eggs.4. Storage only affected oleic, linolenic, linoleic, arachidonic and docosahexaenoic acids (p < 0.05). Total SFA, MUFA, n-6 and ratio of n-3 to n-6 (n-3:n-6) PUFA were significantly higher in CON eggs (p < 0.05). The ratio of SFA to PUFA (SFA:PUFA, p = 0.005) and total n-3 PUFA (p = 0.001) were significantly higher in ORE eggs.5. The n-3:n-6 ratio was significantly impacted by treatment (p = 0.021) and storage (p = 0.031) with no significant interaction. This ratio is important for human health indication and could lead to the development of designer eggs.

Effects of essential oils on heat-stressed poultry: A review

While certain animal species are sensitive to heat stress, poultry particularly modern breeds, are more susceptible to high ambient temperatures. This has major implications for the poultry industry, as heat stress causes large financial losses. These economic losses will probably increase as a consequence of a predicted rise in global temperatures. Heat stress adversely affects various aspects of poultry, including physiological responses, growth and production performance, meat quality, egg quality, and reproductive activities. These effects occur through specific molecular and metabolic pathways. To mitigate the impacts of heat stress, it is crucial to go beyond administrative practices and implement dietary interventions during high ambient temperature. Such interventions aim to optimize the development of stressed bird species in terms of performance, health, and profitability. Essential oils have shown promising in mitigating the negative effects of heat stress and improved antioxidant status, growth and yield performance, as well as meat and egg quality in poultry. They actively participate in certain metabolic and molecular pathways that help to counteract the effects of heat stress. The article discusses the impacts of essential oil supplementation on the relationships between antioxidant enzyme activity, these molecular, and metabolic pathways, as well as various parameters such as growth and yield performance, and product quality heat-stressed poultry.

Thymol and carvacrol supplementation in poultry health and performance

BACKGROUND

Thymol and carvacrol as natural essential oils and phenol compounds are components derived from some medicinal plants, such as thyme and oregano species.

OBJECTIVES

The increasing demands in organic and healthy meat and egg consumption in human society have made it necessary to consider alternative natural compounds for the replacement of chemical compounds in poultry production. The chemical compounds can remain in meat and eggs and cause complications in human health. Therefore, these natural compounds can be fed with a higher safety in poultry production with specific effects. In this regard, the role of thymol and carvacrol as natural compounds in the poultry production has been discussed in the review.

METHODS

In this study, by searching for keywords related to thymol and carvacrol in poultry production in Google Scholar database, the articles related to different aspects of the biological effects of these two phytogenes in poultry production were selected and analyzed.

RESULTS

A review of previous studies has shown that thymol and carvacrol possess a wide range of biological activities, including antibacterial, antiviral, antioxidant, anti-inflammatory, modulating of immunity response and regulating of the gut microbial population. Also, in meat type chickens can promote growth and influence feed utilization. The beneficial effect of this compound was evaluated in hepatic toxicity and demonstrated as a hepatoprotective compound in chickens. Furthermore, these compounds can affect the behavior of layers and influence egg composition, eggshell thickness, and the sensory quality of eggs.

CONCLUSION

It seems that with the increasing demand for healthy protein products, these compounds can be used to improve performance as a substitute alternative for chemical compounds in healthy poultry farms.

Consequences of various housing systems and dietary supplementation of thymol, carvacrol, and euganol on performance, egg quality, blood chemistry, and antioxidant parameters

The present work was carried out to investigate the influences of housing system and dietary essential oils (EOs) supplementation to laying hens on the productive performance, egg quality, immunity, antioxidant parameters, and hematology. A factorial arrangement (2 × 4) was performed, including 2 housing systems and 4 different types of EOs (without EOs, thymol, carvacrol, and euganol) during the production stages (from 28–78 wk of age). Birds were randomly divided into 2 groups with each of 2,000 birds. The first group was moved to laying cages while the second group was a floor reared. Each group was randomly divided into 4 groups (5 replicates of 100 birds each): The first were considered as a control group, and the second, third, and fourth groups were treated with thymol, carvacrol, and euganol EO, respectively. The results showed that hens reared in cage system had higher egg weight (P < 0.05), egg production, egg mass, and feed intake and better feed conversion ratio (P < 0.001) than those reared in the floor system. Blood picture values (except white blood cells), phagocytic index, phagocytic activity, and blood chemistry parameters (except calcium, phosphorus, and urea values) of laying hens were not affected (P > 0.05) by housing system. The groups fed EOs showed a rapid improvement (P < 0.001) in the egg production%, egg weight, egg mass, and egg quality. Thymol group had the highest egg production (P < 0.001). Thymol and eugenol groups had the highest egg weight, egg mass, and egg quality (P < 0.001). The groups fed diets containing thymol or eugenol consumed lower feed and had better feed conversion ratio (P < 0.001) than the control group. Immunity indices (phagocytic activity [P < 0.05], avian influenza [AIH5 and AIH9], P < 0.001) were improved with the presence of EOs in the laying hen diet. These results strongly suggest that dietary EO supplementation could be a successful attempt to improve the productive performance, egg quality, and immunity of laying hens.

Use of Tea Tree Essential Oil (Melaleuca alternifolia) in Laying Hen’s Nutrition on Performance and Egg Fatty Acid Profile as a Promising Sustainable Organic Agricultural Tool

The level of production in a variety of organic production systems is often lower than in other traditional production systems. In poultry production, there is also a direct negative effect of the small scale regarding sustainable organic poultry production. Regardless of differences between organic and conventional production systems, this experiment aimed to investigate the usage of tea tree Melaleuca alternifolia (Maiden and Betche) Cheel essential oils as a natural alternative to antibiotics in hen nutrition on productive parameters, table egg quality and eggs fatty acid profile as a promising sustainable organic agricultural tool. A total of 360 Lohmann Brown hens, aged 54 weeks, divided into three different treatment diets, were supplemented with 0 (T1), 40 (T2) and 80 mg/kg (T3) of M. alternifolia essential oil, respectively. Experimental treatments were replicated four times within 30 birds each. The experiment lasted for a total of 56 days (55 to 62 weeks of hens age). A 56-day experimental had two timetable periods of 28 days each: period 1 (55 to 58 weeks of hen age) and period 2 (59 to 62 weeks of hen age). For compound feed supplemented with M. alternifolia essential oil, daily egg production and the efficiency of nutrient utilization (FCR) was improved significantly (p < 0.05) until the end of week 58, with a significant (p < 0.05) increase in the thickness of eggshell, as well as egg production (p < 0.05). However, egg mass, feed consumption, FCR and albumen height, Haugh unit, and eggshell strength did not show any significant (p > 0.05) differences influenced by essential oil feed supplementation. Lower concentrations of saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA), and higher concentrations of polyunsaturated fatty acid (PUFA), were recorded with M. alternifolia essential oil supplementation, but without significant (p > 0.05) differences. At the end of the experiment, the obtained results showed that the addition of M. alternifolia essential oil to hen nutrition had a positive effect on production parameters and eggs fatty acid profile, with increased eggshell thickness (p < 0.05).

Citrullus lanatus essential oils inclusion in diets elicit nutraceutical effects on egg production, egg quality, and physiological characteristics in layer hens

The study evaluated the effects of Citrullus lanatus essential oils inclusion in diet on egg production, egg quality, and physiological parameters in layer hens. A total of 72 White Leghorn point-of-lay hens at 18 wk were used for the study. The hens were randomly allocated to following 3 dietary treatments: 1) commercial layer diet (control), 2) commercial diet + 1 g C. lanatus essential oil/kg feed (1gCL), and 3) commercial diet + 2 g C. lanatus essential oil/kg feed (2gCL). Each treatment was replicated 8 times arranged in completely randomized design. From the results, an increase in total weight gain, average daily feed intake, and average daily gain was observed with inclusion of the C. lanatus essential oil. In addition, the inclusion of C. lanatus in diet improved the egg mass and feed conversion ratio (FCR). Hens fed C. lanatus-containing diets had higher egg mass (1gCL, 53.35 g ± 0.71; 2gCL, 53.99 ± 0.71 g) compared with the control (52.90 ± 0.71). The C. lanatus containing diets also had lower FCR than the control (1gCL [2.18 ± 0.22] and 2gCL [2.16 ± 0.22] vs. control [2.20 ± 0.71]). With regards to egg quality parameters, inclusion of C. lanatus oil appeared to reduce shell weight and shell ratio, while increasing albumen height and Haugh unit. Diets containing C. lanatus had significantly higher amounts of stearic acid, and linoleic acid was highest (P < 0.05) in the 2gCL fed hens. Birds fed the 2gCL diet (15.29 ± 0.60) had the highest total polyunsaturated fatty acids, total n-6 fatty acids (14.81 ± 0.59) and also had the highest n-6/n-3 ratio. An increase hematological values was observed with inclusion of C. lanatus essential oils in diets. Moreover, tibia bone parameters were also significantly improved with inclusion of C. lanatus essential oils in diets. It can be concluded that C. lanatus essential oil positively affected egg production, and quality and health of layer hens can be used successfully as a natural feed additive.

Effects of bergamot (Citrus bergamia) peel oil-supplemented diets on growth performance, haematology and serum biochemical parameters of Nile tilapia (Oreochromis niloticus)

The present study investigated the effects of dietary Citrus bergamia peel oil (CBO) on growth performance, haematological and serum biochemical responses of Nile tilapia, Oreochromis niloticus. Volatile content of C. bergamia peel oil used in study was detected with GC/MS. The 99.47% of the analysed volatile components were identified in decreasing quantities as limonene, linalool and linalyl acetate. The experimental fish were divided into four groups stocked into triplicate tanks (20 fish/tank), and fed daily with an additive-free basal diet containing 0% (CBO₀), 0.5% (CBO_0.5), 1.0% (CBO₁), 2.0% (CBO₂) of bergamot peel oil for an 8-week period. Results showed that dietary bergamot peel oil especially at 0.5 g 100 g^-1 significantly increased growth performance of fish (p < 0.05). The levels of haemoglobin and haematocrit significantly increased in fish fed with CBO_0.5 and CBO₁ compared with the CBO₀-fed group (p < 0.05), despite no significant difference was observed in CBO₂ group (p > 0.05). Highest haematocrit value was found in the CBO_0.5 group compared with the control group. The serum glucose of the fish fed with CBO_0.5 and CBO₁ feeds decreased significantly compared with the control group (p < 0.05). The highest total protein, lowest cholesterol and triglyceride in serum were observed in fish fed with bergamot oil-supplemented groups. According to the results, it was revealed that 0.5% bergamot oil supplementation to Nile tilapia diets optimizes the growth performance, feed utilization and health status related with blood parameters of the fish.

Effects of selected feed additives on the performance of laying hens given a diet rich in maize dried distiller's grains with solubles (DDGS)

1. A total of 192 ISA Brown hens were given diets containing a high concentration of maize dried distiller's grains with solubles (DDGS) and the effect of selected feed additives on laying performance and egg quality was determined. 2. Birds were allocated to 8 treatment groups with 12 replicates (cages) of two hens and were given, from week 26 to 55, iso-caloric and iso-nitrogenous experimental diets with or without a high concentration of DDGS (200 g/kg). The diet containing DDGS was not supplemented or supplemented with enzymes (xylanase and phytase), sodium butyrate, probiotic bacteria (Lactobacillus salivarius) and a mixture of herbal extracts (Taraxaci siccum, Urticae siccum and Salviae siccum), inulin or chitosan. 3. The inclusion of DDGS in the diet had no effect on number of eggs produced, total egg mass, mean egg weight, feed intake or feed conversion ratio. Egg and eggshell quality parameters were also unaffected by dietary DDGS. The yolk colour score (points in Roche scale) was significantly increased by DDGS inclusion. DDGS in the diet caused some changes in the yolk lipid profile that were rather unfavourable from a dietary perspective (an increase of cholesterol content, and PUFA n-6/PUFA n-3 ratio). 4. During the experimental period (26-55 weeks of age) supplementation of the diet containing a high concentration of DDGS with enzymes, inulin as well as chitosan, increased number of eggs produced and daily egg mass. In older hens (50 weeks of age) inulin positively affected eggshell quality parameters, i.e. shell percentage, thickness and density. Diet supplementation with herb extracts, inulin or chitosan, decreased the content of cholesterol in yolks. 5. The results of this study suggest that DDGS may be incorporated up to a concentration of 200 g/kg in the diet of laying hens without any negative effects on egg performance. Moreover, supplementation of xylanase and phytase, as well as inulin and chitosan, can positively affect the performance of layers given diets with a high concentration of DDGS.