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Enhancing the quality of eggs by using natural food sources has become a very important topic in the last decade. The objective of this study was to determine the influence of natural (marigold and paprika extracts) pigments on the shelf life of eggs from laying hens. This research was carried out for a 6-week period on 168 Lohmann Brown laying hens (45 weeks age) divided into four groups (C, E1, E2 and E3) to assess the performances, external and internal egg quality parameters, egg yolk color, and antioxidant profile. The control group (C) was fed a standard diet (16.39% PB, 2750 kcal EM/kg compound feed) and the experimental diets were supplemented with 0.07% marigold extract (E1), 0.07% paprika extract (E2), and a mixture containing 0.07% of both extracts (E3). In summary, the study demonstrated that adding natural pigments from marigold and paprika extract with highly antioxidant lipid capacity into the diets of laying hens improved egg quality when eggs were stored at 28 days, under both storage temperature conditions (4 °C and 20 °C). [ABSTRACT FROM AUTHOR]

This study was conducted to test the effect of two levels of rosehip meal used together with flaxseed meal on weekly production performances and blood parameters of laying hens. For that, we conducted a trial for 5 weeks on 120 laying hens (Tetra SL hybrid), aged 29 weeks. All three diets had 17.50% crude protein and 2780Kcal/kg metabolizable energy, but compared to the control diet (Con) the experimental diets contained 1.5% rosehip meal and 7% flaxseed meal (Diet1) or, 3% rosehip meal and 7% flaxseed meal (Diet2). The results revealed that only feed intake was significantly (P=0.0001) affected, being lower in experimental groups. Among the haematological parameters, the heterophile were significantly higher (P=0.0377) in both Diet1 and Diet2 groups versus the Con group. From the biochemical parameters analysed, in the lipid profile, glucose and triglycerides were significantly lower in the Diet2 group compared with both the Diet1 and Con groups. Total bilirubin was significantly higher (P=0.0020) in the Diet1 group compared to the Con and Diet2 groups, while the lactate dehydrogenase was lower (P=0.0414) in the samples of the Diet2 group. Overall, the studied ingredients had a slight influence on production performances and improved some blood parameters, especially the lipid profile of the Diet2 group. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the effects of dietary inclusion of yeast, parsley and inulin, as sources of natural antioxidants in poultry diets, on the enrichment of antioxidant nutrients in the egg yolk and on the susceptibility of the yolk to lipid peroxidation during storage. The experiment was conducted on 47-week-old TETRA SL LL laying hens,reared in high temperature (30°C). Experimental dietary treatments differed from control diet (C) by addition of 1% yeast, 2% parsley and 1% yeast or 2% inulin and 1%parsley. The addition of yeast and inulin in laying hens’ diets significantly increased the zinc content in the yolk eggs. The use of yeast and parsley in laying hens’ diets increase the total polyphenol content, vitamin E, lutein and zeaxanthin and concentrations in the egg yolks. In regards to the oxidative stability parameters, a significant decrease in the concentrations of primary oxidation products formed in the egg yolk of experimental groups was seen, proving an efficient inhibition effect of the phytoadditives on peroxyl radical formation. A significant correlation was observed between oxidation products and total polyphenol content of the egg yolks, where lutein and zeaxanthin inhibit the formation oxidation products. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of natural tannins in laying hens' diets on production parameters and the alterations of eggs' physical properties during storage time and temperature. A six weeks experiment was carried out on 168 Lohmann Brown laying hens, 51 weeks of age, accommodated within digestibility cages, structured on 3 levels. The dietary basic structure was the same for all 3 tested groups. The difference between the experimental and control groups was established by the type of plant additive added E1 (0.5% chestnut flour) vs. E2 (0.5% bark oak). At the end of the experiment, 36 eggs/group were collected to evaluate internal and external quality parameters of eggs during storage. These eggs were divided into two parts: 18 eggs/group were kept at room temperature (22°C) and 18 eggs/group were kept in the refrigerator (4°C) for 42 days and analysed to determine shelf time. The results obtained showed that the physical parameters of eggs laid by hens fed with diets supplemented with natural source of tannins (chestnut powder and oak bark) were improved in terms of Haugh Units, yolk colour and eggshell thickness, but only in refrigeration storage conditions. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the effects of dietary inclusion of parsley and inulin, as sources of natural antioxidants in poultry diets, on the enrichment of antioxidant nutrients in the egg yolk and on the susceptibility of the yolk to lipid peroxidation during storage. The experiment was conducted on 47-week-old TETRA SL LL laying hens, reared in high temperature (30°C). Experimental dietary treatments differed from control diet (C) by addition of 2% parsley or 2% inulin. The addition of parsley and inulin in laying hens' diets significantly decreased the iron content in the yolk eggs and increase the total polyphenol content, vitamin E, lutein and zeaxanthin and concentrations in the egg yolks. In regards to the oxidative stability parameters, a significant decrease in the concentrations of primary oxidation products formed in the egg yolk of experimental groups was seen, proving an efficient inhibition effect of the phytoadditives on peroxyl radical formation. A significant correlation was observed between oxidation products and total polyphenol content of the egg yolks, where lutein and zeaxanthin inhibit the formation oxidation products. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of rosehip leaves (RL) supplementation on the production performances and egg quality of laying hens during the first stage of laying. For that, 90 Lohmann Brown Classic hens, aged 26 wk, were randomly assigned to 3 dietary treatments as follows: a control diet (RL0), an experimental diet containing 0.5% rosehip leaves (RL0.5), and an experimental diet containing 1% rosehip leaves (RL1). The laying hens were accommodated in an experimental hall with identical pens (3.96 m2), and controlled microclimate conditions. The dietary treatments were administered for a 6-wk experimental period (26–32 d of age). During this time, production performance of hens was recorded. To assess the impact of RL on egg weight and its components evolution, egg yolk and albumen color, and primary chemical composition of egg constituents were determined every 2 wk. The effect on egg yolk fatty acids profile was determined only at the end of the trial. The results showed that RL0.5 and RL1 dietary treatments significantly improved laying rate, feed conversion ratio and egg mass compared with RL0 group. A significant effect on egg weight and its components was observed only over time, showing that RL has no effect on these parameters. Significant changes in egg yolk coloration were observed over time, with significant increases in L*, a* and b* chromomeric parameters in both RL0.5 and RL1 compared to RL0. Significant alterations were obtained from the sum of egg yolk fatty acids. The RL1 egg yolk presented significantly higher n-3, and significantly lower n-6 fatty acids, compared with both RL0 and RL0.5. Further research is warranted to explore the long-term effects of rosehip leaf supplementation on laying hens performance and egg quality. [ABSTRACT FROM AUTHOR]

Microalgae represent a new field of interest for laying hens' nutrition as they constitute a novel and valuable nutrient source, due to their nutritional composition and richness in polyphenols, polysaccharides and fatty and amino acids. Many studies have studied the effect of using microalgae in laying hen nutrition and their ability to improve health, production and egg quality. Propolis, like microalgae, is a natural source of nutrients with a long tradition in natural medicine. The literature has shown many benefits of using propolis in the diets of laying hens, such as improved productive performance and egg production, health, egg quality. This review makes it clear that including microalgae and propolis in laying hen diet can be an undeniable future nutritional strategy, enhancing standard feed formulations to the benefit of health and egg quality. [ABSTRACT FROM AUTHOR]

Liposoluble vitamins play an important role in poultry metabolism. Vitamin A assures normal growth and development, reproduction performances, and immune function. Vitamin D is requested for proper calcium absorption, prevents oxidative stress, and helps the immune system. Also, vitamin E, which cannot be synthesized by poultry, is crucial for growth and reproduction, improves the immunity system, efficient against oxidative stability. Vitamin K is a key factor for the blood clotting process, has anti-inflammatory effects, and improves bone quality and feed efficiency. Vitamin requirements in laying hens' diets increased compared to the minimum levels published 28 years ago in National Research Council, therefore became vital to update it. Due to the poultry and feed industry's increasing challenges and demands the present requirements must sustain the development and productive potential of modern poultry strains. Therefore it is mandatory that experimental data with different inclusion levels of liposoluble vitamins and with positive effects on growth, production, and health parameters be taken into consideration. Certainly, updated information about liposoluble vitamin variability and efficiency transfer rate from diet to egg would help tremendously the farmers interested in foods biofortification by dietary vitamin supplementation. Overall, liposoluble vitamins are considered essential micronutrients very important to assure balanced poultry nutrition that provides an optimized animal status health. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the transfer of bioactive compounds from sea buckthorn meal (SBM) supplement to eggs and the effect on lipid quality and peroxidation process. Thirty-two weeks old TETRA SL laying hens were allocated to two dietary treatments, 30 birds each (15 replicate pens). The control diet (C) contained a maize-soybean diet and the experimental diet contained the previous C diet with 2% of maize replaced with SBM. Thirty-six eggs from each group were collected in order to determine the quality parameters at the end of experiment. The antioxidant profile of SBM showed that the phytoadditive is a valuable source of vitamin E, xanthophylls and polyphenols. The inclusion of 2% of SBM in the experimental diet led to a more than 25% increase of vitamin E and an almost 50% increase of xanthophylls compared to the control. The markers specific to the coronary risk decreased significantly in the experimental group compared to the control, showing a beneficial effect of dietary SBM on the quality of yolk lipids. The bioactive compounds detected in egg yolk showed a significant (P < 0.05) improvement of the antioxidant profile, the rate of vitamin (A and E), carotenoid (lutein and zeaxanthin) and mineral (iron and zinc) deposition increased after dietary SBM inclusion. Regarding the lipid peroxidation parameters, the dietary SBM inclusion acted in the first phase of the lipid peroxidation process by inhibiting the formation of primary oxidation products (hydroperoxides and conjugated dienes). In conclusion, the sea buckthorn supplementation of laying hen diet improved the bioactive compound concentrations in eggs and delayed the oxidation process of yolk during storage. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the effects of dietary supplementation with tomato peels (TP) and rosehip meal (RM) on their phytochemicals transfer to the egg, the antioxidant profile and the markers of lipid peroxidation in stored eggs. The experiment was conducted on 42-week-old TETRA SL laying hens, which were assigned to three dietary treatments with 30 birds each: the Control group (CON) received a corn-soybean diet containing 6% flaxseed meal without any by-product addition. Groups TP and RM received Diet CON with additionally 2% TP and 2% RM, respectively. Average daily feed intake, feed conversion ratio and laying percentage were not significantly changed by the dietary treatments. Compared to the other groups, the inclusion of dietary TP led to a significant increase in egg weight (p < 0.05) and vitamin E content in eggs (p < 0.05). The dietary inclusion of RM generated a higher vitamin A content in eggs compared to Groups CON and TP (p < 0.10). After 40 d of storage, in Groups CON, TP and RM the vitamin E contents of eggs deceased by 10.1%, 14.2% and 13.3%, respectively, whereas the reduction of the lutein and zeaxanthin concentration in eggs was more pronounced (by 24.8%, 21.8% and 25.5%, respectively). For the most primary as well as for secondary oxidation products, storage time had a significant influence (p < 0.05) on the degradation process of the eggs. After 40 d of storage, the most distinct reduction in the formation rate of secondary oxidation products was observed in Group RM (by more than 30%), while the reduction for Group TP amounted from 15% to 25%, when compared with Group CON. Therefore, the results of the present study showed a significantly positive effect of RM in retarding the lipid peroxidation process during storage. [ABSTRACT FROM AUTHOR]

The aim of this study, carried out on 60 TETRA SL (32 weeks old) laying hens, was to determine the effect of dietary plant mixture (sea buckthorn meal (50%), walnut leaves (25%) and bilberry leaves (25%)) on egg quality. The birds were allocated in two experimental groups, 30 birds each. The control group (C) was fed a conventional diet, without the experimental additive. All diets had similar levels of protein (18.90% (C) and 18.55% (E)) and energy (3962 Kcal/Kg (C) and 4009 Kcal/Kg gross energy (E)). Diet of hens from experimental group was supplemented with 1.0% of plant mixture. In the experimental period, 18 eggs from each group were collected twice (week 2 and 4 of experiment). Eggs were analyzed for proximate composition contents. The experimental group additions of plant mixture increased the crude protein in egg yolk and decreased the crude fat. Our results show that addition of 1.0% plant mixture improved the quality of eggs and it can be recommended in feed for laying hens. [ABSTRACT FROM AUTHOR]

Four plants have been characterized physico-chemical as vegetal phytoadditives (blueberry leaves, walnut leaves, marigold and buckthorn meal) in order to determine their nutritional value for inclusion in laying hens diets as possible alternatives to the use of antibiotics in poultry feed. Chemical determinations revealed a variable protein content ranging between 6.76% (blueberry leaves) and 14.14% (buckthorn meal). Marigolds had significantly higher iron content (1262.54 ppm) and blueberry leaves showed high concentrations of manganese (1410.10 ppm) and zinc (40.37 ppm). The walnut leaves were characterized by high concentrations of: calcium (2.01%), lutein + zeaxanthin (264.10 ppm), total polyphenols (53.94 mg EAG/g) and polyunsaturated fatty acids, especially a-linolenic acid (13.45 g/100 g total fatty acids). The studied phytoadditives will be evaluated in a digestibility trial for their nutritional assessment in laying hens diets. [ABSTRACT FROM AUTHOR]

A 4-week feeding trial was conducted on 48 Lohmann Brown layers (55 weeks) to evaluate the effect on zootechnical parameters and coefficients of apparent absorption of micronutrients (Cu, Fe, Mn, Zn). The layers, assigned to 2 groups, were housed in three-tier digestibility cages (4 layers/cage) which allowed the daily recording of the feed intake and excreta, located in an experimental hall under controlled environmental conditions (temperature: 22.41±0.980C; humidity: 66.35±5.68%; ventilation/chick 0.50±0.24%; CO2 level 686.39±104.38 ppm) and 16h/24h light regimen. The control group (C) received a conventional diet (2760 kcal/kg metabolizable energy and 16.8% crude protein). Compared to C formulation, the experimental diet (E) included 0.50% oils mixture (20% buckthorn oil, 20% sesame oil, 20% rosehip oil, 20% grape oil and 20% walnut oil). The daily feed intake (at weeks 3 and 4) recorded significant decreases (P≤0.05) in group E (113.29 respectively 114.38 g/chick/day) compared to C group (115 respectively 116.13 g/chick/day). Copper absorption in E group was significantly (P≤0.05) higher (with 32.21%) than in C group, which means that the concentrations of Cu in the excreta significantly (P≤0.05) decreased in E group (0.36 mg/chick/day) compared to C group (0.52 mg/chick/day). This is a positive aspect regarding the soil pollution with Cu. For Fe and Mn, the mineral concentrations in the excretion did not differ significantly (P≥0.05), showing that the supplement administered in the E diet did not affect the possible mineral load at the soil level. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate effects of organic sources of manganese (Mn) and iron (Fe) and inulin in diets for laying hens on absorption of these minerals and their deposition in egg and tissue. The study was conducted on 90 Lohmann Brown laying hens in the period from 46-52 weeks of age, assigned to 3 groups with 30 hens/group and 3 hens/cage. The hens from the control group (C) received a diet based on corn, rice bran and soybean meal with 16% of crude protein, as well as 60 mg Fe/kg and 71.9 mg Mn/kg of diet in form of inorganic salts. The formulation of the experimental diets (E1 and E2) differed from C group diet by the replacement of inorganic Fe and Mn salts by organometallic chelates of these elements, at a level of 25% lower than in the premix for group C. As source of inulin, group E1 diet also included 0.5% of dry Jerusalem artichoke, while group E2 diet included 0.5% of a product based on chicory root extract. At the end of the experiment, 6 hens from each group were slaughtered and blood serum and liver samples were collected and assayed for concentration of Fe and Mn. In the final week of the experiment, 18 eggs/group were collected for determination of Fe and Mn concentration in egg yolk. Concentration of measured blood serum parameters (haemoglobin, haematocrit, Fe and Mn) in experimental (E) groups were lower than in group C, but no significant differences (P>0.05) were registered. Absorption coefficients of Mn had higher values in E groups than in group C, with significant increase (P<0.05) registered in group E2. Absorption coefficients of Fe had significantly lower (P<0.05) values for both E groups compared to C group. A significant (P<0.05) increase of Mn concentration in liver was noticed in group E2. No significant differences (P>0.05) between groups were observed for Mn and Fe concentration in egg yolk. [ABSTRACT FROM AUTHOR]

An experiment was conducted on 114 laying hens in order to determine the amino acid apparent digestibility coefficients from diets supplemented with camelina meal, linseed meal and fenugreek seeds. The hens were assigned to 3 groups (C, E1, E2) and housed in metabolic cages (2 hens / cage, 38 hens / group). The control group received a conventional diet for laying hens with the age of 59 weeks. The experimental diets were enriched in PUFA by using 5% linseed meal and 2 % camelina meal (E1); 3% linseed meal, 3 % camelina meal and 1 % fenugreek seed (E2). During the final week of the experiment (for 5 days), the ingesta, the feed leftovers and the droppings were daily recorded with accuracy for each cage, in order to perform the amino acid balance. The digestibility coefficients of the dietary essential amino acids decreased significantly when compared with the control: for lysine 86.85 ± 2.74 % in C, 83.76 ± 3.83 % in E1, 81.34 ± 2.29% in E2; for methionine 87.30 ± 1.43 % in C, 84.48 ± 2.71 in E1, 80.83 ± 1.51% in E2; for cystine 87.30 ± 1.43 in C, 86.66 ± 2.11 % in E1, 86.13 % for E2. The amino acid analysis of laying hen eggs revealed a significant decrease (P≤0.05) of lysine, methionine and cystine in the albumen from E2, and a significant decrease (P≤0.05) of methionine in the yolk from E2, when compared with the control. This fact is correlated with the amino acid digestibility coefficients. The results highlight the decreasing effects of laying hens diets supplemented with oily byproducts on amino acid digestibility. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the influence of Mn and Zn supplements (from organic sources) added to laying hens diets on egg quality. The experiment was conducted for 42 days on 192 Lohmann Brown laying hens (45 weeks old). The birds, housed in cages (2 birds/cage), were divided into 3 groups (C, E1, E2). The three diets had the same basal formulation characterized by 17.96% crude protein and 2724.31 kcal/kg metabolisable energy. The diets for the 3 groups differed by the mineral source, by the level of Mn and Zn from mineral premix, respectively. Diet C had 73 mg Mn (as Mn2O3)/kg feed and 64 mg Zn (as ZnO)/kg feed. Diet E1 used the same level of Mn (as manganese chelate of glycine hydrate with 20% Mn) and Zn (as zinc chelate of glycine hydrate with 25% Zn) as diet C. Diet E2 used two times higher levels of Mn and Zn compared to Lohmann Brown Guide Manual (200 mg Mn and 160 mg Zn/kg feed from organic sources). During this experimental study, every two weeks egg samples were collected randomly (18 eggs/group), and 6 samples of yolk, white and eggshell were formed (3 eggs/sample). The results showed that eggshell breaking strength and eggshell thickness were not significantly (P= 0.05) different between groups. The yolk samples of egg collected from E2 group, contained Zn concentrations significantly (P = 0.05) higher than in groups C, E1 respectively. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the influence of Cu and Zn supplements (organic sources) added to laying hens diets on absorption coefficients and egg yolk concentration. The experiment was conducted for 6 weeks on 192 laying hens, housed in cages (2 birds/cage), divided into 3 groups (C, E1, E2). All batches received a similar basal diet (17.96% CP and 2724,31 kcal/kg ME). Diet E1 used the same level of Cu and Zn as diet C, but in chelated form (6 mg Cu/kg and 60 mg Zn/kg). Compared to C, diet E2 had the same level of Cu (inorganic source) but the Zn concentration was 160 mg /kg from organic source. Every two weeks, egg samples were collected randomly (18 eggs/batch). During the balance weeks, all droppings were daily collected in order to form average weekly samples/cage, from which Cu, Zn was determined by FAAS. The apparent absorption coefficients of Cu did not differ significant, but it was noticed a slight increasing of Cu coefficient for the group which received organic Cu: 20.89% (E1), 18.83% (E2) vs 17.45% (C). Organic source of Zn lead to a better absorption, significant uninsured, for E1 (12.70%) and E2 (15.60%) compared to C (9.07%). Alternatively, the analytical results showed a significant (P⩽0.05) improvement of Zn concentration in egg yolk for E2 (75.86±1.51 mg/kg) compare to C (71.19±2.23 mg/kg) and E1 (73.24±2.24 mg/kg). The chelate source of trace minerals can be a way of obtaining Zn enrichment eggs but only using amounts of Zn above conventional rate. [ABSTRACT FROM AUTHOR]

This experimental study evaluated the supplementation effects of Zn and Mn from laying hens diets on the physical parameters of egg quality. The experiment was conducted for 42 days, on 120 Lohmann Brown laying hens, aged 22 weeks. Birds, accommodated in cages (3 birds/cage), were divided in 4 batches (C, E1, E2, E3). The basal diet (corn, rice, rape meal and soybean meal), identical for all four batches, was characterized by 17.96% protein and 2724.31 kcal/kg metabolisable energy. Diets of the 4 batches differentiated among them by Mn (source MnO) and Zn (source ZnO) levels (mg/kg). Conventional diet of batch C had 71,9 mg Mn/kg NC and 60 mg Zn/kg CF(compound feed). In batch E1 dietary levels of Mn and Zn (85 mg Mn, respectively 145 mg Zn /kg CF) were 5 times higher than NRC requirements, 1994. Batch E2 diet had 100 mg Mn/kg CF and 80 mg Zn/kg CF (according to Lohmann Brown Guide Manual), and batch E3 used double levels in regard to Lohmann Brown Guide Manual (200 mg Mn, respectively 160 mg Zn/kg CF). The results showed that eggshell breaking strength was significantly (P⩽0.05) higher for E3 batch (4,68±0.16 kgF) compared to all other batches. Similarly, E3 batch had a significantly (P⩽0,05) higher Zn concentration in eggshell compared to C and E2 batches. Eggshell thickness was not different between batches. [ABSTRACT FROM AUTHOR]

The experiment was conducted to determine effect of neutral electrolysed water (NEW) in laying hens. 75 Lohmann Brown layers were divided into 3 groups (C, E1 and E2) with 25 layers/group, fed the basal diet. Poultry drinking water was administrated ad-libitum to laying hens, at three levels: 0 (C), 2(E1) and 3% NEW (E2) for 9 weeks. The layers had free access to the feed and water. The daily feed intake of the groups E1 (131.93 ± 5.08 g/day/layer) and E2 (133.97 ± 5.72 g/day/layer) were significantly (P < 0.05) higher than the group C (126.20 ± 5.71 g/day/layer). Egg production and average egg weight were similar among groups. Feed conversion ratio was higher (P < 0.05) for E2 (2.07 ± 0.05 g feed/g egg) than the control group (1.95 ± 0.08 g feed/g egg). Significant difference (P < 0.05) was noticed at the weight of the egg yolk 17.64 ± 1.17 g in group E1 compared to 18.92 ± 0.81 g in group C. Egg white and yolk pH, yolk colour intensity and the Haugh unit were not different among groups. The addition of NEW up to 3% to drinking water did not affect egg production, egg weight and egg quality, yolk weight except. [ABSTRACT FROM AUTHOR]

Simple Summary: Eggs are considered common dietary sources of n-3 polyunsaturated fatty acids (PUFA), but they are susceptible to quality deterioration. In order to reduce oxidation, the best strategy is the addition of antioxidants to hens' diets. Walnut and bilberry co-products, rich in phenolic compounds, are produced in agricultural industries, and are a valuable source of antioxidants for animal nutrition. The dietary inclusion of bilberry and walnut leaves as natural sources of antioxidants in poultry diets led to the accumulation of nutrients with antioxidant activity in the egg yolk, and the susceptibility of the yolk to lipid peroxidation during storage improved. The results of the present study showed that including bilberry and walnut leaves in laying hens' diets enhanced the oxidative stability of the egg yolk and retarded the lipid peroxidation process during storage. The purpose of this study was to examine the effects of dietary inclusion of walnut and bilberry leaves (WL and BL), as sources of natural antioxidants in poultry diets, on the enrichment of antioxidant nutrients in the egg yolk and on the susceptibility of the yolk to lipid peroxidation during storage. The experiment was conducted on 32-week-old TETRA SL LL laying hens, which were assigned to three dietary treatments with 30 birds each. Each treatment was replicated 10 times with three chicks per replicate pen. Experimental dietary treatments differed from control diet (C) by addition of 0.5% BL supplement or 1% WL supplement. The phytoadditives were not significant contributors to the productive parameters. The addition of BL and WL in laying hens' diets significantly increased the total polyphenol content, and the zinc, lutein and zeaxanthin concentrations in the egg yolks. In regards to the oxidative stability parameters, a significant decrease in the concentrations of primary oxidation products formed in the egg yolk of experimental groups was seen, proving an efficient inhibition effect of the phytoadditives on peroxyl radical formation. A significant correlation was observed between primary oxidation products and total polyphenol content of the egg yolks, where zinc, lutein and zeaxanthin are the bioactive compounds that inhibit the formation of secondary oxidation products. [ABSTRACT FROM AUTHOR]

Linseed and camelina seed are used in laying hen diets for obtaining eggs enriched in PUFA, being also a potential source of protein for poultry. The bioavailability of amino acids is an important criterion used to evaluate the efficient utilization of feedstuffs. This study was performed in order to determine the amino acid digestibility coefficients from diets supplemented with oilseeds and fenugreek seeds. An experiment was conducted on 114 laying hens, assigned to 3 groups (C, E1, E2) and housed in metabolic cages (2 hens/cage, 38 hens/group). The hens were fed with a corn-soybean meal based diet. The experimental diets enriched in PUFA were supplemented with 5% linseed and 2% camelina seed (E1), and 2% linseed, 2 % camelina seed and 1% fenugreek seed (E2). During the final week, the ingesta, the feed leftovers and the excreta were daily recorded, in order to form weekly average samples for amino acid balance. The aminoacids were determined by HPLC using a method according to the UE Regulation 152/2009. The digestibility coefficients of the dietary essential aminoacids decreased significantly in E2 (P≤0.05) when compared with the control: for lysine 86.85±2.74% in C, 81.33±1.97% in E2; for methionine 87.30±1.43% in C, 80.99±3.09% in E2; for cystine 87.21±1.40% in C, 85.16±1.48% for E2. The group E1 did not register any significant differences compared with C and E2. The results of this study revealed a decreasing effect on aminoacid digestibility in the group with supplemented fenugreek seed and oilseeds. [ABSTRACT FROM AUTHOR]

Organic trace minerals present a higher bioavailability and stability, therefore lower rates of inclusion in feed will be needed to meet the poultry nutritional requirements which will lead to a lower environmental output. The purpose of this study was to determine the effect of total replacement of the inorganic Mn and Fe salts by organic forms of these elements on nutritional quality of eggs and on apparent absorption coefficients. The study was conducted on 192 laying hens, 2 birds/cage, divided into 3 groups (C, E1, E2). All groups received a similar diet (17.96% crude protein (CP) and 2724.31 kcal/kg metabolizable energy (ME). Diet E1 used the same level of Mn and Fe as diet C, but in chelated form (71.9 mg Mn/kg and 60 mg Fe/kg). Compared to C, diet E2 had the same level of Fe (inorganic source) but the Mn concentration was 200 mg/kg (organic source). Every two weeks, egg samples were collected randomly (18 eggs/group). All droppings were daily collected in order to form average weekly samples/ cage, from which Mn, Fe was determined by FAAS. The analytical results showed a significant (P≤0.05) increasing of Mn concentration in egg yolk for E2 (1.84±0.28 mg/kg) compare to C (1.46±0.16 mg/kg) and E1 (1.59±0.30 mg/ kg). The apparent absorption coefficients of Fe and Mn were higher for E2 compare to the other two groups (E1, C). A possible explanation of these results could be the existent interactions between the trace elements found in animal organism, a high concentration of Mn being able to influence positively the absorption of Fe in organism. The chelate source of trace minerals can be a way of obtaining Mn enrichment eggs but only using amounts of Mn above conventional rate. [ABSTRACT FROM AUTHOR]