Albumen Quality Research Articles

ADIÇÃO DE ÓLEO DE COPAÍBA (Copaifera langsdorffii) E SUCUPIRA (Pterodon emarginatus) NA ALIMENTAÇÃO DE POEDEIRAS: QUALIDADE FÍSICA DE OVOS ARMAZENADOS EM DIFERENTES TEMPERATURAS

Resumo O objetivo deste trabalho foi avaliar os efeitos da adição de óleos vegetais à alimentação de poedeiras semipesadas na qualidade física de ovos armazenados sob refrigeração ® e em temperatura ambiente (TA). As aves receberam ração formulada à base de milho e farelo de soja com a suplementação de níveis crescentes de óleo de Copaifera langsdorffii (CP-0,03; 0,06 e 0,09%) ou Pterodon emarginatus (SC-0,03 e 0,06%) mais um controle negativo (CN). Periodicamente, foram analisados três ovos por tratamento para Unidade Haugh (UH), índice de gema (IG), cor, pH (gema e albúmen) e porcentagens de casca (PC), gema (PG) e albúmen (PA). Para análise estatística dos resultados, foi adotado um modelo misto (SAS 9.3) e as médias foram comparadas pelo teste de Tukey. A inclusão de até CP0,06% CP ou SC0,03% preservou (P<0,05) os valores de UH nos ovos em TA, equivalente aos tratamentos sob R até 14 dias; além disso, a adição dos óleos controlou a elevação do pH das gemas. Concluiu-se que os óleos vegetais suplementados nas dietas de poedeiras influenciaram positivamente na manutenção da qualidade do albúmen e do pH das gemas dos ovos em temperatura ambiente, contudo nenhum efeito adicional foi verificado para os ovos mantidos sob refrigeração.

Hens ranked as highly feed efficient have an improved albumen quality profile and increased polyunsaturated fatty acids in the yolk1

The shelf life of eggs that contain elevated levels of polyunsaturated fatty acids (PUFA) is compromised due to the relative instability and therefore greater potential for lipid peroxidation of unsaturated fatty acids (FA). Poultry that is highly feed efficiency (HFE) exhibits higher systemic levels of antioxidant enzymes and therefore may produce eggs with improved albumen quality and favorable FA profiles that are stable over time. We tested the hypothesis that HFE-laying hens produce eggs with improved internal egg quality and a favorable yolk FA profile prior to and following storage. Following an initial screening phase (7 wk) using 140 Isa Brown layers (28 wk old), the 10 most efficient (FCR < 1.99 ± 0.05) and the 10 least efficient (FCR > 2.30 ± 0.05) hens were identified and designated as HFE and low feed efficiency (LFE) groups, respectively. Internal quality and composition were determined on eggs (n = 10 per group) stored at 15 °C for 0, 14, and 28 d. At 0, 14, and 28 d, the albumen weight, albumen height, Haugh unit (HU), and albumen:yolk ratio of eggs from the HFE group were significantly higher (P < 0.01), whereas the eggs from the LFE group had heavier (P < 0.01) yolk than the HFE group. After 28-d storage, the yolk color score of the LFE group was lower (paler; P < 0.05) compared with that of the HFE group. The relative proportions of total PUFA and the ratio of total PUFA and total saturated fatty acids (SFA) were higher (P < 0.05) in HFE group of eggs. The LFE group of eggs contained higher (P < 0.05) levels of lipid peroxidation marker (thiobarbituric acid reactive substances; TBARS) values both in fresh and in stored eggs. The results suggest that HFE hens produce eggs with greater albumen quality and higher levels of yolk PUFA both at lay and after storage.

Dietary tea polyphenol supplementation improved egg production performance, albumen quality, and magnum morphology of Hy-Line Brown hens during the late laying period.

The aim of this study was to investigate how dietary supplementation of tea polyphenols (TP) and tea catechins (TC) affect laying performance, albumen quality, ovomucin composition, and magnum morphology of laying hens in the late phase of production. Two hundred seventy Hy-Line Brown laying hens (64 wk old) were assigned to a basal diet (the control), the basal diet supplemented with 200 mg/kg tea polyphenols (TP200) or 200 mg/kg tea catechins (TC200). Each treatment had 6 replicates with 15 hens each. The feeding trial lasted 10 wks. Over the course of the trial, dietary supplementation with TP200 significantly increased the egg production (EP) and improved the feed conversion ratio (FCR) in wk 6 to 10 and wk 1 to 10 (P < 0.05). The albumen height and the Haugh unit (HU) of hens fed TP200 were higher than those of hens fed the control diet at wks 8 and 10 (P < 0.05). However, there were no significant differences in the albumen height and the HU between the TP200 and TC200 groups (P > 0.05). The SDS-PAGE analysis indicated that bands of the ovomucin fractions in the TP200 group had the highest intensity compared with those of the control and TC200 groups. Compared with the control, there was a significant increase in protein sulfhydryl (SH) content of the albumen in the TP200 group at the end of experiment, while a significant decrease in protein carbonyl content and protein surface hydrophobicity (P < 0.05). There were also obvious increase in the height and width of the primary folds, epithelial cell height, and cilia height of the simple columnar epithelium in the TP200 group compared with the control and TC200 groups (P < 0.05). In conclusion, dietary supplementation with 200 mg/kg TP can improve performance, albumen quality, and magnum morphology of aged hens. In addition, TP rather than TC could improve the health status of the magnum for aged layers.

Quality, protease inhibitor and gelling property of duck egg albumen as affected by storage conditions.

Physicochemical properties, trypsin inhibitory activity, and gelling properties of albumen from duck egg during 15days of storage at 4°C and room temperature (28-30°C) were studied. As the storage time increased, Haugh unit and moisture content decreased, while the pH value increased (P<0.05). The rate of changes was lower at 4°C. Trypsin inhibitory activity in albumen from egg stored at 4°C was higher than that kept at room temperature throughout the storage time (P<0.05). Nevertheless, no differences in protein patterns were observed during the storage. Based on texture profile analysis, the highest hardness, gumminess, and chewiness were found at day 3 for room temperature and at day 6 for 4°C. Higher values were attained for eggs kept at 4°C. Conversely, albumen gels made from eggs stored at room temperature exhibited higher cohesiveness, adhesiveness, springiness, resilience than those kept at 4°C. The gels had the lowered whiteness when eggs were stored for a longer time, particularly at room temperature. Thus, storage condition directly affected the quality of albumen from duck egg.

Productive performance and egg quality of laying hens fed diets supplemented with garlic and onion extracts

SUMMARY The study was aimed at evaluating the effect of supplementing a diet for laying hens with onion and garlic extracts on their productive performance and egg quality. Two-hundred-sixteen laying hens were divided into 3 groups: standard diet, diet with a 0.0032% addition of onion extract, and diet with a 0.0032% addition of garlic extract. The egg production rate, egg weight, and feed conversion ratio were monitored within the first 17 wk of the laying period. In wk 6, 8, 10, 12, 14, and 16 of the laying period, eggs were analyzed for: weight, weight to yolk ratio, yolk color, albumen quality, and eggshell quality. In wk 7 and 15 of the laying period, analyses were conducted for: yolk color, consistency, aroma, and taste of boiled eggs. The addition of a garlic extract had a positive effect on the production rate in the initial and peak egg-laying period, and significantly determined the aroma and, in the further stage of the production process, also taste of boiled eggs. Administration of the diet with onion extract to hens caused them to begin the egg-laying period later but laying heavier eggs, with a higher content of egg yolk and better quality of albumen. The analysis of the productive performance of hens and quality of eggs indicates the advisability of applying the extract from garlic in commercial flocks of laying hens. In the future, it seems substantiated to analyze the effect of extract supplementation at the end of the laying period.

Proteomic comparison by iTRAQ combined with mass spectrometry of egg white proteins in laying hens (Gallus gallus) fed with soybean meal and cottonseed meal.

Cottonseed meal (CSM) is commonly used in hens’ diets to replace soybean meal (SBM). However, the molecular consequences of this substitution remains unclear. To investigate the impact of this substitution at the molecular level, iTRAQ combined with biochemical analysis was performed in Hy-Line W-36 hens supplemented with a mixed diet of CSM and SBM. Egg weight, albumen height, and Haugh unit were significantly reduced in the CSM100 group (100% crude protein of SBM replaced by CSM) compared with the SBM group (P<0.05). A total of 15 proteins, accounting for 75% of egg white proteins with various biological functions of egg whites, were found to be reduced. This finding may relate to the decrease of albumen quality in the CSM100 group. Oviduct magnum morphology and hormone analysis indicated that a reduced level of plasma progesterone caused reduced growth of the tubular gland and epithelial cells in the magnum, further decreasing egg white protein synthesis in the magnum. These findings help demonstrate the molecular mechanisms of a CSM diet that cause adverse effects on albumen quality, while also showing that SBM should not be totally replaced with CSM in a hen diet.

Effect of different protein ingredients on performance, egg quality, organ health, and jejunum morphology of laying hens

The aim of this study was to evaluate the effect of different protein ingredients on performance, egg quality, organ health, and jejunum morphology of laying hens. A total of 216 32-wk-old Hy-Line W36 laying hens with similar egg production was randomly divided into 3 treatment groups with 6 replicates of 12 birds each. The experimental diets were isocaloric (metabolizable energy, 2 655 kcal/kg) and isonitrogenous (crude protein, 16.5%). The control group was fed a corn-soybean meal basal diet (SBM), and the other 2 experimental diets consisted of a basal diet with 195.0 g/kg low-gossypol cottonseed meal (LCSM) or 292.0 g/kg double-zero rapeseed meal (DRM). The feeding trial lasted 12 weeks. The egg production, daily feed intake, egg weight, and feed conversion ratio were not affected (P > 0.05) by diets used. The daily egg mass was decreased in the LCSM group in wk 7 to 12 (P < 0.05). Albumen height, Haugh unit, albumen weight, albumen proportion, and oviduct index were reduced in the 195.0 g/kg LCSM at wk 12 (P < 0.05), while yolk color was increased (P < 0.05). A lower yolk weight, yolk proportion, abdominal fat, dry matter of the liver, and fat content of the liver were observed in the DRM group at wk 12 (P < 0.05). Using LCSM or DRM as a sole protein ingredient in the diet reduced the ovomucin content of albumen when stored 28 d at 4°C. The villous height of the jejunum in the LCSM group was the lowest among treatments (P < 0.05). The mucosal columnar epithelial cell layer of the magnum in the LCSM group was incomplete, and there was a little albumen secretions in the lumen of the magnum. Together, our results suggest that the 195.0 g/kg LCSM diet may produce an adverse effect on daily egg mass and albumen quality. The adverse effect might be associated with the reduction of absorption ability in the jejunum and secretion capacity in the magnum.

Quality of chicken eggs in relation to their weight category

The purpose of this study was to evaluate selected quality traits of chicken eggs in relation to their weight (weight categories). The experimental material comprised eggs from 250 laying hens (♂ New Hampshire x ♀ Barred Rock). The birds were kept in a poultry house on litter in identical hygienic conditions and fed ad libitum the same compound feed, of appropriate nutritional value, during the rearing and egg production period. At 36 weeks of age 160 eggs were taken at random from the hens and divided into four weight categories: below 57.0 g (group A); 57.1 to 60.0 g (group B); 60.1 to 63.0 g (group C) and above 63.0 g (group D). The quality of the albumen, yolk and shell was evaluated and the concentration and hydrolytic activity of lysozyme was determined in individual albumen fractions. Eggs from group D had the highest share of albumen (60.92%) and the smallest share of shell (10.56%). Furthermore, the albumen of these eggs had the greatest weight (40.19 g) and height (6.61 mm), and the yolks had the highest weight (18.13 g) and darkest colour (13.65 pts). The eggs assigned to group B had greater shell thickness (352.46 μm) and strength (38.2 N). Detailed analysis of lysozyme activity showed that the albumen of the group A eggs had the highest lysozyme concentration and hydrolytic activity in both albumen fractions analysed (0.61%; 131,105 U/ml – thin albumen and 0.38%;80,705 U/ml – thick albumen). The study showed that the heaviest eggs had the most favourable traits for the consumer. They were distinguished by good albumen quality (the greatest weight and height) and yolk quality (the greatest weight and darkest colour). Moreover, their shells were fairly thick (352.37 μm) and the least susceptible to deformation (70.90 μm). On the other hand, the albumen of the eggs in the lowest weight category had the highest concentration and hydrolytic activity of lysozyme.

QUALIDADE INTERNA E EXTERNA DE OVOS DE POEDEIRAS COMERCIAIS COM CASCAS NORMAL E VÍTREA

Resumo Objetivou-se com esta pesquisa avaliar a qualidade de ovos de galinhas poedeiras classificados em ovos de casca normal e vítrea, produzidos por galinhas em três idades distintas (30, 50 e 70 semanas). Para cada idade foram amostrados 45 ovos de cada tipo de casca. O peso dos ovos em ambos os tipos de casca aumentou com o avanço da idade da galinha. Maior concentração de cálcio na casca foi encontrada nos ovos de casca normal em relação aos de casca vítrea, o teor de fósforo não foi influenciado pelo tipo de casca. A deposição mineral da casca foi constante. A espessura da casca aumentou independentemente do tipo de casca, ao longo da vida reprodutiva da galinha e diminuiu quando a ave se tornou mais velha. O percentual de albúmen aumentou, enquanto a percentagem de proteína e pH do albúmen diminuiram ao longo das idades. Percentagem da gema, umidade e pH diminuíram com o aumento da idade da poedeira, enquanto proteína bruta e extrato etéreo aumentaram. Os ovos de casca vítrea apresentaram casca de qualidade inferior àqueles de casca normal sem, contudo, haver um comprometimento da qualidade interna dos ovos.

Effect of Feeding and Withdrawal of Vanadium and Vitamin C on Egg Quality and Vanadium Residual Over Time in Laying Hens

This experiment examined the egg quality of hens fed vanadium (V) and vitamin C (VC) during storage, as well as the V and VC withdrawal on egg quality and V residual in egg. A total of 360 laying hens (31weeks old) were randomly allotted into a 3×2 factorial arrangement treatments (6 replicates and 10 chicks per replicate) with three levels of dietary V (0, 5, and 10mg/kg) and two levels of VC (0 and 100mg/kg) for 19weeks (feeding V and VC 12weeks, recovery 7weeks). The V residual in eggs at 4, 8, and 12th weeks were increased (linear effect, P≤0.01) as V levels increased and was not detected in albumen at 7th week after V withdrawal. Followed by 12-week feeding period, albumen height and Haugh unit of eggs during 2-week storage were decreased (linear and quadratic effect, P<0.01) by dietary V supplementation. Lightness value was increased (linear effect, P<0.01), whereas redness and yellowness value of the eggshell were lowered (linear effect, P<0.01) in V-containing diet. During 7-week withdrawal period, eggs from groups pre-feeding 5 and 10mg/kgV had lower (linear effect, P<0.01) overall albumen height and Haugh unit. The reducing effect on albumen height and HU continued to be observed until the seventh week, whereas the bleaching effect on eggshell color disappeared after 1-week withdrawal. The results indicated that feeding 5 or 10mg/kg V increases egg V residual and reduces egg albumen quality and bleached the shell color, and the impaired albumen quality induced by 10mg/kg of V lasted at least 6weeks after changing to no V supplementation diet. The addition of VC did not show to affect egg quality during storage or recovery phase.

Comparative analysis of the external and internal egg quality in different pure chicken breeds

The present study was conducted to evaluate some parameters of external and internal egg quality of some pure dual chicken breeds. A total of 500 eggs (100 eggs from each breed) were collected to study for egg (weight, shape index), albumen (weight, percentage), yolk (weight, percentage) and shell (weight, percentage, thickness, strength) quality. The eggs were analysed in the laboratory of Department of Poultry Science and Small Animal Husbandry of Slovak University of Agriculture in Nitra. The results showed that the egg weight and egg length of New Hampshire were significantly higher (P 0.05). Differences in albumen weight, albumen percentage, yolk weight and yolk percentage of tested dual chicken breeds were statistically no significant (P>0.05). Albumen height was significantly higher (P 0.05) in egg shell thickness and strength.

Effect of tea polyphenols on production performance, egg quality, and hepatic antioxidant status of laying hens in vanadium-containing diets

This study was conducted to determine the effect of tea polyphenols (TP) on production performance, egg quality, and hepatic-antioxidant status of laying hens in vanadium-containing diets. A total of 300 Lohman laying hens (67 wk old) were used in a 1 plus 3 × 3 experiment design in which hens were given either a diet without vanadium and TP supplementation (control) or diets supplemented with 5, 10, or 15 mg V/kg and TP (0, 600, 1,000 mg/kg) diets for 8 wk, which included 2 phases: a 5-wk accumulation phase and a 3-wk depletion phase. During the accumulation phase, dietary vanadium addition decreased (linear, P < 0.01) albumen height and Haugh unit (HU), and TP supplementation mitigated (linear effect, P < 0.01) this reduction effect induced by vanadium. Eggshell thickness (linear, P < 0.01), redness (linear and quadratic, P < 0.05), and yellowness (linear and quadratic, P < 0.05) were decreased by vanadium and increased by the effect of TP when a vanadium-containing diet was fed. In the depletion phase, the bleaching effect on eggshells induced by vanadium disappeared one wk after vanadium withdrawal. Eggshell thickness, eggshell strength, albumen height, and HU were lower (P < 0.05) in the 15 mg/kg vanadium group compared with the control diet until 2 wk post vanadium challenge, but hens fed 15 mg/kg vanadium and 600 mg/kg TP showed no difference from the control diet only after 1 wk withdrawal. In the liver, the activity of glutathione S-transferases and glutathione peroxidase was increased (linear, P < 0.01) with the TP addition at 5 wk in the accumulation phase in the vanadium-containing diet; the malondialdehyde content increased (linear effect, P = 0.02) with the addition of vanadium. The results indicate that supplementation of 10 and 15 mg/kg vanadium resulted in reduced albumen quality, bleaching effect on eggshell color, and antioxidant stress in the liver. The effect of TP addition can prevent laying hens from the adverse effect of vanadium on egg quality, liver antioxidant stress and shorten the recovery time.

Effect dietary choline supplementation on egg quality and serumbiochemical profile in White Pekin Ducks

The aim of the present study was to evaluate the influence of choline in diet (a TMA precursor) on egg quality, serum biochemistry and presence of off flavour in eggs of White Pekin Ducks. 30 White Pekin ducks (45 weeks age) housed in individual cages were subjected to three dietary treatment groups and were. The dietary treatment groups consisted of two levels of choline as TMA precursor viz; 3g/kg diet, 6g/kg diet and a control diet devoid of choline. The results revealed highly significant (P&lt;0.0001) effect of choline on yolk weight and HU than the control. However the other egg quality traits i.,e egg weight, albumen weight, shell weight, albumen index, yolk index, shape index, shell thickness were not influenced. Serum cholesterol and triglycerides were significantly (P&lt;0.0001) reduced in high choline group (6g/kg diet) followed by low choline group (3g/kg diet) and control. The liver enzymes (SGPT and SGOT) were significantly lower (P&lt;0.0001) in both the supplemented groups as compared to control. No significant effect was found for serum total protein and serum glucose levels. Presence of off flavour (fishy flavour) was more evident in the eggs of choline group (6g/kg diet) than the control group. It can be concluded that the presence of choline in the diet had minimal effect on the egg quality parameters of Pekin ducks except for yolk weight and albumen quality, however there was significant reduction in serum total cholesterol and triglycerides levels.

Limestone particle sizes and lighting regimens on egg and bone quality of laying hens

Abstract:The objective of this work was to evaluate the effect of limestone particle sizes in the diet and of lighting regimes on the egg and bone quality and on the performance of commercial laying hens. Three hundred Hissex White layers, at 18 weeks of age, were distributed in a completely randomized design, in a 5×2 factorial arrangement (coarse limestone in the diet at 0, 25, 50, 75, and 100%; with or without artificial light), with five replicates of six birds. No significant interaction was observed between particle sizes and lighting regime for the evaluated parameters. There was no significant effect of coarse limestone level in the diet on the performance and egg quality of hens; however, bone deformity (3.23 to 4.01 mm), strength (5.19 to 6.70 kgf cm-2), and mineral matter (51.09 to 59.61%) improved as the proportion of coarse limestone increased. For lighting regime, the treatment with artificial light yielded higher Haugh unit values (87.17 vs. 85.54) than that with natural light only. Greater limestone particles improve bone quality of laying hens, and the use of artificial light can benefit the albumen quality of the eggs.

The effect of a probiotic preparation containing Bacillus subtilis ATCC PTA-6737 on egg production and physiological parameters of laying hens

Abstract A total of 288 Lohmann Brown laying hens were randomly divided into two groups (9 replicates of 16 birds each). The hens were housed in three-tier battery cages for 26 weeks, including a two-week pre-laying period. All birds were fed iso-nitrogenous and iso-caloric diets, and had free access to water. Control group (C) hens were fed a basal diet, and experimental group (BS) hens received a basal diet supplemented with a commercial probiotic preparation of Bacillus subtilis ATCC PTA- 6737 at 1×108 CFU/kg feed. The number and weight of eggs laid, feed intake, feed conversion, egg quality, the fatty acid profile and cholesterol content of yolk lipids, and selected blood biochemical parameters of hens were determined throughout the experiment. No significant differences (P&gt;0.05) were noted between the groups in average egg weight, laying performance (%), daily feed intake or feed conversion. Eggs laid by BS group hens received significantly higher scores for yolk color (Roche yolk color fan) and albumen quality (Haugh units), and they were characterized by a significant improvement in shell thickness and breaking strength (P&lt;0.05) in comparison with eggs laid by control group hens. No significant differences (P&gt;0.05) were observed between the groups in the fatty acid profile of yolk lipids, except for a significant increase (P&lt;0.05) in oleic acid concentrations in group BS. No significant differences (P&gt;0.05) were noted between the groups in selected blood biochemical parameters of laying hens. Group BS eggs had a significantly lower (P&lt;0.05) cholesterol content of yolk lipids. It can be concluded that a probiotic preparation containing Bacillus subtilis ATCC PTA-6737 had a beneficial influence on selected performance parameters of laying hens, egg quality and the cholesterol content of yolk lipids.

Effect of Air Velocity on Laying Hen Performance and Egg Quality

<abstract> <b><sc>Abstract.</sc></b> Increasing convective cooling can improve the performance and thermal comfort of commercial poultry when weather or system design limit cooling through other means such as evaporative cooling. Previous work in young hens showed increased egg production rate as feed intake was maintained under heat stress conditions. However, the effects of increased convective cooling on live performance or egg quality in older hens have not been evaluated. The objective of this study was to evaluate the effects of different air velocities on live performance of laying hens from 39 to 48 weeks of age and resultant egg quality. Air velocity treatments included still air, constant 0.76 m s^-1, and constant 1.52 m s^-1. The temperature and relative humidity in the experimental room were maintained at 27.8°C and 82%, respectively. Two 10-week trials were conducted, with two replicate treatment units per trial, for a total of four replicate treatment units. Hens were obtained from a commercial farm, placed in wind tunnels, and provided feed and water ad libitum. Lighting was provided per primary breeder guidelines. Eggs were collected daily, and feed intake was assessed weekly; egg quality attributes including egg weight, albumen quality (Haugh unit score), incidence of meat and blood spots, and egg shell strength were measured twice weekly. Hen-day egg production increased 6.3% and 6.7% over still air for 0.76 and 1.52 m s^-1, respectively (p < 0.0001). Feed intake was significantly depressed for still air when compared to air velocity treatments (p < 0.0001). Mean egg weight increased with increasing air velocity and was significantly different for all treatments (p < 0.0001). Albumen height and quality (Haugh unit) decreased with increasing air velocity and were significantly different between the still air and 1.52 m s^-1 treatments (p < 0.0038). Shell breaking strength significantly decreased for the still air treatment (p < 0.0001) when compared to the air velocity treatments; shell breaking strength was not different between the 0.76 and 1.52 m s^-1 treatments.

Effect of yellow lupine (L. luteus) on the egg yolk fatty acid profile, the physicochemical and sensory properties of eggs, and laying hen performance

The aim of this study was to evaluate the effects of different dietary inclusion of raw yellow lupine seed meal (YLM) on laying hen performance, the fatty acid (FA) profile, physicochemical, and sensory properties of eggs. A total of 224 Lohmann Brown laying hens at 32 wk age were fed isonitrogenous and isocaloric diets for 16 wk. The control diet contained soybean meal (SBM), and in study diets SBM was replaced with YLM at 100, 200, or 300 g/kg. In comparison with soybean, lupine seeds had a higher content of nonstarch polysaccharides (NSP) and raffinose family oligosaccharides (RFO) (29.5 vs. 14.0 and 8.56 vs. 5.91% DM). The dietary 300 g/kg lupine seeds increased the content of NSP and RFO in the ration, from 9.34 to 13.39 and 1.36 to 2.54%, respectively. The YLM inclusion level had no adverse effect on laying performance, including feed intake, FCR, egg production, and egg weight. The final BW of hens fed lupine-based diets were significantly higher compared with the control (P = 0.039). Throughout the study, dietary treatments had no effect on eggshell and albumen quality. An increase in the inclusion rate of YLM was followed by a linear increase (P < 0.001) in yolk color intensity. Dietary treatments had no influence on the aroma, taste, and texture of eggs evaluated in laying hens at 46 wk age. The inclusion of lupine seeds in experimental diets caused a linear increase in n-6 polyunsaturated FA (PUFA) content and the n-6/n-3 ratio (all P < 0.001), but it had no influence on the atherogenic and the thrombogenic indices of egg yolk lipids. The results of this study indicate that YLM can be included at 300 g/kg in layer diets as a partial substitute for soybean meal without compromising laying performance, the physicochemical, and sensory properties of eggs.

EFFECT OF SUPPLEMENTATION OF CHROMIUM NANOPARTICLES ON EGG WEIGHT AND EGG QUALITY CHARACTERISTICS IN LAYERS

A study was conducted to investigate the effect of supplementation of different levels of Chromium nanoparticles (NanoCr) in layers. 360 brown layers of 28 weeks age were randomly allocated to five treatment groups (supplemented with 0, 50, 100, 200 and 400 ppb NanoCr). At 32, 36 and 40 weeks age, eggs were collected to assess the egg weight, yolk, albumen, shell per cent and shell thickness, Haugh unit and egg indices. Egg weight linearly increased at all ages with NanoCr. Albumen per cent significantly increased and yolk and shell per cent significantly decreased (p<0.05) whereas albumen index and haugh unit score at 36 and 40 weeks age significantly increased in NanoCr supplemented groups. These results indicated that NanoCr supplementation to layers improved egg weight and albumen quality.

Effects of laying hens housing system on laying performance, egg quality characteristics, and egg microbial contamination

The objective of this study was to compare the performance, egg quality, and microbial contamination of egg shells from hens maintained in different housing systems, such as conventional and enriched cages, litter, and aviaries. The housing system significantly (P &amp;lt; 0.001) influenced the performance characteristics. The highest egg production, lowest daily feed consumption, and feed conversion ratio were measured in conventional cages compared to litter and aviaries. Higher egg shell and albumen qualities were observed in conventional cages, whereas hens housed in enriched cages and aviaries laid eggs with a higher yolk index (P&amp;nbsp;&amp;lt;&amp;nbsp;0.001). The housing system significantly (P &amp;lt; 0.001) influenced the total count of bacteria on the egg surface and the microbial contamination of Enterococcus and Escherichia coli. The lowest values for the total count of bacterial contamination (P &amp;lt; 0.001) were found in eggs from conventional cages (4.05 log colony-forming units (CFU)/egg) and enriched cages (3.98 log CFU/egg). Eggs from aviaries had 5.49 log CFU per egg, and the highest level of contamination was observed in eggs that were laid on litter (6.24 log CFU/egg). The level of the microbial contamination of egg shells from litter and aviaries was by 2 log CFU higher than in eggs from cages. It could be concluded, from the viewpoint of egg safety, a more suitable substitute for conventional cages are enriched cages and aviaries than litter. &amp;nbsp;

Fatty acid composition, physicochemical and sensory properties of eggs from laying hens fed diets containing blue lupine seeds

Summary This study was undertaken to determine the effect of partial replacement of soybean meal with 10% and 20% of blue lupine ( Lupinus angustifolius) seeds in layer diets on laying performance, the fatty acid profile, physicochemical and sensory properties of eggs. A 20-week study was performed on 150 Lohman Brown hens with 50 birds in each group. Diet supplementation with blue lupine seeds contributed to an increase in the content of neutral detergent fiber (NDF), acid detergent fiber (ADF) and raffinose family oligosaccharides (RFOs) without compromising laying performance. Feed intake was lower (P = 0.004) in groups fed blue lupine seeds. Eggshell weight as a percentage of total egg weight, and eggshell breaking strength were higher in groups fed lupine-supplemented diets (P = 0.002 and P = 0.036, respectively). Eggs from hens fed blue lupine seeds were characterized by lower albumen quality expressed as albumen height (P = 0.001) and Haugh units (P = 0.001). Diet supplementation with blue lupine seeds contributed to an increase in the concentrations of C18:2 n-6 (P = 0.001) and C18:3 n-3 (P = 0.001) fatty acids and total polyunsaturated fatty acids (PUFAs) (P = 0.001) in yolk lipids. Higher dietary inclusion levels of blue lupine increased the levels of C22:6 n-3 fatty acid (P = 0.004) in the egg yolk, thus significantly (P = 0.035) improving the n-6/n-3 PUFA ratio. Dietary treatments had no influence on the sensory properties of eggs, except for yolk color which was most intense (P ≤ 0.05) in eggs from hens fed 20% blue lupine seeds. Our results indicate that blue lupine seeds can be added to layer diets at 20% without compromising laying performance. Blue lupine seeds improved yolk color and the fatty acid profile of yolk lipids.