Hy-Line Brown Hens Research Articles

Effects of high-dose selenium-enriched yeast on laying performance, egg quality, clinical blood parameters, organ development, and selenium deposition in laying hens

Organic selenium (Se) supplementation from Se-enriched yeast (SY) has been advocated and approved for use in animal feeds by some nutritionists and researchers rather than inorganic Se from sodium selenite. However, there is little available safety data of SY in laying hens. A subchronic study was conducted to determine if high-dose SY affects the safety of hens. A total of 768, 30-wk-old, Hy-Line Brown hens were randomly assigned to 1 of 4 groups (192 laying hens per group) with 6 replicates of 32 birds each. After a 2-wk acclimation period, the birds were fed diets supplemented with 0, 0.3, 1.5, or 3.0mg/kg Se from SY for 12 wk. Throughout the study period, clinical observations and laying performance were measured. The hematological and chemical parameters of blood samples and the Se concentration in eggs were examined after SY supplementation for 4, 8, and 12 wk, and the egg quality was measured after 12 wk. At the end of the study, full post-mortem examinations were conducted: breast Se concentrations were measured, visceral, and reproductive organs were weighed, and specified tissues were collected for subsequent histological examinations. Although the Se concentrations in the eggs and breast meat from hens fed 3.0mg/kg of Se from SY were 1036.73% and 2127.93% higher (P < 0.001) than those from hens fed a basal diet after 12 wk, no treatment-related changes of toxicological significance were observed. Therefore, up to 3mg/kg organic Se from SY can be used to supplement the diets for laying hens without adverse effects following 84-d administration.

Nutritional Dietary Supplements to Reduce the Incidence of Fatty Liver Syndrome in Laying Hens and the Use of Spectrophotometry to Predict Liver Fat Content

Fatty liver syndrome (FLS) in laying hens is a metabolic disease that can potentially reduce egg production while compromising the health status of the bird. This study assessed the combined use of B vitamins via the feed (FLS-MIX) or the drinking water (FLS-LIQ) to reduce FLS and the use of spectrophotometry to estimate liver fat content. Individually, caged Hy-line brown hens (n = 288) underwent a pre-experimental period (from week 66 to 67, both included) receiving a Standard diet or a Challenge diet (high energy–low protein) to nutritionally induce the FLS. Subsequently, hens followed a 2 diets (Standard; Challenge) × 3 dietary supplements (NONE; FLS-MIX; and FLS-LIQ) factorial arrangement of treatments from 68 to 73 wk old, both included. Compared to the Standard, the Challenge diet increased liver fat (188 vs. 270 g/kg DM) and reduced feed consumption, lay percentage, and egg mass production (P < 0.05). No differences in lay performance or eggshell quality were observed among dietary supplements; however, FLS-MIX significantly increased (P < 0.05) feed intake relative to NONE. On birds subjected to the Challenge diet, the use of FLS-MIX and FLS-LIQ led to lower (P < 0.05) liver fat relative to NONE. Regression analysis between the L, a+, and b+ values and liver fat content provided significant (P < 0.001) regression equations to estimate liver fat content (R2 = 0.62). Results of this study suggest that B vitamin supplements could be an effective means to reduce liver fat deposition when hens are susceptible of suffering FLS, and that spectrometry could be a reliable tool to estimate liver fat content.

The effect of enzyme and protein source on laying hens performance, eggshell and bone traits

The aim of the study was to investigate the interaction between exogenous phytase with protease and protein source in laying hens diet. A completely randomised design study with a 2 × 4 factorial arrangement was conducted to observe effects of protein source (soybean vs. yellow lupine seeds diet) and enzyme addition (no enzyme vs. phytase or protease or both) on laying hens performance, bone mineralization and some egg traits. One hundred sixty Hy-Line Brown hens at the age of 18 weeks were weighed and randomly assigned to 10 treatments, each with 16 birds. According to the producer recommendation in diets containing enzymes reduced the level of available phosphorus (50% reduction) and digestible amino acids - 5% reduction. The egg production during the entire experiment was similar in all groups without significant differences. The egg weight was also on an equal level in all treatments and it was about 58g. Birds fed different protein source were characterized by similar feed intake and feed conversion ratio during the whole experiment. The feed conversion ratio (FCR) was about 1.9-2.0 in all groups. Tibia ash was affected by enzymes supplementation. There was an interaction between protein source and enzymes addition. Birds from treatments fed with yellow lupine meal (YLM) diets reached highest tibia ash level in a group with phytase addition and in groups with SMB in a group with phytase and protease mix. The inclusion of enzymes improved the thickness of the shell. There was an interaction between protein source and enzyme inclusion. It was an interaction between experimental factors in shell breaking strength. Stronger eggshell was laid by hens from groups fed with the inclusion of yellow lupine meal. Addition of phytase had a positive impact on increasing the strength of eggshell. Only inclusion of enzymes affected significantly on shell elastic deformation in part I of eggs. Eggs from hens fed diets with inclusion of protease and phytase mix were most resistant to elastic deformation.

The influence of Dermanyssus gallinae and different lighting regimens on selected blood proteins, corticosterone levels and egg production in layer hens

Egg production in battery cage systems in commercial poultry farms promotes uncontrolled growth of poultry ectoparasite Dermanyssus gallinae. Intermittent lighting regimens provided a promising alternative for controlling D. gallinae invasions. The study analysed the influence of D. gallinae invasions on selected blood protein fractions (albumin, α-, β-, γ-globulin), corticosterone levels and egg production in Hy-Line Brown layer hens exposed to two lighting regimens: A (16 L:8D) and B (intermittent (4 L:2D); L-light, D-dark). Blood samples were collected from a total of 48 hens (divided into uninfested - UF, and infested - IF groups for each lighting regimen). The concentrations of protein fractions were analysed by electrophoresis on Cormay Gel Protein 100, and corticosterone levels were determined in a radioimmunoassay. The results of the study revealed concentrations of β-globulin and corticosterone levels were significantly higher in IF than UF groups in both lighting regimens. However, both parameters were higher in hens exposed to lighting regimen B than lightening regimen A. Gamma-globulin concentrations were significantly lower in IF than UF groups in both lighting regimens. Egg production was significantly lower in all groups than commercial standard. D. gallinae and intermittent lightening regimen had interaction effect on the corticosterone level in hens. Strong decreasing (negative) linear relationship between corticosterone levels and egg production (r = −0.911) was reported.

Effect of layer genotype on physical characteristics and nutritive value of organic eggs

ABSTRACTThe aim of the study was to evaluate the quality of organic eggs from hens of different genotypes and ages. The study investigated the physical characteristics, nutritive value and foaming properties of egg whites from Hy-Line Brown commercial layers, native Greenleg Partridge hens included in the conservation program, and Araucana hens laying blue-shelled eggs. Genotype had an effect on egg weight, albumen height and Haugh units. The vitamin A content of egg yolks was greater for Greenleg Partridge compared to Hy-Line Brown hens (P < 0.05). The n-6/n-3 PUFA ratio in egg yolks from Greenleg Partridge hens was lower, while the EPA, DHA and PUFA n-3 content were higher than in egg yolks from Hy-Line Brown hens (P < 0.05). Egg yolk cholesterol concentration was similar for the studied hen breeds (P > 0.05). Layer age had a significant effect on egg weight, yolk weight and color, and the presence of meat and blood spots (P < 0.05).

Anti-urease immunoglobulin (IgY) from egg yolk prevents Helicobacter pylori infection in a mouse model

ABSTRACTHelicobacter pylori (H. Pylori) is a potential pathogen found in approximately 50% of the human population, although many infected by it remain asymptomatic. The current treatment regime of it has become less effective because of antibiotic resistance. Accordingly, an alternative treatment with reasonable cost is essential. Urease is an important enzyme that enables the acclimation to harsh acidic conditions in the stomach. IgY implemented therapy is an attractive approach to preventing infection of H. pylori. The present study evaluated the anti-urease IgY effect on the prevention of H. pylori infection. To generate IgY, a 100 ng/ml mixture of purified urease A and B used to immunize Hyline brown hens. Anti-urease IgY was purified from egg yolks and orally administered to SPF C57BL/6 female mice that had been infected with H. pylori. The results demonstrated that anti-urease IgY has greater potential to prevent infection in mice, suggesting a rational therapeutic approach to H. pylori.

PSXVI-22 Protease for laying hens as a strategy to save on feed cost and reduce nitrogen excretion.

Performance of laying hens is influenced by age. With age their nutritional needs change and egg quality tends to decrease. Protease supplementation offers opportunity to reduce crude protein (CP) and amino acid (AA) levels in diets generating savings on feed cost and reducing nitrogen (N) excretion in the environment. This study was conducted to determine the effects of reducing CP and AA in diets supplemented or not with protease on performance and N excretion of aged laying hens. A 6 weeks study was conducted using 240 Hy-Line Brown hens 82-week-old randomly allotted in 120 cages with 8 replications of 5 cages (2 hens/cage) fed one of the following three treatments: 1) PC (Positive Control, 17% CP), 2) NC (Negative Control, -11% CP and AA), 3) PT (NC + 125 ppm Protease, Jefo, Canada). Data were subjected to statistical analyses of variance (PROC Mixed procedure, SAS). LSMEANS with PDIFF option was used to separate treatments means (P<0.05). Difference in CP and AA between PC and NC treatments was voluntarily set higher than the recommended uplift for the protease tested in order to generate substantial drop on performance. Compared to PC, reducing CP and AA in NC diet impaired performance of laying hens. The effect was numerical on feed conversion ratio (P<0.11, +6.8%), observed as a trend on egg mass (P<0.10, -7.4%) and significant on egg weight (P<0.05, -2.7%). Protease supplementation counteracted the negative effects of reduced CP and AA, recovering +1.2% on egg weight (P<0.05), +4.5% on egg mass (P<0.10) and -4.0% on feed conversion ratio (P=0.11). Nitrogen output was lowered (P<0.01) in NC and PT compared to PC. Overall, results showed that protease supplementation on low protein diets and aged layers can successfully be used as a strategy to save on feed costs and lower N excretion in the environment.

Laying performance, blood profiles, nutrient digestibility and inner organs traits of hens fed an insect meal from Hermetia illucens larvae

Given probable the increment in the nutritional needs of both humans and animals, animal production will have increased dramatically by 2050. Insect meals could be an alternative protein source for livestock, and they would also be able to reduce the environmental problems related to intensive animal production system.The aim of this study was to evaluate productive performance, blood analysis, nutrient digestibility, and changes in the internal organs of laying hens fed Hermetia illucens larvae meal (HI) at two different levels in substitution (25 or 50%) of soybean meal (SBM).A total of 162 Hy-line Brown hens (sixteen weeks old) were equally divided into three experimental groups and fed isoprotein and isoenergetic diets.Egg weight, feed intake, and feed conversion rate were not affected by the soybean meal substitution at both inclusion levels of insect meal. Egg mass was positively affected by the insect meal diets, as was the lay percentage, although only at the lowest inclusion level. Dry matter, organic matter, and crude protein digestibility coefficients were lower for the HI50 diet, probably due to the negative effect of chitin. A reduction in serum cholesterol and triglycerides was observed in both insect-meal fed groups, while serum globulin level increased only at the highest level of insect meal inclusion, and, consequently, the albumin to globulin ratio decreased. Overall, a protein replacement of 25% with an insect meal from Hermetia illucens larvae in the diet of laying hens seems to be more suitable and closer to the optimal level.

Feed particle selection and nutrient intake altered by pecking stone consumption and beak length in free-range laying hens

The present study investigated the effects of pecking stones on feeding behaviour of hens from 16 to 46 weeks of age. Eighteen flocks of Hy-Line Brown hens were housed in 2 commercial free-range housing systems. Farm A housed 10 flocks of beak trimmed (infrared beak treatment) hens in fixed sheds. Farm B housed 8 flocks of hens with intact beaks in mobile sheds. On each farm, flocks were equally assigned to control groups (no access to pecking stones) and treatment groups (access to pecking stones). Data were evaluated every 10 weeks. At each time point, 10 hens per flock were housed in individual pens, and each hen was provided with 250 g of mash diet and ad libitum water for 24 h. After 24 h, feed samples were collected and used to determine 24-h feed intake. Nutrient and particle selection was measured by subtracting nutrients and particles present in the leftover feed from the vaules obtained in the offered feed and expressed the change (Δ). In addition, pecking stone consumption was recorded for each flock. Data were analysed separately for each farm using fixed effects of pecking stone availability and hen age. Spearman's rho correlation coefficients and linear regression models were constructed to evaluate the relationship of beak length and pecking stone usage, discrete mean particle size (dMEAN) consumption (Δ dMEAN), and Δ nutrient intake. Hens with access to pecking stones consumed significantly lower quantities of large feed particles (>2.8 mm) on farm A (P = 0.029) and selected significantly more fine particles, on farm B (P = 0.013). Overall, positive relationships (P = 0.001) between beak length and pecking stone consumption, Δ dMEAN, and Δ phosphorus consumption were observed. In conclusion, pecking stone consumption resulted in reduced selection and consumption of feed particles in hens housed on both farms. Further research is warranted to investigate the effect of pecking stones on sensory innervation of the beak.

Effects of Dietary Phosphorus Level on the Expression of Calcium and Phosphorus Transporters in Laying Hens.

The transport of calcium and phosphorus is mainly relied on their corresponding transporters. The aim of this study was to determine the effect of dietary phosphorus level on the expression of the relevant calcium and phosphorus transporters in laying hens, which has a large amount of calcium and phosphorus input from intestine and output from kidney and eggshell gland. Thirty-six 25-week-old Hy-line Brown hens were fed diets with different available phosphorus level (AP, 0.15, 0.41, and 0.82%), respectively. The expression of phosphorus transporters type IIa and type IIb Na/Pi co-transporter (NPt2a, NPt2b), calcium transporter calbindin-D28k (CaBP-D28k), and plasma membrane Ca ATPase 1b (PMCA1b) were measured in small intestine, kidney, and eggshell gland by RT-PCR and western blot. The results showed that serum calcitriol and PTH concentrations were not affected (P > 0.05) by dietary AP levels. Duodenum had the highest mRNA and protein expression level of NPt2b than jejunum and ileum (P < 0.05). The protein expression abundance of CaBP-D28k and PMCA1b were higher in duodenum than that in jejunum and ileum (P < 0.05). 0.15%-AP diet upregulated the ileal mRNA expression level of NPt2b and renal mRNA expression level of NPt2a (P < 0.05), while downregulated the protein abundance of NPt2b and CaBP-D28k mRNA expression in shell gland (P < 0.05). In conclusion, both the Ca and P transporters were highly expressed in duodenum. Low AP diet decreased protein expression abundance of NPt2b in duodenum while upregulated the mRNA expression level of NPt2a in kidney. The result suggests that both the phosphorus absorption in proximal intestine and its reabsorption in kidney are involved in the adaption to low AP diet.

Mineral content of eggs differs with hen strain, age, and rearing environment

Egg nutrient quality is strongly influenced by hen diet but is also affected by rearing environment, hen strain, and hen age. The objective of the current study was to determine the effect of: 1) conventional battery cages, 2) enrichable cage systems, 3) enriched colony housing, 4) cage-free, and 5) free-range rearing systems on mineral concentrations of whole, dried egg (yolk and albumen combined) from TA Tetra White (TW) and Hy-Line Brown (HB) hens at 44, 68, and 88 wk of age. We hypothesized that mineral concentration of eggs would differ among rearing systems but not between strains or with hen age. Hens held in enriched colony housing systems produced eggs with 10% lower Mg and 11% lower Mn levels than conventional hens. Concentrations of Ca and Cu were higher (7 and 8%, respectively) in eggs from TW hens than from HB hens. Eggs from HB hens had 8% higher concentrations of Fe, 6% higher Mg and 5% higher Mn than TW hens. Mn was higher in eggs from 44-wk hens than from 68- or 88-wk hens (16 and 11%, respectively). Interaction effects between rearing environment and hen age were observed for K and Mn concentrations. Eggs from 68-wk hens in conventional rearing systems contained 14 to 21% more K than eggs from conventional hens at 44- and 88 wk and 14 to 18% more than eggs from 68-wk hens in other rearing systems. At 88 wk of age, hens in conventional rearing systems produced eggs with higher Mn concentration than hens in enrichable or enriched colony housing systems (22 and 23%, respectively). Interactions between rearing environment, hen strain, and hen age were observed for egg Zn levels among 44- and 68-wk hens but were not detectable among 88-wk hens regardless of rearing system or hen strain. Observed differences in egg mineral content in our study were small and are unlikely to have substantial impact on human nutrition.

The Effect of the Type of Alternative Housing System, Genotype and Age of Laying Hens on Egg Quality

Abstract The present study investigated the effect of the type of alternative housing system, and genotype and age of laying hens on physical traits of egg shell and contents. It was demonstrated that alternative housing system type influenced egg weight and shape, and eggshell color and yolk color intensity. Eggs from free-range system were heavier and were characterized by more intense yolk color. No effect of alternative housing system type on albumen height, value of Haugh units (HU value) and presence of meat and blood spots was noted. Hen genotype had a significant effect on egg weight and eggshell color intensity in each of the alternative housing systems tested in this study. Hy-line Brown hens laid heavier eggs than hens of native breeds. Genotype was also observed to affect egg content traits (albumen height, HU values and presence of meat and blood spots). Independently of the type of alternative housing system, most blood and meat spots were noted in eggs of hens laying brown-shelled eggs, i.e. R-11 and Hy-line Brown layers. Laying hen age significantly impacted on egg weight, yolk percentage, eggshell traits (color intensity, weight, thickness and strength) and egg content traits (HU value, yolk weight and color intensity, presence of meat and blood spots). Older hens laid heavier eggs with a greater yolk percentage but with thinner eggshell.

Effects of Modified Palygorskite Supplementation on Egg Quality and Mineral Element Content, and Intestinal Integrity and Barrier Function of Laying Hens.

This study was conducted to investigate effects of modified palygorskite (MPal) supplementation on the laying performance, egg quality and mineral element content, immunity, oxidative status, and intestinal integrity and barrier function of laying hens. A total of 360 52-week-old Hyline Brown hens were randomly assigned into four dietary treatments for a 7-week feeding trial. The birds were fed a basal diet supplemented with 0 (control group), 0.25, 0.5, and 1g/kg MPal, respectively. The supplementation of MPal did not alter laying performance and egg quality among groups. Compared with the control group, MPal inclusion decreased lead (Pb) content in yolks at 49days, and either 0.5- or 1-g/kg MPal supplementation decreased Pb accumulation in yolks at 25days and manganese (Mn) accumulation in yolks at 25 and 49days. The contents of jejunal secretory immunoglobulin A (SIgA), ileal SIgA, and immunoglobulin G were decreased by the dietary 0.5-g/kg MPal supplementation. The supplementation of MPal also decreased malondialdehyde content in jejunum and ileum, and decreased serum diamine oxidase activity of the laying hens at 25 and 49days. The inclusion of 0.5 and 1g/kg MPal enhanced villus height in jejunum and ileum, and also increased the ratio of villus height to crypt depth in ileum. In conclusion, MPal supplementation decreased Pb and Mn contents in yolks, and exhibited beneficial effects on the intestinal immunity, oxidative status, and intestinal integrity and barrier function of laying hens and its optimal dosage was 0.5g/kg.

Ulvan extracted from green seaweeds as new natural additives in diets for laying hens

Ulvan extracted from the green seaweed Ulva was added in laying hen diets. The effect of ulvan on laying performance, egg quality, immunity function, and antioxidant capacity was evaluated using Hy-Line Brown hens. Six groups of birds (n = 864, 61 weeks old) were fed on the basal diet containing ulvan at 0, 0.05, 0.1, 0.5, 0.8, and 1% for 8 weeks. The results were compared with the control group. Ulvan at concentrations of 0.1 to 1% can significantly improve the egg production (P < 0.05), and higher concentrations (1%) increased the egg weight and decreased feed conversion ratio of hens (P < 0.05). Ulvan at higher concentrations (0.8%, 1%) also helped to improve the eggshell strength (P < 0.05). Ulvan at concentrations of 0.5 to 1% leads to a yolk color to red tendency, and ulvan at concentrations 0.05 to 1% can significantly decrease cholesterol levels of yolk (P < 0.05). Treatments with high levels (1%) of ulvan showed a positive effect on interleukin-6 as well as 0.8% of ulvan on interferon-γ (P < 0.05). There are significant interactions (P < 0.05) on the time × ulvan level on total antioxidative capacity, malondialdehyde, and superoxide dismutase levels of blood serum. These findings thus suggested that ulvan extract can be used as additives in diets for laying hens.

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.

Sensory quality of mayonnaise formulated with eggs produced by laying hens fed diet enriched with purslane meal (Portulaca oleracea)

The objective of the study was to assess the sensory quality of mayonnaise formulated by egg yolks produced by hens fed purslane meal as a source of omega-3 (n-3) fats, alpha-linolenic acid. Eggs used were produced by Hy-Line Brown hens (38 weeks old) fed five diets suplemented with 0, 2, 4, 6 and 8% purslane meal. A total of 40 eggs of day 29 (n = 8 eggs for each treatment) were collected to formulate mayonnaise. The ingredient composition of mayonnaise was 14% egg yolks, 9% vinegar, 74% corn oil, 1% salt, 1% sugar, and 1% mustard. The parameters included colour, emulsion stability, texture, homogeneity, aroma, taste and flavour of mayonnaise. The findings of sensory evaluation by quantitative descriptive analysis showed that the use of egg yolk from hens fed dietary purslane meal up to 8% resulted in a significant effect on the yellow color of mayonnaise, but did not significantly affect emulsion stability, texture, homogeneity, aroma, taste, and flavour. Based on consumer preference, consumers did not detect any differences in the sensory characteristics between mayonnaise prepared from control eggs and those formulated with eggs produced from dietary treatment. Apparently, there was an increase in colour liking by inclusion of purslane meal. In conclusion, eggs from laying hens fed diets supplemented with purslane meal improved the colour intensity of mayonnaise. Mayonnaise formulation using eggs from diets added with Portulaca oleraceae meal up to a level of 8% can be applied without influencing mayonnaise sensory characteristics and consumer acceptance.

The potential of cholecalciferol and 25-hydroxyvitamin D3 enriched diets in laying hens, to improve egg vitamin D content and antioxidant availability

Abstract Sixty Hy-line brown hens were randomly assigned to four barns ( n = 4) to investigate the effects of cholecalciferol (vitamin D₃) versus 25-hydroxyvitamin D 3 (25-OH-D₃) enriched diets on egg vitamin D concentration, antioxidant activity and egg quality parameters. Experimental design was a 4 × 4 Latin square consisting of 4 experimental treatments and 4 experimental periods. The treatments were (1) 1500 IU of vitamin D₃ (2) 3000 IU of vitamin D₃ (3) 1500 IU of vitamin D₃ and 37.5 μg of 25-OH-D₃ (4) 75 μg of 25-OH-D₃ per kg of feed. Hens offered 75 μg of 25-OH-D₃ had a higher ( P Industrial relevance Vitamin D deficiency is now regarded as a major issue in northern Europe and has been described as a pandemic. A growing interest in vitamin D food fortification in northern Europe to satisfy the current dietary intake recommendations has been observed. The use of a bio-addition approach for increasing vitamin D intake through biofortification of livestock feeds attracts attention. Enrichment of the hen's diet with vitamin D may also supply additional benefits of increasing antioxidant activity. This increase in antioxidant activity may have the ability to increase food quality and extend the shelf life. This study explores the effect of vitamin D enriched diets fed to laying hens on vitamin D egg yolk content and antioxidant activity in the egg. These enriched diets could demonstrate that enrichment of hen diets with 25-hyroxvitamin D₃ may be a useful approach for tackling low vitamin D intakes and improving antioxidant capacity of eggs.

Selected quality traits of eggs and the productivity of newly created laying hen hybrids dedicated to an extensive rearing system

Abstract. The aim of the study was to evaluate the usefulness of hybrids derived from Greenleg Partridge cocks and Rhode Island Red (GPR) hens for an extensive rearing system (RS), with special emphasis on high-quality table eggs. Newly created hybrids were compared to Hy-Line Brown (HLB) hens. The experiment was carried out with a total of 2400 hens. Both hybrid types (H's) were divided into two equal groups according to the rearing system: intensive (I) and extensive (E). The traits analysed in hens were body weight at the 8th, 16th, and 33rd weeks of age; laying production; and feed intake. At the 33rd week of a bird's age, egg quality was evaluated. The results of the study showed different reaction of the hybrids to the rearing system. This may confirm better usefulness of GPR for extensive farming and HLB hens for intensive methods of rearing. Furthermore, it can be concluded that the extensive system had a positive impact on the productivity of GPR birds.

Three hulless oat varieties show economic potential as organic layer feed grain

AbstractHulless oats are of interest as an alternative to corn and wheat in organic poultry diets because they offer potential to enhance agrobiodiversity and produce locally grown feeds both within and outside of corn-growing regions. Hulless oats are easily certified GM-free and have demonstrated nutritional value for poultry. A feeding study was carried out to examine: (i) the effects of substituting corn, wheat or a fraction of each with hulless oats in organic layer diets, and (ii) the importance of oat variety in feed performance. Productivity and economic implications in the context of current organic markets were explored. Experimental diets included an oat-free control, Oat + corn, Oat + wheat and Oat + corn + wheat, each of which was formulated with three hulless oat varieties, AC Gwen, Paul and Streaker. All but the control diet included oats at 200 g kg−1. Three hundred Hy-Line Brown hens were individually caged and allocated to diets in groups of 10 in a completely randomized design with three replicates per diet. Experimental diets were fed between 24 and 32 weeks of age during which time hen health, egg production and egg quality indicators were monitored. Results indicated that hulless oats had no negative effects on hen health and productivity. On the basis of current organic feed ingredient prices and an estimated cost of USD 533 mt−1 for production of oats in the study region, oat containing diets were more expensive than the oat-free control. In an evaluation of revenue based on current market prices for organic eggs, the additional cost was completely offset by larger egg sizes of hens on oat containing diets. There were no major differences associated with oat variety.

Exterior and interior physical quality of egg of laying hens fed diets containing different dietary purslane levels

Purslane is considered a rich vegetable source of alpha-linolenic acid, beta-carotene and various antioxidants. The objective of the study was to investigate the effect of different dietary levels of purslane meal (Portulaca oleracea) in the diets of laying hens on physical quality of eggs. A total of 125 Hy-Line Brown hens (54 weeks old) were placed at individual cages and assigned to five dietary treatments. The diets were supplemented with 0, 2, 4, 6 and 8% purslane meal. Laying hens were fed for 5 weeks after a typical period of adaptation (7 days). Water and feed were provided ad libitum. A total of 25 egg samples of day 28 and day 35 (n = 5 egg yolks for each treatment) were collected to analyse exterior and interior physical quality of eggs. The data were analysed using ANOVA. Differences between treatment means were further analysed using Duncan’s New Multiple Range Test. Results showed that feeding different purslane meal levels in the diets improved egg weight, yolk weight, albumen weight and yolk colour. The highest intensity of yolk colour was obtained with the diet containing 8% purslane meal. However, dietary treatments did not affect egg index, albumen index, yolk index, shell weight, shell thickness and Haugh Unit. It is concluded that including purslane meal to laying hen diets increases the physical qualities of the eggs.