Hy-Line W36 Research Articles

Complexo enzimático à base de xilanase, β-glucanase e fitase em rações para poedeiras comerciais leves em pico de produção

The objective of this work was to evaluate the supplementation of an enzymatic complex based on xylanase, β-glucanase and phytase in light commercial egg laying feeds at peak egg production,performance and egg classification. A total of 288 laying hens of the Hy-Line W36 breed were used in a completely randomized design in split plot with four treatments and six replicates of 12 layer each in four periods of 21 days each. The experimental rations were formulated based on corn and soybean meal, consisting of four types of ration: CP ration - positive control (100% recommended metabolizable energy without enzymes), CN ration - negative control, reductions in 75 kcal of metabolizable energy, 0.12 percentual points (pp) of Ca and P available, CN Ration + 60 g/t Enzyme Complex and CN Ration + 100 g/t Enzyme Complex. The enzyme complex was composed by: xylanase = 12,000 u/g; beta-glucanase = 2500 u/g and phytase = 5000 u/g. The variables evaluated were: average egg production (egg%/ layerday), mean egg weight (g), mean feed intake (g/layer/day), feed conversion per egg mass, and classification according to weight. There was no interaction between the treatments and the evaluation periods (P> 0.05). It is possible to observe that the egg production was influenced by the nutritional reductions of the rations and the inclusion of 100 g/t of the enzymatic complex made it possible to recover the egg production rate, matching the layers of the positive control treatment (P<0.01). Feed intake was higher (P<0.05) for birds receiving 100 g/t enzyme complex compared to hens fed with ration without addition of enzyme complex (negative control). The weight of the eggs responded (P<0.01) to the nutritional reductions of the rations, being lighter in the negative control treatment, but with recovery when adding 100 g/t enzyme complex. The feed conversion was worse (P<0.05) for laying hens fed the feed with 60 g/t of the enzymatic complex tested, mainly due to the lower egg production observed in this treatment. The use of 100 g/t of the xylanase, beta-glucanase and phytase-based enzyme complex for feed formulations with nutrient reductions at 75 kcal ME/kg, 0.12 pp Ca and 0.12 pp P is recommended for laying hens Egg production in order to maximize performance and improve the classification of eggs produced.

Effect of &lt;i&gt;Moringa oleifera&lt;/i&gt; (Lam.) pods as feed additive on egg antioxidants, chemical composition and performance of commercial layers

The present study was designed to investigate the influence of Moringa oleifera (Lam.) pod meal (MPM) on production, immunity, and functional food index of chicken eggs. Two hundred HyLine W36 layer birds aged 50 weeks, 1469 ± 46.63 g, were assigned to four treatments in a completely randomized design, with five replicates and ten birds each. Diets A, B, C, and D were formulated with the same caloric and protein levels, but with differing MPM dose levels of 0, 5, 10, and 15g MPM/kg finisher diet, respectively. Data for production performance, quality, and chemical composition of eggs were analysed by one-way ANOVA, and means were compared with Duncan’s multiple range test. As a result of this study, feed conversion ratio (FCR) and egg mass (EM) were significantly decreased and recorded lowest in Group B, which was offered 5 g/kg above the basal diet. Bioactives such as β-carotene, quercetin, and selenium levels were increased (540, 121, & 72.21μg/100g of yolk, respectively), whereas cholesterol levels in egg yolk and serum were decreased significantly, that is, 201.87 mg/100g and 8.47 mg/dl, respectively. Serum biochemical indicators, including serum glutamic-pyruvic transaminase (SGPT), glucose, creatinine and cholesterol levels, were lowered significantly. Proximate analysis of egg yolk showed that moisture and ether extract were decreased, whereas crude protein (CP), ash and minerals, sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), and phosphorus (P) contents were increased. The outcomes of this study showed that MPM supplementation affects EM, serum biochemistry and bioactive compounds of the egg yolk positively. Keywords : Antibody titers, β-carotene, cholesterol, egg quality, quercetin, selenium

Nest use and patterns of egg laying and damage by 4 strains of laying hens in an aviary system1

Laying hens are strongly motivated to use nests for egg laying, and alternative production systems (e.g., aviaries) provide artificial sites to meet this need and ensure efficient collection of clean, undamaged eggs. However, nests are typically not provided to allow simultaneous use by all hens; therefore, competition or mislaid eggs can result. To understand the influence of strain on laying eggs outside nests and damage to eggs, we compared daily patterns of nests use and egg laying among 4 laying hen strains (Hy-Line Brown (HB), Bovans Brown (BB), DeKalb White (DW), and Hy-Line W36 (W36)). Hens were observed over 3 consecutive days in aviaries with colony nests in the enclosure’s top tier (2 nests/unit, 4 aviary units/strain, 144 hens/unit). The number and location of hens in nests and the number, location and condition of eggs throughout aviaries were recorded. Most eggs (90 to 95%) were laid in nests; however, brown hens consistently laid more non-nest eggs and damaged more eggs than white hens (P ≤ 0.05). Higher nest occupancy by brown hens was correlated with more non-nest and damaged eggs (P ≤ 0.05). In the morning, brown hens occupied more nest space and laid more nest eggs than white hens (e.g., HB vs. DW: 82.97 and 34.66% of space; 91.35 and 68.73% of nest eggs; P ≤ 0.05). At midday, white hens occupied more nest space and laid more nest eggs than brown hens (e.g., HB vs. DW: 28.47 and 15.81% of space; 27.39 and 8.29% of nest eggs; P ≤ 0.05). Brown hens preferred right nest compartments and laid more eggs there, whereas white hens preferred left compartments and W36 laid more eggs there (P ≤ 0.05). These findings indicate that different strains of hens have different patterns of nest use and laying behavior. In brown hens, heavy morning nest use was related to laying eggs outside nests and more damaged eggs, suggesting insufficient space for oviposition in nests. Specific facility design should be matched to hens’ preferences to accommodate behavioral needs of different strains.

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.

Assessment of a phytase included with lactic acid on productive parameters and on deposition of phosphorus, calcium, and zinc in laying hens fed with sorghum–soybean-meal-based diets

ABSTRACTIn an acidic pH, the phytic acid is more soluble and therefore, more susceptible to the action of an exogenous phytase (Phy). 50 Hy-Line W36 hens were randomly allocated into five treatments, each one with 10 replicates (one bird/replicate): (1) Positive Control (0.25% of available phosphorus (Pav)); (2) Negative Control (NC; 0.12% Pav); (3) NC + 0.5% lactic acid (LA); (4) NC + 450 FTU/kg Phy; (5) NC + 0.5% LA + 450 FTU/kg Phy. Low levels of Pav (0.12%) negatively affected the production parameters compared to the 0.25% Pav diet. LA alone only improved the egg laying production, egg mass, and feed intake. When Phy was included, the production parameters improved, being similar from 0.25% Pav diet. Additionally, the deposition of P, Ca, and Zn increased in the bone marrow, as well as Fe contents in the yolk. Phy addition decreased P excretion compared to diets with the same level of Pav. There was no difference between the use of Phy alone or in combination with LA. In conclusion, the addition of Phy into low Pav diets produced results that were similar to those obtained with 0.25% of Pav, without any additive effect seen when LA was also added.

Phytase and protease supplementation for laying hens in peak egg production

The effects of the combination of enzymes in commercial laying hens need to be more explored in literature. To determine if the type of protease affects performance, egg quality, nutrient intake, and morphometry of intestinal mucosa of laying hens in peak egg production and fed with phytase, 780 25-weeks Hy-Line W36 hens were assigned to a completely randomized design composed of five treatments/diets (one positive control, two negative controls, and negative controls plus protease A or B), with 12 replicates of 13 birds each. There was no effect of treatments (P &gt; 0.05) on egg production, egg mass and feed conversion, even though the nutritional restriction imposed by the negative controls reduced egg weight (P = 0.02), albumen height (P &lt; 0.01), and Haugh unit (P &lt; 0.01). Although inclusion of proteases in negative controls did not cause the calculated intake of protein and amino acids to return to the same amount consumed by positive-control hens, egg quality parameters returned to positive control standards with protease A. Intestinal mucosa responded to treatment only at jejunum, where birds fed with protease B showed greater (P &lt; 0.01) villus height and crypt depth than those treated with protease A. These findings suggest that different proteases and phytases interact distinctly and, in consequence, induce different responses on the birds. Moreover, the behavior of egg quality parameters after protease A inclusion in the diet indicates that the nutritional contribution of the combination of this protease with phytase is greater than the contribution of protease alone.

Biochemical Parameters and Histopathological Findings in the Forced Molt Laying Hens

The aim of this study was to evaluate the effects of forced molting using biochemical parameters and histopathological findings in laying hens. 36 Hyline W36 strain laying hens, 90 weeks old were chosen for this research. Eight of these chickens were randomly selected and placed in a cage as the control group before the molting program began. All the others 28 chickens were used for the forced molting program. Eight laying hens were slaughtered at the end of the molting program named as molting group. The remaining 20 hens were fed for 37 days, weighted and slaughtered when they reached the maximum egg production (80%) as postmolting group. Then, blood was analyzed for malondialdehyde, glutathione, catalase, glucose, calcium, phosphorus, albumin, globulin, total protein, triiodothyronine, thyroxine and Vitamin C. The malondialdehyde and glutathione levels of the thyroid and liver tissues were also analyzed along with an examination of the histopathological changes of the liver, ovarium and thyroid glands; and live body, liver, ovarium, thyroid weights and thyroid lengths. In conclusion, it was found that forced molting produces stress and notable side effects in hens, like the oxidant and antioxidant status of the organs, tissue weights and sizes, hormon profiles, blood biochemical and histopathological parameter changes. The activities of thyroid malondialdehyde (p<0.05), liver glutathione (p<0.01), plasma catalase (p<0.001) were significantly decreased in molting group compared to control values, while liver malondialdehyde levels were significantly increased (p<0.001) and thyroid glutathione levels had nonsignificant effect. These levels in molting hens were the first study for veterinary science.

Influence of genetic strain and access to litter on spatial distribution of 4 strains of laying hens in an aviary system

Many laying hen producers are transitioning from conventional cages to new housing systems including multi-tier aviaries. Aviary resources, such as litter areas, are intended to encourage hens’ expression of natural behaviors to improve their welfare. Little research has examined the influence of laying hen strain on distribution and behavior inside aviaries, yet differences could influence a strain's suitability for an aviary design. This research examined how laying hens of 4 strains (Hy-Line Brown [HB], Bovans Brown [BB], DeKalb White [DW], and Hy-Line W36) distributed themselves among 3 enclosed aviary tiers and 2 litter areas at peak lay (25 to 28 wk of age) and after gaining access to litter on the floor (26 wk). Observations of hens’ spatial distribution were conducted immediately before and after, and 3 wk after hens gained access to litter. More HB and BB hens were in upper tiers in morning compared to DW and W36 (all P ≤ 0.05). However, DW and W36 hens roosted in upper tiers in larger numbers than HB and BB during evening (all P ≤ 0.05). More DW and W36 hens were on litter compared to BB and HB, particularly when litter was first accessible (all P ≤ 0.05). The number of hens on litter increased over time for all strains (P ≤ 0.06). White hens on litter occupied open areas in higher numbers (P ≤ 0.05), while more brown hens occupied litter under the aviary after acclimation (P ≤ 0.05). In the dark period, W36 and DW hens were present in higher numbers in upper tiers than HB and BB, while HB and BB showed higher tier-to-tier movement than DW and W36 (P ≤ 0.05). In general, more white hens roosted higher at night and explored litter sooner, while more brown hens were near or in nests in the morning and moved at night. Distinct strain differences indicate that attention should be paid to the match between configuration of the aviary design and strain of laying hen.

By-product of passion fruit seed (Passiflora edulis) in the diet of commercial laying hens

This study evaluated the effects of the inclusion of the by-product passion fruit seed (BPFS) in the diet of laying hens on performance, blood variables, quality, and lipid oxidation in eggs. A total of 384 Hy-line W36 layers (32 wk old) were distributed in a completely randomized design, with six treatments (control, 2.5%, 5.0%, 7.5%, 10.0%, and 12.5% inclusion of BPFS), eight replicates and eight birds each. The productive performance was evaluated for three cycles of 28 d each. There was no difference (P &gt; 0.05) in egg production and feed conversion. However, feed intake showed increased linearly (P &lt; 0.05). The egg weight, egg mass, percentage of eggshell, eggshell thickness, and Haugh unit did not differ (P &gt; 0.05); however, the specific gravity of eggs increased (P &lt; 0.05). Total cholesterol and blood triglycerides decreased linearly (P &lt; 0.05). To evaluate the lipid yolk oxidation, a 6 × 5 × 2 factorial design (six levels of BPFS × five storage periods × two temperatures) was used. There was an interaction (P &lt; 0.05) among the levels of BPFS, time, and storage temperature with the lowest oxidation level of 12.5% when eggs were refrigerated. The BPFS can be included at a level up to 5.0% without compromising bird performance and 12.5% for egg quality, and this level reduced yolk lipid oxidation.

Effects of different levels of sanguinarine on antioxidant indices, immunological responses, ileal microbial counts and jejunal morphology of laying hens fed diets with different levels of crude protein.

This study was carried out to assess the effects of different levels of sanguinarine on antioxidant indices, immunological responses, serum biochemical parameters, ileal microbial counts and jejunal morphology of laying hens fed on diets with different levels of crude protein (CP). A total of 180 laying hens were subjected into nine dietary treatments with four cages of five birds each. Experimental treatments consisted of three levels of CP (85.0, 92.5 and 100% of Hy-Line W36 manual recommendation) and three levels of sanguinarine (0.00, 3.75 and 7.50mg/kg) as a 3×3 factorial arrangement of laying hens which fed during a 70-day feeding trial. The invitro study showed that sanguinarine exhibited sevenfold and threefold decreased antioxidant activities to inhibit 2-2-diphenyl-1-picric hydrazyl free radical as well as ferric ion reducing rather than butylated hydroxyl toluene. Although using the decremental levels of CP caused the increase in heterophil-to-lymphocyte ratio (p<0.01), dietary administration of sanguinarine could suppress the serum cholesterol and malondialdehyde concentrations as well as heterophil-to-lymphocyte ratio (p<0.05). Additionally, decreasing CP content resulted in the decreased percentage of albumin (p<0.05); however, it had no negative effects on humoral immunity. Nonetheless, feeding of at least 3.75mg/kg sanguinarine led to the remarkable increases in serum gamma globulin concentration (p<0.01) and secondary (p<0.05) antibody titres against sheep red blood cells. Moreover, a decline in dietary CP content led to higher villi height and crypt depth (p<0.05; p<0.001) and consequently decreased villi height-to-crypt depth ratio (p<0.001) than the optimum level (100% CP). In spite of the effects of sanguinarine on the suppression of Escherichia coli and Salmonella counts (p<0.05), it markedly enhanced villi height-to-crypt depth ratio as well as lamina propria lymphatic follicles extent, simultaneously (p<0.001). Therefore, in spite of the detrimental effects of feeding low-CP diets on lymphocytes and serum albumin percentages, and villi height-to-crypt depth ratio, the administration of incremental levels of sanguinarine could improve cellular and humoral immunity, decrease ileal microbial counts and in turn improve the intestinal health indices in laying hens.

The effect of replacing soya bean oil with glycerol in diets on performance, egg quality and egg fatty acid composition in laying hens

The objective of this experiment was to replace soya bean oil with glycerol in laying hen diets and assess the change’s effect on performance, parameters of egg quality and the egg fatty acid profile. A total of 60 44-week-old Hy-Line W36 laying hens were distributed according to a completely randomised experimental design into four treatments consisting of glycerol substitutions for soya bean oil dietary at varying inclusion levels (0%, 25%, 50% and 75%), with five replicates of three birds each. Dietary treatments had no significant effect on BW change, egg production, feed intake, feed conversion ratio, egg weight and egg mass of laying hens. The inclusion of glycerol in the diet of laying hens had no significant effect on egg specific gravity, eggshell breaking strength, eggshell weight, eggshell thickness, egg shape index, albumen index, yolk index, haugh unit, albumen pH, yolk pH and egg yolk colour values. The inclusion of glycerol in the diet of laying hens had no significant effect on palmitic, palmitoleic, stearic, oleic and linolenic acid contents of the egg yolk. The linoleic acid and polyunsaturated fatty acid contents of the egg yolk significantly decreased with the higher levels of dietary glycerol supplementation (P<0.05). The results of this study show that it is possible to replace 75% of soya bean oil (4.5% in diet) with glycerol.

Application of low-gossypol cottonseed meal in laying hens’ diet

An experiment was conducted to evaluate the application of dietary low-gossypol cottonseed meal (LCSM) in layers' diets. A total of 432 40-week-old Hy-line W36 laying hens were allocated to one of the six dietary treatments with 6 replicates of 12 birds each. The control group was fed a corn-soybean meal basal diet, and the 4 experimental diets consisted of a basal diet with 50, 98.3, 144.2, or 189 g/kg LCSM, respectively (correspondingly 25%, 50%, 75%, 100% dietary protein provided by soybean meal were replaced by LCSM). The sixth group was fed a basal diet supplemented with free gossypol (FG group). The feeding trial lasted for 12weeks. The results showed that no significant difference was observed on egg production or feed conversion ratio (FCR, feed/egg, g/g) among all groups, but feed intake and egg weight were significantly decreased in the 189 g/kg LCSM group in weeks 46 to 51 (P < 0.05). A significant decrease was not observed in shell strength, shell thickness, and yolk color in all periods, but Haugh unit, albumen height, and egg white protein content were reduced in 189 g/kg LCSM group in weeks 46 to 51 (P < 0.05). No significant differences were found between the control and FG group. There was no obvious difference on plasma levels of total protein, blood urea nitrogen, uric acid, and activities of albumen, alanine aminotransferase, aspartate aminotransferase and the histopathology of liver, kidney, and oviduct in all groups. In conclusion, decreasing feed intake, egg weight, and egg quality were observed in the 189 g/kg LCSM group. However, the adverse effect was not relevant to the presence of FG in LCSM. Dietary LCSM supplementation of 98.3 g/kg was recommended with optimum FCR and without adverse effect on egg production, quality, and health of layers.

&lt;b&gt;Internal quality of laying hen eggs fed on protease at different storage and stocking conditions

Effects on diets with reduction of crude protein and methionine + cystine (RCP) and protease supplementation (PRO) for laying hens at different ages and their influence on the internal quality of eggs at different conditions (STO) and storage times (TM) are evaluated. Four hundred and twenty eggs from commercial Hy-Line W36 laying hens collected at 32, 44 and 58 weeks of age were used. Experimental design was completely randomized in a factorial scheme 3 x 2 x 2 x 2: RCP (control, enhancement of one and two times the enzyme protease), PRO (with and without protease), STO (room temperature and refrigerated) and TM (14 and 28 days), with seven replications of one egg per experimental unit. The factorial scheme 3 x 2 x 2 was used at 58 weeks of age, because TM could not be evaluated. The percentages of egg weight loss, Haugh unit, albumen percentage, percentage and yolk index were evaluated after each storage time. RCP and PRO had no effect on internal egg quality whereas eggs under refrigeration preserved their internal quality regardless of the different storage periods.

Effect of dietary available phosphorus and phytase on production performance of old laying hens and tibia bone quality

Background: Old laying hens are more prone to dietary calcium (Ca) and phosphorus (P) deficiencies as they absorb Ca and P less efficiently than younger hens. OBJECTIVES: In a 2×2 factorial design, the influence of diets with two levels of available phosphorus (AP) and phytase enzyme on the laying performance, egg quality and tibia bone characteristics of laying hens at their late 2nd production phase was studied. METHODS: The experiment used four treatments of 20 Hy-Line W36 hens of 140 weeks old. Treatments 1 and 2 received a 3.5 g kg-1 AP diet while Treatments 3 and 4 received a 2.5 g kg-1 AP diet for 12 weeks. Treatments 2 and 4 received 250 FTU kg-1 phytase in their diet. Laying performance, egg weight, shell weight and shell thickness were measured. On the last day of the experiment, all birds were weighed and blood samples were collected for serum Ca and P measurements. Ten birds from each treatment were sacrificed and both tibiae were excised, defatted, weighed and ashed for Ca and P contents, cortical thickness and bone breaking strength measurements. RESULTS: Hens fed with 2.5 g kg-1 AP diet without enzyme had the lowest body weight gain, serum P, tibia cortical thickness and tibia breaking strength among the treatments (p<0.05). Phytase enhanced body weight gain, egg shell thickness, serum P, tibia weight/body weight and tibia ash/body weight ratios, tibia cortical thickness and breaking strength, particularly in birds receiving 2.5 g kg-1 AP diet (p<0.05). CONCLUSIONS: Phytase may improve bone quality and strength of hens in the late 2nd laying period.

Tryptophan, threonine and isoleucine supplementation in low-protein diets for commercial laying hens

Isoleucine (Ile), threonine (Thr) and tryptophan (Trp) are most likely candidates for becoming third limiting amino acids (AA) in layer diets. This work studied the effect of supplementing Ile, Thr and Trp in low-protein diets on the productive performance, egg quality and serum parameters of Hy-Line W36 laying hens. A total of 360 30-week-old laying hens were distributed in a completely randomized design into 9 treatments with 5 replications of 8 birds each. Treatments consisted of a control diet that was based on corn and soybean meal formulated with 15.5% CP. A second diet with 13% CP was formulated to meet the requirements for all essential AA of the control diet, except for Ile, Thr and Trp. The other treatments consisted of individual and combined supplementation of the aforementioned AA in the 13% CP diet. The reduction of the dietary protein level negatively influenced (p<0.05) the productivity of the hens, impairing egg production, feed conversion (kg kg-1 and kg dz-1), and egg mass. However, these variables were restored with individual and combined supplementation of the three AA in the 13% CP diet. Individually-supplemented diets with Ile, or combined with Thr and/or Trp, resulted in hens with lower (p<0.05) serum uric acid and ammonia concentrations as compared to birds receiving diets with 15.5% (control) and 13% CP. The protein levels can be reduced (13% CP) in the diet of commercial laying hens without compromising performance, egg quality or serum parameters with individual Ile, Thr or Trp supplementation.

Effect of sweet green pepper on yolk color and performance of laying hens

An experiment was conducted to evaluate the effects of sweet green pepper (SGP) on the performance and egg quality of commercial laying hens. A total of 144 Hy Line W36 egg layers were randomly assigned to 4 treatments with 9 replicate groups of 4 hens each. Treatments consisted of the following diets: 1) basal diet (BD), 2) BD + 75 ppm SGP, 3) BD + 125 ppm SGP, 4) BD + 225 ppm SGP. The diets contained 2,730 kcal/kg metabolizable energy and 15.5% crude protein. Egg production and egg quality were monitored for 16 weeks. Feed intake, hen-day egg production, egg mass, and feed conversion per dozen were not significantly affected by the addition of SGP to the diets. The addition of 225 ppm of SGP decreased egg weight. Specific gravity, albumen height, Haugh unit, yolk weight, albumen weight, albumen percentage, and yolk yellowness (b*) were not significantly affected by the addition of SGP. The addition of SGP to the diets increased yolk percentage, yolk color using a Roche fan, and yolk redness (a*). Based on these data, SGP was shown to be a useful feed ingredient for laying hens; it can be included in diets without negative effects on performance and egg quality. However, owing to the depression of egg weight with the inclusion of SGP, it may be of interest to producers and industry to control egg size in old layers and possibly improve shell quality. The addition of SGP to the diets impacted yolk color and may be useful in specialty markets.

The effects of eggshell and oyster shell supplemental as calcium sources on performance, eggshell quality and mineral excretion in laying hens

A study was conducted to determine the influence of different calcium sources in layer diets on performance, eggshell quality and mineral excretions. A total of 72 Hy-Line W36, layer birds of 25 weeks old, were distributed in 6 experimental groups randomly. In each experiment group there were 4 replicates, and in each replicates there were 3 birds. During the 12 weeks experiment period, birds were fed 6 experimental diets. Experimental diets were consisted of various calcium sources for meeting the calcium requirements. It was control (limestone), 1/3 eggshell, 1/3 oyster shell, 1/3 eggshell+1/3 oyster shell, 2/3 eggshell and 2/3 oyster shell. Dietary different sources of calcium had no significant effect on body weight change, feed conversion ratio, eggshell breaking strength, eggshell thickness, and eggshell phosphorus and magnesium contents (p > 0.05). The different sources calcium had a significantly effect on egg production, egg weight, egg mass, feed intake and eggshell weight in laying hens (p < 0.01; p < 0.05). The different calcium sources had significantly effect on eggshell calcium content, and calcium, phosphorus and magnesium excretion in hens (p < 0.01). Results of the present study observed that laying hens were not advantageous for performance by fed with eggshell and oyster shell as calcium sources.

Mixed crude glycerin in laying hen diets: live performance and egg quality and fatty acid profile

This study evaluated the performance and the quality and fatty acid profile of eggs from laying hens fed diets containing mixed crude glycerin (MCG; 80% vegetable fat + 20% animal fat). A total of 240 39-week-old Hy-Line W36 laying hens were distributed according to a completely randomized experimental design into six treatments consisting of graded MCG dietary inclusion levels (0, 1.5, 3.0, 4.5, 6.0, and 7.5%), with five replicates of eight birds each. Feed intake linearly decreased (p<0.05) with increasing MCG inclusion levels. The percentages of myristic, palmitic, and α-linolenic acids in the eggs linearly decreased as MCG dietary levels increased (p<0.05), while α-linoleic acid, polyunsaturated fatty acids (PUFA) and ω-6/ω-3 ratio linearly increased. Excreta moisture linearly increased with increasing levels of MCG inclusion (p<0.05). MCG may be included in up to 7.5% in layer feeds without impairing performance or egg quality, but levels up to 5.54% reduce SFA egg content. However, the inclusion of MCG in layer diets increases ω-6/ω-3 ratio in the eggs.

Effects of packaging, mineral oil coating, and storage time on biogenic amine levels and internal quality of eggs

This study was carried out with the aim of evaluating the effects of mineral oil application on eggshells and the use of plastic packages with lids on the physical-chemical and microbiological quality and biogenic amine contents of eggs stored under refrigeration for up to 125 d. A total of 1,920 eggs from 46-wk-old Hyline W36 laying hens were randomly distributed into 4 groups soon after classification: (i) 480 eggs were stored in pulp carton tray packages; (ii) 480 eggs were stored in plastic packages with lids; (iii) 480 eggs were stored in carton packages after the application of mineral oil; and (iv) 480 eggs were stored in plastic packages with lids after the application of mineral oil. The internal quality was measured by Haugh units, by the counts of mesophilic and psychrotrophic microorganisms, by the most probable number of total and thermal-tolerant coliforms, by the counts of molds and yeasts, by the analysis of Salmonella spp. and Staphylococcus spp., and by the levels of biogenic amines in the egg yolk and albumen. The application of mineral oil to the eggshell resulted in higher Haugh unit values throughout storage, and the use of plastic packages altered the internal quality. The application of mineral oil and the use of packaging had no effects on the microbiological and biogenic amine results. Microbiological analyses showed the absence of Salmonella spp., Staphylococcus aureus, thermal-tolerant coliforms, and fungi. However, the highest counts of mesophilic (1.1 × 107 cfu/g) and psychrotrophic (6.7 × 107 cfu/g) microorganisms were recorded. The highest values of biogenic amines detected and quantified were putrescine (2.38 mg/kg) and cadaverine (7.27 mg/kg) in the egg yolk and putrescine (1.95 mg/kg), cadaverine (2.83 mg/kg), and phenylethylamine (2.57 mg/kg) in the albumen. Despite these results, the biogenic amine levels recorded were considered low and would not be harmful to consumer health.

Aflatoxins, hydroxylated metabolites, and aflatoxicol from breast muscle of laying hens

Aflatoxins (AF) are toxic fungal secondary metabolites that are pathological to animals and humans. This study identified and quantified AF (AFB1, AFB2, AFG1, AFG2) and their hydroxylated metabolites (AFM1, AFM2, AFP1) and aflatoxicol (AFL) from laying hen breast muscles. Aflatoxins pass from cereal feed to the laying hen tissues, causing economic losses, and from there to humans. To detect the passage of AF from feed to hen breast muscle tissues, an experiment that included 25 Hy-Line W36 121-wk-old hens was performed for 8 d. Hens in individual cages were distributed into 3 groups: a control group, with feed free of AFB1, and 2 experimental groups, with feed spiked with 2 AFB1 dosages: 30 µg·kg−1 (low) or 500 µg·kg−1 (high). The daily feed consumption per hen was recorded and afterward hens were euthanized and breast muscles were collected, weighed, and dried individually. Aflatoxins were extracted by 2 chemical methods and quantified by HPLC. Both methods were validated by lineality (calibration curves), recovery percentage (>80%), limit of detection, and limit of quantification. The AF (µg·kg−1) averages recovered in control breast muscles were as follows: AFB1 (18); AFG1, AFM2, and AFL (0); AFG2 (1.3); AFM1 (52), and AFP1 (79). Hens fed with feed spiked with 30 µg·kg−1 of AFB1 had AFG1 (16); AFG2 (72); AFM1 (0); AFM2 (18); AFP1 (145); and AFL (5 µg·kg−1). Hens with feed spiked with 500 µg·kg−1 of AFB1 had AFG1 (512); AFG2 (7); AFM1 (4,775); AFM2 (0); AFP1 (661); and AFL (21 µg·kg−1). The best AF extraction method was Qian and Yang's method, modified by adding additional AF from both Supelclean LC18 SPE columns; its limit of detection (0.5 ng·mL−1) was lower compared with that of Koeltzow and Tanner, which was 1 ng·mL−1.