Multivariate analysis of sources of polyunsaturated fatty acids, selenium, and chromium on the productive performance of second-cycle laying hens

An experiment was conducted to evaluate the effect of the intake of a mixture of fish and sacha inchi oils (iOM), organic selenium (iSe), and organic chromium (iCr) on egg production (EP) and feed conversion ratio (FCR) of Isa Brown second-cycle laying hens (SCLH) for 16 weeks (91-106 weeks old). Egg production and FCR were evaluated using multivariate models that included conventional equations and artificial neural networks (ANN) to study multiple nutritional interactions as alternatives to univariate dose-response models. Based on the best models, iOM, iSe, and iCr levels were optimized, and a global sensitivity analysis was implemented to quantify their influence on EP and FCR. The modified logistic model was selected as the best strategy to represent EP. In the case of FCR, an ANN model with a feed-forward architecture and softmax transfer function was selected as the best alternative. One of the scenarios to simultaneously optimize EP (89.1%) and FCR (1.94 kg feed/kg egg) at 16 weeks of production was established with 3.3 g/hen·day of iOM, 0.132 mg/ hen·day of iSe, and 0.176 mg/hen·day of iCr. However, optimization considering only FCR results in much lower optimal iCr levels (between 0.083 and 0.105 mg/hen·day) with a slight decrease in EP (87.9%). The global sensitivity analysis showed that iSe is an essential factor associated with the increase in EP, and iCr is the most influential factor for the decrease in FCR. When both criteria were taken into account simultaneously from a desirability function, iSe was the most critical factor.(AU)

The Protective Role of Silymarin to Ameliorate the Adverse Effects of Ochratoxin-A in Laying Hens on Productive Performance, Blood Biochemistry, Hematological and Antioxidants Status

This study was planned to examine the effect of silymarin on diminishing adverse effects of ochratoxin-A (OTA) in laying hens. A total number of 300 Inshas, local layer hens of 28 weeks of age were randomly distributed into 4 groups with 5 replicates each (15 hens). The birds were fed on the following treatments, (Control): fed a hen diet without any supplementation; (SL): fed the control diet supplemented with SL (1000 mg/kg feed); (OTA-diet): was fed the control diet contaminated with 1 ppm of OTA/kg diet, and (OTA+SL): fed the OTA-diet plus SL (1ppm OTA+1000 mg SL/kg feed). Results showed that feeding OTA at 1 ppm reduced productive performance compared with those fed the control diet. In OTA treated groups the total erythrocytes count, leukocytes count, PCV and Hb were decreased when compared to the control and SL groups. Albumin, globulin and serum total proteins in OTA treated groups were significantly lower when compared to the control and SL groups. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were significantly increased in OTA fed groups in comparison with the control and SL groups. Creatinine and uric acid were increased in OTA treated groups but were almost normal in the SL group. The results showed that OTA had a severe effect on liver and kidney, but SL treated group had normal liver and kidneys showing its hepatoprotective effects.(AU)

Production Layer Salmonella Enteritidis Control through Dry Fed Pre & Probiotic Products

ABSTRACT Increasing interest in multiple strain Bacillus probiotics and parietal yeast fractions as feed ingredients for egg laying hen diets has also led to food safety questions. This study was undertaken to evaluate the ability of these products to reduce Salmonella Enteritidis colonization. Sixty Hy-Line hens aged 56 weeks were placed in individual cages and fed a mash diet containing one of the following treatments, control, Bacillus spp. probiotic, yeast cell wall, or a combination of yeast cell wall and Bacillus probiotic. At 60 weeks of age all hens were challenged orally with 7 x 107 CFU/bird of Salmonella Enteritidis. At 61 weeks of age, birds were humanely euthanized, by cervical dislocation and the ceca aseptically removed and cultured for S. Enteritidis prevalence and number by the Most Probable Number method. There was no significant difference in prevalence of Salmonella Enteritidis between the control and any treatments. The control birds had 4.37 log10 MPN/g of S. Enteritidis detected in the ceca. The Probiotic group had 2.96 MPN/g, a reduction of 1.41(p 0.05) and the yeast cell wall group had 2.89 MPN/g a reduction of 1.48 (p 0.05). The combination had 3.60 MPN/g a numerical reduction of 0.78 (p=0.14). The yeast cell wall and Bacillus probiotic groups significantly reduced the amount of Salmonella Enteritidis in the ceca of the laying hens.

Production Performance and Egg Quality of Laying Hens as Influenced by Genotype and Rearing System

ABSTRACT The aim of this study was to evaluate the effect of rearing systems and genotypes on production performance and egg quality. Isa Brown and New Hampshire genotypes were used in this study. These two genotypes were housed in floor and organic rearing systems. During the experimental period, which lasted one year (52 weeks), the following production performance parameters were recorded: egg production, daily egg mass, feed consumption, feed conversion efficiency, and mortality. Fifteen eggs per group were collected for analysis at 64 weeks of hen age. These samples were evaluated for external parameters (egg weight and egg shape index), internal parameters (albumen height, Haugh unit, and the proportions of albumen, yolk and shell), eggshell quality parameters (shell thickness, shell deformation and shell breaking strength), and eggs chemical composition (dry matter, minerals, protein and lipids). Generally, Isa Brown hens had better production performance than New Hampshire hens. At the same time, organic New Hampshire layers performed better than floor-reared ones. Genotype had a significant effect on all ten egg quality parameters (external, internal and eggshell quality), rearing system independently affected only egg weight, and the interaction of the observed factors significantly influenced seven parameters. Genotype had a significant effect on three of the four chemical composition parameters, while no significant effect of the rearing system was established on the chemical composition of eggs. The rearing system x genotype interaction significantly affected the eggs protein content.

Levels of Polyamines in Feces of Laying Hens Fed with Agave Fructans (Agave Tequilana, Weber) in Association with the Quality and Production of Egg

ABSTRACT In this study two experiments were carried out, the effect of a diet supplemented with fructans of Agave tequilana Weber, was analyzed in Hy-line hens in regards to their egg quality and production as well as on the levels of the polyamines, putrescine, spermidine and spermine in their feces. In the first study 300 Hy-line W-36 hens per group, which were aged 36 weeks, were randomly separated as follows for each of the three treatments. One group of 100 hens was fed with a diet supplemented with 0.1% fructans. Another group of 100 hens was supplemented with 0.2% fructans and a group of 100 hens without any fructans was added as a control group. Feed consumption was lower in the supplemented groups compared to the control group (p 0.05). Egg yolk quality was measured using Haugh units. The quality of the shell was studied using an Egg Force reader (g pressure/mm2). Putrescine levels was measured in 10 animals in each group. In the second study, 1,155 laying hens, aged one day from the Hy-line W-35 genetic line were also randomly divided into three groups containing 385 hens in each one (A, B, C). Egg laying levels and weight was measured during 35 weeks. The egg laying percentage increased considerably in hens ingesting supplemented diets (p 0.05) and the egg weight was greater mainly in the supplementation with 0.1% fructans (p 0.05). Thus, it was shown that diet supplementation with fructans of agave improves egg quality and homeostasis and food consumption in the Hy-line hen.

Influence of Effective Microorganism Supplementation to the Drinking Water on Performance and Some Blood Parameters of Laying Hens Exposed to A High Ambient Temperature

In the present study, seventy-two 30-week-old laying hens (Brown Hisex) were separated into two groups (control and treatment) and fed with a standard layer diet. In the treatment group the amount of effective microorganism (EM) added to the drinking water is equal to1000 ppm EM dose. Throughout the 8-week study period, 16 h thermoneutral (20-22 ºC) and 8 h hot (35-37 ºC) environmental temperature regime was applied daily. The results indicated that EM supplementation affected performance and some egg quality characteristics of layers exposed high environmental temperature. Feed intake and conversion ratio, yolk index, albumen index, yolk colour b, Haugh unit were decreased by supplemental EM. Serum glucose, cholesterol, triglycerides, calcium, total oxidant- antioxidant concentration were not affected by EM. It is concluded that EM supplementation in laying hens could have potential to improve feed intake and feed conversion ratio under high environmental temperature. However, supplemental EM with drinking water decreased some egg quality parameters.(AU)

Influence of Effective Microorganism Supplementation to the Drinking Water on Performance and Some Blood Parameters of Laying Hens Exposed to A High Ambient Temperature

In the present study, seventy-two 30-week-old laying hens (Brown Hisex) were separated into two groups (control and treatment) and fed with a standard layer diet. In the treatment group the amount of effective microorganism (EM) added to the drinking water is equal to1000 ppm EM dose. Throughout the 8-week study period, 16 h thermoneutral (20-22 ºC) and 8 h hot (35-37 ºC) environmental temperature regime was applied daily. The results indicated that EM supplementation affected performance and some egg quality characteristics of layers exposed high environmental temperature. Feed intake and conversion ratio, yolk index, albumen index, yolk colour b, Haugh unit were decreased by supplemental EM. Serum glucose, cholesterol, triglycerides, calcium, total oxidant- antioxidant concentration were not affected by EM. It is concluded that EM supplementation in laying hens could have potential to improve feed intake and feed conversion ratio under high environmental temperature. However, supplemental EM with drinking water decreased some egg quality parameters.

Multivariate modeling strategies to predict nutritional requirements of essential amino acids in semiheavy second-cycle hens

An experiment with 23 diets was performed to evaluate the effect of digestible lysine (Lys), digestible methionine + cysteine (Met+Cys), and digestible threonine (Thr) on egg production of H&N Brown second-cycle laying hens (SCLH) for 20 weeks (92-111 weeks of age) in cages under environmental conditions. Body weight (BW), feed intake (FI), feed conversion ratio (FCR), egg weight (EW), number of hen-housed eggs, and livability were also evaluated during the experiment. Diets were formulated from a central composite design that combined five levels of Lys, Met+Cys, and Thr ranging from 727 to 1159, 662 to 1055, and 552 to 882 mg/kg, respectively. Egg production (EP) data were evaluated through three different modeling strategies: egg production models, multivariate polynomial models, and artificial neural networks (ANN). A cascade-forward neural network with logsigmoid transfer function was selected as the best model according to goodness-offit statistics in both identification and validation data. One of the best scenarios for EP of H&N Brown SCLH under specific outdoor conditions was established at Lys, Met+Cys, and Thr levels of 1138, 1031, and 717 mg/hen·day, respectively. The ANN model may be an appropriate tool to study and predict EP of H&N Brown SCLH based on the combination of three different levels of essential digestible amino acids. The strategies included in this work may contribute to improving poultry performance based on modeling techniques to study other production parameters in terms of different nutritional requirements and productive conditions.

Influence of Low and High-density Diets with Yeast Supplementation on Feed Intake, Nutrient Digestibility, Egg Production and Egg Quality in Hy-line Brown Laying Hens

A total of 432 laying hens (40 weeks old) were used in a 10- weeks feeding trial. The birds were randomly assigned to 1 of 4 treatments with 18 replications (6 birds per replication) in a 2×2 factorial arrangement with low-density diet (LD), and high density (HD) diets supplemented with or without (0.1 %) of yeast. Laying hens feed intake during the 5th, 6th and 10th weeks has significantly increased (p<0.05) in LD diet and HD diet supplemented with (0.1 %) of yeast supplementation. However, egg production and broken rate was not affected with or without yeast and density diet. The quality of egg and shell color during the 5th, 6th, and 7th weeks has significantly reduced (p<0.05) by yeast supplementation with HD and LD diet. Eggshell strength was significantly improved at week 4, moreover albumin height was also significantly improved by yeast supplementation diets at week 5. During week 1 and 2 the yolk color was higher in LD diet and HD diet compared with yeast supplementation. However, eggshell strength was significantly improved on HD diets than LD diets during the 4th and 7th weeks. Eggshell color and albumen height were significantly decreased in laying hens fed HD or LD diets during week 5 and 6. The apparent total tract digestibility (ATTD) of dry matter (DM), nitrogen (N), and Energy was not affected (p<0.05) by laying hens fed with or without yeast and HD than LD diets. In summary, 0.1% of yeast supplementation proved a positive impact on feed intake and egg quality of layer chicken.(AU)

Influence of Low and High-density Diets with Yeast Supplementation on Feed Intake, Nutrient Digestibility, Egg Production and Egg Quality in Hy-line Brown Laying Hens

A total of 432 laying hens (40 weeks old) were used in a 10- weeks feeding trial. The birds were randomly assigned to 1 of 4 treatments with 18 replications (6 birds per replication) in a 2×2 factorial arrangement with low-density diet (LD), and high density (HD) diets supplemented with or without (0.1 %) of yeast. Laying hens feed intake during the 5th, 6th and 10th weeks has significantly increased (p<0.05) in LD diet and HD diet supplemented with (0.1 %) of yeast supplementation. However, egg production and broken rate was not affected with or without yeast and density diet. The quality of egg and shell color during the 5th, 6th, and 7th weeks has significantly reduced (p<0.05) by yeast supplementation with HD and LD diet. Eggshell strength was significantly improved at week 4, moreover albumin height was also significantly improved by yeast supplementation diets at week 5. During week 1 and 2 the yolk color was higher in LD diet and HD diet compared with yeast supplementation. However, eggshell strength was significantly improved on HD diets than LD diets during the 4th and 7th weeks. Eggshell color and albumen height were significantly decreased in laying hens fed HD or LD diets during week 5 and 6. The apparent total tract digestibility (ATTD) of dry matter (DM), nitrogen (N), and Energy was not affected (p<0.05) by laying hens fed with or without yeast and HD than LD diets. In summary, 0.1% of yeast supplementation proved a positive impact on feed intake and egg quality of layer chicken.

Effects of chromium yeast supplementation on productive and metabolic responses of laying hens fed diets containing different energy levels

This study evaluated the effects of chromium yeast (Cr yeast) and two apparent metabolizable energy (AME) levels on productive performance, egg quality, and lipid and carbohydrate metabolism in laying hens. A total of 192 Bovans White laying hens at 47 weeks of age were randomly assigned to eight dietary treatments (six replicates each) in a 4 × 2 factorial arrangement: four levels of supplemental Cr (0, 0.2, 0.4, and 0.8 ppm as Cr yeast) and two AME levels (2,780 and 2,900 kcal AME kg−1). No significant effect of Cr yeast supplementation on feed intake, egg weight, egg production, intact eggs, egg mass, feed conversion ratio, or egg quality was observed. Egg quality parameters and Cr content in the yolk were not affected by dietary treatments. Plasma glucose and lipid levels were not influenced by either Cr yeast or AME levels used in this study. However, Cr yeast supplementation improved yolk percentage and hepatic glycogen content. The inclusion of Cr yeast at 0.2 and 0.4 ppm induced the highest hepatic glycogen content with the energy levels 2,900 and 2,780 kcal AME kg−1, respectively. Laying hens fed 2,900 kcal AME kg−1 showed the highest abdominal fat. The results observed in the present study support the hypothesis that the lack of positive effects of Cr yeast supplementation on production performance and egg quality may be related to good management practices, as the birds were not subjected to stressful conditions.

Superdosing Phytases in the Diets of Light Laying Hens: Productive Performance and Bone Quality

Two experiments were carried out with the objective of evaluating the effect of superdosing of two phytases on performance, egg quality, digestive organ biometry and bone quality of light hens in the first (58 weeks) and second (87 weeks) productive cycle. In the first cycle, 270 light hens were used, in which a completely randomized design was adopted in a 2 x 2 + 1 factorial scheme (bacterial phytase or fungal phytase x 450 FTUs or 900 FTUs + control diet). In the second cycle, 270 hens were used, following the same design as the previous experiment. The performance and quality of the eggs were evaluated in both cycles, and the biometry of the digestive organs and bone characteristics were also evaluated in the first experiment. There was no effect in the comparison between the means for the performance and egg quality (in both experiments), or for the biometric variables and bone characteristics (first experiment). There was no significant interaction between the factors for any of the variables in the two experiments. In the first experiment, egg production was higher with bacterial phytase and egg weight with fungal phytase. The mineral matter showed greater value with 450 FTUs. It is recommended to use bacterial phytase produced from Escherichia coli as it improves the performance of light laying hens. The dosage of 450 FTUs improves the mineral content of light laying hens and the use of phytase in the laying hen diet implies a lower feed cost.

Superdosing Phytases in the Diets of Light Laying Hens: Productive Performance and Bone Quality

Two experiments were carried out with the objective of evaluating the effect of superdosing of two phytases on performance, egg quality, digestive organ biometry and bone quality of light hens in the first (58 weeks) and second (87 weeks) productive cycle. In the first cycle, 270 light hens were used, in which a completely randomized design was adopted in a 2 x 2 + 1 factorial scheme (bacterial phytase or fungal phytase x 450 FTUs or 900 FTUs + control diet). In the second cycle, 270 hens were used, following the same design as the previous experiment. The performance and quality of the eggs were evaluated in both cycles, and the biometry of the digestive organs and bone characteristics were also evaluated in the first experiment. There was no effect in the comparison between the means for the performance and egg quality (in both experiments), or for the biometric variables and bone characteristics (first experiment). There was no significant interaction between the factors for any of the variables in the two experiments. In the first experiment, egg production was higher with bacterial phytase and egg weight with fungal phytase. The mineral matter showed greater value with 450 FTUs. It is recommended to use bacterial phytase produced from Escherichia coli as it improves the performance of light laying hens. The dosage of 450 FTUs improves the mineral content of light laying hens and the use of phytase in the laying hen diet implies a lower feed cost.(AU)

Effect of Dietary Supplementation of Full-Fat Canola Seeds on Productive Performance, Blood Metabolites and Antioxidant Status of Laying Japanese Quails

The present study was carried out to evaluate the effects of dietary supplementation of different levels of full-fat canola seeds (FFCS) on productive performance, blood metabolites and antioxidant status of laying Japanese quails. A total of 360, 8-week-old quails were divided into a completely randomize design with 4 dietary experimental groups and three pens each, each pen containing 30hens. The experimental groups were fed iso-caloric and iso-nitrogenous diets supplemented with FFCS at levels 0, 50, 100 and 150 g/kg diet. The experiment lasted 16 weeks. All supplemented groups showed significant effects in the final body weight (g), hen feed consumption (g/hen/day), egg mass (g egg/hen/day) and hen-day egg production (%). However, egg weight (g) at 8-12 weeks of age reduced significantly. Moreover, feed conversion ratio (g feed/g egg), did not alter among groups. Egg quality criteria were not affected by FFCS supplementationexcept for the egg shape index which decreased significantly at 10 and 15% FFCS groups. Serum total protein, albumen, uric acid, creatinine, hepatic enzyme activities, triiodothyronine, total cholesterol and HDL-cholesterolconcentrations were not altered. However, serum triglycerides and LDL-cholesterol showed significant reduction in all treated groups. Furthermore, serum glutathione peroxidase level was greatly influencedin supplemented groups, while malondialdehyde level reduced significantly. In conclusion, FFCS inclusion in Laying Japanese quail diets up to 15% enhanced the laying performance, blood lipids profile and anti-oxidative status. Thus, it can be regarded as alternative sources of energy and protein in poultry rations.(AU)

Effect of Dietary Supplementation of Full-Fat Canola Seeds on Productive Performance, Blood Metabolites and Antioxidant Status of Laying Japanese Quails

The present study was carried out to evaluate the effects of dietary supplementation of different levels of full-fat canola seeds (FFCS) on productive performance, blood metabolites and antioxidant status of laying Japanese quails. A total of 360, 8-week-old quails were divided into a completely randomize design with 4 dietary experimental groups and three pens each, each pen containing 30hens. The experimental groups were fed iso-caloric and iso-nitrogenous diets supplemented with FFCS at levels 0, 50, 100 and 150 g/kg diet. The experiment lasted 16 weeks. All supplemented groups showed significant effects in the final body weight (g), hen feed consumption (g/hen/day), egg mass (g egg/hen/day) and hen-day egg production (%). However, egg weight (g) at 8-12 weeks of age reduced significantly. Moreover, feed conversion ratio (g feed/g egg), did not alter among groups. Egg quality criteria were not affected by FFCS supplementationexcept for the egg shape index which decreased significantly at 10 and 15% FFCS groups. Serum total protein, albumen, uric acid, creatinine, hepatic enzyme activities, triiodothyronine, total cholesterol and HDL-cholesterolconcentrations were not altered. However, serum triglycerides and LDL-cholesterol showed significant reduction in all treated groups. Furthermore, serum glutathione peroxidase level was greatly influencedin supplemented groups, while malondialdehyde level reduced significantly. In conclusion, FFCS inclusion in Laying Japanese quail diets up to 15% enhanced the laying performance, blood lipids profile and anti-oxidative status. Thus, it can be regarded as alternative sources of energy and protein in poultry rations.

Arthrospira (Spirulina) Platensis Can Be Considered as a Probiotic Alternative to Reduce Heat Stress in Laying Japanese Quails

This study was conducted to investigate the effects of Arthrospira platensis (Spirulina platensis, SP) on feed intake, feed conversion ratio, egg weight, hen day egg production, intestinal microflora, heat stress biomarkers, and HSP70 gene expression in laying Japanese quails (Coturnix coturnix japonica) suffering heat stress condition. A total of 250 female quails were allocated to 5 treatments, 5 replicates and 10 birds in each replicate in a completely randomized design. Experimental treatments included: 1) basal diet, 2) basal diet+ 0.03 % probiotic, 3) basal diet+ 0.1 % SP, 4) basal diet+ 0.3 % SP, 5) basal diet+ 0.5 % SP. During the last 6 days of the experiment, the quails were exposed to 8h of 34±1°C. The birds had free access to feed and water during the experiment. The results showed that using probiotic and different levels of Spirulina had no significant effect on laying performance of Japanese quails (p>0.05). Probiotic supplement increased Lactobacil bacteria population in laying quails ileum under heat stress (p 0.05). Different levels of SP decreased Escherichia coli population in laying quails ileum suffering heat stress (p 0.05).SP at the level of 0.5% caused the lowest blood Malondialdehyde level, heterophil, and H/L ratio (p 0.05).However, HSP70 gene expression in the heart or the liver of laying quails was not different (p>0.05). In conclusion, the results of the present study revealed that SP at the level of 0.5 % has the potential to be considered as a probiotic alternative in the diet of laying quails suffering heat stress condition.

Effects of different proteases on commercial laying hens at peak production

We evaluated the effect of adding proteases in diets of laying hens at peak production on the performance, egg quality, relative weight of digestive organs, and intestinal morphometry. Hy-Line W36 layer hens (390; 28-39 weeks old) were distributed in five treatments, with 13 animals each, with six replicates. The treatments were: control (standard formulation without nutritional reduction or protease inclusion), negative control A - NCA (nutritional reduction according to protease A matrix, without protease), negative control B - NCB (nutritional reduction according to protease B matrix, without protease), NCA + protease A, and NCB + protease B. The experimental period lasted 12 weeks, divided into three cycles of 28 days. Hens subjected to treatments (NCA and NCB) showed a decrease in feed intake. However, the addition of proteases A and B promoted improvement in this trait. The diets NCA and NCB had a negative influence on the production rate of the hens, but the diet supplementation with protease B resulted in significant improvement on egg laying rate. Hens subjected to nutritional reduction presented the worst results regarding mass and conversion by egg mass. However, the addition of enzymes reversed these results. Although the diets did not affect the relative weights of yolk, albumen, eggshell, Haugh unit, and specific gravity of the eggs, a higher eggshell thickness was observed in hens that received NCA, NCB, and NCB + protease B diets. The diets did not influence the relative weights of digestive organs and the small intestine morphometry. Hens fed diets supplemented with A and B have performance recovered in relation to those that received diets with reduced levels of nutrients.(AU)

Arthrospira (Spirulina) Platensis Can Be Considered as a Probiotic Alternative to Reduce Heat Stress in Laying Japanese Quails

This study was conducted to investigate the effects of Arthrospira platensis (Spirulina platensis, SP) on feed intake, feed conversion ratio, egg weight, hen day egg production, intestinal microflora, heat stress biomarkers, and HSP70 gene expression in laying Japanese quails (Coturnix coturnix japonica) suffering heat stress condition. A total of 250 female quails were allocated to 5 treatments, 5 replicates and 10 birds in each replicate in a completely randomized design. Experimental treatments included: 1) basal diet, 2) basal diet+ 0.03 % probiotic, 3) basal diet+ 0.1 % SP, 4) basal diet+ 0.3 % SP, 5) basal diet+ 0.5 % SP. During the last 6 days of the experiment, the quails were exposed to 8h of 34±1°C. The birds had free access to feed and water during the experiment. The results showed that using probiotic and different levels of Spirulina had no significant effect on laying performance of Japanese quails (p>0.05). Probiotic supplement increased Lactobacil bacteria population in laying quails ileum under heat stress (p 0.05). Different levels of SP decreased Escherichia coli population in laying quails ileum suffering heat stress (p 0.05).SP at the level of 0.5% caused the lowest blood Malondialdehyde level, heterophil, and H/L ratio (p 0.05).However, HSP70 gene expression in the heart or the liver of laying quails was not different (p>0.05). In conclusion, the results of the present study revealed that SP at the level of 0.5 % has the potential to be considered as a probiotic alternative in the diet of laying quails suffering heat stress condition.(AU)

Effects of an antibiotic and two phytogenic substances (cinnamaldehyde and 1, 8-cineole) on yolk fatty acid profile and storage period-associated egg lipid peroxidation level

This study was aimed at determining the effects of two phytogenic antioxidants, namely, cinnamaldehyde and 1,8-cineole, and an antibiotic added to laying hen feed on the fatty acid profile of egg yolk and the weight loss and lipid peroxidation levels of eggs stored for different periods. Ninety-six 48-week-old Bovans White hens were randomly assigned to four groups, each with four replicates of six hens per replicate. The four groups were provided with the following feeds: maize and soybean-based laying hen feed, basal ration (control group); basal ration added 500 mg/kg of an antibiotic; basal ration added 100 mg/kg of cinnamaldehyde; and basal ration added 100 mg/kg of 1,8-cineole. At the end of an eight-week feeding schedule, 48 eggs, including 12 from each group, were used for yolk fatty acid analysis. In total, 240 eggs, including 48 eggs for each of the five different storage periods tested (1, 14, 28, 42, and 56 days), were collected for the detection of egg weight loss and yolk malondialdehyde (MDA) levels. The feed supplements cinnamaldehyde and 1,8-cineole were determined to have significantly reduced lipid peroxidation in the yolk of eggs stored for 14, 28, 42, and 56 days, when compared with the results of the control group and antibiotic-treated group. Furthermore, dietary cinnamaldehyde supplementation was determined to have decreased the yolk level of myristic acid, a saturated fatty acid, and to have increased the yolk level of oleic acid, the major unsaturated fatty acid found in egg yolk (46.28%) in comparison with the levels measured in the other three groups. Cinnamaldehyde and 1,8-cineole were determined to extend the shelf life of eggs by providing protection against free oxygen radicals. Cinnamaldehyde could be used as an alternative feed supplement to enrich the yolk fatty acid profile in unsaturated fatty acids.(AU)

Requirement of Digestible Methionine + Cystine to Molted Laying Hens

The present study aimed to determine the ideal requirement of digestible methionine + cystine to molted laying hens. The experimental period lasted 105 days, divided into five periods of 21 days. 144 Hisex White laying hens with 84 weeks-of-age were used. The experimental design was completely randomized with treatments constituted for six levels of digestible methionine + cystine (0.45, 0.50, 0.55, 0.60, 0.65, and 0.70%) in the diets, with four replicates of six birds each. Data collected were evaluated by polynomial regression at 5%. There was a significant effect (p 0.05) of digestible methionine + cystine on feed intake, energy intake, protein intake, egg production, and egg mass. Internal egg quality presented positive linear effect (p 0.05) on albumen height and yolk color. External egg quality was affected (p 0.05) in eggshell %, eggshell thickness and eggshell resistance, where the level of 0.60% of digestible methionine + cystine in the diets provided eggshells with better quality (higher percentage, thicker and breaking resistance). Differences (p 0.05) were also observed in glucose and triglycerides concentration, with 0.60% of digestible methionine + cystine in the diets presenting better equilibrium. Results of the present study suggested that higher levels of digestible methionine + cystine improved the performance and internal egg quality of molted laying hens. The level of 0.60% of digestible methionine + cystine provided better eggshell and equilibrium on blood biochemistry.(AU)