Oxidative stress is defined as the imbalance between prooxidants and antioxidants (in favor of the pro-oxidants). Reactive oxygen species (ROS) are produced in the body continuously as a part of normal metabolism. Under normal physiological conditions a healthy balance exists between prooxidants and antioxidants. However, when the defense system gets disturbed due to fast growth, inadequate diet supply, disease, or other stressors, body is not able to synthesize the enzymes needed to destroy ROS or repair the damage. In the intensive system of poultry production birds are exposed to several stressors which may result in oxidative stress and lead to poor performance. Antioxidants in the animal body work together as the so called “antioxidant system” to prevent damaging effects of free radicals and toxic products of their metabolism. Vitamin E is considered as a very potent antioxidant in biological systems and found to be beneficial in counteracting the adverse effect of oxidative stress. The knowledge of antioxidant defense systems will serve as guiding principle for establishing most effective nutrition support to minimize oxidative stress. Such an approach will enhance bird health and welfare, product quality and will increase economic returns and the sustainability of poultry production. The current review describes the role of vitamin E as an antioxidant in alleviating oxidative stress in poultry.

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Quantitative trait locus (QTL) mapping of external egg traits in chickens was carried out with 143 microsatellite markers using 388 F₂ hens obtained from an intercross of a Japanese Large Game (Oh-Shamo) male and three White Leghorn females. External egg traits, such as the weight and length of eggs and the weight, thickness, strength, and color of eggshells were measured at three different stages of egg production, i.e. early, middle, and late stages. QTL analyses revealed 10 significant and three suggestive QTLs with main effects on external egg traits on chromosomes 1, 2, 4, 5, 8, 10, 11, 12, 17, and Z. The QTL alleles derived from Oh-Shamo, one of the indigenous Japanese breeds, uniquely increased most external egg traits, whereas some QTL alleles had opposite effects on phenotypic differences between Oh-Shamo and White Leghorn. The QTLs detected accounted for 3.09-15.39% of the phenotypic variances. Although the QTLs on chromosomes 5, 8, and Z were found throughout all three stages, the others were identified at only one or two stages. Epistatic QTLs for external egg traits were not detected in the present study. The age-related changes of our main-effect QTLs illustrate one aspect of the complex genetic basis of external egg traits.

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In contrast to other farm animals, the matrilineal structure of domestic goose has remained an open question. In this study, we analyzed mitochondrial DNA control region sequence variation of 245 domestic geese to discern the main matrilineal components and their phylogenetic relationships. The result of phylogenetic analysis indicated the distinct lineage of clade II and the result of network analysis further suggested the major group of Chinese native goose breeds (subclade S) and introgressive goose breeds (subclade G). Except Yili geese, all Chinese domestic goose breeds were clustered in S, whereas clade II were widely distributed in 2 European breeds, Yili geese as well as 3 domestic Graylag geese. The results support that Chinese domestic goose breeds (except the Yili breed) originated from Swan goose (Anser cygnoides) while European goose breeds originated from Graylag goose (Anser anser). In total, 17 Landoise and 16 White Roman geese were clustered in subclade G together with 1 domestic goose (A. anser, AY112966), which supported the previous finding that European geese originated from Graylag goose (A. anser). But 9 unanticipated samples of two Chinese domestic goose breeds including 7 Lion-head geese and 1 Zhedong White goose in haplotype H9 were also clustered in subclade G as well as 3 Lion-head geese in haplotypes H13, H15 and H16 and 2 Zhedong White geese in haplotypes H18 and H19, which may be caused by the potential gene introgressions between swan goose breeds and graylag breeds with a directional contribution towards graylag geese.

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Silkie fowl are very famous in China and Japan, however the egg production rate of the Silkie fowl is very low because of broodiness. Authors have examined the polymorphisms of the 5′-flanking region of the prolactin gene in Taihe Silkie fowl and identified a 24-bp In/Del locus, but no In/In Silkie individuals have been found. In this study, In/In individuals were constructed from an In/Del×In/Del population in order to examine the unique characteristics of Silkies. The relationships between production traits and DNA markers of the three candidate genes were studied. To produce In/In Silkie individuals, male and female individuals with the In/Del locus in the fourth generation of the Silkie fowl selection population were crossed. Genotyping was performed for the prolactin In/Del locus, the DNA marker of neuropeptide Y, and the dopamine D2 receptor. In this study, 27 Del/Del, 39 In/Del, and 21 In/In female individuals and 13 Del/Del, 26 In/Del, and 17 In/In male individuals were found. All In/In individuals had the Silkie fowl characteristics. A significant effect of neuropeptide Y was found on eggshell strength (p<0.05) in female birds, and a significant effect of prolactin and dopamine D2 receptor gene was found on the body weight at 50 day in male birds (p<0.05).

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This research was conducted to evaluate the effect of organic acid blends (OAB) of ascorbic (A), citric (C), malic (M), sorbic (S), and tartaric (T) acids provided through the drinking water on growth performance, blood constituents, and immune response of broiler chickens from hatch to 42 d of growth. Three-hundred 1-d-old Ross broiler chickens were randomly divided into 4 treatment groups (1 control and 3 experimental) of 5 replicates (15 birds per replicate). Control group was given ordinary water and treatments were given continuously the acidified water using three different blends consisting of: OAB₁=A:C:M, OAB₂=A:S:M, and OAB₃=A:T:M. Blends were prepared with ratio 35:60:5 and were used at a concentration of 0.5% (wt/vol). The results showed that all OAB had no significant effect on live body weight (LBW); however, an improvement on feed consumption (FC), feed conversion ratio (FCR), and survival rate (SR) were observed as compared to the control. Birds supplied with OAB₁ presented the lowest FCR (1.803), FC (96.19 g/bird/day), and the highest SR (95.63%). Blood constituents (hematocrite, total protein, and albumin), enzymatic activity (gamma glutamyl transpeptidase and aspartate aminotransferase), immune response, organs weight, and pH values of different gastrointestinal tract segments were not affected by administering the OAB. However, reductions in the alanine aminotrasferase activity and an increment in the aspartate aminotransferase:alanine aminotrasferase ratio were observed in groups provided with the OAB₁ and OAB₃, respectively. From these results, it is concluded that OAB₁ could be used as an alternative for improving FC, FCR, and SR in broiler chickens.

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The research was carried out on 75 Cobb 500 broilers, which were divided into three groups. During the last three weeks of fattening broilers were fed finisher diets supplemented with β-alanine (P1=control group, P2=0.5% β-alanine and P3=1% β-alanine). The research objective was to evaluate effects of β-alanine supplemented to designed broiler diets on the quality of broiler muscle tissue and concentration of carnosine. After slaughtering, the following traits of muscle tissue quality were measured: initial and final pH value (measured 45 minutes after slaughtering pH₁, and 24 hours after cooling pH₂), drip loss, color (Minolta colorimeter, expressed as CIE L*, CIE a* and CIE b* values), softness of meat and cooking loss. Samples of breast and thigh muscle tissue were used for determination of moisture, fat, protein, collagen and carnosine. Intensity of lipid oxidation (TBARS) was determined in breast muscle tissue. Statistical analysis proved that supplementation of 1% β-alanine to broiler diets significantly lowered portion of collagen in thigh muscle tissue (P1=1.28% compared to P3=1.06%), while it increased cooking loss in breast muscle tissue (P1=24.23% compared to P3=33.29%). Supplementation of β-alanine to diets (0.5% or 1%) affected more intensive a* color in breast muscle tissue (P1=1.78 compared to P2=2.88 and P3=2.82). Analysis of results referring to concentration of carnosine in broiler tissue showed that supplementation of 1% of β-alanine increased concentration of carnosine in breast muscles from 756.15 μg/g of tissue (P1) to 911.01 μg/g of tissue (P3), while thigh muscle tissue exhibited significantly higher concentration of carnosine already within dietary supplementation of 0.5% of β-alanine (P1=371.78 μg/g of tissue compared to P2=540.29 μg/g of tissue and P3=526.83 μg/g of tissue; P<0.05). Feeding treatments and time of meat storage had no effect on TBARS values.

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The objective of this study was to investigate the effects of corn naturally contaminated with low levels of aflatoxins (AF) on performance, calcium (Ca) and phosphorus (P) metabolism, and bone mineralization in broilers. Four hundred and fifty 1-d-old male broiler chicks were randomly allotted to control (no AF), and the diet with the corn contaminated with AF as a substitute for 50% or 100% of the corn in control (HAC or AAC). The broilers in HAC and AAC were administered with 6.5-8.0 and 13.0-16.0 μg AF/kg BW per day respectively in overall period (1-42 d). Ten birds per treatment were selected at d 43 to explore the apparent digestibility of Ca and P using all excreta collection method after 2 days adaptation. The AAC diet reduced (P<0.05) the performance of birds in overall period, whereas the HAC diet temporarily decreased (P<0.05) the performance of birds in starter phase (1-21 d). The corn contaminated with AF had no effect (P>0.24) on the apparent digestibility of Ca and P. The increasing AF intake content linearly increased (P<0.001) serum parathyroid hormone (PTH) level, and decreased (P<0.05) serum 1,25-dihydroxychocalciferol and P concentrations on d 42. On d 21, the AAC diet reduced (P<0.05) tibia breaking strength (TBS) when compared to control or HAC group, however, it did not affect (P>0.10) the percentages of ash, Ca and P in tibia. On d 42, the increasing AF intake level linearly decreased (P<0.05) TBS, and the percentages of Ca and P in tibia. These results indicated that the low level of AF intake had negative effects on the P metabolism and bone mineralization of broilers at exposure of 42 days, which might relate to the changes in vitamin D and PTH metabolism.

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This study investigates the combined effect of bamboo charcoal powder and bamboo vinegar liquid (BCV) on the growth, fecal microflora population and intestinal morphology in Betong chickens. A total of 128 4-week-old Betong chickens were fed a basal diet supplemented with BCV at 0, 0.5, 1 and 1.5% level ad libitum for 16 weeks. The 1% inclusion of BCV gave the best growth performance. Carcass traits (yield) and visceral organs were not significantly affected by BCV. Jejunal villus height and jejunal villus area were also the highest in the 1% BCV group. At 140 days of age, colony counts of fecal Escherichia coli and Salmonella spp. were comparatively low with 1 and 1.5% BCV. The present results suggest that BCV could be used at a level of 1% in Betong chicken diets.

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An experiment was conducted to determine the interaction between fat source and xylanase supplementation on the performance, utilisation of energy and fat, and caecal microbiota counts in broiler starters fed wheat-based diets. The experimental design was 2×2 factorial arrangement of treatments, which included two fat sources (60 g/kg soybean oil or tallow) and two levels of enzyme supplementation (without or with exogenous xylanase). Irrespective of the fat source, xylanase supplementation increased (P<0.01) the weight gain and lowered (P<0.01) the feed per gain. Birds fed diets with soybean oil diets had higher (P<0.001) weight gain, fat retention and fat digestibility, and lower feed per gain compared to those fed tallow supplemented diets. Feed intake was not affected (P>0.05) by dietary treatments. Xylanase addition improved (P<0.01) the apparent metabolisable energy in diets containing either fat source, but the effect was more pronounced in birds fed the diet containing tallow. The number of Lactobacillus spp. was lowered (P<0.05) by enzyme supplementation in birds fed tallow diets, but unaffected (P>0.05) in those fed soybeans oil diets. The number of Clostridium spp. was found to be higher (P<0.01) in birds fed enzyme-supplemented diets. Overall, under the conditions of the present study, the addition of xylanase improved the growth and feed efficiency of broiler starters and the responses were not influenced by the fat source.

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Relationships between digesta pH, body weight and nutrient utilization of broilers at different ages were investigated in the current study. Ninety 1-d old chicks were raised together for 10 d, and then were divided into 3 groups of 30 birds each for the starter, grower, and finisher phases batches. Each batch was divided to two groups comprising the 10 lightest (L) and the 10 heaviest (H) birds with the 10 median birds excluded from study. At the end of each phase, the digesta pH of the intestinal sections was measured in the birds. The ileal digesta and total excreta voided were collected for nutrient and energy utilization determination. In starter and grower phases, the H birds consumed more feed (P<0.05) and grew faster (P<0.05) than the L birds. The H birds had lower (P<0.05) digesta pH compared with the L birds irrespective of the phase. The digesta pH was lower (P<0.05) for birds during the grower than during the starter phase (except in the crop) and greater (P<0.05) during finisher compared with grower phase (except in the crop and jejunum). The birds in H group had lower (P<0.05) proventricular pH compared with the L group independent of the age of birds whereas the cecal pH was lower (P<0.05) for birds in H group during the grower phase. The crop, caecal, and jejunal pH at different growth phases had positive correlation with the ileal energy digestibility and total tract nutrient and energy retention. It was concluded that individual variability in body weight and nutrient utilization in grower and finisher phases were partly explained by variability in jejunal and caecal pH and that this may be related to the type of microbes colonizing the gastrointestinal tract (GIT).

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Soybean meal (SBM) is the most widely and expensive protein source used in the formulation of poultry diets; however, when the price of SBM increases, poultry nutritionists seek alternative sources that are more economical in formulating least-cost rations. This research aimed to evaluate the effects of air classified sunflower meal (SFM) in diets of turkeys on their growth performance, carcass yields and meat quality. A total of 140 1-d-old female turkeys (Nicholas 500) were randomly assigned to two dietary treatments which were fed from hatch to 16 wk. The birds were fed two wheat middlings-based diets comprising of a control diet which contained SBM (145 g/kg) and a test diet containing micronized-air classified SFM (172 g/kg) as the main protein source. The substitution of SBM with sunflower had no adverse effect on growth performance and dressing percentage, improving breast and thigh muscles relative weights of the turkeys. A significant effect was found for feed intake (P<0.05) which was lower in birds fed diet containing sunflower compared to those fed soybean, without however any negative effects on feed efficiency (P<0.05). Meat from turkeys fed the sunflower diet had less cholesterol (P<0.01) and higher concentrations of phospholipids (P<0.01). Our results suggest that replacing the conventional SBM as protein source, with micronized-air classified SFM in diets of turkeys can improve carcass quality and favourable lipid profile without adverse effects on growth traits, reducing also the production costs.

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The influence of various valine analogues on protein synthesis of chicken embryo myoblasts was examined. Valine and its analogues (D-valine, methylvaline, valinol) were supplemented into Medium 199 containing 20 ng/ml of chicken insulin-like growth factor-I (IGF-I) instead of fetal calf serum (FCS). Influence of branched chain amino acids (isoleucine, leucine, valine) on myoblast protein synthesis was also examined. The levels of valine analogue concentration were based on the valine concentration (213 μM) in Medium 199, and the concentrations of supplements were set at 213 μM (×1 of valine in Medium 199) and 2,130 μM (×10 of valine in Medium 199). Protein synthesis was measured by incorporation of ³H-phenylalanine. Methylvaline, which is one of valine derivatives having a methylated amino group, and D-valine, which is an optical isomer of L-valine, had no influence on myoblast protein synthesis although the concentrations of these compounds were 10-times higher (2,130 μM) than that of valine in Medium 199. Leucine and valine had the potency to increase protein synthesis of chicken embryo myoblasts. The supplementation of valinol, which is one of valine derivatives having a hydrated carboxyl group, with 10-times higher concentration than that of valine in Medium 199, decreased myoblast protein synthesis. These results suggested that valinol could be used as an inhibitor of myoblast protein synthesis.

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An experiment was conducted to investigate the effect of monochromatic and mixed light color on performance, bone, meat quality, blood properties and immunity of broiler chicks. In experiment 1, 1,200 Ross×Ross 1-day old chicks were equally allotted to the following 8 light treatments with 3 replications: red (R), yellow (Y) green (G), blue (B), mixed R×Y, Y×G, and G×B light colors. Fluorescent white light was the control. Experiment 2 considered similar treatments (6 treatments with 4 replications) except R and R×Y were not tested. Light (24 L: 0 D) and intensity (0.1 watts/m²) was maintained at the bird’s head level. Weight gain during weeks 2-3 increased in the G and G×B groups (P<0.05). Weight gain was higher (P<0.05) in the B and G×B treatments at week’s 4-5. Similar weight gains were noted in experiment 2. Monochromatic B and the G×B mixed lighting groups showed increased meat pH, decreased shear force, and L* in both experiments. Birds reared under B light had reduced (P<0.05) blood glucose in both experiments and reduced HDL and LDL levels in experiment 1. Circulating levels of IgG and IgA were increased with exposure to the monochromatic Y and G treatments at 21 days and to B light at 35 days of age (P<0.05). In conclusion, the mixed G×B lighting treatment enhanced growth performance and showed similar bone and blood properties and immunity of broiler chicks compared to those of monochromatic G or B light.

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The ex vivo culture of avian embryos is a technique for the long-term culturing of embryos outside of their own shell and shell membrane. It allows easy access to the developing embryos and embryo manipulation. The two-step system is widely applied when the culture is performed after oviposition. Japanese quail as well as bobwhite quail are used as models for avian safety assessment as recommended by the Organisation for Economic Co-operation and Development (OECD) guidelines. However, biological studies on the bobwhite quail have been more limited than those on the Japanese quail. We have developed a more simplified ex vivo culture protocol for the two species of quail embryos from the blastoderm stage through to hatching using a single surrogate eggshell. Hatchabilities of 31% and 27% were obtained in bobwhite quail and Japanese quail embryos, respectively. The simple system described in the present study is an easy and acceptable procedure.

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The aim of this study was to test the effect of different sodium bicarbonate concentrations on marination performances and meat quality properties. A total of 203 samples were obtained from an homogenous batch of 24 h post mortem chicken breast meat and were subjected to vacuum tumbling in a sodium chloride solution (1.0% wt/w in final product), containing 7 different sodium bicarbonate concentrations from 0 to 0.5%. Meat pH after marination linearly responded with about 0.17 pH unit increase per 0.1% unit addition of bicarbonate. The largest marinade uptake (11.4%) was observed in samples tumbled with 0.30% bicarbonate solution, while the uptake was levelled off, thereafter higher concentrations (0.40 and 0.50%). Cook loss showed a decreasing trend with the increase of bicarbonate level by estimating a 1.8% decrease for 0.10% of bicarbonate addition. Overall appearance of meat was not changed, while the use of sodium bicarbonate was able to improve meat texture by decreasing hardness and chewiness. By using low-resolution Nuclear Magnetic Resonance (LR-NMR) analysis, it was observed that water seemed to exert a plasticizing effect on some biopolymers, so that the total LR-NMR signal fluctuations were not always proportional to the water adsorption. Finally, water gain following marination does not correspond to an increase in the freezable water amount, as detected by differential scanning calorimetry. In conclusion, this study showed that sodium bicarbonate is a superior marinating agent and greater marination performances are obtained when using a concentration no higher than 0.3%.

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In the present study, the effect of various dietary ratios of linoleic acid (LNA) to α-linolenic acid (ALA), and vitamin A (Retinyl Acetate) on egg quality and some blood metabolites was examined in laying hens kept at high ambient environmental temperature. Three hundred and sixty laying hens were fed rations supplemented with different combinations of canola oil and linseed oil to have LNA to ALA dietary ratios of 20:1, 10:1, 4:1, 2:1, 1:1 and 1:2, each with 3000 IU or 10000 IU vitamin A/kg of diet (6×2 factorial; under Completely Randomized Design). Various blood metabolites, egg cholesterol, egg triglycerides and egg-yolk fatty acids were determined during the last week of the study. The results showed that serum triglycerides, serum total- and low density lipoprotein-cholesterol, and blood glucose were similar (P>0.05) in laying hens; fed on various dietary LNA/ALA ratios and vitamin A levels. Consequently, egg cholesterol and egg triglycerides were also similar (P>0.05) for the all dietary treatments. However, Serum high density lipoprotein-cholesterol increased (P=0.045) with the decrease in dietary LNA/ALA ratio. The n-3 polyunsaturated fatty acids (PUFA) in egg yolks from laying hens were increased (P<0.001) while, the n-6 PUFA and the ratio of n-6 to n-3 fatty acids were decreased (P<0.001) with the decrease in dietary LNA/ALA ratio. It was recommended that a dietary ratio of 4:1 or less between LNA and ALA was quite beneficial for the production of eggs by the hens with desirable quantities of n-6 and n-3 PUFA that are suitable for human consumption.

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Dry-cured duck is a high quality meat product processed by the traditional dry-curing procedure. The objective of this paper was to study the physical-chemical parameters and microstructure of the duck muscle during the manufacturing process. Thirty six ducks were used in this study and samples were taken after dry salting, marinating, piling, and drying for 6 days and 12 days. The increase in NaCl, TBA, protein, fat, and shear force were observed whereas water, cooking loss, L*, a*, b* and myofiber diameter decreased during the whole process. It showed the quality parameters such as NaCl, TBA, shear force and water were strongly correlated and associated with the microstructural changes of the muscles.

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Title: The Effect of Raw and Processed Common Vetch Seed (Vicia sativa) Added to Diets of Laying Hens on Performance, Egg Quality, Blood Parameters and Liver Histopathology.
Authors: Adem Kaya, Mehmet A. Yuörück, Nurinisa Esenbuuğal, Aysel Temelli and Özlem Ekinci
Journal of Poultry Science 50: 228-236, 2013

The above article published online on July 25, 2013 has been withdrawn by the request from authors.

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Following corrections have been requested by authors.

Determination of Phosphorus Requirement for Post Molted Laying Hens using Nonlinear and Multivariate Nonlinear Mixed Effects Models
Authors: Saeed Khalaji, Amir H. Naderi, Seyed N. Mousavi, Mojtaba Zaghari and Ahmad Malakzadegan
Journal of Poultry Science 51: 22-28, 2014


Before correction:
¹Department of Animal Science, Faculty of Agricultural Sciences, Malayer University, Malayer, 6571995863 Iran

Correspondence: S. Khalaji, Department of Animal Science, Faculty of Agricultural Sciences, Malayer University, Malayer, 6571995863 Iran


After correction:
¹Department of Animal Science, College of Agriculture and Natural Resource, University of Tehran, Karaj 31587-11167, Iran

Correspondence: S. Khalaji, Department of Animal Science, College of Agriculture and Natural Resource, University of Tehran, Karaj 31587-11167, Iran

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