POULTRY SCIENCE JOURNAL
Year:2017 | Volume:5 | Issue:1|Papers Count:10

Chicken eggs represent an important source of protein to the growing human population and also supply repositories of unique genes that could be used worldwide. The inheritance of shank feathering trait is dominant upon non-feathering shank trait in chicken which is based on two factors: pti-1L and pti-1B that are located on Chromosomes 13, 15, and 24. Using 185 fertile eggs collected from two genetic lines (shank feathering and non-feathering shank) of White Kurdish chicken, we found that egg weight highly (P<0.01) correlated with yolk weight (r2=0.520, 0.704, respectively), albumen weight (r2=0.918, 0.835), and shell weight (r2=0.626, 0.225). The first two principal components explained the greatest variance in both the White with shank feathering (85.6% of total variance) and non-feathering shank (76.5%). Therefore, differences in the component traits of the eggs between the two genetic lines may be influenced by the same gene actions as shank feathering trait. According to these results, the two genetic lines of Kurdish chicken yield significant differences in the internal traits of eggs.

We investigated the effects of a wheat-based diet (WBD) supplemented with different levels of zinc on the performance, intestinal viscosity, immune system and lipid peroxidation of broiler chickens. A total of 240 Ross 308 day-old male broiler chicks were weighed and assigned to six dietary treatments with four replicates (floor pens) of ten birds per pen. Dietary treatments consisted of a WBD without Zn supplement in mineral premix (control), or with 20, 40, 60, 80, and 100 mg/kg of Zn in the diet. Feed intake, body weight gain, and feed conversion ratio were recorded after 21 days. On day 21, blood serum malondialdehyde concentration, intestinal digesta viscosity, and some internal organs were measured. Antibody titer against Sheep red blood cells (SRBC) were measured on days 7 and 14 after injection. For evaluation of cutaneous basophil hypersensitivity (CBH) response, on d 20, phytohemagglutinin was injected subcutaneously into toe web and 12 and 24 hrs after injection, the thickness of the web was measured.Supplementation of the WBD with 20, 40, 60, and 80 mg Zn/kg significantly improved feed conversion ratio (P<0.05).Supplementation of Zn significantly decreased the relative weight of abdominal fat pad as well as jejunal viscosity (P<0.05). Also, Zn supplementation (at all concentrations except 20 mg/kg) significantly decreased serum malondialdehyde concentration (P<0.05). Anti-SRBC titer was significantly increased by supplementation of the WBD with 20 mg/kg Zn (P<0.05). Supplementation of the WBD with 40 mg/kg Zn significantly increased CBH response (P<0.05). Overall, the results of this study indicate the importance of Zn supplementation in WBD for improvement of FCR and physicochemical properties of the intestinal contents. Also, supplementation of Zn in the WBD is effective in enhancing immune system responses and antioxidative defense.

The current study was conducted to investigate the effects of genetic and non-genetic factors on body weight and carcass traits of Japanese quails. Two strains of Japanese quail (150 wild quails and 150 white quails) were used as base population. Four mating groups were used to produce progenies: wild male× wild female, white male × wild female, wild male× white female and white male × white female. Quails were weighed then slaughtered at 35 days of age. The carcass traits consisting carcass weight, breast meat weight, thigh meat weight, skin weight, and abdominal fat weight were recorded after slaughter and after removing feathers, internal organs, and digestive system. Based on these weights, the percentages of carcass, breast, thigh, skin, and abdominal fat were estimated. The effects of sex, hatch, and mating group on body and carcass composition traits were investigated. Sex had a significant effect on all traits (P<0.01), with the exception of the thigh percentage. Moreover, female birds showed higher values for all traits. There were significant differences between hatches and mating groups and wild male× wild female offspring showed highest values of carcass weight, breast weight, thigh weight, skin weight and abdominal fat weight (P<0.01). The heritability estimates for body and carcass related traits were moderate to high (0.22 to 0.66). The carcass percentage traits showed lower heritability, ranged from 0.22 to 0.33.Genetic correlations between body weight and carcass weight, skin weight, breast weight, thigh weight, and abdominal fat weight were moderate to high (0.37 to 0.94). These results showed that selection for increasing body weight and decreasing abdominal fat will improve carcass related traits.

This investigation aimed to study polymorphism of growth hormone (GH), growth hormone receptor (GHR), and insulin like growth factor 1 (IGF-1) genes and their associations with growth and carcass traits in Mazandaran native chicken.200 male chicks were reared and slaughtered at 12 weeks of age. Traits including live weight at 4, 8 and 12 weeks of age, body weight and weights of heart, liver, gizzard, spleen, and abdominal fat, pH of meat, water holding capacity of the meat and intramuscular fat were recorded. Before dissecting birds, blood samples were collected and DNA was extracted. The frequency of alleles (+and -) were determined to be 0.627 and 0.373 for GH locus, 0.715 and 0.285 for GHR locus, and 0.407 and 0.593 for IGF-1 gene locus, respectively. Hardy-Weinberg equilibrium study using Chi-square test showed that the studied population was not in Hardy-Weinberg equilibrium. Analysis of phenotypic and genotypic data showed a significant association between genotypes of GH gene and live weights at 8 and 12 weeks of age and carcass weight. Significant associations were found between the GHR gene with live weight at 12 weeks of age and carcass weight and also between IGF-1 gene with abdominal fat and intramuscular fat (P<0.05). Generally, it can be concluded that GH, GHR and IGF-1 genes can be used as candidate genes for improving growth and carcass traits in Mazandaran native fowls.

The effects of Silymarin on growth performance, internal organs, and some blood parameters were investigated in Japanese quail that were subjected to oxidative stress induced by carbon tetrachloride (CCl4). An experiment was conducted as a completely randomized design in a factorial arrangement (2 × 2) with four replicates of 30 birds each.Factors included two levels of Silymarin (0 and 1 mL/kg of body weight (BW)) and two levels of CCl4 (0 and 1 mL/kg of BW). Results showed that Silymarin did not affect productive parameters, whilst CCl4 significantly (P<0.05) reduced feed intake and body weight gain.Silymarin did not affect the relative weights of breast, gizzard and heart, whereas CCl4 reduced relative weights of breast and heart. Both Silymarin and CCl4 administration resulted in higher pancreases relative weight. Birds treated with Silymarin had greater blood serum concentration of total protein and lower concentrations of glucose, triglyceride and total cholesterol (P<0.05). In contrast, birds that received CCl4 showed decreased total protein and increased glucose concentrations of blood serum (P<0.05). The interaction effect between Silymarin and CCL4 showed that Silymarin ameliorated the adverse effects of CCl4 on blood albumin. Treatment of CCl4 increased blood concentration of alkaline phosphatase compared with Silymarin (P< 0.05). This study showed that Silymarin may be a useful antioxidant source to ameliorate the adverse effects of oxidative stressors in Japanese quail.

The effects of antibiotic, probiotic, and prebiotic as dietary feed additives on carcass composition as well asSalmonella counts and its serotypes in droppings and intestine of broiler chickens on days 1, 28, and 56 of experiment were investigated. Dietary treatments were control diet (basal diet without additives), OXYT diet (basal diet with 600 ppm of the antibiotic oxytetracycline), GRO-UP diet (basal diet with 500 ppm probiotic), and MOS-500 or MOS-1000 diets (basal diet with 500 or 1000 ppm mannan oligosaccharide prebiotic, respectively). From an initial total of 190 day-old Arbor acres broiler chicks, two birds were randomly selected from each treatment and sampled forSalmonella. The remaining 180 birds were randomly allotted to the five dietary treatments with three replicates of 12 birds each. Feed and water were suppliedad libitum. The results indicated that breast, neck, drumsticks and liver yields significantly affected by the inclusion of feed additives (P<0.05). Significant differences were observed in average Salmonella counts in both the intestines and droppings of broiler chickens at different days of experiment (P< 0.05).Salmonella Gallinarum and Salmonella Typhi were serotypes identified in the droppings and intestine of broiler chickens. Our findings reveal that the inclusion of prebiotic oligomanno or probiotic GRO-UP as antibiotic substitutes in diets of broiler chickens can rapidly reduce some Salmonella serotypes and aid to the control Salmonella organisms.

Eggshell quality is the main trait to assess egg quality. Marker assisted selection can be used to improve this trait. During eggshell formation, a mass of inorganic minerals is deposited. The Sodium Channel (SCNN1) gene family plays an essential role in cation transportation and SCNN1g is a member of this gene family. The objective of this study was to estimate the frequency of SCNN1g gene variants and to find its associations with eggshell quality in Hy-Line breed.100 hens were randomly selected and their eggs and blood samples were collected.DNA was extracted and purified using the phenol-chloroform method and genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. GLM procedure of SAS software was used to evaluate the association of SCNN1g gene polymorphism with egg weight, specific gravity, eggshell strength, eggshell weight, and eggshell thickness. Based on the polymorphism of SCNN1g gene, three genotypes were observed including AA, AG, and GG with frequencies of 0.26, 0.57, and 0.17, respectively. Genotype only had a significant effect on eggshell strength (P<0.05). Other traits were not significantly influenced by genotypes of this gene. Therefore, introducing this gene in marker-assisted selection programs may improve eggshell strength of Hy-Line breed.

We investigated the effects of dietary supplementation of zinc (ZnO; 0, 40, 80, 120 and 160 mg/kg) and Vit E (α-tocopheryl acetate; 0 and 40 IU/kg) on egg production, egg quality and Zn content of egg fractions and tissues in Japanese quails. Using a 5 × 2 factorial design, a total of 960 Japanese quails (Coturnix coturnix japonica) at day 70 of age were housed in cages and randomly assigned into one of ten experimental treatments, each with four replicates of 24 birds (16 females and eight males per replicate). Egg production was greater (P<0.05) in birds fed diets containing 160 mg/kg of zinc (Zn) than those fed basal diet (control diet), but vitamin E supplementation had no effect on egg production. Quails fed basal diet supplemented with 80 mg/kg Zn showed a significant improvement in their feed conversion ratio compared to the other birds.Birds supplemented with 80, 120 and 180 mg/kg Zn had stronger egg shells than those fed the control diet, while shell thickness was lower in birds supplemented with 0 and 40 mg/kg of Zn (P<0.05). Enrichment of Zn in egg yolk increased when birds received diets supplemented with 80, 120 and 160 mg/kg Zn compare to control group (P<0.05).Supplementation of diet with Zn increased serum concentration of Zn when fed to quails at 120 mg/kg (P<0.05). Thigh muscle, thigh bone, and liver Zn concentrations increased with concentration of Zn supplementation (P<0.05). Vitamin E supplementation had no effects on laying performance, egg shell quality, and Zn concentrations in egg fractions and tissues of Japanese quail.

In order to use the “Trinidad de Guedes" phosphorite (TGP) as a supplement of calcium and phosphorus in animals, its concentrations of heavy metals were determined and their deposition was analyzed in broilers. Toxic elements were determined using atomic absorption spectrophotometry. The mean levels of heavy metals found in TGP were 82.5 mg/kg lead (Pb), 7.2 mg/kg cadmium (Cd), 1056.9 mg/kg manganese (Mn), 1.3 mg/kg mercury (Hg), 10.4 mg/kg arsenic (As), 210.6 mg/kg zinc (Zn), and 121.3 mg/kg copper (Cu). All concentrations of heavy metals were below harmful levels, with the exception of Pb, which was above its maximum tolerable value. The levels of heavy metals accumulated in bones and feathers of broilers fed TGP were determined in a feeding trial. An amount of 300 day-old broilers from commercial hybrid crossing (HE21) were allocated into three treatments in a completely randomized design, with four replicates of 25 broilers each. The three treatments were a control containing dicalcium phosphate as calcium and phosphorus source, and two experimental treatments with TGP replacing dicalcium phosphate at levels of 50 and 100%. There were no differences between treatments for levels of toxic elements accumulated in feathers, femurs and tarsus of broilers. The amounts of heavy metals accumulated in the analyzed organs showed that TGP can replace dicalcium phosphate (DCP, the traditional source of calcium and phosphate) without causing harm to animal health nor bioaccumulating heavy metals.

The study was designed to investigate the effects of dietary Seleniumenriched radish sprouts (Se-RS), Vitamin E (Vit E), andRhodobacter capsulatus (RC) on immunity, cholesterol concentration, and fatty acid composition in broiler meat. A total of 100 two-week-old male broiler chicks were randomly assigned into five dietary groups: I) Control; II) Se-RS (5μg/kg Se-RS); III) Se-RS+RC (5 mg/kg Se-RS+0.2 g/kg RC); IV) Se-RS+Vit E (5mg/kg Se-RS+50 mg/kg Vit E) and V) Se-RS+RC+Vit E (5 mg/kg Se-RS+0.2 g/kg RC+50 mg/kg Vit E). Diets and clean drinking water were offeredad libitum. After the end of 3-wk of feeding period, serum cholesterol and triglycerides concentrations were lower (P<0.05) in broilers fed Se-RS+RC+Vit E supplemented diet compared to the control diet. At the end of the 6-wk feeding period, birds fed the Se-RS+RC+Vit E diet significantly (P<0.05) reduced cholesterol and triglycerides concentrations and improved the ratio of unsaturated fatty acids to saturated fatty acids in broiler meat.The highest (P<0.05) number of leukocytes was observed in broilers fed Se-RS+RC+Vit E supplemented diet. Foot web index and weights of spleen, bursa, and thymus were significantly (P<0.05) higher in birds fed Se-RS+RC+Vit E compared to the control diet. Our findings suggest that there are dual benefits of supplementing broiler diets with Se-RS+RC+Vit E because of improvements in the bird’s immunity and meat quality that is important for health conscious consumers.