POULTRY SCIENCE JOURNAL
Year:2017 | Volume:5 | Issue:2|Papers Count:10

The aim of this study was to determine whether the age of broilers can influence their response to tannin-rich diets. A total of 340 one-day-old mixed sex Ross 308 broiler chicks were distributed among five experimental groups with four replicates and 17 birds each in a completely randomized design. A high-tannin feedstuff, Oak acorn, was included into diets (at a level of 25%) and fed to birds at different stages of the rearing period. The control group was fed a corn-based diet (without Oak acorn) for the entirety of the study, while the other four groups were fed diets containing Oak acorn during one of the following periods: starter (d 1 to 21), finisher (d 22 to 42), last five weeks (d 8 to 42), or total period of the experiment (d 1 to 42). We found that performance traits (feed intake, body weight gain and feed conversion ratio) and tibia characteristics were similar among the control group and groups fed Oak acorn during the starter and finisher periods. However, feeding chicks with Oak acorn from 8 to 42 or 1 to 42 d of age significantly reduced overall body weight gain and increased overall feed conversion ratio (P<0.05). Tibia characteristics were also negatively affected in chicks that received Oak acorn during the last 5 weeks and entire period of the experiment (P<0.05). In addition, birds fed Oak acorn had higher liver weights at 21 d of age (P<0.05). In conclusion, broilers response to dietary tannins is influenced by age.Oak acorn could be successfully included in broiler diets during the starter or finisher stages up to 25% without adverse effects on performance and tibia characteristics. In contrast, chronic inclusion of Oak acorn (5 or 6 weeks) decreases growth performance and may have deleterious effect on tibia characteristics.

481 fresh fertilized eggs of three Kurdish local chickens (Black with brown neck, White with shank feathering, and White with nonfeathering shank) were collected at pre-molting (355 eggs) and postmolting (126 eggs) stages to evaluate external egg traits. A venine caliper was used to determine the length and breadth of eggs to calculate Shape index. Results indicated that egg weight increased in all genetic groups (P<0.05) at post-molting stage compared with premolting stage. There was a significant difference in egg length between pre- and post-molting periods from the black chicken with brown neck and white chicken with shank feather, but not from the white chicken with non-feathering shank. Also, egg breadth was similar between preand post-molting periods from black with brown neck and white with shank feather, but was different from white with non-feathering shank.Shape index was also similar between pre- and post-molting periods for white with shank feather, but were significantly different (P<0.05) for black with brown neck and white with non-feathering shank. The results of this study indicate that egg external traits improved during post-molting period than pre-molting, and variations between egg layers for external traits could be due to the genetic makeup.

This experiment was conducted to assess the effects of Silymarin on oxidative status, bone characteristics, and some blood parameters in Japanese quail subjected to oxidative stress induced by carbon tetrachloride (CCl4). The experiment was performed as a completely randomized design with four replicates, each with 30 birds, using a 2 × 2 factorial arrangement with two doses of Silymarin (0 and 1 mL/kg BW) and CCl4 (0 and 1 mL/kg BW). Results revealed that the interaction between Silymarin and CCl4 on concentrations of total cholesterol, triglycerides, glucose, albumin, calcium, and alkaline phosphatase were significant (P<0.05). In contrast, concentrations of phosphorus, total protein, and high density lipoprotein-cholesterol in blood serum did not differ between experimental treatments.Experimental treatments had a significant effect on superoxide dismutase activity in blood serum (P<0.05), but not on glutathione peroxide activity and malondialdehyde concentration. Experimental treatments significantly affected the weight, thickness, and external and internal diameters of tibia bone (P<0.05), but not its length, ash, volume, and density. This study shows that Silymarin has potential to attenuate adverse effects of oxidative stress induced by CCl4 in Japanese quail.

This study was designed to evaluate the effects of nanocurcumin (NC) on oxidative stress and histology of embryonic chicken heart. NC was injected into the yolk of 4-day-old embryonic eggs at one of three doses: 10 ppm (NC10 group), 100 ppm (NC100 group), and 1000 ppm (NC1000 group). The control group received normal saline. Oxidative stress in heart tissue was evaluated by measuring malondialdehyde (MDA) concentration, glutathione (GSH) content, and ferric reducing antioxidant power (FRAP). Serum lipids and cardio-histolopathogy were also measured. There were no significant differences in GSH, FRAP, and MDA levels between the control and treatment groups (P> 0.05). The serum lipid profile was altered in the NC100 group, with reduced levels of triglyceride (TG) (P<0.01) but higher levels of HDL-c (P<0.01) compared to the control. Heart histology was similar between NC10 and NC100 treatments compared to the control group. However, heart sections in NC1000 revealed focal areas of disrupted cardiac muscles and mild infiltration of mononuclear inflammatory cells between muscle fibers. It was concluded that NC at a concentration of 100 ppm did not damage heart tissues in chicken embryo and could be used as a valuable molecule for cardiovascular disease prevention.

This study was conducted to estimate the genetic parameters influencing egg quality in Khorasan Razavi native fowl. (Co) Variance components were estimated by the Bayesian statistical methodvia Gibbs sampling in GIBBS3F90 software.1000 eggs (28-29 weeks old) were collected from 775 hens of the ninth generation of Khorasan-Razavi Province native fowl breeding center. External (egg weight, specific gravity, long length, short length, shape index, shell strength, shell weight, shell thickness) and internal (yolk diameter, yolk height, yolk weight, yolk index, albumen diameter, albumen height, albumen weight, albumen index, Haugh unit) egg quality traits were measured.Six univariate animal models were used for estimation of genetic parameters and the best model for each trait was determined by deviance information criterion (DIC). Genetic and phenotypic correlations between traits were estimated using bivariate animal model. Direct heritability estimates ranged from 0.10 (egg width) to 0.39 (yolk index). For all traits except albumen diameter and albumen index, the inclusion of maternal effects in the model resulted in considerable reduction in direct heritability. Genetic correlations of egg weight with shell strength and shell thickness were negative. In conclusion, due to genetic correlations among external and internal egg quality traits, selection based on egg weight and shell thickness may improve external and internal egg quality traits. Also, including maternal effects in the form of genetic or permanent environment in the statistical model resulted in more accurate estimates for most traits.

This study investigated the resistance of variousSalmonella strains to betalactam antibiotics.Salmonella Minnesota (36 strains) and Salmonella Heidelberg (24 strains) were isolated from broiler chickens and carcasses by the Disk Diffusion Test and resistance genesbla CTX-M-8, bla ACC-1 andbla CMY-2 were detected by PCR. Of the 60 strains tested, 80% were resistant to at least one antibiotic. Specifically, 66.7% were resistant to amoxicillin/clavulanic acid and 75% were resistant to cefotaxime. Among the amoxicillin/clavulanic acid resistant strains, thebla CMY-2 gene was detected in 40%, bla ACC-1 in 37.5% and bla CTX-M-8 in 7.5%. Among the cefotaxime resistant strains, we detected the genesbla CTX-M-8 in 13.3%, blaACC-1 in 33.3%, and bla CMY-2 in 31.1%. The presence of cefotaximeand amoxicillin/clavulanic acid-resistantSalmonella in poultry, and the prevalence of extended spectrum betalactamases and AmpCbetalactamases in these strains are of huge concern to public health and economy.

This study was conducted to determine the effects of various doses and particle sizes (micro or nano) of dietary zinc and zinc oxide on growth performance, serum enzyme activities, carcass characteristics, and zinc requirements in Japanese quails. A total of 576 day-old Japanese quails (both sexes) were housed in 36 deep litter floor pens. Birds received a basal corn–soybean meal diet that was deficient in zinc (27 mg zinc/kg) for 10 days post-hatching in order to deplete them from zinc reserves.Then, quails were randomly allocated to nine dietary treatments: a control treatment (27 mg of Zn/kg of diet), or one of four levels of Zn (25, 50, 75, and 100 mg/kg of diet) that were one of two ZnO particle sizes (micro or nano ZnO). Birds were fed the experimental diets from 10 to 40 days of age. Body weight and feed intake per pen were measured every 10 days and feed conversion ratio was calculated. On day 40, two males per replicate were slaughtered and carcass characteristics were measured. A quadratic increase in body weight gain (P<0.01) and feed conversion ratio (P<0.05) were found in zincsupplemented quails between 20 to 30 d. Increasing dietary Zn levels significantly increased the relative weights of testes (P<0.01), and thigh (P<0.05). In this study, the optimal dietary Zn levels for body weight gain of Japanese quails were 90 mg/kg of diet for birds 10-20 days old, 70 mg/kg of diet for birds 20-30 days old, and 59 mg/kg of diet for birds 30-40 days old.

This experiment was carried out to study the effects of Coenzyme Q10 (CoQ10) and vitamin C (VC) on growth performance and blood biochemistry in broiler chickens under heat stress conditions. One of three levels of CoQ10 (0, 20, and 40 mg/kg of diet) and one of two levels of VC (0 and 250 mg/kg of diet) were supplemented to diets of chicks (from 1-42 d of age) in a 3 ´ 2 factorial arrangement. Each dietary treatment had four replicate pens (10 chicks/pen). In order to create chronic heat stress, the house temperature was set at an ambient temperature of 35±2oC for 8 hrs daily (09: 00 to 17: 00) between 25-42 d of age. Feed intake, body weight gain (BWG), and feed to gain ratio (F: G) were recorded at d 10, 25 and 42. At the end of experiment, two chicks/pen were randomly selected to assess blood components.CoQ10 supplementation improved BWG and F: G during 11-25 days, 26-42 days, and the whole period of the experiment (P<0.05), while VC supplementation improved BWG and F: G only during 11-25 d of age.Blood glucose, cholesterol and triglycerides concentrations were reduced (P<0.05) by addition of CoQ10 to the diet. Both Supplementation of CoQ10 and VC together lowered heterophil (H) count but increased lymphocyte (L) count, thereby reducing H/L ratio (P<0.05). Serum concentrations of corticosterone and T4 were positively affected by dietary supplementation of CoQ10 (P<0.05), but no differences were obtained with addition of VC to the diet. In conclusion, our observations demonstrated that dietary supplementation of 40 mg/kg CoQ10 or 250 mg/kg VC improves the growth performance of broiler chickens under the heat stress.

The objective of this study was to investigate the effects of feeding electron irradiated flaxseed (FS) on performance, carcass characteristics, blood parameters, digesta viscosity, and nutrient digestibility in broiler chickens. In a 2 × 2 factorial arrangement, 320 day-old broiler chicks were randomly assigned to one of five experimental diets, each with four replicates containing 16 chicks each. Dietary treatments included a corn-soybean meal-based diet (control), and diets containing 10% or 20% raw flaxseed (FS10, FS20), or 10% or 20% flaxseed irradiated at 20 kGy (RFS10, RFS20). Feeding irradiated flaxseed improved body weight gain in grower and finisher periods of the experiment (P<0.05). Birds fed FS20 had a lower (P<0.05) body weight gain in finisher period as well as lower breast muscle percentage in comparison to chicks fed FS10. Thigh percentage was greater in chicks fed FS20 compared to chicks fed FS10 (P<0.05). Liver percentage decreased (P<0.05) in birds fed RFS20 compared other treatments. Birds fed FS20 and RFS20 had significantly lower aspartate aminotransferase activity compared to birds fed FS10 and RFS10 (P<0.05). Dry matter, organic matter, and ether extract digestibility decreased (P<0.05) as the levels of FS increased. Apparent digestibility of dry matter, organic matter, and ether extract in irradiated FS increased in birds fed raw flaxseed.Irradiation of flaxseed significantly decreased digesta viscosity compared to diets containing raw irradiated flaxseed (P<0.05). Results of this study demonstrated that irradiation increases the inclusion level of flaxseed in broiler diets without any negative impacts on broiler performance.

This study was conducted to investigate the effects of fennel ethanol extract on egg production, serum parameters, and bone attributes of laying hens administered carbon tetrachloride (CCl4). A total of 192 Hy-Line W-36 laying hens were assigned to four treatments of four replications in a completely randomized design for 9 weeks (36-44 weeks of age). Experimental groups consisted of 1) positive control (PC) diet (basal diet only), 2), negative control (NC) diet (basal diet+30 mL CCl4/kg diet), 3) NC diet plus 50 mg fennel extract/kg diet (50F), 4) NC diet plus 100 mg fennel extract/kg diet (100F). Egg production and feed intake were recorded weekly. At the end of the experiment, blood samples were collected and bone mineralization and strength were measured. The higher dose of fennel extract (100 mg) increased (P< 0.05) egg production and feed intake, and decreased (P<0.05) cracked egg percentage compared to positive control group. Serum concentrations of Ca and P were also higher in this group (P<0.05) while the lipid levels and activities of hepatic enzymes in the serum were lower (P<0.05). This group also had improved (P<0.05) Ca and P retention in tibia bone, and also greater tibia shear force and stiffness.However, these improvements did not restore the state to the same level as that observed in chickens in the positive control. In conclusion, supplementing 100 mg of fennel extract to diets of layers administered with CCl4 partially ameliorates the detrimental effects of CCl4, and also could improve egg production, serum parameters, and bone attributes.