Poultry Science Journal
Volume:3 Issue: 2, Summer-Autumn 2015

This experiment was conducted to investigate the effects of different levels of L-carnitine on productive performance, egg quality and blood parameters in laying hens. Forty eight Hy-Line W-36 egg Layers were weighed at 90 weeks of age and randomly allocated into 16 cages (three hens per cage). Four dietary treatments were prepared by supplementing L-carnitine (0, 50, 100 and 150 mg/kg of diet) to corn-soybean meal diet and offered ad libitum to hens. After two weeks of acclimatization, the eggs were weighed daily and feed intake as well as egg quality traits were measured biweekly. At the end of the experiment, two hens from each cage were selected to determine blood parameters and two eggs from each replicate were collected for cholesterol analysis. Results showed that L-carnitine supplementation at 100 and 150 mg/kg significantly increased egg production and egg mass, but decreased yolk cholesterol content. Hens receiving diet containing 50 mg/kg L-carnitine had significantly higher Hough unite, but lower progesterone than the hens fed control diet (P < 0.05). The results of this study showed that supplementing hen's diet with L-carnitine had beneficial effects on productive performance and decreased yolk cholesterol concentration; so it can be used as an effective supplement in the diet of laying hens.

In a 42-d experiment, 576 one-day-old Vencobb 308 broiler chicks were used to investigate the effects of lecithin extract (0.5 g/kg), choline chloride 60% (1 g/kg) and Bio choline (1 g/kg) in diets of moderate and high energy in a 4 × 2 factorial arrangement on performance and certain physiological traits in broiler chickens. Inclusion of Bio choline and lecithin extract in diet significantly increased average daily gain (ADG) and improved feed conversion ratio (FCR) in overall (1 to 42 d) period (P < 0.05). Performance efficiency index (PEI) was improved in the birds fed with Bio choline compared to those fed control diet. Broilers fed on diets containing Bio choline and lecithin extract had less abdominal fat percentage than those fed choline chloride or control diet. Regardless of dietary energy level, supplementation of diet with Bio choline, choline chloride and lecithin extract significantly decreased liver lipid concentration (LLC) (P < 0.05). Aspartate amino transferase (AST) activity increased in the serum of broilers fed high energy diets, while it was decreased in the birds received diets containing choline chloride. Lipotropic compounds decreased serum AST activity in the birds fed on high energy diets. Addition of Bio choline and lecithin extract to diet significantly decreased serum γ–glutamyl transferase (GGT) activity (P < 0.05). Results of the present study revealed that dietary supplementation of commercial lipotropic compounds could remove potential detrimental effects from high energy diets through reducing liver fat and maintaining liver health.

Six hundred 1-d-old male broilers (Ross 308) were assigned to four experimental groups; each was composed of 5 floor pen replications of 30 birds including control (no enalapril), 15, 30 and 60 ppm enalapril in the drinking water. From d 21 to 49, all the chicks were exposed to low ambient temperature to induce ascites. Mortalities were inspected to determine the cause of death and diagnose of ascites. At the end of the experiment (wk 7), 2 chickens from each replicate were randomly selected and slaughtered. Body weight gains (BWG), feed intake (FI) and feed conversion ratio (FCR) were calculated. Plasma protein, glucose, red blood cell (RBC), white blood cell (WBC), triglyceride, high density lipoprotein (HDL), malondialdehyde (MDA), activity of alkaline phosphatase (ALP), aspartate transferase (AST), alanine transferase (ALT), creatine kinase (CK), total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were also determined. Results showed that enalapril for 30 and 60 ppm, significantly improved FCR and enhanced BWG when measured at day 49. These levels of enalapril compared to the other groups, significantly reduced MDA level and GPx activity, but increased T-AOC and SOD activity in plasma. Moreover, enalapril at levels of 30 and 60 ppm, significantly reduced AST, ALP and CK activities in plasma. Mortality due to ascites and right to total ventricular weight ratio (RV/TV) were significantly low in groups received enalapril at greater levels (≥30 ppm). Compared to the control, enalapril increased HDL. In conclusion, enalapril could improved growth performance and reduced mortality in broilers.

In the first experiment, the chemical composition, apparent metabolizable energy (AME), AME corrected for nitrogen (AMEn), true metabolizable energy (TME), TME corrected for nitrogen (TMEn) values of the sweet almond meal were determined in adult Leghorn cockerels. The second experiment was performed to evaluate the effects of different levels of sweet almond meal (SAM) at 0, 100, 200 and 300 g/kg on Japanese quail's growth performance, some blood metabolites, relative weight of different organs, meat quality and egg yolk's cholesterol in a completely randomized design with 288 Japanese quails including 4 treatments, 4 replicates and 18 birds per replicate. The metabolizable energy values of SAM were following: AME = 3734, AMEn = 3648, TME = 3908, TMEn = 3746 kcal/kg as fed basis. Feed intake, feed conversion ratio (FCR) and live weight gain and relative weight of different organs in the birds fed diets with different levels of SAM were not statistically different from control. SAM at 300 g/kg level showed the lower serum total cholesterol and low density lipoprotein (LDL) (P < 0.05) compared to control and 100 g/kg SAM. Dietary treatments had no significant effect on the total cholesterol content of quail's eggs. Malondialdehyde (MDA) concentration in breast meat samples after 40 days freezing decreased, whereas the level of SAM increased (P < 0.01). In general, SAM without any adverse effect on growth performance is a good source of energy and protein and can be used up to 300 g/kg of the Japanese quail diets.

The objective of this study was to investigate the effects of three levels of threonine (100, 95 and 90% of NRC requirements) with or without of multi strains probiotic (Primalac) on performance, carcass characteristics and blood metabolites of Japanese quails. A total of 180 one-day old male Japanese quails were randomly allocated to six treatments with three replicates and 10 birds per each. The experiment was done from 0 to 6 weeks of age. Growth performance traits including weight gain, feed intake and feed conversion ratio were recorded. At the end of the experiment six birds per treatment were slaughtered and carcass characteristics were measured. Blood sampling was taken at 42 days of age. The results of this study indicated that supplementation of probiotic did not affect feed intake, weight gain and feed conversion ratio in quails. In contrast, feed conversion ratio was improved in birds fed with 100% of threonine requirements. All carcass traits, except for liver weight, were not influenced by threonine levels and dietary probiotic supplementation. Liver percentage was higher in birds fed diets without probiotic. The results showed that serum glucose was affected by threonine levels. However, the other blood metabolites such as cholesterol, triglyceride, HDL and LDL were not influenced by the threonine levels. In this regard, non of blood metabolites were influenced by probiotic supplement, except for cholesterol. In conclusions, the supplementation of probiotic did not affect growth performance in Japanese quails. However, use of threonine at 100% NRC requirements improved feed efficiency in Japanese quails.

The objective of the present study was to estimate heritability values for some performance and egg quality traits of native fowl in Isfahan breeding center using REML and Bayesian approaches. The records were about 51521 and 975 for performance and egg quality traits, respectively. At the first step, variance components were estimated for body weight at hatch (BW0), body weight at 8 weeks of age (BW8), weight at sexual maturity (WSM), egg yolk weight (YW), egg Haugh unit (HU) and eggshell thickness (ST), via REML approach using ASREML software. At the second step, the same traits were analyzed via Bayesian approach using Gibbs3f90 software. In both approaches six different animal models were applied and the best model was determined using likelihood ratio test (LRT) and deviance information criterion (DIC) for REML and Bayesian approaches, respectively. Heritability estimates for BW0, WSM and ST were the same in both approaches. For BW0, LRT and DIC indexes confirmed that the model consisting maternal genetic, permanent environmental and direct genetic effects was significantly better than other models. For WSM, a model consisting of maternal permanent environmental effect in addition to direct genetic effect was the best. For ST, the basic model consisting direct genetic effect was the best. The results for BW8, YW and HU, were different between the two approaches. The reason behind this tiny differences was that the convergence could not be achieved for some models in REML approach and thus for these traits the Bayesian approach estimated the variance components more accurately. The results indicated that ignoring maternal effects, overestimates the direct genetic variance and heritability for most of the traits. Also, the Bayesian-based software could take more variance components into account.

The antimicrobial effectiveness of different extracts of Chicory (Cichorium intybus L.) plant including methanolic, ethylic acetate, chloroformic, and aqueous extracts was evaluated by Disk Diffusion method. The ethylic acetate extract showed higher antibacterial activity against E. coli compared with others. Then, effects of different levels of ethylic acetate extract on growth performance and blood parameters of broilers subjected to high ambient temperature was investigated. The experiment was conducted as a completely randomized design using 5 dietary treatments including a control diet, 3 levels of the Chicory ethylic acetate extract (150, 250, and 350 mg/kg feed) and one level of probiotic with 4 replicates of 20 broiler chicks in each. The temperature was increased to 35°C with 50% relative humidity for 5 h daily, starting from 11 d until 42 d of experimental period. Body weight gain, feed intake and feed conversion ratio were determined during the experiment. Blood samples were collected from two birds in each replicate for studying serum components. There was no significant difference between body weight gain, feed intake, and feed conversion ratio in birds fed with different diets at 1-10 d of age. Inclusion Chicory extract at 350 mg/kg and probiotic increased body weight gain and improved feed conversion ratio during 11-24 d and 0-42 d (P < 0.05). There were no significant differences in feed intake of broilers treated with Chicory extract and probiotic compared with control. The serum concentrations of triglyceride and very low-density lipoprotein (VLDL) significantly decreased in birds received Chicory extract at the levels of 250 and 350 mg/kg feed compared with the other treatments (P < 0.05). No significant difference was observed between treated groups and control for serum high density lipoprotein (HDL) and low density lipoprotein (LDL) concentrations. It seems that dietary supplementation of Chicory ethylic acetate extract at levels higher than 250 mg/kg feed has growth promoting effect which can result in improving growth performance and decreasing blood lipids of broilers exposed to heat stress condition.

An experiment was conducted to study the effects of carbon tetrachloride (CCl4) on post peak performance and serum enzymes of Hy-Line W-36 laying hens from 32-36 weeks of age. The experiment was carried out with a total of 192 laying hens in a completely randomized block design. During the experiment laying hens were allocated to 4 groups consisted of T1) no CCl4 as control diet, T2, T3 and T4) control diet supplemented with 1, 3 and 5 mL CCl4/100 g diet, respectively. Each experimental group was divided into 6 blocks of 8 hens each. Egg production, cracked egg percentage and feed intake were recorded weekly. Blood samples were taken from wing veins of hens at the middle and end of the experiment to measure serum hepatic enzymes of alkaline phosphatase (ALP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Data showed that in comparison with the control group, inclusion of CCl4 to the diets had no significant effect on performance parameters. However, by increasing the level of CCl4, egg production was linearly decreased and feed intake was linearly increased (P < 0.05). The effect of CCl4 on cracked eggs was significant and this effect was linearly increased (P < 0.05). Dietary supplementation of 3 and 5 mL CCl4 elevated the serum concentration of hepatic enzymes of ALP, AST and ALT, linearly (P < 0.0001). In conclusion, the dietary supplementation of CCl4 has the ability to decrease the performance and egg quality. CCl4 is also a potent hepatic toxicity inducer and may damage liver hepatocytes. Therefore, the level of 3 mL CCl4 was assigned as the one had the maximum negative effect on serum hepatic enzymes concentration (maximum liver damage) alongside the minimum negative effect on laying hen performance for further studies.

This study was conducted to evaluate the long-term effects of in ovo injection of nano-silver, thyme and savory extracts in broiler breeder eggs on growth performance, lymphoid organ weights, immune and blood parameters and bone mineral concentration of broiler chicks. A total of 560 fertilized broiler breeder eggs were divided into 7 groups. On d 5 of incubation, eggs were treated with the following groups. Group 1 (control, no injection); group 2 (placebo, 1 mL of 0.9% NaCl); group 3 and 4 (placebo + 30 and 45 mg of nano-silver, respectively); group 5 and 6 (placebo + 75 and 100 mg of thyme, respectively) and group 7 (placebo + 75 mg of savory). After hatch, chickens were fed a corn-soybean meal diet under the controlled conditions and slaughtered at 14 and 21 d of age for sample collection and analysis. The lymphoid-organ weights and growth rate were not affected by dietary treatments at 14 and 21 d of age. The results also showed that nano-silver injected into broiler breeder eggs during incubation improved the bone mineral concentration and cell-mediated immunity at 14 and 21 d of age, respectively. Humoral immunity was improved by thyme and savory extracts (P < 0.05). Overall, the effect of in ovo injection of nano-silver, thyme and savory extracts during embryonic development is a potential means to improve immune activities of broiler chickens, while does not have any detrimental effect on embryo hatchability.