جستجوی مقالات مرتبط با کلیدواژه "newcastle" در نشریات گروه "علوم دام"

Olive leaf extract (OLE) can be used as a rich source of antioxidants due to its polyphenol compounds. The purpose of this research was to measure the antioxidant activity and the effect of aqueous (AOLE) and alcoholic (HOLE) extracts of olive leaves on performance, quality characteristics of eggs, biochemical blood serum, hematology, and immune response of laying hens. This experiment was conducted with 440 high-line laying hens (25 weeks old) in the form of 11 experimental treatments, with 5 replications and each replication including 8 hens for three periods of 28 days in a completely randomized design with five levels of AOLE (200, 400, 600, 800 and 1000 mg/kg) and five levels of HOLE (200, 400, 600, 800 and 1000 mg/kg). The DPPH method was used to measure the antioxidant activity of the extract. Functional traits were measured periodically. Blood was taken from the wing vein for serum biochemical and hematological analysis. Injection of the Newcastle vaccine was performed on the 40th day of the experiment, and blood was taken from the wing vein seven days later. The results showed that birds receiving 1000 levels of AOLE and HOLE had the highest percentage of production compared to the control treatment. The highest number of white blood cells and heterophils and antibody titers against Newcastle virus were observed in birds treated with 1000 HOLE levels. In general, the use of 1000 mg/kg of aqueous and alcoholic extract of olive leaves improves the performance and quality of laying eggs.

During the last two decades, the use of antibiotics in poultry diets as animal growth promotors and growth inhibitors of harmful microorganisms has been stopped in different parts of the world (Roth et al., 2019), which led to a decrease in poultry performance and an increase in the prevalence of diseases (Jha et al 2019; Adhikari et al 2020). Researchers have proposed various ways to improve production efficiency, including the use of probiotics, prebiotics, symbiotic, plant extracts, enzymes and organic acids (Gadde et al 2017; Yadav et al 2019). As the age of laying hens increases, the quality of the egg shell decreases, which is due to the increases in weight and size of eggs, the direct effect of age on the structure of the shell, decreased bone calcium uptake and etc (Curtis et al 2005; Curtis 2008). Heat stress has negative effects on the human health and animal performance and product quality. High ambient temperatures cause reduced egg production, egg weight, egg quality (especially egg shell thickness and strength), impaired immunity and poor poultry welfare (Elnagar et al 2010, Ebied et al 2012). The impaired performances of poultry subjected to heat stress (HS) have been associated with a number of factors, including poor appetite and reduced feed intake (due to activation of the hypothalamic-pituitary-adrenal axis), impaired digestion and metabolism, altered endocrine status (increased corticosterone concentration and reduced thyroid hormones concentrations), metabolic shifts at the systemic and cellular levels and changes in body composition (Elnagar et al 2010, Azad et al 2010, Ebied et al 2012, Safdari-Rostamabad et al 2017). Therefore, it is important to design the strategies or ways of minimizing the negative effect of heat stress as part of methods to maintaining egg production, egg quality and poultry welfare. There are several strategies to reduce the effects of heat stress in the laying hens, including use of feed additive, vitamins, organic minerals and antioxidants. In this study, researchers evaluated the effects of MultiAct-L® (Contains probiotics, prebiotics, organic acids, enzymes, organic form of Zn, Mn, Cu, Fe, Co, Cr and antioxidants) on production performance, egg quality, Newcastle disease antibody titer, antioxidant capacity and gut morphology of laying hens subjected to HS in late laying cycle.

Two hundred and sixteen LSL-Lite laying hens (90 weeks of age) were randomly assigned to three dietary treatments with six replicates and twelve birds in each replicate. Dietary treatments were: 1) basal diet based on a corn-soybean meal 2) basal diet with 0.3 % MultiAct-L® and 3) basal diet with 0.5% MultiAct-L®. The birds were exposed to 36±1°C for 6 hours per day. Egg production, egg weight, feed intake, egg mass and feed conversion ratio were recorded weekly and mortality was recorded daily. Egg mass was calculated by multiplying the total number of eggs laid per hens by the average egg weight. At the end of experimental period, one bird from each replicate (close to cage average weight) was slaughtered, and blood samples were taken for analysis. Blood samples were collected from the jugular vein and then serum samples were separated at 3000 ×g for 10 min. Total antioxidant capacity, malondialdehyde, glutathione peroxidase, superoxide dismutase, glucose, cholesterol, triglycerides, uric acid, albumin, calcium and phosphorus were measured using analytical kits. Serum titer to Newcastle disease virus was determined by hemagglutination inhibition test. Villus height, villus width, crypt depth, villus surface area and villus height/crypt depth were measured in the jejunum section of the small intestine. The data were analyzed using the general linear model procedure of the SAS (2003). The Duncan multiple range test was used to determine the significant differences between treatment means.

MultiAct-L® did not affect the body weight gain of laying hens (P>0.05). The results also showed that feeding MultiAct-L® enhanced the feed intake, egg production, egg weight and egg mass (P<0.05). Feed conversion ratio was improved and mortality was lower in the treatments receiving 0.3 or 0.5% MultiAct-L® than the control group (P<0.05). In agreement with our findings, Deng et al. (2012) and Zhang et al. (2017) reported the significant increase of egg production, feed intake and egg weight by dietary supplementation of probiotic in laying hens subjected to HS. Supplementation of 0.3% MultiAct-L® to diet decreased the abnormal eggs (P>0.05). Shape index, Haugh unit, yolk weight, albumen weight, shell weight, shell thickness and egg specific gravity were not affected by dietary treatments (P>0.05). Similarly, Bozkurt et al. (2012) showed that egg quality parameters weren’t affected by dietary supplementation of essential oil or mannan oligosaccharide in laying hens subjected to heat stress. MultiAct-L® supplement did not significantly affect the titer of antibody against Newcastle disease virus at days 10 and 30 post-vaccination (P>0.05). There was no significant difference in the total antioxidant capacity and glutathione peroxidase among experimental treatments (P>0.05); however, dietary MultiAct-L® supplementation had increased the superoxide dismutase levels and decreased malondialdehyde levels in serum (P<0.05). Blood glucose, cholesterol, triglycerides, uric acid, albumin, calcium and phosphorus in experimental treatments were not significantly different between the control group and the MultiAct-L®-treated groups (P>0.05). No significant changes in villus height, villus width, villus surface area, crypt depth and villus height to crypt depth ratio were observed between three groups at the end of the 8 weeks experimental period (P>0.05). Similarly, Deng et al. (2012) showed that villus height, villus width, crypt depth in the ileum weren’t affected by dietary supplementation of probiotic in laying hens subjected to HS.

As for the results of this study, Multiact-L® could improve laying performance and antioxidant status in laying hens subjected to heat stress during the late laying period.

The effect of dried corn steep liquor (DCSL) and probiotics on growth performance, intestinal microbial population and humoral immune response of broilers using 320 one-day-old Ross 308 broilers in a 2 × 4 factorial arrangement experiment with four DCSL levels (zero, two, four and six percent) and two levels of probiotic LactoFeed® (zero and 150 mg/kg) were evaluated in a completely randomized design with eight treatments, four replicates and 10 birds per replication for 42 days. Body weight gain, feed intake, feed conversion ratio, lactic acid and coliform bacterial populations, as well as the response of broiler chickens' humoral immune system against Newcastle disease, bronchitis and influenza viruses were measured. In the grower, finisher and whole period effect of LactoFeed probiotics and DCSL and their interaction on body weight gain and feed conversion ratio were not significantly different. In the starter period, birds fed diets containing four percent DCSL consumed more feed and gained more weight than chickens fed diet without DCSL (P<0.05). Interaction of six percent DCSL and probiotic increased feed intake in the starter period compared to diet lacking these compounds (P<0.05). The greatest antibody titer against Newcastle disease, influenza and bronchitis viruses was observed at six percent of DCSL (P<0.05). The interaction of DCSL and probiotics decreased the population of coliforms and increased the population of lactic acid bacteria (P<0.05). According to the results of this study, the use of DCSL and probiotics in the diet of broilers improves the humoral immune response and intestinal microbial population.

The aim of this research was to investigate the immune system responses against sheep red blood cells (SRBC) and Newcastle disease virus (NDV) in two sexes of both wild and Italian speckled quails. To compare phenotypic differences of two sexes for humoral immune responses a one-way analysis was applied, and a simple animal model using the MCMCglmm package of R software was used for genetic analysis, assuming variance components between the two sexes are different. Phenotypic comparison between males and females did not show a significant difference in any of the strains. In both strains, heritability of humoral immunity in males was higher than females. Results indicated that heritability of IgT in males (0.187), and IgY in females (0.177) were higher than other estimates in wild strain. The highest heritability was related to the NDV, which was estimated to be 0.214 and 0.268 in males and females, respectively. Therefore, genetic selection for IgN can be expected to improve the performance of the birds’ humoral immune system. Likewise, according to the higher estimates of immune responses in males, genetic selection of humoral immune responses for IgN, leads to higher genetic progression.

The present study was conducted to investigate the effects of deitary protein density (low, medium and high) and nano adjuvant on performance, antibody titres against Newcastle disease and blood parameters of broiler chickens. Two hundred fourty one-day old Ross 308 broiler chickens were allocated to six dietary treatments based on a completely randomized design in a factorial arrangment of 2×3 with two levels of nano adjuvant and three levels of protein. Feed intake (FI), body weight gain (BWG) and feed conversion ratio (FCR) were measured at the end of the experiment. On days 28 and 42, antibody titres against Newcastle disease virus were measured. Two birds per replicate were selected on day 42 and their blood samples were collected in order to determine white blood cell differential counts. The main effect of protein density on BWG was significant (P0.05). Despite of significant effect of protein density in the diets on body weight gain of the chicks, this effect on antibody titres against Newcastle disease and white blood cells counts was not significant. There was some advantage for nano adjvant use on antibody titers against Newcastle disease and white blood cells counts of broiler chickens.

This study was carried out to investigate the effects of dietary levels of an active phospholipids source on immune system response in broilers using 180 male Ross 308 broilers chicks. Experimental diets containing 0, 0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6 % of active phospholipids were prepared in a way that metabolizable energy, protein and other nutrients was the same in them. Blood samples were collected at days 16 for Newcastle test, day 41 for differential measurement of white blood cells and at days 36 and 45 for SRBC test. The obtained results showed that different levels of active phospholipids source had no significant effect on lymphoid organs, number of heterophil, lymphocyte, monocyte, basophil, heterophil to lymphocyte ratio, IgG and IgM titer as well as anti-Newcastle antibody titer in broilers. In conclusion, it seems that levels of used active phospholipids source had no effect on the evaluated immune parameters in this experiment.

In order to study the effect of green tea and fish oil on performance and antibody titer against Newcastle disease, 405 day-old broiler chickens were evaluated in a 3×3 factorial experiment using completely randomized design. Chicks were divided into 9 parts and each part was split into 3 groups. Each part was fed by diet containing 0% (T0), 0.75% (T0.75) or 1.5% (T1.5) dry powder of green tea and 0% (F0), 0.75% (F0.75) or 1.5% (F1.5) fish oil. Feed intake, gain weight and feed conversion ratio were estimated weekly. The vaccine of Newcastle was inoculated at 8 and 17d. To assay the antibody of Newcastle by HI test, blood samples were collected from five checks of each group from brachial vein at 25, 32 and 39 d. The results showed that there was no difference between treatments on the feed conversion ratio (P>0.05) and the lowest weight gain (30.43) and the highest feed intake (72.25) were observed by 1.5% fish oil and 1.5% green tea. At 39 d, the highest level of antibody (3) was obtained by 1.5 % fish oil (P<0.05). At 32 and 39d, the levels of antibody against Newcastle was lower in 1.5% green tea (2.09 and 2.18, respectively) than 0% green tea (2.64 and 2.84, respectively; P<0.05). Therefore, the addition of 1.5% fish oil and 1.5% green tea to diet of broiler chickens increased and decreased the humoral immunity responses against Newcastle disease, respectively.

Vaccination at proper time is one of the main strategies to control Newcastle disease. The value of each vaccine depends on the level of antibody production after vaccination. The Levamisol hydrochloride seems to stimulate immune response after vaccination. In this study 225 one day old broiler chickens are divided into 5 groups and each group is separated in 3 repeat. Group1 is considered as control group (without drug administration). Group 2 received Levamisol hydrochloride 2mg/kg subcutaneously in the first day and this was repeated weekly for 6 weeks. Group 3 received 10mg/kg Levamisol hydrochloride each day orally from the first day for 6 weeks. Group 4 received levamisole hydrochloride 2mg/kg simultaneously with vaccine of Newcastle disease subcutaneously. Group 5 received 10mg/kg Levamisol hydrochloride orally after being vaccinated for 24 hours. Sampling was carried out 11 days after vaccination. The result shows that there is a significant difference in mean of antibody titer against ND virus and number of the blood lymphocytes between experimental and control group in stage 1 and 2 of vaccination, but there are no significant differences in stage 3 of vaccination. Administration of Levamisol hydrochloride did not influence feed conversion rate and the mean of body weight in any week of growing period. Therefore, it seems that administrating levamisole hydrochloride after vaccination can stimulate immune response to vaccine. However, using levamisole hydrochloride could help immunity system to produce antibody in the primary age.