BACKGROUND: Lead (Pb) induced oxidative stress is known to suppress growth performance in broiler chickens. The current study was carried out in an attempt to describe the specific underlying mechanisms of such phenomenon. OBJECTIVES: The objective of this study was to investigate the effect of Pb-induced oxidative stress on performance, antioxidant status and behavioral responses of broiler chicken. METHODS: Eighty day-old broiler chicks were randomly assigned to 2 dietary treatment groups of 4 pen replicates, namely i) basal diet containing no lead supplement (control) and ii) basal diet containing 200 mg Pb/kg of diet. RESULTS: The results showed that addition of lead decreased body weight gain (p<0.01) and feed conversion ratio (p<0.01). Also, consumption of contaminated diet significantly increased MDA and H/L Ratio and significantly decreased SOD and GPx activity (p<0.01). Moreover, addition of 200 mg/kg diet significantly increased sitting pasture and aggression behavior and decreased feeding behavior (p<0.01).               CONCLUSIONS: Our data conclude that Pb-induced oxidative stress adversely suppressed feed conversion ratio and growth performance. The proposed underlying mechanism for such phenomenon is Pb-induced oxidative stress by impaired antioxidant status and feeding behavior decreased the growth performance.

BACKGROUND: The insoluble fiber content of poultry feeds is often considered as an unfavorable factor which reduces the nutritive value of diet. OBJECTIVES: The effects of barley hulls on performance traits of broiler chickens were evaluated. METHODS: The experiment was carried out using 200 Ross 308 broiler chickens in a completely randomized design with 5 treatments and 4 replicates. The experimental diets  consisted of a control hulls-free diet and four diets containing 0.75 or 1.5 percent barley hulls with particle sizes of less than 1 mm or between 1-2 mm. RESULTS: The dietary type did not affect feed intake of the experimental groups. In the whole the experimental period, the weight gain and feed conversion ratio in the broiler chickens feed, the diet that contained 1.5% barley hulls with 1-2 mm particle size improved compared to the control group (p<0.05). In the jejunum, fiber feeding resulted in an increased goblet cell number as compared to the control group (p<0.05). Unexpectedly, barley hulls feeding reduced the villi height compared to the control group (p<0.05). In jejunum the crypt depth in control birds was more than the treatment fed 1.5% barley hulls with less than 1 mm particle size (p<0.05). The ratio of crypt depth to villus height in control group was more than the birds fed the diet that contained 1.5% barley hulls with less than 1 mm particle size (p< 0.05). In ileum the chickens fed the control diet had more lactobacillus and less Escherichia coli than the majority of the treatment fed barley hulls. CONCLUSIONS: Inclusion of 1.5% barley hulls with particle size of 1-2 mm in diet improved performance traits of broiler chickens. On the other hand, using 1.5% barley hulls as a lignocelluloses source increased lactobacillus growth and reduced Escherichia coli population. This alteration in intestinal micro flora suggests a prebiotic effect for barley hulls in the gastrointestinal tract of broiler chickens.

BACKGROUND: Heat stress is very important in poultry production. OBJECTIVES: To evaluate the effect of oral elatoninsupplementation and increasing of dark period on biochemical profile of broiler chickens under Heat Stress (HS). ETHODS: A total of 200 day- old broiler (Arian) chicks were randomly allocated in to 4 groups (dark ,melatonin, negative and ositive controls). Melatonin group  received 40 mg melatonin/kg  diet from 30-40 days of age and chickens of dark group were xposed to  a  special lighting schedule from 10-40 days of age. All groups (except negative control) were daily exposed to HS (39± 1 c) for 6 hours per day from 35-40 days of age. At the end of 6 weeks, body weight was measured. At 30, 35, and 40 days, serum uric acid, glucose, total protein, albumin, globulin, activity of AST  and creatinine were measured.  atawas analyzed by ANOVA and Tukey test in SPSS software. RESULTS: In 30 days, there was no significant difference etween groups. In the day 35, only serum uric acid of melatonin group was significantly increased in comparison with egative control. Also, serum uric acid of melatonin group  increased significantly in 40 days in comparison with other roups, as melatonin plays an important role in the antioxidant defense system and uric acid is an important antioxidant inchickens. Serum glucose of positive control compared to other groups significantly increased in 40 days. Other biochemical parameters were not significant. In this study,the mean body weight of dark group was significantly decreased. The  percentage of mortality rate in negative control, dark, melatonin and positive control  treatments was zero, 4 ,5  and 10% respectively. CONCLUSIONS: These results demonstrate that  dark period and oral melatonin supplementation  candecrease HS.

BACKGROUND: Stocking density is one of the most important problems in the poultry industry, which impair their production and welfare.OBJECTIVES: This experiment was done to evaluate the effect of organic selenium supplementation on the growth performance, blood metabolites, and the meat quality of broiler chickens in different stocking densities.METHODS: 216 one-day-old male broiler chickens (Ross 308) were used in 2×2 factorial arrangements by 2 stocking densities (7 and 15 birds/m2) and 2 levels of selenomethionine (0 and 0.4 mg/kg) in a completely randomized design with 4 treatments and 4 replicates.RESULTS: The feed intake (FI), and body weight gain (BWG) were significantly affected by the stocking density and selenomethionine (SE-MET) supplementation in the overall experiment (P<0.05). FI and BWG decreased and feed conversion ratio decreased in 15 bird’s density, while SE-MET inclusion improved these traits (P<0.05). Increasing stocking density increased the plasma glucose (P<0.05). Blood glutathione peroxidase and lymphocyte levels reduced at 15 bird’s density, while increased by 0.4 mg SE-MET supplementation (P<0.05). Increasing stocking density increased blood heterophil, while SE-MET inclusion decreased it (P<0.05). Meat pH and cooking loss were not affected by stocking density. Dripping loss (DL) increased, and water holding capacity (WHC) decreased at 15 bird’s density, but 0.4 mg SE-MET decreased DL and significantly increased WHC (P<0.05).CONCLUSIONS: It was concluded that increasing stocking density had the negative effects on the growth performance and meat quality of broiler chickens; however, the supplementation of 0.4 mg of SE-MET to diet can improve the growth performance, blood metabolites and meat quality of broiler chickens.

A study was carried out in the month of September, 2022 to know the economics on rearing of indigenous (local) comparative broiler birds at the Poultry Unit of SCS college of Agriculture, Rangamati, Assam Agricultural University, Dhubri, Assam. For the study, day old chicks of indigenous and broiler, 100 numbers each were introduced in deep litter system of management. Broilers were marketed at the completion of 6 th week, while the indigenous birds were kept up to 8 th week and then marketed. Mean body weight was found to be 2082.67±14.85 g and 658.29±3.49 g in the case of broilers and indigenous birds at 6 th week and 8 th week respectively. The feed conversion ratio (FCR) was recorded as 1.64 and 2.29 for broiler and indigenous birds, respectively. The cost of production per kg bird is Rs.114.70 and Rs. 227.90 for broiler and indigenous birds respectively. The net profit calculated in production of broilers and indigenous was Rs. 5100.00 and Rs. 7450.00 respectively. Benefit cost ratio (BCR) in broiler and indigenous bird was found to be 1.22.1.00 and 1.53:1.00, respectively.

In this project, 270 broiler chickens one day old were used to demonstrate the effect of the addition of the amino acid cysteine ​​added to the diets of birds contaminated with aflatoxin B1 on the liver and kidneys. The experiment was divided into 9 equal groups; &amp; each group had 30 birds with 3 replicates, and each replicate had 10 birds. The control group was without addition. As for the treated groups, cysteine, ​​and aflatoxin B1 were added to their diets at 40%, 80% &amp; 160% cysteine, and aflatoxin B1 was added at 0 ml, 4 ml &amp; 8 ml, respectively. The variables collected were liver &amp; kidney histopathology, Alanine aminotransferase (ALT), and Aspartate aminotransferase (AST) levels. When adding cysteine to a bird's diet contains Aflatoxin B1 not observed in blood ALT amount. The histopathological examination showed fibrosis in the liver and degeneration and dilatation of cortical tubules in the kidney. The amount of AST in the blood was greater at 28 days of age, specifically in G2 (Cysteine 80%) &amp;G3 (Cysteine 160%) at Aflatoxin B1 0 ml, which caused significant damage to the liver. The giving of cysteine 40, 80&amp; 160% in birds' feed contaminated with AflatoxinB1 0, 4&amp; 8ml, which is intake by birds, has harmful effects on the health of the liver.

The study designed to investigates the anatomical and histological structures of the thymus gland in broiler chick embryos. &nbsp;Ten healthy, normal embryos at 12th and 20th days old chick embryos was used, divided into five embryos for each age. The thymus was well developed at 12th day chick embryo, Anatomically consisted of 6-8 lobes which are similar in both sides .small, translucent bean shaped lobes that became pale in color at 20th day old embryo, these lobes located in both sides of the neck, positioned parallel to the jugular vein and vagus nerve. &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Histological structures of thymus gland were composed of capsule, cortex and medulla.&nbsp; At 12th day old of chick embryo the thymus was surrounded by a thin connective tissue capsule, which septa extends into the gland stroma to form a lobulation for each lobe, the cortex and medulla was not differentiated at this age. At 20th day old chicks embryo, the lobules start to recognize and composed of external dark stained cortex with a high population of lymphocytes and internal light stained medulla with less abundant of lymphocytes , reticular fiber and epithelial reticular cells with the appearance of Hassall's corpuscles.

This study was carried out on serum samples collected from broiler breeder chicken flocks vaccinated with avian influenza (AI) H5N1 inactivated vaccine. These flocks included 23 flocks aged 13 to 47 weeks reared in close houses in 7 sites; two vaccinated breeder flocks for HI antibody monitoring by 5 weeks interval samples and 8 flocks aged 41 weeks reared in different sites with identified females and males samples. The vaccine was used in a dose of 0.2 ml at 1 day in hatchery and revaccinated with 0.5 ml at age of 18 days, 19- 20 weeks and 40 weeks. Hemagglutination inhibition (HI) test was carried out against homologous antigen. The study pointed out that AI H5N1 inactivated vaccine under field application induced irregular and low HI titres following the 1st two doses ranged from log 2 0.0 to 4.15 with great variation between flocks, where samples with titre 0-2 ranged from 20 to 100%. The 3rd dose at 19-20 weeks was essential to elevate HI titres 3.25 to 7.44 with more homogenizes flock immunity and lower percentage of titres 0-2 ( 0-20 %) and as measured by HI test. Revaccination of layer flocks at 40 weeks (fourth dose) improves flock immunity facing stress of egg production as evaluated by HI (5.52 - 6.33) and lower negative percentage (5.5-11.7%). Monitoring of breeder flock every 5 weeks is essential to detect proper time of revaccination as each flock has its HI antibody curve. There was a difference in HI tit re rang log 2 0.33 to 1.2 between male and female chicks reared in the same house, but this variation not affecting flock mean. Birds at aged 41 weeks having titres < log2 3 (Seronegative) were protected when exposed to contact with infected flock as showed no clinical signs or change in HI titres after 12 days. In conclusion the usage of homologous inactivated H5N1 vaccine in 4 doses in layer flocks was of value in improving chicken immunity to AI H5N1 wild strain circulate in our field

A total of 90 one-day-old male broiler chicks were fed on balanced ration for 15 days and then divided into 3 equal groups. Control group fed ration probiotic free, group 2 and 3 fed ration supplemented with probiotic at concentration levels 0.5 and 1.0g/kg ration respectively for 4 weeks.It was found that probiotic improve body weight gain and feed conversion ratio. Relative organs weights were not altered in groups of birds fed ration mixed with probiotic. Serum values of biochemical parameter (AST, ALT, ALP, total protein, A/G ratio, Ph) were not significantly changed in comparison to control group. Probiotic enhance the immune response of broiler chickens in a dose dependent relation as documented by increasing the serumNDHI antibody geometric mean titres to ND vaccine, phagocyte percentage and phagocytic index of peripheral blood monocyte of broiler chickens. We concluded that probiotic composed of 3 strains of bacteria (Pediococcus acidilactici, Pediococaoccus pentosaceus and Bacillus Amylolique- faciens) in addition to 2 strains of yeast( Pichia farinose and Dekera anomala ) enhance body weight gain, feed conversion, growth performance and Newcastle disease antibody titres in broiler chickens. Moreover, probiotic was safe as proved by serum biochemical profile and relative organ weight of male broiler chickens.

ABSTRACT 210 one day old broiler chicks were used in this study. They were divided in to two groups. The first kept on commercial diet as (control); the second group was given thiamin (vit. Bl) in dose 10 mg /bird was added to same commercial diet. Glucose concentrations, total cholesterol, total protein and the activity of the blood enzymes were determined. Results revealed a significant (p0.05) for this vitamin on the blood enzymes activity. The physiological impact of these changes were discussed.