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.

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.

A feeding trial was carried out with 216 day-old Vencobb-400 broiler chicks distributed to six experimental groups with six replicates, each replicate containing six chicks, in deep litter for 35 days. The experimental groups were fed with control ration (T1), ration with oxytetracycline (OTC) at 50 mg/kg (T2), ration with cinnamon oil (CO) at 250 mg per kg and coated sodium butyrate either at 0.09 (T3) or 0.18 (T4) per cent levels and ration with CO at 500 mg per kg and CSB either at 0.09 (T5) or 0.18 (T6) per cent levels. The coated sodium butyrate used in this experiment was encapsulated with a vegetable fatty acid containing 30% sodium butyrate. The economics of raising broilers up to 35 days with different levels of CO with CSB supplementation was calculated based on the actual cost of feed per kg live weight gain. The increase in the revenue was Rs. 2.79 per kg live weight in group supplemented with CO at 250 mg per kg and CSB at 0.09 per cent (T3) when compared to control. Returns were found to be better in group supplemented with CSB @ 0.09 per cent and CO @ 250 mg per kg than the dietary oxytetracycline group. A decrease (Rs.0.43) in the revenue of per kg live weight gain was recorded in T3 (CO @ 250 mg per kg and CSB @ 0.09%) when compared to antibiotic group (T2) but this decrease was marginal and not significant. This is an important observation in this study as to the industry’s attempts to avoid use of antibiotics in feed.

This study aimed to determine the prevalence of coccidiosis in broiler farms in Duhok Province, Iraq. A cross-sectional study was performed from June to October 2023. 600 fresh fecal samples were collected from the litters of the suspected farms, and the parasitological examinations were carried out using standard methods by using both direct fecal and flotation fecal methods for searching for coccidian oocysts. Also, 600 intestine and ceca samples were collected from the same chicken for macroscopic examination to report the presence of any pathological changes in the intestine and the ceca. The study findings revealed a high prevalence rate of coccidiosis (60%) among broiler farms in Duhok Province. Regarding ages, the ages 4-6 weeks were observed the most prevalent for infection (66.56%) than in other age groups. This study revealed that the infection rate of coccidiosis was higher in the Autumn season than in the summer season. According to the gross examination, most cases showed positive for Eimeria tenella (4433%), which indicates cecal coccidiosis and (55.7%) were positive with other Eimeria spp. Finally, some positive cases of Eimeria tenella were found infected with other species. The prevalence of coccidiosis among broiler farms was high in this study, especially, cecal coccidiosis and this is associated with several risk factors such as poor management, bad ventilation systems, humidity, and inadequate biosecurity systems in the farms.

The effect of 10 times (10x) overdose of enrofloxacin was studied in broiler chickens. One hundred and eighty chicks were classified in 3 equal groups. The first group received normal theurapeutic dose of enrofloxacin (1x) in drinking water for the first 5 consecutive days of age and repeated again at 24th -28th day of age. The second group received 10x (overdose) at the same ages. The third group was left non-medicated as a control group. Blood samples were taken on the 6th, 14th, 29th and 34th day of age for different laboratory tests. Enrofloxacin at 10x caused a decrease in the value of the following parameters: HI antibody titers to NDV vaccine at the 14th and the 34th day of age, serum albumin at the 10th day of age, hemoglobin at the 29th and the 34th day, lymphocytic count and IBDV ELISA titers at 29th day of age, uric acid at 29th day, phagocytic activity at 34th day, Lactobacillus spp. count in duodenum, feed conversion efficiency and body weight gain. The 10x (overdose) increased serum urea and creatinine at 29th day of age, serum AST and ALT at 29th and 34th day of age, and heterophilic count. Histopathological degeneration in liver, spleen, kidneys, bursa of Fabricius and thymus were demonstrated by 10x (overdose) of enrofloxacin. Challenge with vNDV caused 66.6% mortality in birds received the 10x (overdose) compared with 33.3% in the vaccinated non treated control group.

This study was carried out to evaluate the immunomodulating effects of, inactivated cells of Propionibacterium acnes and cell wall lipopolysaccharide (LPS) of the a pathogenic E. coli (INMUNAIR® 17.5) 0.5ml/ L and 1-3, 1-6 β-glucans (BETAPOLO®) 1 ml / L on the immune response of chickens to Newcastle disease (ND) vaccine. The results showed that administration of IMR before vaccination was resulted in food conversion rate (FCR) higher than after vaccination . Significantly higher NDV HI antibody titers in IMR and Betapolo medicated groups as compared with control groups which in turn induce high protection rate in challenge test .Thymus, spleen and bursal indices of control negative showed significantly lower values than vaccinated medicated and non- vaccinatedmedicated groups (P≤ 0.05).