BACKGROUND: Thyme extract has the antimicrobial and antioxidant components that can be useful for the broilers under heat stress condition. OBJECTIVES: This experiment was conducted to investigate the effects of Thymus vulgaris extract in comparison with some common feed additives on performance, blood biochemical parameters and antibody response in broiler chickens under heat stress conditions. METHODS: This study was conducted using 192 one-day-old male broiler chicks (Ross 308) in a completely randomized design with 8 treatments in 4 replicates and 6 chicks per replicate. Treatments were as follows: 1) basal diet + standard temperature conditions (positive control); 2) basal diet + heat stress conditions (negative control); 3) negative control + 200 mg virginiamycin; 4) negative control + 150 mg Protoxin probiotic, 5) negative control + 250 mg vitamin C, 6) negative control + 250 mg vitamin E, 7) negative control + 250 mg thyme extract, and 8) negative control +500 mg thyme extract per kg diet. RESULTS: Dietary thyme extract at the rate of 500 mg/kg as well as probiotic and vitamin E increased (P<0.05) body weight gain (2202, 2183 and 2199, respectively) and improved feed conversion (1.65, 1.74 and 1.66, respectively) compared with negative control group (body weight gain 1960 g and feed conversion ratio 1.96). Moreover, 500 mg/kg dietary thyme extract, probiotic and vitamin C reduced triglycerides, total cholesterol and low density lipoprotein during heat stress conditions (P<0.05). All dietary supplements groups significantly increased antibody titers against red blood cells as compared with negative control. CONCLUSIONS: In general, the results of the present study suggest that thyme extract at the level of 500 mg/kg of diet can be recommended as an alternative to the common feed additives to improve growth performance and health benefits of the heat-stressed broilers.

BACKGROUND: Phosphorous is an essential nutrient for poultry. Receiving too much phosphorous by livestock and excretion of excess phosphorus, can lead to environmental pollution. OBJECTIVES: Determining the ileal and total tract digestibility of phosphorus and calcium in di-calcium phosphates produced in Iran. METHODS: A total of 720 day-old male Ross 308 broilers were randomly divided into 8 treatments with 6 replicates of 15 birds in each. In control treatment phosphoric acid was used as a source of phosphorus. The other dietary treatments included one of the seven domestic samples of di-calcium phosphates (A to G). Chromium oxide was used as a marker in the diets. On day 21, after collecting of feces, all birds were slaughtered via neck dislocation. Then, the last one-third of ileum was removed. The contents of the intestine were collected for each replicate and after drying were sent to the laboratory to determine the chromium oxide, phosphorus, and calcium amounts. Percentage of ileal and total tract digestibility of phosphorus and calcium for each sample were calculated separately. RESULTS: The effect of type of di-calcium phosphate samples in feed on ileal and total tract digestibility of calcium and phosphorus was highly significant (p < /em> < 0.001). Ileal digestibility in control was 69.8 percentage, while the lowest was observed in the E and F samples, and the highest value was related to sample A. Digestibility for phosphorus in control diet was 53.4 percentage throughout gastrointestinal tract. The lowest amounts of total tract digestibility of phosphorus were observed in treatments E and F, respectively, while the highest total tract digestibility was related to treatment A with 47.9 per cent. CONCLUSIONS: It could be concluded that ileal digestibility is more accurate in evaluating phosphorus bioavailability and sample A had the highest biological value, while the lowest was related to the samples E and F.

This study was carried out to assess the effects of dietary supplementation of yeast-based Zn, Se, and Cr on growth performance, carcass characteristics, immune response, and histomorphological changes in broiler chickens. A total of 1092 one-day-old unsexed broilers of Ross 308 strain were randomly allocated into two equal treatment groups (6 equal replicates/ group). Birds were fed the dietary treatments from day 1 to day 35 of age. The first group was fed a basal diet without yeast-based Zn, Se and Cr supplementation (control). The second group was fed a basal diet supplemented with 1.5 mg, 0.15 mg and 2 µg / kg diet of Zn, Se, and Cr, respectively. The yeast-based Zn, Se and Cr increased (P<0.05) the growth rate, carcass traits and improved feed conversion ratio compared to control. The antibody titer against avian influenza and the relative weight of bursa, thymus and spleen were increased (P < 0.05) in broilers supplemented with yeast-based Zn, Se, and Cr compared with the control. The intestinal villi height and crypt depth and bursa diameters were increased in broilers fed the yeast-based Zn, Se and Cr supplemented diet. In addition, there was an increase in the lymphocytic infiltration in the bursa and a decrease in germinal centers in the submucosal lymph nodules of the ileum of birds supplemented with yeast-based Zn, Se and Cr compared to the control. In conclusion, dietary supplementation of yeast-based Se, Cr, and Zn in combination could improve growth performance, carcass traits, immune responses and histo-morphological parameters in broiler chickens.

Fowl adenovirus can cause important diseases in chickens such as inclusion body hepatitis, hepatitis hydropericardium syndrome, and gizzard erosion and ulceration. Inclusion body hepatitis has been regularly reported from many countries. This is the first case report from Turkey, describing an outbreak of inclusion body hepatitis in broiler farms due to fowl adenovirus-8b (FAdV-8b). Broiler flocks with mortality about 10% were visited in Turkey, and necropsy was performed on dead birds. Samples were subjected to PCR assay to detect FAdV and other viral pathogens. After sequencing, phylogenetic analysis was performed and the nucleotide sequences of hexon genes were compared with the FAdV sequences data available in GenBank. Clinical signs such as anorexia, depression, ruffled feathers, huddling, and greenish diarrhoea were observed. Mortality started at the 8ᵗʰ day of age and ranged from 10% to 14%. Necropsy showed severe hepatitis, jaundice, and pancreatitis. The main necropsy findings included a pale, enlarged, haemorrhagic, and friable liver along with swollen and haemorrhagic kidneys and spleen. PCR and sequence analysis revealed the presence of fowl adenovirus serotype 8b (FAdV-E). This is the first report on characterisation and the pathological lesions associated with FAdV in broilers in Turkey. Our findings suggest that FAdV strains could be an emerging pathogen in Turkish broilers and could actively contribute to hepatitis and immunosuppression.

Objective: This study was conducted to compare between the nanoparticles of copper (Cu-NP) and copper sulfate (CuSO4) effect on immunity, pro-inflammatory cytokine, oxidant/antioxidant balance, different behavioral patterns, growth rate, and weight gain by adding them in drinking water of broilers. Materials and Methods: One hundred and fifty broiler chicks of 1-day-old were randomly divided into three groups: the first group was the control, the second group received CuSO4 in drinking water (10 mg/l), and the third group received Cu-NP in drinking water (10 mg/l) with replicates (n = 25) for 5 weeks of age. Blood samples collected for estimating immunoglobulins (A, G, and M), superoxide dismutase, pro-inflammatory (IL-6), erythrocyte sedimentation rate, heterophil/ lymphocyte (H/L) ratio, malondialdehyde (MDA), corticosterone hormone, and lymphoid organs index weight. Moreover, behavioral observations were undertaken from the 2nd week until the 5th week of age for measuring different behavioral patterns (feeding, drinking, crouching, body care, and comfort behaviors). Chicks were individually weighed weekly (gm); also, the weight gain, the intake of food, and the ratio of feed conversion were calculated. Results: Cu-NP administration has improved the blood profile, lymphoid organs index weight in Cu-NP treated broilers in relation to control and CuSO4 treated groups. Conversely, erythrocyte sedimentation rate, H/L ratio, MDA, and corticosterone hormone were reduced by Cu-NP treat¬ment. Moreover, Cu-NP has a positive effect on all behavioral patterns more than other groups which significantly reflect on the weight of the body, gaining of weight, and the intake of food in the Cu-NP treated group of birds. Conclusion: The findings in this study stated that when the drinking water of broilers was supple¬mented with Cu-NP, there might be an improvement in the immunity, behavior, and productive performance more efficiently than CuSO4. [J Adv Vet Anim Res 2020; 7(1.000): 16-25]