Veterinary Research Forum

Abstract This study aimed to evaluate the effects of different copper sources experimental copper sulfate (CS), copper methionine (CM), copper carbohydrate, copper dihydrogen phosphate (CP), and nano copper (CN) on growth performance, carcass characteristics and intestinal histomorphology in broiler chickens. A total number of 300-day-old broilers were randomly assigned to five dietary treatments with six replicates each. During the finisher and the whole experimental periods, CM- and CN-fed birds had the highest and lowest body weight gain, respectively compared to the birds in other treatments. Consumption of the CM diet increased the feed intake compared to the different treatments. Feed conversion ratio was increased by consumption of CN compared to CM during the finisher and the whole experimental periods. In the duodenum, villus height (VH) was significantly increased by CN as compared to control. In the jejunum, consumption of both the CM and CC diets caused the lowest VH, whereas dietary CN inclusion resulted in the highest VH. The VH/crypt depth (CD) ratio was at the lowest and the highest levels by CM and CN, respectively. In the ileum, villus width was numerically decreased by CP. The CS-fed birds had the highest CD between the treatments. The VH/CD ratio was higher in CP and CN-fed birds compared to CS ones. Moreover, the goblet cell number was decreased by dietary CP compared to CM. In conclusion, broiler performance was increased by both CM and CP sources of copper, with methionine-based copper being suggested as a component of chicken diets.

Abstract Male and female broiler chickens differ in performance and this will cause unwanted experimental errors in research. For this reason, single-sex or mixed-sex broilers are used in most studies. This study aimed to assess the performance differences between groups of chickens with varying male/female ratios to determine how sex ratio can affect performance criteria. Birds (N = 550) were separated by sex and placed in 11 groups (pens) according to the male/female ratios, including group 1 (10 males + 0 female), group 2 (9 males + 1 female), group 3 (8 males + 2 females), group 4 (7 males + 3 females), group 5 (6 males + 4 females), group 6 (5 males + 5 females), group 7 (4 males + 6 females), group 8 (3 males + 7 females), group 9 (2 males + 8 females), group 10 (1 male + 9 females), and group 11 (0 male + 10 females). The results showed that male broiler chickens had higher feed intake and body weight gain than female broiler chickens, but the feed conversion ratio was not affected by gender. The digestibility of phosphorus, bone strength, bone density, bone calcium and phosphorus, pH, and redness and water holding capacity of meat were higher in male broilers. The dripping loss was higher in female broilers. This study showed that male and female broiler chickens differed in most of the parameters examined in the research, and the use of separate breeding affected the research results. 

Abstract Two hundred and fifty male 1-day-old broiler chicks (Ross 308) were used to investigate the effects of dietary supplementation of turmeric and cinnamon powders on meat quality and lipid peroxidation of broilers under heat stress condition. The five treatment groups were control (recommended temperature for Ross 308), heat stressed (32 ± 1 ˚C from 9:00 AM to 5:00 PM during finisher period) and heat stressed birds fed with 0.50% turmeric, 0.50% cinnamon and a blend of cinnamon and turmeric (0.25% turmeric + 0.25% cinnamon). The results showed that there were no significant differences between the treatments for ether extract, ash and crude protein contents of thigh meat at 42 day of age (p > 0.05). Heat stress decreased the pH value and dry matter (DM) content of thigh meat, whereas the consumption of all experimental diets (turmeric, cinnamon and both of them) compensated the decreased pH and DM values due to heat stress to some extent but could not restore them to the level of control treatment (p< 0.01). Furthermore, the thigh meat lightness was increased under heat stress (p < 0.05). The thiobarbituric acid reactive substances and free radicals scavenging activity were increased in thigh meat of broilers reared under heat stress (p < 0.05), while these parameters were reduced by the combination of both plants (p < 0.01). It was concluded that heat stress reduces antioxidant properties and quality of thigh meat and dietary supplementation of turmeric and cinnamon powders together can remove the detrimental effects of heat stress on meat quality.

Abstract Three levels of lysine (90, 100 and 110% of Ross requirement) and of pyridoxine (3, 6 and 9 mg kg^-1) were used in a 3 × 3 factorial experiment to investigate the growth and blood antioxidant ability of broilers under high ambient temperature. None of the dietary supplements affected the weight gain during the starter and grower periods. Although no significant differences were detected between the treatments during the entire period, high lysine level fed birds had a lower weight gain. At any levels of pyridoxine, high lysine fed birds were lighter than others. Neither the lysine nor pyridoxine changed the feed intake or feed conversion ratio during the starter, grower and entire period. However there was no significant difference between the treatments for blood malondialdehyde (MDA) concentration, medium lysine fed birds had lower blood MDA than other ones. No significant effects on blood triglyceride, total protein and blood superoxide dismutase activity were indicated with addition of any lysine or pyridoxine level. Medium lysine fed birds had decreased blood glutathione peroxidase activity compared to the birds of other treatments. It was concluded that providing the proposed dietary lysine requirement of Ross strain during heat stress ensuring the best body weight gain and body antioxidant ability. Higher lysine level causes the retarded weight gain due to higher excretion of arginine from the body and consequently higher lipid peroxidation.