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0.05). Moreover, thigh or breast meat pH and color indices (lightness, redness and yellowness) were not changed by dietary lysine or betaine supplementation (P>0.05). None of the experimental treatments affected the bone indices (ash, calcium and phosphorous) but the tibia diameter which was increased by dietary lysine supplementation (P<0.05). It seems that dietary lysine and betaine consumption in broiler chickens adjust the osmotic pressure in gastrointestinal cells and hence protect these cells under stress condition such as the cold situation of current experiment and thus help for the higher L-carnitine synthesis in body. The higher L-carnitine production results in lower carcass fat and greater protein synthesis and improved carcass efficiency (higher breast and thigh meat production). Consequently, body oxygen requirements and right ventricle to total ventricle ratio reduced and this causes the lower ascites mortality.
Conclusion:
The consumption of betaine and lysine improves the performance, carcass quantity (increased carcass, and thigh and breast weights) and quality (decreased abdominal fat weight), and ascites mortality of broiler chickens. Moreover, no effects of lysine and betaine were detected on meat nutrient contents, pH and color indices and bone parameters.]]>
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75% coverage and 5 for complete coverage. The wing and tail were further evaluated on a scale of 0 to 2 for the occurrence and severity of poor feathering with 0 indicating no defect; 1 for lesion and torn feathers, and 2 indicating blisters had developed on the shaft, near failure of feather to emerge from the follicle, broken feathers and retarded feathering. Tibia bone morphometric parameters, i.e. weight, diameter, length, density, volume and ash, were determined. The serum mineral concentration was measured in the fasting state at the end of the experiment. At this time, a total of 3mL of the blood samples was accumulated in plain vacutainer tubes from the veins under the wing. After collecting, the blood samples were left undisturbed for at least 1 hour to reach the room temperature. The serums were centrifuging at 3,000 rpm for 15 minutes. The obtained sera were kept in 1.5mL micro tubes at -80°C until they were analyzed for mineral concentration. The method of American Society for Testing and Materials, D4638–03 standard, was used for preparing the serum and feather samples.
Results and Discussion:
The results showed that treatments supplemented with mineral premix caused increase in average daily gain and feed intake compared to the control group (P<0.05), but the difference among mineral premix-supplemented groups was not significant (P>0.05). Feed conversion ratio in the starter period was not affected by the experimental treatments; nevertheless, in the growing and finishing periods a significant difference was indicated compared to the control. Bone parameters including weight, diameter, length and volume showed significant differences to the control group; but the difference for density and ash were not significant. Effects of dietary trace mineral supplementation on the feathering scores of broilers were described.. The results showed that the effect of trace mineral supplementation was significant for feather coverage and defect feather in both wing and tail regions (P<0.05). Feathering score was increased and the amount of damaged feathers was reduced in concordance with the increase in mineral supplementation. Serum concentration of Ca increased in response to trace mineral supplementation. Feather K (p<0.01) and Zn (p<0.05) concentrations were affected by the dietary treatments. Serum concentration of Zn increased linearly in proportion to the dose of Zn supplementation when 10, 25 or 40 mg/kg Zn were added to the basal diet. The diagnostic usefulness of feather analysis is confirmed by authors who have proven the correlation between the concentration of basic elements in feather and their concentrations in the body both in the physiological and pathological states. With regard to the use of feather as a nondestructive monitoring tool, it is noticeable that it presented inter-tissue correlation with the serum in most occasions.
Conclusion: Feather could be considered as an appropriate criterion to diagnose the mineral status in the body.]]>
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