اثر مقایسه‌ای ویتامین c با مکمل نانو ویتامین c برعملکرد رشد، مورفولوژی روده و فراسنجه‌های خونی جوجه‌های گوشتی تحت شرایط تنش گرمایی

زمینه مطالعاتی: این آزمایش به منظور بررسی اثر سطوح مختلف نانوویتامین c و ویتامین c بر عملکرد رشد و برخی فراسنجه‏های خونی جوجه‏های‏گوشتی تحت تنش گرمایی انجام شد. روش کار: این آزمایش در قالب طرح کاملا تصادفی روی 280 قطعه جوجه نر یک‏‏‏ روزه سویه راس 308 با هفت تیمار شامل تیمار شاهد و سه سطح نانو ویتامین c (50، 100 و 200 میلی‌گرم بر کیلوگرم جیره) و سه سطح ویتامین c (50، 100و 200 میلی‌گرم بر کیلوگرم جیره) و چهار تکرار (هر کدام شامل 10 پرنده)، انجام شد. دنتایج: میانگین مصرف خوراک روزانه در جوجه‌‌هایی که تیمار 200 میلی گرم ویتامین c در کیلو گرم جیره را دریافت کرده بودند نسبت به جوجه‌هایی که سطح 200 میلی‌گرم نانو ویتامین c در کیلوگرم جیره و جوجه‌هایی که تیمار 100 میلی‌گرم ویتامین c در کیلوگرم جیره را دریافت کرده بودند، بیشترین مقدار بود. جوجه‌هایی که تیمار حاوی 50 میلی‌گرم نانو ویتامین c در کیلوگرم جیره راه دریافت کردند بیشترین افزایش وزن روزانه، بهترین ضریب تبدیل غذایی، بیشترین افرایش وزن نسبی سینه و بیشترین مقدار عرض پرز روده را داشتند. بیشترین افزایش وزن نسبی لاشه مربوط به جوجه‌‌‌‌‌‌هایی بود که تیمار 200 میلی‌گرم ویتامین c در کیلو گرم جیره را دریافت کردند. بیشترین وزن نسبی طحال مربوط به جوجه‌هایی بود که تیمار حاوی 100 میلی‌گرم ویتامین c در کیلو‌گرم جیره را دریافت کردند. ببیشترین طول پرز به عمق کریپت مربوط به جوجه‌هایی بود که تیمار حاوی 100 میلی‌گرم ویتامین c در کیلوگرم جیره را دریافت کردند. نتیجه گیری نهایی: بنابرنتایج این آزمایش استفاده از سطوح 50 و 200 میلی‌گرم نانو ویتامین c در کیلو‌گرم جیره به ترتیب می‌تواند باعث بهبود عملکرد رشد و بهبود خصوصیات لاشه و افزایش مقدار آنزیم گلوتاتیون پراکسیداز در شرایط تنش گرمایی در جوجه‌های گوشتی شود.

comparison the effects of vitamin c with nano vitamin c supplement on growth performance, immune responses, intestine morphology and blood parameters of heat stressed broiler chickens

introduction:a the use of vitamin c in conditions of heat stress and poultry rejuvenation compared to this stressor has been recorded by researchers for many years (nameghi 1386). . the experiment was a completely randomized design with 7 treatments and 4 replications, 10 birds each. treatments included: control diet, 3 level of vitamin c (0, 100 and 200 mg/kg) and 3 level of nano vitamin c (0, 100 and 200 mg/kg). the experimental diets were based on corn and soybean. during the experiment, water and food were offered ad libitum. body weight and feed intake at the end of each period were measured and used to calculate body weight gain and feed conversion ratio. at d 42 one bird from each replicate was selected and killed to measure the internal organ weights. also, the weight and length of the jejunum were calculated, and partly for intestinal morphology in formalin 10%. results and discussion: the effect of dietary treatments on feed consumption in broiler chickens was significant (p<0.05). chickens that received 200 mg of vitamin c kg-1 diet had the greatest feed intake than other chicks. the results of this study was in line with the results of kutlu and forbes (1993) who reported that 250 mgof vitamin c increased these parameters. experimental treatments had a significant effect on the weight gain of chicks (p<0.001). chickens that received 50 mg nano vitamin c had the greatest weight gain compared to other treatments. according to these results, roshani et al. (2006) reported that vitamin c during the stress period improved the feed intake and daily weight gain. sahin and kucuk (2002) reported that the use of 200 mg vitamin c /kg of diet improved the feed intake of quails under stress conditions. gross (1988) showed that vitamin c under stress conditions caused an increase in daily weight gain in broiler chicks. in another study, ping et al. (2011) showed that nano multivitamin improved weight gain, feed intake and reduced mortality. chicks fed 50 mg nano vitamin c had the best conversion ratio compared to other treatments. the results of this experiment are consistent with the results of alba et al. (1393), kutlu and forbes (1993), and amakye et al. (2000). they reported that the use of vitamin c supplementation significantly reduced the feed conversion ratio compared to the control group. sahin and kucuk (2002) reported that using 200 mg/kg of vitamin c improved feed consumption and feed conversion ratio under heat stress. researchers reported that vitamin c supplementation in summer did not have a significant effect on the relative weight of the thigh, which is similar to the results of this experiment (konca, 2009). relative weight of breast and carcass was affected by experimental treatments and a significant difference was observed between the groups. the greatest relative weight of the carcass was related to birds received 200 mg vitamin c kg-1 diet. the greatest relative weight was related to treatment with 50 mg nano vitamin c. according to these results, sahin et al. (2002) reported that vitamin c supplementation of 250 mg/kg of diet improved live weight, nutritional efficiency and carcass traits. also, roshani et al. (2006) reported that vitamin c supplementation during the stressful period significantly increased the weight of the chest. rafie et al. (1393) reported that 250 mg/kg vitamin c increased breast weight and could somewhat reduce the negative effects of heat stress. darmankouhi (2005) reported that ascorbic acid increased the carcass quality and yield under heat stress conditions. relative weight of liver was not affected by experimental treatments. the effect of treatments on relative weight of spleen was significant (p<0.05). chickens fed 100 mg of vitamin c had the greatest relative spleen weight.