饲用黄丝藻粉的急性毒性和亚慢性毒性试验

试验旨在通过研究黄丝藻粉对大鼠的急性毒性和亚慢性毒性试验，初步评价其饲用安全性。5 000 mg/kg体重黄丝藻粉灌胃给予Wistar大鼠进行急性毒性试验；黄丝藻粉按0、1 250、2 500、5 000 mg/kg 添加于饲料中饲喂大鼠，进行90 d亚慢性毒性试验。每周称量大鼠体重与饲料消耗，分别于喂养 45、90 d 时剖检，进行血常规和血液生化指标检测，计算脏器系数，并对主要脏器进行组织病理学检查。结果表明，5 000 mg/kg体重黄丝藻粉给予大鼠均未出现死亡，LD₅₀>5 000 mg/kg体重，根据WHO对化学物质的毒性评级，黄丝藻粉属于实际无毒物质。亚慢性毒性试验中，高、中、低剂量黄丝藻粉饲喂大鼠90 d后平均饲料消耗、体增重、脏器系数与对照组相比均无显著差异（P>0.05）。各处理组血常规指标、低剂量组血液生化指标与正常对照组相比均无显著差异（P>0.05）；高、中剂量组除血液总胆固醇（CHO）、甘油三酯（TG）显著低于对照组（P<0.05）外，其他血液生化指标均无显著差异（P>0.05）；高、中剂量组总胆固醇和甘油三酯均在大鼠正常生化指标范围内；解剖及主要脏器HE染色检查均未发现明显变化。试验结果表明，黄丝藻粉属于实际无毒物质；5 000 mg/kg添加剂量喂养大鼠90 d，未观察到明显的有害作用，有望在动物饲料中添加应用。

Acute Toxicity and Subchronic Toxicity Test of Tribonema Powder

The purpose of the experiment was to evaluate the feeding safety of Tribonema by the acute toxicity and subchronic toxicity test on rats.5 000 mg/(kg·BW) of Tribonema powder was given to Wistar rats by gavage for acute toxicity test.The rats were fed with 0,1 250,2 500 and 5 000 mg/kg of Tribonema powder for 90 days.The weight and feed consumption of rats were measured every week.The rats were dissected at 45 and 90 days after feeding.The blood routine and biochemical indexes were detected.The organ coefficient was calculated and the main organs were examined by histopathology.The results showed that there was no death in the rats treated with 5 000 mg/(kg·BW) of Tribonema powder.LD₅₀ was more than 5 000 mg/(kg·BW).According to WHO’s toxicity rating of chemicals,Tribonema powder belonged to the actual non-toxic substances.In the subchronic toxicity test,there was no significant difference in the average feed consumption,body weight growth and organ coefficient of rats fed with high,medium and low doses of Tribonema powder after 90 days compared with the control group (P>0.05).There was no significant difference in blood routine indexes and blood biochemical indexes between low dose group and control group (P>0.05).Besides the blood total cholesterol (CHO) and triglyceride (TG) in the high and middle dose groups were significantly lower than those in control group (P<0.05),there was no significant difference in other blood biochemical indexes (P>0.05),but the CHO and TG in the high and middle dose groups were all in the normal biochemical indexes of rats within the scope.No significant changes were found in gross anatomy and HE staining of main organs.The results of this experiment showed that the Tribonema powder belonged to the actual non-toxic substance,the rats were fed with 5 000 mg/kg for 90 days,and no obvious harmful effect was observed,which was expected to be applied in animal feed.