饲喂不同竹类食物对圈养亚成年大熊猫碘营养生理的影响

Effects of Different Bamboo Parts on Iodine Nutrition Physiology of Captive Sub-Adult Giant Pandas

【目的】旨在了解亚成年大熊猫在采食竹子不同部位时的碘营养生理特征,探究适宜的监测指标。【方法】选取19只健康亚成年大熊猫,依次采食竹叶(竹叶采食期)、竹茎(竹茎采食期)和竹笋(竹笋采食期)。并在竹叶采食期、竹茎采食期和竹笋采食期分别进行3次、1次和2次代谢试验,每次代谢试验间隔28 d,连续3 d采集尿样,测定碘、甲状腺激素和硫氰酸盐水平。各采食期结束时采集血样,测定碘和甲状腺激素含量。各采食期间采集竹子样品,测定碘含量。【结果】竹叶碘含量远高于竹茎和竹笋(P<0.05);采食竹子不同部位对血清碘、fT4和T3含量及尿碘、fT4水平有显著影响(P<0.05);血清碘与血清fT4、尿碘显著正相关(P<0.05);尿fT3与血清fT3显著正相关(P<0.05)。【结论】采食不同竹类食物影响亚成年大熊猫血清和尿碘及fT4含量;血清碘和尿碘可作为亚成年大熊猫碘营养状况的监测指标;血清fT4、fT3和尿fT3可作为亚成年大熊猫甲状腺功能的监测指标,但尿样指标的指示性次于血清指标。

【Objective】This study was designed to understand the iodine nutrition physiology of subadult giant pandas when they were fed with different parts of bamboo,and to explore suitable monitoring indicators. 【Method】Nineteen healthy sub-adult giant pandas were selected and fed sequentially with bamboo leaves(bamboo leaf stage),bamboo culm(bamboo culm stage)and bamboo shoots(bamboo shoot stage). Metabolic tests were carried out for three times during the bamboo leaf stage,once during the culm stage and twice during the shoot stage. The interval of each metabolic test was 28 days. Urine samples were collected for three consistent days during each metabolic test. Then,the concentrations of iodine,thyroid hormone and thiocyanate were detected. Blood samples were collected at the end of each feeding stage,and serum iodine and thyroid hormone were determined. Bamboo samples were collected during each feeding stage to determine the iodine content.【Result】The iodine content of bamboo leaves was significantly higher than that of bamboo culm and bamboo shoots(P<0.05). Consuming different parts of bamboo had significant effects on serum iodine,fT4 and T3 contents and urinary iodine and fT4levels(P<0.05). Serum iodine was positively correlated with serum fT4 and urinary iodine(P<0.05).Urinary fT3 was positively correlated with serum fT3(P<0.05).【Conclusion】Consumption of different bamboo parts affected the contents of iodine and fT4 in serum and urine of sub-adult giant pandas. Serum iodine and urinary iodine can be used as indicators monitoring the iodine nutritional status of sub-adult giant pandas,while serum fT4,fT3 and urine fT3 can be used as indices monitoring their thyroid function. However the indicators of urine samples are inferior to serum indicators.