This experiment was conducted to determine the outflow rate of solids and fluid using double markers of chromium (Cr) and cobalt ( Co) from the first compartment in alpaca and rumen in sheep. Three health?y male alpacas [(27.0±4.6) kg] and Jinzhong sheep [(26.2±2.7) kg] were selected. The results showed as follows: estimated by multicompartmental model, in comparison to sheep, solid slow outflow rate k1 showed a decreasing tendency (3.44%/h vs. 4.32%/h, P=0.072) and solid fast outflow rate k2 was significantly lower in alpaca (16.90%/h vs. 35.06%/h, P<0.01). There was no significant difference to solid outflow rate k estimated by exponential model between alpaca (5.13%/h) and sheep (5.14%/h) (P>0.05). Mean residence time ( MRT) of alpaca was higher than that of sheep in both models. Estimated by gamma 4 model and expo?nential model, no significant difference was recorded to fluid outflow rate k between alpaca ( 6.21%/h and 7.73%/h) and sheep (7.02%/h and 8.43%/h) (P>0.05). The volume (6.23 L) and out follow speed of the first compartment in alpaca(0.44 L/h) were significantly lower than those in sheep (10.69 L and 0.90 L/h) ( P<0.05) . In conclusion, gastrointestinal retention time of digesta in alpaca is longer than that in sheep, and the difference can partly explain the reason that alpaca has a higher roughage digestion rate.%本试验旨在确定羊驼第一胃室与绵羊瘤胃固相和液相外流速率. 选用1周岁健康的公羊驼[(27.0±4.6) kg]与晋中公绵羊[(26.2±2.7) kg]各3只,通过钴(Co)和铬(Cr)双标记法测定固相和液相外流速率. 结果显示,根据MC模型羊驼固相慢速外流速率k1(3.44%/h)有低于绵羊(4.32%/h)的趋势(P=0.072),固相快速外流速率k2,羊驼(16.90%/h)极显著低于绵羊(35.06%/h)(P<0.01);根据指数模型羊驼固相外流速率k(5.13%/h)与绵羊(5.14%/h)差异不显著( P>0.05);模型所得羊驼食糜胃肠道平均滞留时间高于绵羊. 根据G4 模型和指数模型,羊驼液相外流速率k(分别为6.21%/h和7.73%/h)与绵羊(分别为7.02%/h和8.43%/h)差异不显著( P>0.05) ,2种模型所得液相外流速率k差异不显著( P>0.05) ,但羊驼第一胃室容积(6.23 L)和外流速度(0.44 L/h)极显著低于绵羊瘤胃容积(10.69 L)和外流速度(0.90 L/h) ( P<0.01). 结果提示,食糜在羊驼体内的消化时间长于绵羊,这可能是羊驼粗饲料消化率高的原因之一.
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