黄羊消化道内不同大小食物颗粒的分布

DISTRIBUTION OF FOOD PARTICLES WITH DIFFERENT SIZE IN THE DIGESTIVE TRACT IN MONGOLIAN GAZELLE (PROCAPRA GUTTUROSA)

研究了黄羊消化道内 7个部位 (瘤胃、网胃、瓣胃、皱胃、小肠、盲肠和直肠 )食物粒径的分布规律。粒径大于 1 0mm的大颗粒食物 ,在瘤、网胃中所占的比例较大 ,分别为 5 7 8%和 3 9 4 1% ,在瓣胃以及瓣胃以下的消化道内容物中所占的比例急剧下降 ,小于 10 % ;而粒径小于 1 0mm的食物颗粒在瓣胃以及瓣胃以下的消化道中所占的比例却显著地增大 ,瓣胃中所占的比例为 88%～ 95 2 %。由于食物营养质量的季节性变化 ,黄羊消化道内食物粒径分布也呈现出明显的季节性变化。

The contents of different parts of the digestive tracts were used to determine the fragmentation process of ingesta in Mongolian gazelle (Procapra gutturosa). After measurement of the intact body, operation and necessary measurements, about 150 ml contents were sampled from seven representative parts (rumen, reticulum, omasum, abomasums, small intestine, caecum and rectum) of the digestive tract. The samples were gently washed over a series of sieves with different apertures of 2 0 mm, 1 0 mm, 0 5 mm, 0 25 mm and 0 106 mm in this order by tap water. Washing time was about 25～30 seconds. The relevant particles with different size retained in different sieves, the size of retained particles by 1 0 mm aperture, for example, is between 1 0 mm and 2 0 mm. Retained food particles were taken out, dried at 80℃ for 48 hours by an electric oven, then weighed to the nearest 0 0001 g by an electronic balance. The particle distributions were evaluated by the weight percentages of different particle sizes. The sequence of weight contributions of food particles of different size throughout these parts were of significant difference. The coarsest particles (>2 0 mm) and coarse particles (>1 0 mm) occupied 43 0% and 57 8% in the rumen, and 24 0% and 39 41% in the reticulum respectively, but decreased to be almost negligible at the omasum and thereafter. The proportions of fine and medium sized particles (<1 0 mm) together occupied 88%～95 2% in the omasum and thereafter. It was clear that particle sizes were abruptly reduced from the reticulum to the omasum. The propotion of the coarse particles (>1 0 mm) accounted for less than 12 0% in the omasum and thereafter, and did not change greatly. For the nutritional value of the forage changes in different seasons, the statistics analysis result showed that there also were significant seasonal changes in the fragmentation process of ingesta.