生长牦牛血清钙和磷变化规律分析

Changes of blood serum levels of calcium and phosphorus

利用原子吸收法和色谱法,对3组(G1:5～15月龄;G2:17～27月龄;G3:29～39月龄)生长牦牛血清中钙和磷浓度的变化规律进行了跟踪分析。结果表明:生长牦牛血清钙浓度为(10 235±0 809)mg/dL,与普通牛相当;但血清磷为(5 567±1 361)mg/dL,明显低于普通牛,导致血清钙与磷之比值较高,表明牦牛缺磷问题突出。各年龄段生长牦牛血清钙浓度顺序依次为G1<G2<G3(P<0 01),但血清磷浓度的年龄排序有所不同,受采样初期未完全断奶的影响在3组牛中最高(P<0 01),而在G2牛则小于G3组(P<0 05),与血清钙年龄排序一致。月份/季节对血清钙和血清磷浓度有极显著地影响(P<0 01),二者浓度变化与牧草营养供给水平一致,均在牧草营养最丰富的9月份达到最高值,分别为11 383mg/dL和6 822mg/dL,显著高于其余各月份(P<0 01)。血清钙与体重、血清钙与磷以及血清磷与体重均呈极显著的正相关(P<0 01),相关系数分别为0 459、0 196和0 337。研究结果表明,终年放牧在高寒草原的牦牛普遍缺钙缺磷,缺磷问题尤为突出。开展钙、磷补饲,并注意保持补饲料中钙、磷的适宜比例能极大提高补饲效益。

Blood serum levels of calcium and phosphorus of 3 groups (G1, G2 and G3) growing yaks (5-15, 17-27 and 29-39 month old resp.) were determined bimonthly in a year round using of atomic absorption and colorimetric procedures. Blood sampling began on September 26 in 1997 and ended on July 26 in 1998, with body-weights measured accordingly. The results showed that average of serum calcium concentration is (10.235±0.809) mg/dL, which seems to be comparable with that of cattle. However, serum phosphorus concentration is (5.567±1.361) mg/dL,which is obviously lower than that of cattle and leading to a higher ratio of calcium to phosphorus. It suggested that phosphorus was obviously deficient in growing yaks. The levels of serum calcium among groups had an rank of G1<G2<G3(P<0.01), which was't consistent with that of cattle reported, but the serum levels of phosphorus had a different rank with the G1 being the highest, which is actually due to a incompletely weaning of the group, and the rank of phosphorus of G2 and G3 is same as that of calcium with G2 being lower than G3 (P<0.05). Months/seasons had a significantly effect on the serum levels of calcium and phosphorus (P<0.01) and the serum levels of calcium and phosphorus showed a month/seasonal pattern. Both levels of calcium and phosphorus reached the highest in September 11.383 mg/dL and 6.822 mg/dL resp.All correlations(r) between the level of calcium and body weight, calcium and phosphorus, phosphorus and body weight had positively significant correlation weight (r=0.459, 0.196 and 0.337 resp.). The results indicate that problems of deficiency of calcium and phosphorus, especially phosphorus, are common in plateau pasture in a whole year, especially in cold months/seasons. Conducting supplement of calcium and phosphorus and paying attention to keep suitable proportion of the two mineral elements accordingly will surely make great supplement efficiency for yak raising area.