磷酸脲对羔羊血清和肌肉钙、磷含量及血清相关代谢激素含量的影响

摘要

This experiment was conducted to study the effects of different levels of urea phosphate supplemen-tation on calcium ( Ca) and phosphorus ( P) contents in serum and muscle and related hormone contents in ser-um of lambs. Eighty Dorper×thin-tailed Han F1 crossbred lambs were randomly divided into 5 groups with 8 replicates per group and 2 lambs per replicate. Soybean meal and some other protein feeds were replaced by 0, 1.0%, 4.0% and 8.0% of urea phosphate in concentrate, respectively. During the 12-day adaptation period, the ratio of concentrate to roughage was 1∶1, and lambs were fed ad libitum; during the 60-day experimental period, the intake of ratio of concentrate to roughage was 1∶1, and the actually intake of urea phosphate levels were 0 (control group), 0.5% (0.5% group), 1.0% (1.0% group), 2.0% (2.0% group) and 4.0% (4.0%group) , respectively. On 1 ( the starting day of adaptation period) , 13 and 73 days, blood samples were col-lected from 8 lambs of each group before morning feeding to determine the contents of Ca, P ( 1, 13 and 73 d) parathyroid hormone ( PTH) , calcitonin ( CT) and 25-hydroxy vitamin D ( 25-OH-VD) ( 1 and 13 d) . On 73 days, six lambs of each group were slaughtered and the longissimus dorsi was sampled to analyze the contents of Ca and P. The results showed as follows: 1 ) in serum, Ca content decreased and P content in-creased with the increasing level of urea phosphate. Serum Ca content showed no significant difference on 1 and 73 days among groups (P>0.05), while that of 4.0% group was significantly lower than that of the other groups on 13 days ( P<0.05) . No significant difference was found in serum P content on 1 day ( P>0.05) . Se-rum P content of 4.0% group was significantly higher than that of control, 1.0%, and 2.0% groups on 13 days ( P<0.05) . On 73 days, serum P content of 4.0% group was significantly higher than that of control and 0.5%groups ( P<0.05) , and control group was significantly lower than that of 1.0%, 2.0%, and 4.0% groups ( P<0.05) . 2) There were no significant differences of Ca and P contents in longissimus dorsi among groups ( P>0.05) . 3 ) The differences among the contents of PTH and 25-OH-VD in serum were not significant ( P>0.05) . The content of CT in 1. 0% and 2. 0% groups was significantly lower than that of control and 4. 0%groups on 13 days (P<0.05). In conclusion, Ca content decreases while P content increases in serum and muscle with the supplementation of urea phosphate. Serum of PTH and 25-OH-VD contents are not affected by urea phosphate. The supplementation of urea phosphate can significantly change serum CT content. The supple-mentation of 4.0% of urea phosphate inhibits the increase in weight of lambs.%本试验旨在研究不同磷酸脲添加量对羔羊血清和肌肉钙( Ca)、磷( P)含量及血清相关激素含量的影响。选用80只F1代杜寒杂交羔羊,随机分为5组,每组8个重复,每个重复2只。分别在各组精料中添加0、1.0%、2.0%、4.0%和8.0%的磷酸脲以替代部分豆粕等蛋白质饲料。预试期为12 d,正试期为60 d。预试期内饲喂精料和粗料比为1∶1,自由采食。正试期内肉羊精料和粗料采食量比为1∶1,各组实际采食饲粮中的磷酸脲含量分别为0(对照组)、0.5%(0.5%组)、1.0%(1.0%组)、2.0%(2.0%组)和4.0%(4.0%组)。每组选取8只羊在1(预试期开始当天)、13和73 d晨饲前采集血液,测定1、13和73 d血清钙、磷含量及1和13 d血清甲状旁腺素( PTH)、降钙素( CT)、25-羟基维生素D(25-OH-VD)含量；73 d每组选取6只羊屠宰,取背腰最长肌进行肌肉中钙、磷含量的测定。结果表明：1)随饲粮中磷酸脲添加量的增加,血清钙含量降低,磷含量增加。其中,血清钙含量在1和73 d时各组间差异不显著(P>0.05),但在13 d时4.0%组显著低于其他各组(P<0.05)。血清磷含量在1 d时各组间差异不显著(P>0.05)；13 d时4.0%组显著高于对照组、0.5%组和2.0%组(P<0.05)；73 d 时4.0%组显著高于对照组和0.5%组( P<0.05),对照组显著低于1.0%组、2.0%组、4.0%组( P<0.05)。2)各组背腰最长肌中的钙、磷含量差异不显著( P>0.05)。3)血清中各组间的PTH、25-OH-VD含量差异不显著( P>0.05)；13 d时,1.0%组和2.0%组的血清CT含量显著低于对照组和4.0%组( P<0.05)。由此可见,磷酸脲的添加可使得血清和肌肉中钙含量降低、磷含量增加,对血清PTH和25-OH-VD含量无显著影响,但会引起血清CT含量的显著变化；饲粮添加4.0%的磷酸脲会引起羔羊增重受到抑制。