Acharya M, Burke J M, Coffey K P, Kegley E B, Miller J E, Smyth E, Welborn M G, Terrill T H, Mosjidis J A, Rosenkrans C
J Anim Sci. 2016 Apr;94(4):1592-9. doi: 10.2527/jas.2015-9910.
Prolonged feeding of sericea lespedeza (SL) previously led to reduced serum concentrations of Mo, a cofactor in an enzyme complex that may be involved in weight gain. The current objective was to determine the effect of Mo supplementation on changes in serum, fecal, urine, and liver concentrations of trace minerals in lambs fed SL leaf meal pellets. Thirty ram lambs weaned in May (84 ± 1.5 d of age and 27 ± 1.1 kg; D 0) were blocked by BW, breed type (full or three-fourths Katahdin), and EBV of parasite resistance and randomly assigned to be fed 900 g/d of an alfalfa-based supplement (CON; = 10) or a SL-based supplement ( = 20) for 103 d. Supplements were formulated to be isonitrogenous and isocaloric and to meet trace mineral requirements. Within the SL group, individual lambs were administered either 5 mL water or 5 mL of water with 163.3 mg of sodium molybdate (SLMO). Serum was collected on d 28, 56, and 104; a liver sample was collected by biopsy on d 104 to determine concentrations of trace minerals. Data were analyzed using a mixed model and orthogonal contrasts. Serum concentrations of Mo increased in response to the drench and were greatest in SLMO lambs and then CON lambs and lowest in SL lambs ( < 0.001). Concentrations of Mo in the liver ( < 0.001) were similar between CON and SLMO lambs and were lower in SL lambs than other groups. Serum ( < 0.001) and liver ( = 0.013) concentrations of zinc (Zn) were reduced in both SL and SLMO lambs compared with CON lambs. Serum concentrations of cobalt (Co) increased in CON lambs compared with SL and SLMO lambs between d 0 and 56 but were similar on d 104 (diet × day, < 0.005) as with concentrations in the liver. Serum and liver concentrations of copper (Cu) were greatest ( < 0.001 and < 0.001, respectively) in CON lambs followed by SL lambs and then SLMO lambs. Serum concentrations of selenium (Se) tended ( = 0.10) to be reduced in SL lambs compared with CON and SLMO lambs, but concentrations in the liver were reduced in SL lambs compared with CON lambs and even more so in SLMO lambs ( < 0.003). Although the dietary Mo did increase stores of Mo in the animal and reduced copper, trace minerals associated with metalloproteins-Mo, copper, selenium, and zinc-were reduced in the liver of SL- and/or SLMO-fed lambs. These reductions could be associated with the lower weight gains previously observed after prolonged feeding of SL.
此前长期饲喂绢毛胡枝子（SL）会导致血清中钼（Mo）的浓度降低，钼是一种酶复合物中的辅助因子，可能与体重增加有关。当前的目标是确定补充钼对饲喂SL叶粉颗粒的羔羊血清、粪便、尿液和肝脏中微量元素浓度变化的影响。30只五月断奶的公羔羊（84±1.5日龄，体重27±1.1千克；第0天）按体重、品种类型（纯种或四分之三卡他丁）和寄生虫抗性的估计育种值进行分组，并随机分为两组，一组每天饲喂900克基于苜蓿的补充料（对照组；n = 10），另一组每天饲喂900克基于SL的补充料（n = 20），持续103天。补充料配方为等氮、等热卡，并满足微量元素需求。在SL组内，每只羔羊分别灌服5毫升水或5毫升含163.3毫克钼酸钠的水（SLMO）。在第28、56和104天采集血清；在第104天通过活检采集肝脏样本以测定微量元素浓度。数据采用混合模型和正交对比进行分析。灌服后血清钼浓度升高，SLMO组羔羊最高，其次是对照组羔羊，SL组羔羊最低（P<0.001）。对照组和SLMO组羔羊肝脏中的钼浓度相似（P<0.001），SL组羔羊肝脏中的钼浓度低于其他组。与对照组羔羊相比，SL组和SLMO组羔羊血清（P<0.001）和肝脏（P = 0.013）中的锌（Zn）浓度均降低。与SL组和SLMO组羔羊相比，对照组羔羊在第0天至56天血清钴（Co）浓度升高，但在第104天与肝脏中的浓度相似（日粮×天数，P<0.005）。对照组羔羊血清和肝脏中的铜（Cu）浓度最高（分别为P<0.001和P<0.001），其次是SL组羔羊，然后是SLMO组羔羊。与对照组和SLMO组羔羊相比，SL组羔羊血清硒（Se）浓度有降低趋势（P = 0.10），但与对照组羔羊相比，SL组羔羊肝脏中的硒浓度降低，SLMO组羔羊降低更明显（P<0.003）。尽管日粮中的钼确实增加了动物体内钼的储备并降低了铜含量，但在饲喂SL和/或SLMO的羔羊肝脏中，与金属蛋白相关的微量元素——钼、铜、硒和锌——含量降低。这些降低可能与此前长期饲喂SL后观察到的体重增加较少有关。
