Solanum glaucophyllum（ルリヤナギ, リュウキュウヤナギ, スズカケヤナギ）の分娩前単回投与で乳牛の分娩後の低カルシウム血症を予防できると報告した論文。単回投与後3-5日間はカルシウム濃度が上昇（約2mg/dL）している。機序は活性型ビタミンD3（1,25-(OH)2D3）を上昇させることを介している。そもそもSolanum glaucophyllumは牛に高カルシウム血症を引き起こす有害植物として知られているようで、それを分娩前の短期間使用することで薬のように使ってしまおうというアイデア。
学位論文は日本語でも読めるようだ。
宇都宮大学 家畜繁殖生理学
ルリヤナギ乾燥粉末の給与による 乳牛の低カルシウム血症の予防に関する研究
Ishii J, Uramoto A, Nagao Y, Goto H
Anim. Sci. J. 2015 Oct;86(10):869-77
PMID: 26208138
Abstract
Solanum glaucophyllum (SG) contains 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) glycosides. We investigated the effect of SG on hypocalcemia in cows. Serum levels of 1,25-(OH)2D3, total calcium and phosphorus dose-relatedly increased after feeding with SG, while serum magnesium and chloride levels fell (P < 0.05). We also performed an ethylenediaminetetraacetic acid (EDTA) infusion to induce artificial hypocalcemia. Cows that had been fed 4.0 mg/kg body weight of SG daily for 2 weeks had a higher serum concentration of total calcium at the end of EDTA infusion than those not fed SG (P < 0.05). In a field trial, multiparous cows were assigned to one of four groups: (1) no SG, (2) 1.3 g or (3) 2.6 g of SG daily from 14 days before the estimated calving day until 3 days after calving, or (4) a single feed of 35.75 g SG at 3 days before the estimated calving day. The concentrations of serum total calcium after the calving in each treatment group were (1) 7.4, (2) 7.9, (3) 8.0 and (4) 8.9 mg/dL and higher for (4) than for (1) (P < 0.05). The data suggests that feeding a high dose of SG before the calving may maintain higher concentrations of serum calcium after the calving.