钙(Ca)是家禽产蛋和维持骨骼健康最重要营养元素之一.为更好了解钙对蛋鸡龙骨微结构参数和骨骼元素浓度的影响,将180只罗曼白蛋鸡随机分成对照组和低钙饮食组,饲粮钙浓度分别为3.37％和1.5％.蛋鸡饲养于富集笼,每组6个重复,每个富集笼为1个重复,每个重复15只蛋鸡,试验周期20～37周.分别在第25、29、33和37周收集龙骨样品测量骨矿物质密度、骨微结构参数和骨元素浓度.结果表明,随蛋鸡年龄增加,低钙组蛋鸡正常龙骨比例减少,龙骨损伤率高于对照组,37周龙骨偏离率为31.25％,骨折率为56.25％.低钙组龙骨微结构参数与对照组相比,TV、Conn.D.、Tb.Sp、BS、BS/BV、BMD降低(P<0.05),BV、BV/TV、Tb.Th、DA增加(P<0.05).低钙组蛋鸡钾、铁、铜、锶、钼、锰、锌、钒、硒、铊、铅含量增加(P<0.05),钙、镍、锂、汞含量下降(P<0.05).产蛋期饲喂低钙水平日粮影响蛋鸡龙骨生长和代谢,改变龙骨骨密度、微观结构和元素稳态,损害龙骨质量和蛋鸡健康.

In order to prepare Beta-Cyfluthrin EW with good stability and wettability, normal complex emulsifier was used to screen formulation, and determine the particle size distribution of formula with laser particle size instrument, and measure the surface tension and contact angle of formula with OCA20 (used Pendant Drop-method and Sessile & Captive Drop-method respectively). 4 kinds of Beta-Cyfluthrin EW formulation with good stability were found, their D50 were around 0.8-2.12 μm, and the particle size increased after heated storage; the surface tension of liquids ranged from 40 mN/m to 53 mN/m, significantly lower than those of deionized water (73.66 mN/m); the contact angle on apple leaves of liquids ranged from 46° to 74°, and obviously decreased within 60 s. In all the 4 kinds of formula, the 13# pesticide contained the lowest surface tension and the minimum contact angle when the solutions were dropped on apple leaves, and the contact angle decreased significantly. The research showed that, 4 kinds of formula contained good stability and wet ability, and the 13# formula was the optimum formulation, wetting and spreading fast, so it was suitable for apple tree spraying.