Munkittrick T W, Nebel R L, Saacke R G
Department of Dairy Science, Virginia Polytechnic Institute and State University, Blacksburg 24061-0315.
J Dairy Sci. 1992 Mar;75(3):725-31. doi: 10.3168/jds.S0022-0302(92)77809-6.
A study utilizing two morphologically distinct sperm populations in a heterospermic trial was conducted to evaluate the effect of microencapsulation on accessory sperm number in artificially inseminated cattle. Inseminates consisted of an equal number (100 x 10(6) of morphologically normal and tapered sperm. In reciprocal inseminates, one of the two sperm types was encapsulated in protamine sulfate microcapsules, and the other type was unencapsulated. Insemination of both sperm types that were unencapsulated served as the control. Thirty-one embryos were nonsurgically recovered 6 d postinsemination, and accessory sperm within the zona pellucida were counted and morphologically classified as normal or tapered. Microencapsulated sperm contributed 25.7% of the accessory sperm obtained for inseminates containing microcapsules. Microencapsulation did not affect the total number of accessory sperm per embryo; however, encapsulation did reduce accessory sperm for the specific sperm type encapsulated. The proportion of morphologically normal to total accessory sperm recovered were 65.8% when both sperm types were unencapsulated, 35.4% when normal sperm were encapsulated, and 80.6% when the tapered sperm were encapsulated. High accessory sperm numbers per embryo were related to embryo quality (P less than .01). Mean accessory sperm and standard deviations for degenerate embryos and for embryos classified fair to poor, good, and excellent were 1.7 +/- 2.9, 11.1 +/- 8.6 24.9 +/- 33.9, and 84.3 +/- 58.3. We conclude that sperm inseminated in protamine sulfate microcapsules can be released and can attach to the zona pelucida of ova in vivo. Microencapsulation failed to increase accessory sperm numbers under conditions of this experiment in which insemination was 12 h after estrus was first detected.
在一项异精受孕试验中，利用两种形态不同的精子群体进行了一项研究，以评估微囊化对人工授精牛副精子数量的影响。授精精液由数量相等（100×10⁶）的形态正常和锥形精子组成。在相互授精中，两种精子类型之一被包裹在硫酸鱼精蛋白微囊中，另一种类型未被包裹。两种未包裹精子类型的授精作为对照。授精后6天通过非手术方法回收了31个胚胎，并对透明带内的副精子进行计数，并根据形态将其分类为正常或锥形。微囊化精子占含有微囊的授精精液中获得的副精子的25.7%。微囊化不影响每个胚胎的副精子总数；然而，包裹确实减少了被包裹的特定精子类型的副精子。当两种精子类型都未被包裹时，回收的形态正常的副精子占总副精子的比例为65.8%，当正常精子被包裹时为35.4%，当锥形精子被包裹时为80.6%。每个胚胎的高副精子数量与胚胎质量相关（P<0.01）。退化胚胎以及分类为差、良、优的胚胎的平均副精子数和标准差分别为1.7±2.9、11.1±8.6、24.9±33.9和84.3±58.3。我们得出结论，硫酸鱼精蛋白微囊中授精的精子可以释放并能在体内附着于卵子的透明带。在本实验中，在首次检测到发情后12小时进行授精的条件下，微囊化未能增加副精子数量。
