Castro Eleonor, Gil Andrés, Solari María Angélica, Farias Nara Amélia
Department of Parasitology, Faculty of Veterinary, Lasplaces 1550, C.P. 11600, Montevideo, Uruguay.
Vet Parasitol. 2005 Nov 5;133(4):363-7. doi: 10.1016/j.vetpar.2005.06.003.
A trained observer direct count method to measure horn fly population was evaluated to determine the reliability (inter-observer agreement) and its validity when compared with a "gold standard" method (video film). All the counts were performed with the animals restrained in a chute in a single herd. A direct count of horn flies by each of two observers on opposite sides of the animal was made. In addition a videotape recording of the counting surface on each animal was made. Horn flies were counted on 80 cows in the morning twice monthly from 22 October 1999 to 24 March 2000. The correlation between observer counts was high as was the correlation between observer counts and counts made from a videotape recording. Direct counts by trained observers were highly reliable and had good validity. However, videotape recording can be useful when the horn fly population is high, because it is faster in the field than the direct count method. The results of this study suggest that the direct count method can be used with confidence under field conditions.
对一种用于测量角蝇种群数量的经过训练的观察者直接计数法进行了评估，以确定其可靠性（观察者间的一致性）以及与“金标准”方法（录像）相比时的有效性。所有计数均在单个畜群中，将动物限制在斜槽内的情况下进行。由两名观察者在动物相对两侧各自对角蝇进行直接计数。此外，还对每只动物的计数表面进行了录像记录。从1999年10月22日至2000年3月24日，每月两次在早晨对80头奶牛进行角蝇计数。观察者计数之间的相关性很高，观察者计数与录像记录计数之间的相关性也很高。经过训练的观察者进行的直接计数具有高度可靠性和良好的有效性。然而，当角蝇种群数量很高时，录像记录可能会很有用，因为在野外它比直接计数法更快。本研究结果表明，直接计数法在野外条件下可以放心使用。
