Frequency of bovine gastrointestinal nematodes in three humid, subtropical areas of Mexico

Abstract

The genera and species of bovine gastrointestinal (GI) nematodes were recorded from 1995 to 1997 throughout four seasons, in three different humid, wet, subtropical locations, i.e.: Sauta, Medellin, and Tizimin (Mexico's states of Nayarit, Veracruz, and Yucatan, respectively). In each location, five freshly weaned, GI nematode-free calves were placed on grasslands, during four time periods. Placements were performed as follows: a) mid raining season (August), b) late raining season (November), c) early dry season (February), and d) early raining season (June). After a 30-day, free-range period cattle were slaughter and adult GI nematodes were collected and identified. Means and standard deviations of nematode species were as follows: Sauta, Haemonchus contortus 32+-8, 615+-115, 267+-87, and 20+-4, Bunostomum phlebotomum: 5+-1, 2+-2, 2+-2, and 0, Oesophagostomum radiatum: 84+-22, 46+-21, 76+-39, and 22+-14, and Trichuris ovis 8+-1, 104+-21, 92+-35, and 112+-38, Medellin, H. contortus 326+-152, 613+-210, 1167+-387, and 12+-8, H. similis: 30+-21, 56+-22, 35+-16, and 0, Cooperia punctata: 320+-185, 414+-409, 47+-28, and 0+-0, B. phlebotomum: 10+-7, 2+-2, 5+-2, and 0, O. radiatum: 106+-42, 228+-61, 72+-39, and 228+-144, Tizimin, H. contortus: 160+-58, 440+-380, 1514+-718, and 300+-184, C. punctata: 46+-31, 90+-84, 930+-1180, and 55+-34, O. radiatum: 4+-4, 26+-33, 0, and 7+-7, for the animals placed in August, November, February, and June, respectively. Significant differences (P<0.05) were found among the three locations. Genera and species varied in terms of both presence, and quantity.