Comparison of two methods for the quantification of gastrointestinal nematode infective larvae from pasture

Autor(es)

Sabiao de Toledo Piza, Marina Lais ^[1] ; de Almeida, Fabiana Alves ^[2] ; Pariz, Cristiano Magalhaes ^[3] ; Costa, Ciniro ^[3] ; Talamini do Amarante, Alessandro Francisco ^[2]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, Fac Med Vet & Zootecnia, UNESP, Programa Posgrad Zootecnia, Botucatu, SP - Brazil

^[2] UNESP, Dept Parasitol, Inst Biociencias, Botucatu, SP - Brazil

^[3] UNESP, Dept Melhoramento & Nutr Anim, Botucatu, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SEMINA-CIENCIAS AGRARIAS; v. 40, n. 2, p. 713-722, MAR-APR 2019.
• Citações Web of Science: 1

Resumo

The economic losses caused by gastrointestinal nematodes are one of the biggest obstacles in the small ruminants production. Understanding the population dynamics of the infective larvae (L3) in the pasture is the key point to develop control programs, and reliable results depend on the used methodology to quantify L3 numbers. The use of the sampling directly from the pasture appears as a viable option, since it is not required the use of animals with an esophageal fistula or tracer animals, decreasing the costs involved in the study. Therefore, the present project. which had as objective evaluate the efficiency of two collection methods for quantification of L3 in the pasture, utilized 64 lambs (n = 16) allocated to four integrated crop-livestock systems (treatments) with 12 paddocks each. Pasture samples were collected every nine days. The W method consists in traversing the area in the form of a W and again an inverted W, forage samples being collected every 10 steps, and the Square method, in tossing a 0.16 m(2) square to four random points within the area, the forage within the square being collected after each toss. After the forage samples had been processed, the L3 were recovered and identified. Cohen's Kappa coefficient (k) was determined. The W-transect and Random-plot methods did not differ (p >= 0.05) with respect to the number of L3 recovered from the pasture. and a positive correlation was found between them, suggesting agreement with one another, being that when the number of L3 recovered by the W-transect method increases, the same occurs in the Random-plot technique. The Random-plot method, which is already used to collect samples of forage for chemical analyses, can also be employed to estimate the pasture contamination by L3. The W-transect and Random-plot methods showed to be important in the epidemiological study of gastrointestinal nematodes in sheep. Therefore, the use of both on the same occasions and with different purposes, with one complementing the information that is not provided by the other, may be more effective in the investigation of enviromental contamination by L3 of gastrointestinal nematodes. (AU)

• Processo FAPESP: 13/13702-3 - Produção de silagem de milho em consórcio com capim-marandu e feijão-guandu e modalidades de sobressemeadura de aveia para terminação de cordeiros semi-confinados
• Beneficiário: Cristiano Magalhães Pariz
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 15/25413-1 - Sistema de integração lavoura-pecuária como método de controle da contaminação da pastagem por helmintos gastrintestinais de ovinos
• Beneficiário: Marina Lais Sabião de Toledo Piza
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 15/25718-7 - Profilaxia da verminose ovina utilizando o sistema de integração lavoura-pecuária (ILP)
• Beneficiário: Fabiana Alves de Almeida
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado