Resumen

MORALES, Gustavo et al. Classification by Famacha method and their relationship among haematocrit value and the e.p.g. counts in sheep reared under grazing conditions. Zootecnia Trop. [online]. 2010, vol.28, n.4, pp.545-556. ISSN 0798-7269.

The present work was carried out in a farm where cattle and sheep are reared simultaneously, located in Palmasola municipium, Falcón state. All 164 sheep (82 Bergamasca, 41 West African and 41 cross breed Bergamasca x West African) were submitted to McMaster counting technique with a oversaturated saline solution as flotation liquid. Determination of the haematocrit values was done by means of the microhematocrit centrifugation method. The color of the ocular mucous membrane of each examined sheep was compared with the color chart called Famacha in order to evaluate the degree of anaemia clinically by classifying the color of the conjunctivae ocular membrane. The integration of these different criteria were made prior by hand and after by means of multivariate methods (Discriminant Analysis) allowed the classification of sheep in three groups: resistants, resilients and sensitives. The fraction within the flock of resistants sheep was dominant (82,31%), followed by the resilients (12,8%) and for the sensitive ones in the last place (4,87%). The sensitive fraction of sheep was observed in the Bergamasca breed. The coloration of the conjunctive ocular reflected in an appropriate way the value of the haematocrit, validating the use of the Famacha chart positively as a useful tool in the control of the gastrointestinal parasitism in sheep reared under our conditions. The e,p,g. counts among the resilients and sensitives groups were similar, but very superior to this one in the resistants animals. The selection of the animals to drench with anthelmintic by means of the color of the conjunctive ocular causes a drastic reduction of the contamination of the pasture, given that the animals whose conjunctive ocular were pink, pink white or white the e.p.g counts were the highest.

Palabras clave : Haemonchus contortus; Famacha; resistant; Resilient; Sensitive; Conjunctive ocular; haematocrit, e.p.g count; gastrointestinal parasitism control.

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