Emmanuel Emydio Gomes Pinheiro

Immunocastration of goats using anti-gonadotrophin releasing hormone vaccine

The aim of this study was to evaluate the immuno-sterilizing action of anti-gonadotrophin-releasing hormone (anti-GnRH) vaccine in goats. Eighteen male goats were randomly distributed to receive three treatments: T1 (control) - whole animals, and T2 and T3 - application of 0.5 and 1.0 mL of anti-GnRH vaccine, respectively, with six replicates and one goat per experimental unit. Vaccine was administered at 8 months of age and 30 days after the first immunization. Testicular biometry was evaluated monthly, along with seminal collections, for the physical and morphological evaluation of semen. At the time of slaughter, the testicle were collected, and fragments were measured and removed for histological evaluation. The data were evaluated for normality by the Shapiro-Wilk test, followed by appropriate statistical tests for each variable. A reduction in width and length of the right and left testicles was observed and, consequently, the scrotal circumference of the immunized animals reduced after the second vaccine application (P < 0.05). Thirty-days after the first vaccine application, there was a negative effect on seminal production and quality; and 60 days after the second application, a pronounced reduction was observed in all seminal parameters in the vaccinated animals, including azoospermia (83.33% of animals; P < 0.05). Vaccine application reduced testicular weight, seminiferous tubule diameter, and gonadosomatic and tubulosomatic index (P < 0.05), but did not influence the proportion of testicular parenchyma components (P > 0.05). Two applications of the anti-GnRH conjugate are effective for the immunological castration of goats, and the 0.5 mL dose is recommended for use in crossbred goats.

Toxic plants for livestock in Recôncavo of Bahia, Northeastern Brazil. A Review

A survey on toxic plants for livestock was performed in the Recôncavo region of Bahia state, Brazil. Hundred forty interviews were realized with farmers and, technical area from 28 counties. The following plants were described as toxic for livestock: “Manipueira” byproduct of Manihot spp., leaves of Manihot spp., scraper of Manihot spp., Manihot esculenta and Brachiaria spp. In addition, less frequent poisonings by Cestrum axillare, Metternichia princeps, Ipomoea asarifolia, Ricinus communis, Dieffenbachia spp., Amorimia rigida and, Palicourea aeneofusca. Three plants previously unknown as toxic, but mentioned by the respondents as poisonous, were Poincianella pyramidalis, Momordica charantia L. and Erythrina mulungu. Only P. pyramidalis was tested and resulted toxic to goats and sheep, causing malformations in fetuses. Experiments with other plants are necessary to confirm their toxicity.