Sorological evaluation of commercial vaccines against enterotoxemia in goats.

Enterotoxemia in sheep and in goats is caused by the effects of the epsilon toxin of C/ostridium perfringens type D, being considered the main infectious cause of mortality in those animal species. The main prophylactic measures include adequate nutritional management and vaccination of ali animais using vaccines of high immunogenic power. Six commercial vaccines containing in its formulation the epsilon toxoid of C. perfringens type D were sorogically evaluated. Eighty four female goat kids, whose mothers had no previous vaccination history against clostridioses were used. They were divided into six groups of 14 animais each. The animais of the control group didn't receive any vaccine dose and the animais from the groups 1 to 5 received two vaccine doses, The first vaccine dose was applied at 45 days of life (day zero) and the second dose at 75 days (30 days after the first dose). Blood samples were collected from the goat kids at the days zero, 30, 60, 90, 120 and 150 after the beginning of the experiment, in order to evaluate the immunologic response. The Indirect ELlSA technique was used for the quantification of the antibodies against epsilon toxin in the samples of blood serum of the animais. In day zero, no animal presented titre considered protector. The largest number of animais considered protected was found at day 60, in response to the two initial doses of the vaccine (days O and 30, first and second doses, respectively). Only tive animaIs which received the vaccine 1 and one animal which received the vaccine 3 stayed wilh titres of antibodies considered up to 150 days after the first vaccine dose. Based on the results, it was concluded lhat the evaluated vaccines showed small amount of epsilon toxoid in the commercial formulations, a crucial fact for lhe low efficiency of. the vaccines. For commercial reasons, the vaccines against the clostridioses present versatile formulations, with several toxoid types, used for various animal species, which certainly contributed to reduce their effectiveness in preventing the iIInesses caused by the clostridia or their toxins.

Sensibilidade antimicrobiana de Staphylococcus spp. isolados de bovinos, bubalinos e caprinos com mastite.

O trabalho objetivou avaliar a resistência dos isolados de Staphylococcus spp. de ruminantes (caprinos, bubalinos e bovinos) com mastite a alguns antibióticos -lactâmicos pela presença do gene Bla-Z e produção de biofilme. O perfil de resistência dessas bactérias aos antibióticos ampicilina, penicilina G e oxacilina foi realizado pelo método de Kirby-Bauer. A produção do biofilme foi avaliada pela aderência em microplaca, e a presença do gene blaZ por PCR. Isolados de caprinos não foram resistentes a oxacilina, mas, 25% foram resistentes a penicilina e 25% a ampicilina. Nos isolados de bovinos, 23% apresentaram resistência à oxacilina, 67% à ampicilina e 64% à penicilina G. Em 46% dos isolados de bubalinos, observou- 1Estudante de

Influence of lactation stages and rain periods on subclinical mastitis in meat producing ewes.

Mastitis negatively influences the survival and weight gain of ovines for meat production. The purpose of this study was to investigate, in sheep for meat production, the occurrence of subclinical mastitis in ewes at the end of lactation and beginning of the consecutive lactation and to assess the composition and cellular characteristics of milk as a function of different rainfall indices. Mammary halves (821) of Santa Ines (479) and Morada Nova (342) ewes were examined. Milk samples were collected in two different moments of lactation: at weaning and postpartum of the consecutive lactation. Sample collection periods were called ?dry? or ?rainy? according to the rainfall index in the month immediately before the month of collection. The occurrence of subclinical mastitis at weaning in the Santa Ines and Morada Nova ewes were 16.4 and 12.6% in the dry period, and 17.7 and 23.5% in the rainy period, respectively. In the consecutive lactation period, the occurrences were 26.7 and 27.7% in the dry period and 41.8 and 39.1% in the rainy period, for the Santa Ines and Morada Nova ewes, respectively. Postpartum stage was critical for the occurrence of subclinical mastitis, as compared to that at the end of the previous lactation. Occurrence of the disease negatively influenced the SCC in the milk at the beginning of lactation and changed its composition, mainly in the rainiest periods, probably due to a difficulty in maintaining hygiene in the environment where the animals remained.