Influence of seasonality on the physiological and seminal parameters of buffaloes in the western region of Pará1 / Influência da sazonalidade nos parâmetros fisiológicos e seminais de búfalos da região oeste do Pará

Awareness of the physiological changes that occur when animals are subjected to climatic changes that are considered stressful is essential to maintain animal welfare and to be able to exploit their reproductive potential efficiently and rationally. The present study was carried out to evaluate climatic variables' influence on physiological parameters, and Murrah buffalo ejaculates reared in a humid tropical climate in the Amazon. The immediate analyzes pertinent to the physical and morphological characteristics of the ejaculates were carried out and corresponded in the rainy season (RS) volume of 3.4±2.0mL; the mass activity of 4.4±0.5; motility of 80.4±5.6%; vigor of 4.4±0.4; concentration of 657,300±237,865.1 x 106sptz/mL; major defects of 9.0±2.6%; minor defects of 11.2±3.9%; total defects 20.2±5.3% and sperm plasma membrane integrity (SPMI) 84.8±5.6%, whereas in the non-rainy season (nRS), the results were 4.0±2.1mL; the mass activity of 3.0±1.0; motility of 56.2±13.4%; vigor of 3.0±1.0; concentration of 586,000±291,925.9 x 106sptz/mL; major defects of 20.8±9.9%; minor defects of 27.5±6.3%; total defects 48.3±9.3% and SPMI of 57.9±12.4%. Furthermore, a statistical difference (P<0.05) was observed for the parameters mass activity, motility, vigor, major defects, minor defects, total defects, and sperm plasma membrane integrity between both periods. The data on heart frequency, superficial temperature (head, back, groin, and scrotal pouch) showed a statistical difference between both periods (P<0.05). To conclude is necessary specific management in the non-rainy season that thermal stress is not a determining factor in reducing the reproductive quality of buffaloes; it is necessary to use means to improve animal welfare; one alternative is to use baths regularly for these animals or provide constant access to areas of rivers or lakes, as well as shading, preventing the buffaloes from being directly exposed to the unfavorable thermal environment.(AU)

O conhecimento das alterações fisiológicas que ocorrem quando os animais são submetidos a alterações climatológicas consideradas estressantes é fundamental para manter o bem-estar animal, e poder explorar o seu potencial reprodutivo de forma eficiente e racional. O presente estudo foi realizado com o objetivo de avaliar a influência de variáveis climáticas sobre parâmetros fisiológicos e de ejaculados de búfalos, da raça Murrah, criados em clima tropical úmido da Amazônia. As análises imediatas pertinentes às características físicas e morfológicas dos ejaculados foram realizadas e corresponderam no período chuvoso (PCh) o volume de 3,4±2,0mL, turbilhonamento de 4,4±0,5; motilidade de 80,4±5,6%; vigor de 4,4±0,4; concentração de 657.300±237.865,1 x 106sptz/mL; defeitos maiores de 9,0±2,6%; defeitos menores de 11,2±3,9%; defeitos totais de 20,2±5,3% e integridade da membrana plasmática (IMP) de 84,8±5,6%, enquanto que no período não chuvoso (PnCh), os resultados foram de 4,0±2,1mL; turbilhonamento de 3,0±1,0; motilidade de 56,2±13,4%; vigor de 3,0±1,0; concentração de 586.000±291.925,9 x 106sptz/mL; defeitos maiores de 20,8±9,9%; defeitos menores de 27,5±6,3%; defeitos totais de 48,3±9,3% e IMP de 57,9±12,4%. Observou-se diferença estatística (P<0,05) para os parâmetros movimento de massa, motilidade, vigor, defeitos maiores, defeitos menores, defeitos totais e integridade da membrana plasmática entre os dois períodos. Dados de frequência cardíaca, temperatura superficial (cabeça, dorso, virilha e bolsa escrotal) diferiram estatisticamente entre os períodos (P<0,05). Conclui-se que se faz necessário usar de um manejo específico no período não chuvoso para que o estresse térmico não seja um fator determinante na redução da qualidade reprodutiva dos búfalos, para isto se faz necessário utilizar de meios para melhorar o bem-estar animal, sendo uma das alternativas fazer uso de banhos regularmente para estes animais, ou disponibilizar acesso constante destes a áreas de rios ou lagos, assim como sombreamentos, evitando que os búfalos fiquem expostos diretamente ao ambiente térmico desfavorável.(AU)

Influence of organic chromium supplementation on the performance of beef calves undergoing weaning-related stress / Influência da suplementação com cromo orgânico no desempenho de bezerros de corte submetidos ao estresse da desmama

Dietary chromium supplementation before, during, and after weaning was conducted to evaluate the hypothesis that chromium supplementation could reduce weaning-induced cortisol release in beef calves. We examined the effects of chromium supplementation in 150 crossbred calves (male and female) between five and six months of age. The calves were randomly divided by sex and breed into two equal homogeneous groups (n=75). One group was used as the control, and the other experimental group received supplementation with 0.9mg of chromium carbon-amino-phospho-chelate per 100kg BW. The chromium supplement was mixed with mineral salt for the consumption of 0.1% of BW, and the supplement was administered via creep feeding 60 days before and 60 days after forced weaning. Calves were weighed, and their blood and urine samples were obtained at four time-points: T0 (60 days before weaning), T1 (at weaning), T2 (48 hours after weaning), and T3 (60 days after weaning). Blood samples were used to determine chromium, cortisol, total protein, and albumin concentrations, and urine samples were used to determine urinary creatinine and chromium levels. Cumulative weight gain was higher in calves supplemented with chromium before weaning and during the experiment (P<0.05). In addition, weaning-related stress caused an increase in chromium excretion in the urine, and chromium supplementation reduced stress, which resulted in lower cortisol and total protein levels during weaning.(AU)

O estudo foi realizado para avaliar a hipótese de que a suplementação dietética com cromo antes, durante e após a desmama possa diminuir a concentração de cortisol causado por este processo em bezerros de corte. Para tal, foram utilizados 150 bezerros mestiços, machos e fêmeas, entre cinco e seis meses de idade. Os animais foram divididos randomicamente por sexo e grupo genético em dois grupos homogêneos (n=75), um mantido como controle e outro suplementado com 0,9mg de carboaminofosfoquelato de cromo/100 kg PV misturado a um sal proteinado para ser consumido na base de 0,1% do PV via creep feeding, no decorrer de 60 dias antes e 60 dias após à desmama forçada. Os animais foram pesados e foram coletadas amostras sanguíneas e urinárias no M0 (60 dias antes da desmama), M1 (desmama), M2 (48 horas após a desmama) e M3 (60 dias após à desmama) para determinação de cromo, cortisol, proteína total e albumina no sangue e da concentração urinária de creatinina e cromo. O ganho acumulado de peso foi superior nos bezerros suplementados com cromo antes da desmama e no decorrer de todo o experimento (P<0,05). A suplementação com cromo reduziu os teores de cortisol e de proteína total durante a desmama. O estresse da desmama provocou aumento da excreção de cromo pela urina.(AU)

Occurrence of Toxoplasma gondii antibodies in Dasyprocta aguti from Brazil: comparison of diagnostic techniques.

In this study, the occurrence of antibodies to Toxoplasma gondii in Brazilian agouti (Dasyprocta aguti) was compared by modified agglutination test (MAT) and indirect fluorescent antibody test (IFAT) using anti-capybara conjugate. Sera from 109 animals were tested using MAT (1:25 cut-off) and IFAT (1:16 cut-off); 19% were positive by MAT, and 18% were positive by IFAT. Overall, the 17 IFAT-positive samples were also positive for MAT. The four positive MAT samples with a titer < or = 200 were IFAT negative. All negative samples obtained by MAT matched with the results of the IFAT. Comparing both tests, and considering MAT as the gold standard, the sensitivity of IFAT was 81%, the specificity was 100%, the accuracy was 97%, the positive predictive value (PPV) was 100%, and the negative predictive value 96%. The kappa value agreement was 87.3% (75.1-99.6%). The anti-capybara conjugate can be successfully used to perform IFAT in Brazilian agouti with maximum specificity and PPV.