RESUMEN
O objetivo deste estudo foi avaliar o efeito in vivo e in vitro do óleo de citronela (Cymbopogon nardus (L.) Rendle) no carrapato de bovinos (Boophilus microplus). O óleo foi obtido de folhas frescas pelo processo de destilação e o rendimento foi de 0,7 por cento. Para as experimentações in vitro foram usadas sete (0; 0,5; 1,0; 10,0; 25,0; 50,0; 100,0 por cento) e nove (0,1; 0,25; 0,5; 1,0; 2,0; 10,0; 25,0; 50,0; 100 por cento) concentrações de óleo de citronela, sendo testadas em fêmeas ingurgitadas. A eficácia observada foi de 0; 44,2; 92,1; 85,6; 87,8; 87,0; 88,9 e de 0,7; 2,8; 51,6; 79,3; 81,0; 87,1; 86,7; 89,5 por cento, respectivamente. Os resultados sugerem que o óleo de citronela pode ser usado no controle do carrapato bovino.
This research was aimed at evaluating in vitro and in vivo effects of citronella (Cymbopogon nardus (L.) Rendle) oil on catle ticks. The volatile oil was obtained from de fresh leaves of citronella grass by steam destilation and the yelds was 0.7 percent. Seven (0; 0.5; 1.0; 10.0; 25.0; 50.0; 100.0 percent) and nine (0.1; 0.25; 0.5; 1.0; 2.0; 10.0; 25.0; 50.0; 100.0 percent) concentrations of citonella oil were used on in vitro trials with engorged female ticks. The efficacy control ticks was 0; 44.2; 92.1; 85.6; 87.8; 87.0; 88.9 and 0; 0.7; 2.8; 51.6; 79.3; 81.0; 87.1; 86.7 89.5 percent, respectively. These sugest that the citronella oil can be practical used for controlling of catle ticks.
RESUMEN
Soybean by-products are currently used in Rio Grande do Sul, Brazil, as a source of protein in dairy cows. However, the high protein breakdown of this feed source in the rumen causes loss of the intrinsic quality of the protein and increases plasma urea with deleterious consequences to animal metabolism. Thermal treatment of soybean can overcome this limitation. The aim of this study was to evaluate the metabolism of dairy cows fed with thermally treated soybean and raw soybean, through the analyses of the metabolic profile of plasma and milk. Twelve Holstein cows in mid-lactation period were studied using four treatments: commercial concentrated of protein, soybean meal, raw soybean and roasted soybean. Protein and urea levels in milk were measured in morning and afternoon samples. Data were arranged in a Latin square design (4 treatments and 3 animals in each square). There were no significant differences in glucose, beta-hydroxybutyrate, calcium, phosphorus and magnesium concentrations among treatments. Cows consuming raw and thermally treated soybean had higher levels of plasma cholesterol. Cows consuming roasted soybean had lower level of plasma and milk urea in the morning. Afternoon milk samples had higher levels of urea than morning samples. It is suggested that thermally treated soybean was effective in diminishing the breakdown of protein in the rumen. It is better to employ morning milk samples to evaluate metabolic profile than afternoon samples.