Marcelo Arnt Brito

Composição do sangue e do leite em ovinos leiteiros do sul do Brasil: variações na gestação e na lactação

Dairy sheep industry has increased intensively in southern Brazil, however, without the corresponding knowledge of variations on metabolic and hematological parameters and on milk composition, with application in research and clinical activities. This work was carried out on Lacaune sheep, intensively grazed in the county of Bento Goncalves (RS), in southern Brazil. Blood samples were collected from the jugular vein for metabolic profiles and hematology. Samples were taken randomly from 14 sheep in each of the following periods: nonpregnant ewes; at 60, 90 and 120 of pregnancy and at 7, 30, 60 and 140 days of lactation. During the lactation period, milk samples were also taken to assay the physico-chemical composition. Milk acidity, protein and fat levels were different from reference levels in another countries. The most relevant changes on metabolic profile were noticed at the end of gestation and at the beginning of lactation. Urea values showed variation (P<0.05) during the gestation and lactation periods. The levels of glucose and fructosamine decreased and the BHB increased significantly at the end of gestation period (P<0.05). During the lactation period glucose level lowered and cholesterol level increased significantly (P<0.05). Phosphorus level lowered, specially at 30 days post parturition (P<0.05). Hematologic parameters did not show variation during the physiologic periods studied. An exception was the segmented neutrophils that increased with the advance of the gestation (P<0.05). The data presented here may help for further nutrition and metabolic studies on dairy sheep and milk quality.

Listeriose em rebanho de ovinos leiteiros na região serrana do Rio Grande do Sul: relato de caso

Clinical cases of listeriosis in two Lacaune rams, fed silage in a lot, are reported. Histological examination of nervous tissue revealed purulent meningoencephalitis, and L. monocytogenes was detected in nervous tissue by immunohistochemistry procedures. This disease should be suspected when oral lesions are visible in dairy sheep fed low quality silage.

Variação estacional na qualidade do sêmen de carneiros Lacaune no Brasil

Existem poucos dados sobre a producao de semen da raca Lacaune, no sul do pais. Assim, o objetivo deste estudo foi o de avaliar a producao e a qualidade do semen de carneiros desta raca, criados no estado do Rio Grande do Sul (RS). Foram utilizados 12 carneiros, de idades entre 1-4 anos, criados em condicoes intensivas. O semen foi colhido por vagina artificial e foram avaliadas as caracteristicas quantitativas e qualitativas e a circunferencia escrotal, do inverno de 2002 ate a primavera de 2003. Com excecao da concentracao espermatica, foram observadas variacoes estacionais em todas as caracteristicas estudadas. O volume variou de 1.1 ± 0.4 mL, no inverno de 2002, a 1.5 ± 0.4 mL no outono de 2003. O numero total de espermatozoides por ejaculado variou de 4.0 ± 3.3x10(9) (inverno de 2002) a 5.7 ± 3.3x10(9) (verao de 2003). Observou-se variacao estacional significativa (P < 0,05) na circunferencia escrotal em 2002, bem como variacao significativa entre as idades dos animais, no inverno do mesmo ano. Os valores medios da producao espermatica observados no verao e o outono foram superiores aos obtidos no inverno e primavera. O verao e outono foram considerados as estacoes mais indicadas para a utilizacao de machos da raca Lacaune em programas reprodutivos, no RS. Mais estudos devem ser conduzidos, para a verificacao de efeitos estacionais sobre o congelamento do semen.