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

Abstract

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 Gonçalves (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.