RESUMO

The objectives were to evaluate the effects of injectable vitamin E during the last 3 wk prepartum on the incidence of retained fetal membranes (RFM) and reproductive performance. Dairy cows (n=890), 390 Holsteins (132 nulliparous and 258 parous) and 500 crossbred Holstein × Gyr (199 nulliparous and 301 parous), from 3 dairy farms in Brazil were assigned to the study. In all 3 farms, from October to March, prepartum cows grazed tropical grasses and received 2 kg/d of a mixture of finely ground corn, soybean meal, and minerals and vitamins. From April to September prepartum cows received a total mixed ration composed of corn silage, finely ground corn, soybean meal, and minerals and vitamins. During the prepartum period, cows were fed 280 (farm 1), 390 (farm 2), and 480 IU (farm 3) of supplemental vitamin E per day, and throughout postpartum, cows were fed 370 (farm 1), 500 (farm 2), and 600 (farm 3) IU of supplemental vitamin E. Within each farm, cows were randomly assigned to remain as untreated controls or to receive 3 i.m. injections of 1,000 IU each of dl-α-tocopherol administered at 19.2 ± 4.3, 12.9 ± 3.3, and 6.2 ± 2.9 d before calving (VitE). Blood was sampled from 141 cows immediately before enrollment to determine the α-tocopherol and cholesterol statuses. Blood was also sampled and analyzed for concentrations of cortisol and nonesterified fatty acids in the last 3 wk of gestation. The serum concentration of α-tocopherol or α-tocopherol:cholesterol ratio did not differ between treatments and averaged 2.97 ± 0.10 µg/mL and 4.46 ± 0.16 × 10(-3), respectively. In total, 53.2% of the cows had an inadequate concentration of serum α-tocopherol based on the 3.0 µg/mL cut-off for adequacy. The risk of RFM decreased as serum α-tocopherol increased. Milk production did not differ between controls and VitE cows. Treatment with injectable α-tocopherol decreased RFM from 20.1 to 13.5%, decreased incidence of stillbirth from 14.9 to 6.8%, and tended to decrease death by 200 d postpartum. VitE cows tended to have improved pregnancy per insemination at first AI (36.7 vs. 30.1%) because of decreased pregnancy loss from 31 to 62 d of gestation (12.5 vs. 20.5%). Despite a similar insemination rate, VitE cows had 22% greater pregnancy rate than control cows. Cows receiving vitamin E had decreased circulating cortisol and nonesterified fatty acids around calving. In summary, when cows were fed limited amounts of supplemental vitamin E, 28 to 48% of the recommendations, prepartum supplementation with injectable α-tocopherol decreased incidence of RFM and improved reproduction.

Assuntos

RESUMO

Analisou-se o hemograma de 177 amostras de sangue de fêmeas bovinas da raça Holandesa nos primeiros 90 dias pós-parto. As amostras foram colhidas de vacas não reagentes ao antígeno (GP 51) do vírus da leucose dos bovinos, distribuídas em dois grupos (I: puerpério fisiológico; II: puerpério com retenção dos anexos fetais) e subdivididas em quatro grupos de acordo com o momento de colheita. Nos primeiros 10 dias após o parto, o eritrograma não sofreu influência da retenção dos anexos fetais. Com a evolução do puerpério, observou-se, nas vacas com retenção dos anexos fetais, anemia de grau leve entre o 10º e 30º dia pós-parto. O leucograma dos animais com retenção dos anexos fetais foi predominantemente linfocitário, caracterizado por leucopenia, neutropenia com desvio à esquerda degenerativo e eosinopenia. A partir do 10º dia após o parto, o leucograma não foi influenciado pela retenção dos anexos fetais.(AU)

Hematological profiles of 177 blood samples from Holstein cows were determined during the first 90 days after parturition. Blood samples were collected from cows that were non-reactive to the bovine leukosis virus (GP 51) antigen. The animals were divided into two groups (group I: physiological puerperium and group II: puerperim with retained fetal membranes), and subdivided into four groups, based on the time that the samples were collected. During the first 10 days after parturition, retained fetal membranes did not influence the erythrogram. However, with the evolution of the puerperium period, a mild anemia was observed from the 10th to the 30th day postpartum in cows with retained fetal membranes. The leukocyte profile was predominantly lymphocytic, characterized by leucopenia induced by neutropenia with a left degenerative shift and eosinopenia. From the 10th day postpartum, the retained fetal membranes did not influence the leukogram.(AU)

Assuntos

RESUMO

Analisou-se o hemograma de 177 amostras de sangue de fêmeas bovinas da raça Holandesa nos primeiros 90 dias pós-parto. As amostras foram colhidas de vacas não reagentes ao antígeno (GP 51) do vírus da leucose dos bovinos, distribuídas em dois grupos (I: puerpério fisiológico; II: puerpério com retenção dos anexos fetais) e subdivididas em quatro grupos de acordo com o momento de colheita. Nos primeiros 10 dias após o parto, o eritrograma não sofreu influência da retenção dos anexos fetais. Com a evolução do puerpério, observou-se, nas vacas com retenção dos anexos fetais, anemia de grau leve entre o 10º e 30º dia pós-parto. O leucograma dos animais com retenção dos anexos fetais foi predominantemente linfocitário, caracterizado por leucopenia, neutropenia com desvio à esquerda degenerativo e eosinopenia. A partir do 10º dia após o parto, o leucograma não foi influenciado pela retenção dos anexos fetais.

Hematological profiles of 177 blood samples from Holstein cows were determined during the first 90 days after parturition. Blood samples were collected from cows that were non-reactive to the bovine leukosis virus (GP 51) antigen. The animals were divided into two groups (group I: physiological puerperium and group II: puerperim with retained fetal membranes), and subdivided into four groups, based on the time that the samples were collected. During the first 10 days after parturition, retained fetal membranes did not influence the erythrogram. However, with the evolution of the puerperium period, a mild anemia was observed from the 10th to the 30th day postpartum in cows with retained fetal membranes. The leukocyte profile was predominantly lymphocytic, characterized by leucopenia induced by neutropenia with a left degenerative shift and eosinopenia. From the 10th day postpartum, the retained fetal membranes did not influence the leukogram.

Assuntos