RESUMO
The aim of this study was to determine risk factors associated with milk fever (MF) occurrence in Costa Rican grazing dairy cattle. A total of 69,870 cows from 126 dairy herds were included in the study. Data were collected in the Veterinary Automated Management and Production Control Program software by the Population Medicine Research Program of the Veterinary Medicine School, National University of Costa Rica, from 1985 to 2014. To determine the risk factors for MF, 2 logistic regression mixed models were evaluated. The first model used breed, month of calving, ecological life zone, herd nested within ecological life zone, and parity as fixed effects. The second model excluded first-lactation animals and cows without production information, had the same fixed effects of the first model, and added previous MF case, previous lactation length, previous dry period length, previous corrected 305-d milk yield, and calving interval length as fixed effects. Both models used animal and year as random effects. Of the 235,971 recorded lactations, 4,312 (1.83%) reported MF event. The significantly associated risk factors for MF occurrence, ranked by their highest odds ratio (OR), were parity (OR = 52.59), previous dry period length (OR = 4.21), ecological life zone (OR = 3.20), breed (OR = 3.04), previous corrected 305-d milk yield (OR = 2.39), previous MF case (OR = 2.35), and month of calving (OR = 1.36). The findings of this study are the first data reported using an epidemiological approach to study risk factors for MF in Costa Rican dairy cattle. Some of these results might be used to improve preventive management practices at the farms to reduce the incidence of this metabolic disease in grazing dairy herds.
Assuntos
Doenças dos Bovinos/epidemiologia , Paresia Puerperal/epidemiologia , Animais , Bovinos , Doenças dos Bovinos/etiologia , Costa Rica/epidemiologia , Indústria de Laticínios , Feminino , Incidência , Modelos Logísticos , Estudos Longitudinais , Paridade , Paresia Puerperal/etiologia , Gravidez , Fatores de RiscoRESUMO
The objective was to describe the relationship between concentration of serum nonesterified fatty acids (NEFAs) at calving and the incidence of periparturient disorders in Chilean Holstein dairy cows (Bos taurus). The study was conducted at two dairies (central Chile) with 700 milking cows each and similar management. Between July 2006 and March 2007, 350 cows were selected, and concentrations of serum NEFAs were determined at calving. The incidence of milk fever (MF), retained fetal membranes (RFMs), metritis, and clinical mastitis from calving to 100 d in lactation were consistently recorded. The relationship between concentration of serum NEFAs at calving and the incidence of periparturient diseases was determined using logistic regression. The main explanatory variable was concentration of serum NEFAs at calving. The incidence of MF, RFM, metritis, and mastitis was 5.4%, 15.6%, 10.8%, and 14.4%, respectively. There was no association between concentration of NEFAs at calving and the incidence of these conditions when the median value of NEFAs (0.9 mEq/L) was used as a cutoff. However, when the 75th percentile (1.2 mEq/L) was used as the cutoff, cows with values <1.2 mEq/L were 0.45 and 0.32 times as likely to develop clinical mastitis and MF, respectively, compared with cows with values >or=1.2 mEq/L. When the 90th percentile (1.6 mEq/L) was used as a cutoff, cows with values <1.6 mEq/L were 0.25 times as likely to develop clinical mastitis compared with cows with values >or=1.6 mEq/L. As a continuous variable, for every 0.1 mEq/L increment in NEFAs at calving, cows were 1.11 times more likely to experience clinical mastitis. In conclusion, cows with NEFA concentrations >or=1.2 mEq/L had a higher incidence of clinical mastitis and MF than that of cows with values <1.2 mEq/L.
Assuntos
Doenças dos Bovinos/sangue , Ácidos Graxos não Esterificados/sangue , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Feminino , Incidência , Mastite Bovina/sangue , Mastite Bovina/epidemiologia , Complicações do Trabalho de Parto/sangue , Complicações do Trabalho de Parto/epidemiologia , Complicações do Trabalho de Parto/veterinária , Paresia Puerperal/sangue , Paresia Puerperal/epidemiologia , Parto , Gravidez , Análise de Regressão , Fatores de RiscoRESUMO
No decorrer de 1987 e 1988 acompanhou-se o aparecimento de casos clínicos de hipocalcemia, durante o puerpério, em vacas leiteiras da raça Holandesa ou mestiças Gir-Holando, de uma propriedade do Vale do Paraíba, Estado de Säo Paulo. A incidência de hipocalcemia foi de 4,25 por cento. Näo se observou influência do grupo genético e da época do ano (seca ou chuva) no aparecimento da afecçäo. Quanto maior a ordem de lactaçäo maior a incidência de hipocalcemia, näo ocorrendo a enfermidade em vacas com menos de três lactaçöes. A hipocalcemia foi mais frequente no decorrer do primeiro dia pós-parto, 64,10 por cento, que no segundo 30,80 por cento, e após, 5,10 por cento. A maioria dos casos, 84,10 por cento, foi detectada em animais que apresentavam o segundo estádio clínico da afecçäo (depressäo, paralisia flácida etc.), mais do que no terceiro (comatose, depressäo da consciência etc) ou no primeiro (tetanias, hiperexcitabilidade etc) estádios. Todas as vacas acometidas foram tratadas com doses crescentes de cálcio injetável, num máximo de nove gramas, até a recuperaçäo do animal. Quanto maior a dose de cálcio empregada maior o sucesso acumulado no tratamento. O exame laboratorial do soro sanguíneo revelou que vacas com afecçäo apresentaram hipocalcemia, hipofosfatemia e hipermagnesemia quando comparadas com vacas parturientes hígidas