RESUMO
This study aimed to evaluate the relationship between prepartum subclinical hypomagnesemia (pre-SHMg) and the occurrence of dystocia, metritis, clinical mastitis, lameness, and subclinical hypomagnesemia postpartum (post-SHMg) in pasture-based dairy cows. Also, the difference in means of prepartum magnesium (Mg) concentration by postpartum health events was evaluated. A total of 890 dairy cows from 32 commercial farms located in southern Chile were enrolled. Cows were examined twice, once between 30 and 3 days before and once between 3 and 30 days after calving. Blood samples were collected on both assessments, and cows were considered as having SHMg if serum total Mg < 0.65 mmol/L. On the postpartum visit, cows were evaluated for metritis and lameness. Information about clinical mastitis and dystocia was collected from on-farm records. Data were analyzed using multivariable mixed linear models and multivariable mixed logistic regression models. The overall prevalence of pre-SHMg was 9.9%, and its presence was associated with the occurrence of post-SHMg (odd ratio [OR] = 5.7; P < 0.0001) and metritis (OR = 3.1; P = 0.04). However, we did not detect an association between pre-SHMg and dystocia, clinical mastitis, or lameness after calving. Prepartum serum Mg concentrations were lower in cows that developed post-SHMg than those that did not (LSM ± SE = 0.75 ± 0.02 mmol/L vs. 0.83 ± 0.02 mmol/L; P < 0.0001). In conclusion, pre-SHMg was associated with a higher risk of post-SHMg and metritis in grazing dairy cows but not other postpartum health events.
Assuntos
Doenças dos Bovinos , Magnésio , Período Pós-Parto , Animais , Bovinos , Feminino , Chile/epidemiologia , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/sangue , Gravidez , Magnésio/sangue , Magnésio/análise , Distocia/veterinária , Distocia/epidemiologia , Prevalência , Endometrite/veterinária , Endometrite/epidemiologia , Endometrite/sangue , Deficiência de Magnésio/veterinária , Deficiência de Magnésio/epidemiologia , Deficiência de Magnésio/sangue , Mastite Bovina/epidemiologia , Mastite Bovina/sangue , Coxeadura Animal/epidemiologia , Coxeadura Animal/etiologia , Coxeadura Animal/sangue , Indústria de LaticíniosRESUMO
OBJECTIVE: To determine whether plasma protein concentrations were altered in ponies with alimentary laminitis. ANIMALS: 12 adult ponies. PROCEDURE: Acute laminitis was induced in 6 ponies by oral administration of carbohydrate (85% corn starch, 15% wood flour); the other 6 ponies were used as controls. A physical examination was performed and blood samples were collected immediately before and 4, 8, 12, 24, and 28 hours after administration of carbohydrate. Plasma protein concentrations were determined by means of sodium dodecyl sulphate-polyacrylamide gel electrophoresis. RESULTS: 19 plasma proteins ranging from a molecular weight of 24,000 to a molecular weight of 350,000 were identified in all 12 ponies. Plasma concentrations of proteins with molecular weights of 350,000 (fibrinogen), 130,000 (ceruloplasmin), 118,000 (c-reactive protein), 67,000 (alpha1-antitrypsin I), 65,000 (alpha1-antitrypsin II), 50,000 (haptoglobulin), and 45,000 (acid glycoprotein) were significantly increased in ponies with laminitis, compared with concentrations in control ponies. CONCLUSION: Changes in plasma protein concentrations are detectable within 4 hours after the onset of alimentary laminitis in ponies. Clinical Relevance-Measurement of plasma protein concentrations may be useful in monitoring the progression of laminitis in ponies.