Cattle lameness is an important welfare concern that also has an economic impact on the dairy industry. It can be a significant problem among pasture-based herds. Our objectives were to identify cow-and herdlevel factors related to lameness and hoof lesions in dairy cows grazing year-round in Minas Gerais, Brazil. We performed a cross-sectional study in 48 pasturebased dairy herds, visiting each farm in a single visit. We evaluated 2,262 cows for mobility score (0-3) and 392 cows for hoof lesions. We used a questionnaire and checklist to capture herd management data. All information obtained was used to build multivariable models. The factors associated with lameness were low body condition score, longer time spent in the corral, being kept in paddocks during the drought period, and poor hygiene. For hoof lesions, track features were the most significant factor in determining the likelihood of heel horn erosion, white line fissure, and sole hemorrhage-by more than 3 times. Different factors related to unhygienic conditions such as leg cleanliness, frequency of cleaning, and longer time spent in the corral were associated with infectious hoof lesions. Poor human-animal relationship was related to sole hemorrhage, but patient handling of cows on the track was a protective factor against interdigital hyperplasia. The results of this study suggest that improving hygiene conditions, track features, and cow handling can improve dairy cattle mobility scores in pasture-based farms under tropical conditions. These findings also represent a first step toward planning actions aimed at decreasing lameness and hoof lesions in the studied region.

We used 31 crossbreed dairy cows to compare the energetic profile in summer and winter. Blood samples were taken weekly prepartum, at calving and on days 2, 5, 10, 15, 21 and 30 postpartum. All metabolic indicators analyzed were influenced by the physiological status. The glucose concentrations were higher during winter while the triglyceride concentrations and lactate dehydrogenase (LDH) were higher in the summer. The season influenced the concentrations of cholesterol, AST and GGT, showing a different pattern between summer and winter. Non-esterified fatty acids (NEFA) and beta-hidroxibutirate (BHB) were not influenced by the season. Cows that calved during winter had a greater body condition score (BCS) and lost more BCS until calving. During summer, 32.26% of the animals and 29.03% during winter had NEFA concentrations above the optimum level and 22.58% of the animals in summer and 19.35% in the winter had subclinical ketosis at some point during the transition period, making then more susceptible to diseases.

No abstract

Avaliaram-se comparativamente os efeitos de duas soluções contendo concentrações iguais de cloreto de sódio, cloreto de potássio e magnésio, porém, uma delas contendo cloreto de cálcio e dextrose (SEDex), e a outra propionato de cálcio (SEProp), sobre parâmetros clínicos, proteínas plasmáticas totais, densidade urinária, pH urinário e glicose na urina de equinos (dois machos castrados e duas fêmeas) submetidos à um delineamento crossover 4x2. Os animais foram desidratados experimentalmente com duas aplicações de furosemida na dose de 1mg kg-1, além de jejum hídrico-alimentar de 24 horas, anteriormente aos tratamentos com as soluções, as quais foram administradas por via enteral em fluxo contínuo através de sonda nasogástrica de pequeno diâmetro numa taxa de infusão de 15 mL kg-1 h-1. A desidratação induzida provocou desidratação discreta. As soluções ocasionaram expansão da volemia, diminuiu a densidade urinária e não alterou os parâmetros clínicos dos padrões de referência. Além disso, a SEProp ocasionou glicosúria.

Several direct or indirect methods can be used to assess immunoglobulin G (IgG) concentrations in calves, which evaluates the transfer of passive immunity (TPI). Radial immunodiffusion (RID) is the gold standard method to measure serum IgG in bovines. Previous studies have shown that colostrum provides several molecules in addition to immunoglobulins, which play an important role in the passive immunity of the calf. However, no studies have yet determined the level of interference of these components in the immunity, health and survival of calves. In this sense, the objective of this study is to review the methods of evaluation available for the laboratory and field diagnosis of TPI in calves and discuss the main aspects of each technique. Several methods available for TPI evaluation in calves may provide insights into the various components of colostrum involved in passive immunity.