Factors associated with lameness prevalence in lactating cows housed in freestall and compost-bedded pack dairy farms in southern Brazil.

The aim of this cross-sectional study was to investigate factors associated with lameness in dairy cows on intensive farms in southern Brazil. Farms (freestall: n = 38; compost-bedded pack: n = 12) having on average 274 (range: 41-901) lactating cows were visited once in 2016 (March to October). Potential risk factors for lameness at the cow, pen and herd levels were investigated through inspection of facilities, examination of cows and the use of data collected on routine management practices. All milking cows on each farm were assessed for gait score and BCS (n = 13,716). Associations between lameness, days in milk (DIM), BCS, parity, and test-day milk yield were investigated in 16 farms with available data (n = 5,301 cows). Mixed-effects linear and logistic regressions were used to model the data. Within-herd lameness prevalence was 41.1% (range: 13.8-64.5, SD = 11.3). First- and second-lactation cows after 120 DIM and older cows after 335 DIM were more likely to be observed lame than early lactation cows. Greater parity and low BCS (≤ 2.75) were associated with increased odds of lameness. Severely lame cows had lower milk yield (on average 1.3 kg/d) than non-lame cows. Freestall dairies using mattresses as stall base had greater within-pen (95% CI: 52-69%) and herd-level (38-57%) lameness prevalence than compost-bedded farms. Higher lameness prevalence was observed on farms having slippery feed bunk alley floors (32-49%) and shortened dry periods (< 60 days: 32-42%). First-lactation pens had lower predicted within-pen lameness prevalence (0-4%) and special-needs pens higher (52-73%) compared with the prevalence observed in compost-bedded fresh-cow pens (19-41%). Freestall pens using sawdust deep-bedding had greater (46-68%) within-pen lameness prevalence, but the prevalence in barns using sand was not different from compost-bedded farms. Given the high lameness prevalence observed in this study, there is a great opportunity for implementation of lameness prevention programs. Providing walking surfaces with high traction that facilitates mobility and using soft and deep-bedded material, such as compost and sand (and avoiding the use of mattresses) may reduce lameness prevalence in the types of dairy farms visited in this study.

Readily Available Water Access is Associated with Greater Milk Production in Grazing Dairy Herds.

In this cross-sectional study, we measured the association between water provision and milk production on intensively managed small-scale grazing dairy herds. Farms (n = 53) were categorized according to water provision as follows: (1) Restricted-cows did not have access to a water trough while on pasture; and (2) Unrestricted-cows had free access to a water trough while on pasture. Herd main breed and feeding practices were included in a model to assess the effect of water provision category on farm average milk yield/cow/d. The effect of pasture condition and environmental variables on milk production were also assessed, however were not retained on the final model. Herds provided with unrestricted access to drinking water produced on average 1.7 L more milk per cow/d (p = 0.03) than herds with restricted access to drinking water. Predominantly Holstein herds produced 2.8 L more milk per cow/d (p < 0.01) than non-Holstein herds. Each extra kg of concentrate offered per day increased milk yield by 1.1 L/cow/d (p < 0.01). In conclusion, providing free access to drinking water while grazing was associated with greater milk production.

Lameness on Brazilian pasture based dairies - Part 2: Conversations with farmers and dairy consultants.

A farmer or a dairy consultant's ability to identify and properly treat lame dairy cows is key to managing lameness on farms. However, this ability is dependent on their knowledge and perceptions regarding lameness. To date these topics are poorly understood in all dairy systems. To our knowledge, this is the first study that uses a qualitative approach to describe the perception of lameness in Brazilian pasture-based dairy farms. The aim of this study was firstly, to contextualize farmers and dairy consultants' culture and knowledge on the topic of lameness and, secondly, to understand how these factors may influence lameness management on the farms. In-depth face-to-face semi-structured interviews were done with participating farm owners (n = 21) and dairy consultants (n = 13). Thematic analyses of the interview content provided evidence that the dairy community's overarching culture around lameness acts as a barrier preventing positive actions targeting lameness control and prevention. The emerging themes identified indicate that lameness is a vague, ill-defined concept among both farmers and dairy consultants working in this region. There was a shared belief that pasture-based systems have a low risk for lameness. Furthermore, the prevailing culture for tackling lameness was reactive, particularly in the case of lame cows affected by physical trauma or environmental factors. Treatment was frequently delayed and the misuse of antibiotics was evident. Described community culture was rationalised via the cognitive dissonance and health belief models. We suggest that increased dialogue, including educational efforts within the community, may lead to increased sensitivity of risk perception of lameness within the community and in turn trigger appropriate diagnosis and treatment of lame cows.

Lameness on Brazilian pasture based dairies-part 1: Farmers' awareness and actions.

This cross-sectional survey aimed to verify farmers' awareness and knowledge about lameness in grazing dairy cows and to analyze their perspectives and actions intended to control this issue. Farms (n = 44, mean herd size: 42, SD = 11.2) located in southern Brazil were visited twice in 2015. On the first visit the farmers were requested to answer a questionnaire on lameness knowledge (relative importance as a health issue, aetiology, impacts on culling) and management (prevention, treatment and veterinary assistance) on their farms. Farmers were asked to estimate the number of lame cows present on their farms at each visit. All lactating cows on each farm were locomotion scored by a veterinarian to estimate lameness prevalence on both visits. Intra-class correlation coefficients (ICC) were used to test similarity between the veterinarian and farmer estimated lameness prevalence. Mixed-effects linear models were fitted to investigate the associations between veterinarian lameness estimated prevalence and farmers' answers regarding lameness importance and impacts on culling cows at the farms. On average, farmers underestimated lameness prevalence during both visits; however, when assessing only severe lameness, veterinarian and farmer prevalence lameness ratings were very similar on the second visit (ICC 0.8, 95% CI: 0.6-0.9, n = 43, P < 0.01). The veterinarian's estimated lameness prevalence was about 10% higher on herds where farmers identified lameness as a primary health issue (40.24%) or as a reason for culling (41.7%) versus farms where the farmer did not recognize lameness as a health concern or reason for culling. Farmers' most reported causes of lameness on their farms were categorized as hoof trauma, inadequate feeding practices associated with acidosis-laminitis, high moisture on walking surfaces, and individual features of cows. Farmers mentioned frequently that they made use of antibiotics and topical hoof products to treat lame cows; they also reported low use of anti-inflammatories/analgesics and hoof trimming as treatment remedies and no one mentioned adoption of regular preventative measures for lameness. Farmers reported having no training on lameness management, and cited an overall lack of veterinary support to control lameness on their farms. The farmers seemed unaware of the extent of lameness on their farms. Interventions aimed at reducing lameness in small scale herds in this region of Brazil should include a preventative veterinary assistance approach focused, initially, to increase farmers' knowledge and awareness on lameness.

Cow- and herd-level factors associated with lameness in small-scale grazing dairy herds in Brazil.

This cross-sectional study aimed to assess lameness occurrence and to identify the associated risk factors in small-scale grazing dairy herds. Forty four farms (mean lactating herd size was 42 cows, SD = 11.2, range: 28-74) located in the south of Brazil were visited twice, approximately 4 months apart, in 2015. Locomotion was scored in 1633 and 1836 cows at the first and second visit, respectively. Potential risk factors for lameness were assessed through inspection of cows and facilities, and a questionnaire for farmers about herd management practices. Multilevel logistic regressions, using herd as random effect, were fitted to investigate the cow-level risk factors for accumulated incident (not lame at the first visit but lame on the second), chronic (lame on both visits) and recovered (lame at the first visit but sound on the second) cases of lameness. A multilevel linear regression, using municipality as a random effect, was fitted for herd-level analysis. Cumulative lameness incidence between two visits (1110 cows in 41 herds) was 29.6% (range: 0-80); lameness prevalence (n = 44 herds) was 31% (10-70) and 35% (5-76) at the first and second visits, respectively. The odds of incident cases were greater in Holstein cows [odds ratio (OR) = 4.0, 95% confidence interval 2.1-7.6] compared with Jerseys, in cows in parities 2-3 (OR 2.5, 1.4-4.4) or >3 (OR 6.6, 3.3-13.1) relative to parity 1, in cows having a low body condition score (BCS) of 2-2.75 or 3 on the first visit (OR 2, 1.1-3.7), and in cows with observed hoof abnormalities (OR 2.5, 1.3-4.7). Similar associations were found for chronic cases, with Holstein and crossbred cows having greater odds of lameness, compared to Jersey, and chronic cases being more likely in cows with increasing parity, with BCS at first visit of 2-2.75, and with presence of hoof abnormalities. Jersey or crossbred cows (OR 3.2, 1.3-8.1) and cows in parity 1-2 (OR 3.6, 1.6-8.4) had higher probability of recovery from lameness. Having a herd composed of Holstein cows was associated with 13.5% (CI 4.3-22.8) greater incidence of lameness (n = 35). For every 1 km/h increase in the average speed of movement of the herd to or from milking, lameness incidence increased by 5% (CI 0.1-10). Given that the occurrence of lameness was high there is great opportunity to reduce lameness in this population. This study highlights some management and prevention practices that may reduce lameness in these grazing herds.

Prevalence and risk factors for transition period diseases in grazing dairy cows in Brazil.

The aim of this cross-sectional study was to describe the incidence risk of dystocia, retained placenta (RP), pathological recumbence (down cow), the prevalence of metritis and subclinical ketosis (SCK), and the risk factors for SCK, metritis, and RP in grazing dairy herds in Southern Brazil. Fifty-three herds were visited 2-6 times from February to October of 2015. Body condition score (BCS), breed, days in milk (DIM), parity and disease status were recorded for each cow that was between 3 and 21 DIM at the time of the visits. Management practices were determined using a survey and environmental inspection was performed on each visit. SCK was identified if blood ß-hydroxybutyrate was ≥1.2mmol/L and metritis by inspection of the vaginal discharge; cows were assessed once between 3 and 21 DIM. Multilevel logistic regression models, controlling for farm as a random effect, were built to identify risk factors for each disease and to assess the proportion of variance at the herd and cow levels. Models were constructed based on causal diagrams and variable screening. Overall, prevalence of SCK and metritis and incidence risk of RP were 21, 11 and 14%, respectively. Reported incidence risk of down cow was 6% and displaced abomasum was 1%. The odds (OR; 95% CI) of a cow having SCK were higher in herds with high (>10%) incidence of down cows (2.7; 1.4-5.0), limited access to water (1.9; 1.1-3.1), Jersey cows (OR: 2.2; 1.2-4.1) and in cows that were in third or greater lactation (2.9; 1.4-5.5). BCS 3.0-3.5 decreased the odds (0.4; 0.2-0.8) of metritis, while DIM, RP and being in a herd with a dirty holding area increased the odds of metritis by 1.1 (1.1-1.2), 19.5 (9.9-38.3) and 2.1 (1.0-4.2) fold, respectively. Parity >2 and dystocia increased the odds of RP by 2.4 (1.2-4.6) and 3.0 (1.6-5.4) fold, respectively. Jersey breed, use of a maternity pen and keeping the newborn calf with the cow >12h decreased the odds of having RP by 0.1 (0.0-0.4), 0.5 (0.3-1.0) and 0.4 (0.2-0.8) times, respectively. The variation in disease occurrence was largely dependent on cow-level factors. However, herd level risk factors also influenced disease occurrence and should be considered in order to design better preventive transition period diseases protocols.