Evaluation of risk factors of omphalitis in newborn beef calves with indoor housing.

BACKGROUND: Omphalitis is the third most common cause for diseases and infections in newborn calves. Its risk factors are well described in dairy production, but data in beef production is limited. OBJECTIVE: To identify and quantify the risk factors of omphalitis in cow-calf operations with seasonal indoor calving period. ANIMALS: Nine hundred sixty-four calves included from 22 cow-calf operations in central France were included. METHODS: A prospective cohort study involved data collection during two visits for each calf. Simple and multivariable logistic regression analyses evaluated the association between omphalitis and the variables. RESULTS: Among 964 included calves, 311 (32.3%) calves had an omphalitis. Accounting for farms' random effect, risk factors for omphalitis highlighted by the univariable analysis were: absence of navel disinfection (odds ratio (OR) = 2.3, [1.45-3.04]), wetness of bedding calving area (OR = 1.8-2.1, [0.78-2.83]-[0.63-3.57]), cleanliness of calves' pen (OR =1.6-2.8, [1.22-2.27]-[2.02-3.84]), wetness of calves' pen bedding (OR = 1.7-3.2, [1.12-2.06]-[3.08-3.84]), calf weight at birth >50 kg (OR = 2.0-5.0, [1.02-2.38]-[1.51-11.1]), umbilical cord length <3 cm (OR = 2.2-2.3, [1.53-3.11]-[1.24-4.38]), and sex (male vs female) (OR = 2.6, [2.08-3.69]). The multivariable analysis, accounting for farms' random effect, showed that the absence of navel disinfection (OR= 2.2, [1.44-3.09]), wetness of bedding calving area (OR = 1.9-2.4, [0.55-2.83]-[0.59-3.28]), calf weight at birth >50 kg (OR = 1.9-2.6, [1.03-2.56]-[1.43-12.5]) and sex (male vs female) (OR =2.4, [2.09-3.49]) were risk factors for omphalitis. CONCLUSIONS AND CLINICAL IMPORTANCE: These observations may help identify animals at early risk (>50 kg, male, short umbilical cord) and pay particular attention to the wetness of bedding and cleanliness of housing. This study highlights the importance of calving-pen bedding, calf characteristics and navel disinfection.

Failure of Passive Immunity Transfer Is Not a Risk Factor for Omphalitis in Beef Calves.

Omphalitis is the third most frequent disease in newborn calves after neonatal diarrhea and bovine respiratory disease (BRD), but limited data on the prevalence and risk factors are available in the literature. Failure of passive immunity transfer (FPIT) is recognized as a major risk factor for diseases and mortality in calves. However, the association between omphalitis and FPIT remains poorly described. To assess this association, 964 suckler beef calves from 22 farms were included in a longitudinal cohort study for 5 months. Each calf was examined twice (mean ages: 4.4 and 11.1 days old) to diagnose omphalitis through clinical examination and ultrasonographic evaluation (USE) if necessary. Measurements of the total solids percentage (TS-%Brix) and total protein (TP) were performed on the serum during the first visit to evaluate the calves' passive immunity status. FPIT (fair and poor) was defined as serum %Brix < 8.1 or TP < 5.1 g/dL; among calves with omphalitis, 14% had FPIT and among calves without omphalitis 12% had FPIT. The omphalitis prevalence was 32.3% in calves without any other disease (overall prevalence of 30.9%). No statistical association between the prevalence of omphalitis and FPIT was observed. Further research is needed to identify the risk factors and promote the prevention measures for omphalitis in cow-calf systems, such as calving difficulty, hygiene of housing, and navel disinfection.

Cost of lameness in dairy herds: An integrated bioeconomic modeling approach.

Foot disorders are costly health disorders in dairy farms, and their prevalence is related to several factors such as breed, nutrition, and farmer's management strategy. Very few modeling approaches have considered the dynamics of foot disorders and their interaction with farm management strategies within a holistic farm simulation model. The aim of this study was to estimate the cost of foot disorders in dairy herds by simulating strategies for managing lameness. A dynamic and stochastic simulation model (DairyHealthSim) was used to simulate the herd dynamics, reproduction management, and health events. A specific module was built for lameness and related herd-level management strategies. Foot disorder occurrences were simulated with a base risk for each etiology [digital dermatitis (DD), interdigital dermatitis, interdigital phlegmon, sole ulcer (SU), white line disease (WLD)]. Two state machines were implemented in the model: the first was related to the disease-induced lameness score (from 1 to 5), and the second concerned DD-state transitions. A total of 880 simulations were run to represent the combination of the following 5 scenarios: (1) housing (concrete vs. textured), (2) hygiene (2 different scraping frequencies), (3) the existence of preventive trimming, (4) different thresholds of DD prevalence detected and from which a collective footbath is applied to treat DD, and (5) farmer's ability to detect lameness (detection rate). Housing, hygiene, and trimming scenarios were associated with risk factors applied for each foot disorder etiologies. The footbath and lameness detection scenarios both determined the treatment setup and the policy of herd observance. The economic evaluation outcome was the gross margin per year. A linear regression model was run to estimate the cost per lame cow (lameness score ≥3), per case of DD and per week of a cow's medium lameness duration. The bioeconomic model reproduced a lameness prevalence varying from 26 to 98% depending on the management scenario, demonstrating a high capacity of the model to represent the diversity of the field situations. Digital dermatitis represented half of the total lameness cases, followed by interdigital dermatitis (28%), SU (19%), WLD (13%), and interdigital phlegmon (4%). The housing scenarios dramatically influenced the prevalence of SU and WLD, whereas scraping frequency and threshold for footbath application mainly determined the presence of DD. Interestingly, the results showed that preventive trimming allowed a better reduction in lameness prevalence than spending time on early detection. Scraping frequency was highly associated with DD occurrence, especially with a textured floor. The regression showed that costs were homogeneous (i.e., did not change with lameness prevalence; marginal cost equals average cost). A lame cow and a DD-affected cow cost €307.50 ± 8.40 (SD) and €391.80 ± 10.0 per year on average, respectively. The results also showed a cost of €12.10 ± 0.36 per week-cow lameness. The present estimation is the first to account for interactions between etiologies and for the complex DD dynamics with all the M-stage transitions, bringing a high level of accuracy to the results.

The Marginal Abatement Cost of Antimicrobials for Dairy Cow Mastitis: A Bioeconomic Optimization Perspective.

Maintaining udder health is the primary indication for antimicrobial use (AMU) in dairy production, and modulating this application is a key factor in decreasing AMU. Defining the optimal AMU and the associated practical rules is challenging since AMU interacts with many parameters. To define the trade-offs between decreased AMU, labor and economic performance, the bioeconomic stochastic simulation model DairyHealthSim (DHS)© was applied to dairy cow mastitis management and coupled to a mean variance optimization model and marginal abatement cost curve (MACC) analysis. The scenarios included three antimicrobial (AM) treatment strategies at dry-off, five types of general barn hygiene practices, five milking practices focused on parlor hygiene levels and three milk withdrawal strategies. The first part of economic results showed similar economic performances for the blanked dry-off strategy and selective strategy but demonstrated the trade-off between AMU reduction and farmers' workload. The second part of the results demonstrated the optimal value of the animal level of exposure to AM (ALEA). The MACC analysis showed that reducing ALEA below 1.5 was associated with a EUR 10,000 loss per unit of ALEA on average for the farmer. The results call for more integrative farm decision processes and bioeconomic reasoning to prompt efficient public interventions.

Ultrasonography of the cranial part of the thorax is a quick and sensitive technique to detect lung consolidation in veal calves.

BACKGROUND: In the veal calf industry, bovine respiratory disease is the main cause of morbidity and mortality. Lung ultrasonography (LUS) is an accurate technique to diagnose bronchopneumonia in calves. Due to the economic constraints faced by the industry, a screening technique able to rapidly examine large numbers of calves is required. OBJECTIVE: To determine if lung ultrasonography focusing on the cranial part of the thorax (1st to 2nd intercostal space (ICS) on the right and 2nd to 3rd on the left) and/or on the middle part of the thorax (3rd to 5th ICS on the right and 4th to 5th on the left) (alternative techniques) are rapid screening techniques as sensitive as LUS of the entire lung (reference technique) to identify calves with lung consolidation lesions. METHODS: Data on 300 veal calves aged 33.1 ± 8.0 days and weighing on average 67.5 ± 4.0 kg at LUS from two farms were analysed. Systematic LUS of the entire lung was performed on all calves and a lung consolidation score was given to different parts of the thorax. Agreements between the alternative and the reference techniques were measured by Cohen's κ, McNemar's test and weighted κ. RESULTS: Agreement between LUS focusing on the cranial + middle part or on the cranial part only of the thorax and the reference technique were almost perfect with a cutoff of 1 cm. The relative sensitivity of these two alternative techniques was high (> 93%). CONCLUSION: Lung ultrasonography of the cranial + middle part or on the cranial part only of the thorax are quick and sensitive techniques to identify veal calves with lung consolidation lesions shortly after arrival at the facility.

Congenital lacrimal fistula in two prim'Holstein calves.

Two 4- and 8-month-old prim'Holstein calves were presented for chronic epiphora. Examination of the affected eyes revealed an abnormal duct opening inferonasal to the medial canthus. A diagnosis of congenital lacrimal fistula was made based on conventional and computed tomographic-dacryocystography findings. These revealed an ectopic channel connecting the nasolacrimal duct to the skin opening near the medial canthus. Both of the calves were surgically treated with resection and closure of the ectopic duct and placement of a nasolacrimal stent.

Urinalysis and determination of the urine protein-to-creatinine ratio reference interval in healthy cows.

BACKGROUND: There are no reference intervals for urinalysis in cattle. HYPOTHESIS/OBJECTIVES: Characterize the urine of healthy cows, establish urine protein-to-creatinine ratio (UPC) reference intervals, and test possible differences among dairy and beef cattle, age groups, or stage of lactation. ANIMALS: Seventy-seven dairy and 74 beef 2.5 to 17 year-old cows of different breeds housed mainly in free stall. METHODS: In this prospective study, urine specimens were collected by catheterization. Complete urinalysis was performed within 1 hour including specific gravity, dipstick evaluation, visual urine pH evaluation with 0.3 pH unit graded strips, and microscopic evaluation of the sediment. Urinary protein and creatinine concentrations and protein electrophoresis were determined on frozen aliquots. RESULTS: Overall reference intervals were 1.020 to 1.045 for USG, 7.0 to 8.7 for pH, and 0.04 to 0.25 for UPC; because of differences in creatinine concentration, UPC was lower in beef (0.04-0.14) than in dairy (0.05-0.25) cows and in the latter in dry than lactating cows. With dipstick evaluation, most analytes were absent except for blood, ketone, and protein in 24.7, 16.0, and 64.7% of cases, respectively. Microscopic evaluation revealed less than 3 red blood cells, leukocytes, and epithelial cells in 84, 99.3, and 100% cows, respectively. No band was observed at electrophoresis, except in 1 case at MW ~66 000. CONCLUSIONS AND CLINICAL IMPORTANCE: Creatininuria is higher in beef than dairy cows and proteinuria is likely more efficiently characterized by protein concentration than by UPC.

Hematology reference intervals for adult cows in France using the Sysmex XT-2000iV analyzer.

In order to develop bovine hematology reference intervals (RIs) in accordance with new international recommendations, we analyzed 156 blood specimens of healthy adult dairy and beef cows from 32 farms with a Sysmex XT-2000iV analyzer, and by manual scoring of platelet clumps and white blood cell (WBC) differential. We established RIs by the nonparametric method, and examined effects of age, production type (beef vs. dairy), and stage of lactation. RIs could not be determined for platelet count and indices because clumps were observed in 80% of specimens. Optical and impedance red blood cell (RBC) counts were similar, although statistically different. RIs for analyzer and manual WBC differentials were not different except for lymphocyte concentration, the subpopulations of which were counted manually. Hematocrit was higher in beef than dairy cattle, and hemoglobin was lower in early lactation. Increases in RBC count, mean corpuscular volume, mean corpuscular hemoglobin, and RBC distribution width were noted with increasing age, along with decreases in WBC count, neutrophils, and lymphocytes. Most RIs in our study, with the exception of neutrophils, were similar to those previously reported using a flow cytometry analyzer.

Herd-level and territorial-level factors influencing average herd somatic cell count in France in 2005 and 2006.

Mastitis is a multifactorial disease and the most costly dairy production issue. In spite of extensive literature on udder-health risk factors, effects of metabolic diseases, farmers' competencies and livestock farming system on somatic cells count (SCC) are sparsely described. Herd-level or territorial-level factors affecting monthly composite milk weighted mean cow SCC (CMSCC) were analysed with a linear mixed effect model. The average CMSCC was 266,000 cells/ml. Half of the herds had CMSCC >300,000 cells/ml for 2-6 months a year, and 15% of herds for more than 7 months a year. CMSCC was positively associated with the number of cows, having a beef or fattening herd in addition to the dairy herd, the monthly average days in milk, the yearly age at first calving, the yearly proportion of purchased cows and the yearly culling rate. Moreover, a positive association is reported between CMSCC and the monthly proportion of cows probably with subacute ruminal acidosis (fat percentage minus protein percentage ≤0·30%, for Holstein) and negative energy balance (protein to fat ratio ≤0·66, for Holstein), the yearly average calving interval, having at least one dead cow and the mean monthly temperature. The association was negative for a predominant breed other than Holstein, the monthly milk production, the yearly dry-off period length, the monthly first calving cow proportion, having an autumn calving peak, being a Good Breeding Practices member, the monthly number of days with rain, the altitude and the territorial cattle density. CMSCC varied widely among the 11 dairy production areas. In conclusion, this study showed the average CMSCC for the French dairy cows, compared with international results. Moreover, it quantified the contribution of several factors to CMSCC, in particular metabolic diseases and the farm environment.