Get access to all handy features included in the IVIS website
- Get unlimited access to books, proceedings and journals.
- Get access to a global catalogue of meetings, on-site and online courses, webinars and educational videos.
- Bookmark your favorite articles in My Library for future reading.
- Save future meetings and courses in My Calendar and My e-Learning.
- Ask authors questions and read what others have to say.
The marginal cost of lameness in dairy herds: an integrated bioeconomic modelling approach
Robcis, R., Raboisson, D., N'Diaye...
Get access to all handy features included in the IVIS website
- Get unlimited access to books, proceedings and journals.
- Get access to a global catalogue of meetings, on-site and online courses, webinars and educational videos.
- Bookmark your favorite articles in My Library for future reading.
- Save future meetings and courses in My Calendar and My e-Learning.
- Ask authors questions and read what others have to say.
Read
Objectives
Lameness is a major concern in dairy cattle and foot disorders are responsible for 92% of total lameness cases. Different strategies are available for the farmers to manage lameness: short-term actions (curative trimming, footblocks, antibiotics, footbaths) and overall medium and long-term actions (hygiene, detection, preventive trimming). The objective of this study is to estimate the marginal cost of lameness and foot disorders, to define optimal bioeconomic strategy for managing lameness in dairy herds.
Materials and methods
A dynamic and stochastic simulation model (DairyHealthSim©) was used to simulate as precisely as possible the herd dynamics, reproduction management, the production and health events. The model offers a holistic representation of a dairy farm and simulates the interaction between production functions, diseases or damage function and veterinary or damage control functions according to farmer’s practices. This model was previously used for studies on mastitis, reproduction and culling. A specific development (DHS-Lame) was done for lame and its different herd-level management strategies. Lame occurrences are simulated with a base risk for each aetiology of lameness (digital dermatitis – DD, interdigital dermatitis – ID, interdigital phlegmon – IP, sole ulcer – SU, white line disease – WLD), associated to a relative risk according to a farmer’s practices. Lameness is simulated as lame state machine (lame score – LS – from 1 to 5) associated to a DD state machine (M1 to M4.1). The impacts are computed on milk production and heat expression. Once detected, lame cows are treated, and a recovery rate is applied depending on aetiology and treatment. A total of 880 scenarios were run including (i) housing (concrete vs. textured) (ii) hygiene (2 different scrapping frequencies), (iii) the existence of any preventive trimming or not, (iv) different thresholds of detected DD prevalence from which a collective footbath is applied to treat DD and (v) detection rate scenarios to represent farmer ability to detect lame. The economic evaluation is performed to calculate farmers risk adjusted income for each scenario and the marginal cost is calculated as an income loss per additional case for each lame aetiology and for additional lame cow (LS ≥3) Calibration was done thanks to peer-review literature review, grey literature or authors’ experience if not available.
Results
The simulation results show a lameness prevalence varying from 27% to 83% depending the scenarios, showing a high capacity of the model to represent field. Digital dermatitis represented half of total lameness cases, followed by ID, SU, WLD and IP. Validity of the model was overall considered as very good.
Housing surface scenarios dramatically influence the prevalence of SU and WLD, while scrapping frequency and footbath threshold for application mainly determine the presence of DD. Results interestingly shows that preventive trimming allows a better reduction in lame prevalence than spending time for early-detection. Scrapping frequency was highly associated with DD occurrence, especially with a textured floor. The observed prevalence of DD reaches a plateau when the threshold of footbath application is over 30% (R2 = 0.94). Lameness prevalence variations also show a sensitive negative impact on total milk yield, with a logarithmic trend (R² = 0.8).
Economic results show that the milk losses represent the first component of lame costs, in agreement with literature. The marginal cost curve for the prevalence of lameness shows a downward logarithmic trend (lower marginal cost for higher prevalence): the marginal cost for lameness ranges from 193€ to 5€ while prevalence ranges from 25% to 60%, all aetiologies included. For DD, the marginal cost ranges from 248€ to 12€ with a prevalence range from 10 to 35%. For WLD and SU, the marginal cost ranges is from 281€ to 87€ and from 414€ to 22€ respectively for prevalence ranging from 2.5% to 5.5% and from 4% to 25% respectively.
Conclusions
The models allow to mimic with high precision the lame dynamics in the herd. The marginal cost of lame describes a downward logarithmic trend, meaning lower cost of one extra lame case for higher prevalence. The present tool can also be used as support for decision making and to identify the best strategy depending on the farm contexts.
Keywords: Lameness, economics, cow, management.
Get access to all handy features included in the IVIS website
- Get unlimited access to books, proceedings and journals.
- Get access to a global catalogue of meetings, on-site and online courses, webinars and educational videos.
- Bookmark your favorite articles in My Library for future reading.
- Save future meetings and courses in My Calendar and My e-Learning.
- Ask authors questions and read what others have to say.
Comments (0)
Ask the author
0 comments