Use of Infrared Thermography for Detection of Mastitis in Bovines: A Non-Invasive Technique
Amit Kumar*, Naveen Kumar, Anamika, and Dinesh
Department of Veterinary Surgery and Radiology
Department of Veterinary Public Health and Epidemiology
Department of Animal Genetics and Breeding
Lala Lajpat Rai University of Veterinary and Animal Science, Hisar (Haryana), India-125004
Corresponding author: Amit Kumar, amitdhartterwal@gmail.com
ABSTRACT
Bovine mastitis is a condition characterized by persistent inflammation of the udder tissue, which can be caused by physical trauma or microbial infections. It is a serious and potentially life-threatening infection of the mammary glands, particularly prevalent in dairy cattle worldwide. Mastitis is a major concern for the dairy industry, as it leads to significant economic losses. Various biomarkers and on-farm tests are available to detect subclinical mastitis, which is crucial for timely and successful treatment in order to minimize both financial and biological damages associated with the condition. One promising method for early detection of subclinical mastitis is infrared thermography (IRT). This rapid and non-invasive technique enables the identification of thermal changes in the udder skin that are indicative of subclinical mastitis. By facilitating early detection, IRT can assist veterinarians and herdsmen in promptly identifying subclinical mastitis cases and initiating immediate and effective treatment. This, in turn, helps in reducing the negative impacts of mastitis on the affected animals and the overall herd health.
Keywords: Infrared thermography, mastitis, bovines
INTRODUCTION
Mastitis refers to the inflammation of the mammary gland, leading to physiological, biochemical, and pathological changes in the udder tissue, which in turn affects the quality of milk produced (Radostits et al., 2007). Subclinical mastitis is defined as an infection without apparent signs of gross udder inflammation, yet it causes alterations in milk composition that remain unnoticed by visual examination. Mastitis commonly arises from the complex interplay between microbial infections, host factors, environmental conditions, and management practices, making it a multifactorial disease.
One prominent sign of mastitis is the inflammation of the udder, characterized by a reddened and hardened mass. The affected mammary gland becomes hot to the touch, causing pain and discomfort to the animal. Animals may resist having their udder touched and may even kick to prevent milking. If milked, the milk obtained is typically contaminated with blood clots, foul-smelling brown discharge, and clumps of milk. The severity of inflammation can range from subclinical, clinical, to chronic, depending on factors such as the nature of the causative agent, age, breed, immunological health, and lactation stage of the animal (Viguier et al., 2009). Mastitis poses a significant challenge to the dairy industry worldwide, as it is the most prevalent and costly disease among dairy animals, resulting in substantial economic losses for dairy farmers.
Farmers are particularly concerned about subclinical mastitis (SCM) in dairy cows, as its incidence is higher compared to the clinical form. In most animal farms, the monitoring of subclinical and clinical mastitis is typically carried out through indirect tests such as pH measurement, electrical conductivity, somatic cell count (SCC), California mastitis test (CMT), culture tests, and biomarker tests. Early detection of mastitis using non-invasive technology is crucial to minimize economic losses for both the dairy industry and farmers. Skin surface temperature serves as a critical indicator of the organism’s bio-physiological health status. In response to infection-induced inflammatory reactions, local blood circulation, metabolism, and skin surface temperature increase. Monitoring the heat emitted from the udder can aid in the early detection of mastitis. Infrared thermography (IRT), which utilizes a highly sensitive thermal camera, can effectively monitor subtle changes in skin surface temperature. The integration of IRT with mobile-based applications can play a significant role in various aspects of dairy farm management.
Mastitis stands as one of the most prevalent and economically burdensome infectious diseases in dairy cattle worldwide. Delayed diagnosis of subclinical mastitis, along with the lack of suitable and precise techniques and insufficient awareness, contributes to the higher prevalence and incidence of clinical mastitis. Consequently, affected animals experience significant reductions in milk production, with estimated losses ranging from 100 to 500 kg per cow per lactation (Srivastava, 2015). In India, the prevalence of subclinical mastitis is higher (buffaloes: 5-20%; cows: 10-50%) compared to clinical mastitis (1-10%) (Joshi and Gokhale, 2016). A study conducted by Bangar et al. (2015) reported prevalence rates of subclinical mastitis ranging from 20.73 to 78.55% in crossbred cows and from 15.78 to 81.60% in local cows in India. As a result of both subclinical and clinical mastitis, Indian farmers face substantial economic losses.
Diagnostic techniques for mastitis: Various methods are available for the detection of mastitis in dairy animals, including visual examination of the udder, assessment of milk color, and evaluation of milk parameters such as pH, electrical conductivity (EC), California mastitis test (CMT), and somatic cell counts (SCC). Recent studies have indicated that EC, CMT, and SCC are better predictors of both subclinical and clinical mastitis. In subclinical mastitis, the increased milk pH may be associated with higher concentrations of alkaline blood constituents like sodium and bicarbonate ions, which are caused by inflammation of the mammary gland and increased permeability of blood capillaries (Guha et al., 2010). Additionally, elevated milk pH during mastitis may be due to reduced acidity associated with decreased lactose content in mastitic milk (Ahmad et al., 2005).
The normal range of electrical conductivity in milk is typically between 4.0 and 5.0 mS/cm, while infected quarters exhibit higher values ranging from 5.63 to 6.71 mS/cm at 25°C (Syridion et al., 2013). Mastitis milk generally has higher electrical conductivity compared to normal milk, likely due to changes in ion concentrations resulting from inflammatory changes in mammary tissue, as well as increased milk sodium and chloride concentrations (Kamal et al., 2014). CMT is considered the gold standard cow-side test for identifying subclinical mastitis and is positively associated with SCC (Radostits et al., 2007). The SCC of milk from healthy udders typically ranges from 50,000 to 100,000 cells/ml, with a threshold value of less than 200,000 cells/ml (Sinha et al., 2014). The increase in SCC during infection may be attributed to bacterial invasion of the mammary glands, which attracts circulating polymorphonuclear neutrophils (PMNs) and leads to an increase in dead and sloughed-off mammary epithelial cells, thereby elevating the somatic cell counts in milk (Radostits et al., 2007).
It’s important to note that SCC, EC, and pH values can be influenced not only by mastitis but also by non-mastitic factors such as species, breed, parity, and stage of lactation, which may contribute to variations in critical threshold values among different studies. Moreover, the threshold values of milk depend on the specific fraction of milk considered for the identification of mastitis (Syridion et al., 2013). Therefore, there is a need for early identification of mastitis using non-invasive technology. Early detection enables the implementation of effective management interventions, leading to increased milk production, improved milk quality, reduced milk waste due to treatment, decreased veterinary expenses, and subsequent economic losses (Willits, 2005).
Infrared Thermography technique:
Infrared (IR) radiation, which falls within the wavelength range of 700 nm (frequency 430 THz) to 1 mm (300 GHz), can be used in thermography. According to the Stefan-Boltzmann law, all objects emit infrared radiation in proportion to their temperature through conduction, convection, and radiation (Poikalainen et al., 2012). Infrared thermography (IRT) enables the detection of changes in body surface temperature caused by variations in blood flow. Skin temperature is a reliable indicator of organ health since animals dissipate excess heat through their skin, and heat exchange occurs between the core body and skin via blood circulation (Collier, 2006). IRT has advanced significantly in technology and can measure local and temporal changes in body surface temperature. It is a non-invasive and radiation-free tool that provides pictorial images of animals (Soroko et al., 2014). IRT has shown potential for disease diagnosis in bovine species and can rapidly and safely detect mastitis by measuring the local temperature increase resulting from inflammatory reactions even before visible symptoms occur (Stelletta et al., 2012).
Udder health is crucial for clean milk production, and effective management practices aim to reduce udder infections. Monitoring the milking process using IRT can contribute to better udder health management, as the cleanliness of the udder surface influences temperature measurement results (Poikalainen et al., 2012). Subclinical and clinical mastitis are major concerns due to the economic losses they cause in the dairy industry, including reduced milk production, poor milk quality, increased culling rate, additional labor, and expenses for treatment and control measures. Subclinical mastitis, in particular, leads to greater economic losses and may result in permanent reductions in milk productivity and quality (Halasa et al., 2007). Early detection of subclinical mastitis through IRT can aid in diagnosing the infection, identifying the causative agent, and implementing effective management interventions. The sensitivity and specificity of subclinical mastitis detection using IRT are similar to those of the California mastitis test (Polat et al., 2010). High correlation has been observed between somatic cell counts (SCC) and udder skin surface temperature, with an increase in temperature greater than 1°C serving as an indicator of mastitis in Holstein and Brown Swiss cows (Colak et al., 2008). However, IRT may not be as effective in detecting subclinical mastitis in Gir cows, but it can still be used to identify temperature variations on the skin surface at different udder regions (Porcionato et al., 2009).
Diagnosis of clinical mastitis is easier as it can be based on visible abnormalities (Kurjogi and Kaliwal, 2014). Generally, udder surface temperature increases during mastitis in dairy animals, primarily due to contagious pathogens and environmental factors. The extent of temperature change depends on factors such as the affected quarter, mastitis pathogen, treatment, and management, including environmental factors (Oliveira et al., 2013). Both clinical and subclinical mastitis affect milk production, with an average decrease of 50% and 17.5%, respectively (Singh and Singh, 1994). Subclinical mastitis has a higher prevalence than clinical mastitis (Mdegela et al., 2009). Various researchers have documented a wide range of differences in udder surface temperature changes between healthy quarters and those affected by subclinical and clinical mastitis, making IRT a promising tool
CONCLUSION
Maintaining good udder health is crucial for ensuring clean milk production, and effective management practices can help reduce udder infections. Mastitis, a major concern in the dairy industry, leads to significant economic losses. While laboratory methods exist for its diagnosis, there is a need to explore highly sensitive non-invasive techniques for early detection. Infrared thermography (IRT) is a non-invasive diagnostic tool that can be used for the early detection of subclinical mastitis in dairy cows. By using a highly sensitive thermal camera, IRT can detect subtle changes in udder temperature resulting from physiological changes during subclinical and clinical mastitis. Therefore, infrared thermography shows promise as a suitable tool for the early detection and screening of mastitis in dairy cattle.
REFERENCES
- Ahmad, T., Bilal, M.Q., Ullah, S. and Muhammad, G. (2005). Effect of severity of mastitis on pH and specific gravity of buffalo milk. Pak J Agri Sci., 42: 3-4.
- Bangar, Y.C., Singh B, Dohare, A.K. and Verma, M.R. (2015). A systematic review and meta-analysis of prevalence of subclinical mastitis in dairy cows in India. Trop Anim Health Prod., 47: 291–297.
- Colak, A., Polat, B., Okumus, Z., Kaya, M., Yanmaz, L.E. and Hayirli A. (2008). Short communication: early detection of masti-tis using infrared thermography in dairy cows. J Dairy Sci., 91: 4244 – 4248.
- Collier, R.J. Dahl, G.E. and Van Baale, M.J. (2006). Major advances associated with environmental effects on dairy cattle. J Dairy Sci., 89: 1244-1253.
- Guha, A., Gera, S. and Sharma, A. (2010). Assessment of chemical and electrolyte profile as an indicator of subclinical mastitis in riverine buffalo (Bubalus bubalis). Haryana Vet., 49: 19-21.
- Halasa, T., Huijps, K., Ostera’s, O. and Hogeveen, H. (2007). Economic effects of bovine mastitis and mastitis management: a review. Vet Quart., 29: 18-31.
- Joshi, S. and Gokhale, S. (2006). Status of mastitis as an emerging disease in improved and periurbandairy farms in India. Ann New York Acad Sci., 1081: 74-83.
- Kamal, R.M., Bayoumi, M.A., Abd, E. and Aal, S.F.A. (2014). Correlation between some direct and indirect tests for screen detection of subclinical mastitis. Int Food Res J., 21: 1249-1254.
- Kurjogi, M.M. and Kaliwal, B.B. (2014). Epidemiology of bovine mastitis in cows of Dharwad District. Int Sch Res Notices., 2014 pp 1-9.
- Mdegela, R.H., Ryoba, R., Karimuribo, E.D., Phiri, E.J., Loken, T. and Reksen, O. (2009). Prevalence of clinical and sub-clinical mastitis and quality of milk on smallholder dairy farms in Tanzania. J South African Vet Assoc., 80: 163–168.
- Oliveira, L., Hulland, C. and Ruegg, P.L. (2013). Characterization of clinical mastitis occurring in cows on 50 large dairy herds in Wisconsin. Dairy Sci., 96(12): 7538-7549.
- Poikalainen, V., Praks, J., Veermae, I. and Kokin, E. (2012). Infrared temperature patterns of cow’s body as an indicator for health control at precision cattle farming. Agron Res Biosyst Eng., 1: 187-194.
- Polat, B., Colak, A., Cengiz, M., Yanmaz, L.E., Oral, H., Bastan, A., Kaya, S. and Hayirli A. (2010). Sensitivity and specificity of infrared thermography in detection of subclinical mastitis in dairy cows. J Dairy Sci., 93: 3525-3532.
- Porcionato, M.A., Canata, T.F., De Oliveira, C.E.L. and Santos, M.V.D. (2009). Udder thermography of Gir cows for subclinical mastitis detection. Bio Eng., 3: 251-257.
- Radostits, O.M., Gay, C.C., Hinchcliff, K.W. and Constable, P.D. (2007). Veterinary Medicine: A textbook of the diseases of cattle, horses, sheep, pigs and goats. 10th ed., Saunders Company, London.
- Singh, P.J. and Singh, P.B. (1994). A study of economic losses due to mastitis in India. Indian J Dairy Sci., 47: 265–272.
- Sinha, M.K., Thombare, N.N. and Mondal, B. (2014). Subclinical Mastitis in Dairy Animals: Incidence, Economics, and Predisposing Factors. The Scientific World Journal. Volume 2014, Article ID 523984, 4 pages.
- Soroko, M., Dudek, K., Howell, K., Jodkowska, E., Henklewski, R. (2014). Thermographic evaluation of race horse performance. J of Equine Vet Sci., 34(9): 1076–1083.
- Srivastava, A.K. (2015). Mastitis in Dairy Animal: Current Concepts and Future Concerns. Satish Serial Publishing House, Delhi, India.1-5.
- Stelletta, C., Gianesella, M., Vencato, J., Fiore, E. and Morgante, M. (2012). Thermographic Applications in Veterinary Medicine. In: [Prakash RV (ed)] Infrared Thermography. In Tech, China, 117-140.
- Syridion, D., Layak, S.S., Mohanty, T.K., Kumaresan, A., Kalyan, D., Manimaran, A., Prasad, S. and Venkatasubramanian, V. (2013). Effect of production system on milk quality parameters in Holstein Friesian crossbred cows. Indian J Dairy Sci., 66: 424-431.
- Viguier, C., Arora, S., Gilmartin, N., Welbeck, K. and O’Kennedy, R. (2009). Mastitis detection: current trends and future perspectives. Trends Biotechnol., 27: 486-493.
- Willits, S. (2005). Infrared thermography for screening and early detection of mastitis infections in working dairy herds. In: Proceedings of Inframation. Las Vegas, 2005 USA. 1–5.