EARLY DETECTION OF HIDDEN MASTITIS IN DAIRY CATTLE USING INNOVATIVE SURF FIELD MASTITIS TEST AT FARMER’S LEVEL
Mastitis is an important disease of dairy animals. It is an inflammation of the mammary gland (udder) that causes physical and chemical changes in milk and leads to pathological condition of the glandular tissue. It is generally associated with poor hygienic and husbandry practices. Bruising of mammary tissue or teats from traumas, nursing, flies bites, or other wounds predisposes the females to mastitis. The infection rate of mastitis in cows with pendulous udder is higher than those having non-pendulous udder (Sori et al., 2005). A wide range of pathogens including viruses, bacteria, fungi and their toxins can cause the disease. The primary reservoir of contagious pathogens is the mammary gland itself. Frequency of contagious pathogens among mastitis cases is greater (Sori et al., 2005). The infectious agent enters through the milk canal, interacts with the mammary tissue cells and multiplies. The mammary tissue reacts to these toxins and becomes inflamed. The dairy industry is facing a great set back due to high prevalence and incidence of mastitis in milch animals. Subclinical mastitis affects milk quality and quantity causing great economic loss for producers (Swinkels et al., 2005; Halasa et al., 2007). Annual losses in the dairy industry due to mastitis was approximately 2 billion dollars in USA and 526 million dollars in India, in which subclinical mastitis are responsible for approximately 70% of these losses (Varshney and Naresh, 2004). Apart from causing huge economic losses, this disease also posses the risk for the transmission of zoonotic diseases like tuberculosis, brucellosis, sensors to detect mastitis and abnormal milk has been increasing considerably in recent years (Brandt et al., 2010)
It goes without saying that the quality of raw milk available to the general public and to milk processing industry in India is appallingly poor. This is partly because at the very least, every fifth Indian cow and buffalo is afflicted with bacterial infection of the udder called ‘mastitis’. This disease not only reduces the milk production potential of the dairy animals (to the tune of 20 to 25%) but the milk produced by the affected animals is also unfit for human consumption owing to unacceptably high number of pus cells and noxious products of bacterial growth in the milk. In a pattern analogous to tuberculosis or hepatitis in human being, majority of affected cows and buffaloes suffer from the subclinical (hidden) form of mastitis in which the affected animal is bereft of overt manifestations of the disease.All over the World, mastitis or swelling of the udder is considered to be the most important production-limiting disease of the daily industry. This dairy scourge not only reduces the milk yield of affected animals (nearly 15 to 20%) but also renders the milk unsuitable for human consumption.
Mastitis results from the growth of germs in the udder. It occurs in 2 forms:
(1) Clinical mastitis in which there is visible swelling in the udder/teat and noticeable changes in milk such as flakes, clots etc. (2) Sub-clinical or hidden mastitis in which swelling in the udder is so mild that there is no visible change in the milk or in the udder/teat.
Subclinical or hidden form of mastitis is 15-40 times more common than the clinical mastitis. Clinical cases are preceded by hidden form of mastitis. Research conducted in India over the past 4 decades has shown that about 25% of cows and 15% of buffaloes are afflicted with subclinical form of mastitis. An early diagnosis of hidden mastitis is imperative to save the udder and prevent transmission of disease producing organisms to other animals in the herd. It is also important from public health viewpoint in so far as the milk of animals affected with sub-clinical mastitis contains disease producing bacteria, their toxins, abnormal milk constituents as well as pus cells. Mastitis causes a tremendous increase in the number of white blood cells in the milk.
Mastitis like any other inflammation in the body causes a tremendous increase in the number of white blood cells in the milk (pus cells). In the context of milk, these cells are called milk somatic cells.The dairy experts & Researchers at the Department of Clinical Medicine and Surgery, University of Agriculture, Faisalabad, (Pakistan) have pioneered a study demonstrating that a 3% solution of a house-hold detergent viz. Surf Excel (Unilever India Ltd.) can be used for an early farmer’s level detection of sub-clinical (hidden) mastitis. This test has been named as Surf Field Mastitis Test.
Unique attributes of Surf Field Mastitis Test
The desirable features of this innovative mastitis detection test include:
- Compatibility with the technical capabilities of farmers who happen to be mostly illiterate in the developing countries. Owing to a facile nature of the test procedure, even an illiterate farmer can learn to conduct this test within a few minutes.
- Desirable sensitivity (72.81 and 66.22 in cows and buffaloes respectively) of detection vis-à-vis other expensive similar tests like California Mastitis Test and the gold standard of mastitis diagnosis i.e. microbiological examination of aseptically collected milk samples.
- Availability of the required reagent, i.e. Surf Excel Powder (Unilever India Ltd.) in almost every village.
- User’s friendly nature of the test.
Procedure of Surf Field Mastitis Test and its interpretation:
a) Procedure
- Prepare a 3% solution of the household detergent viz. Surf Excel (Unilever India Ltd.). To this end, dissolve 5-6 teaspoonfuls of the Surf Excel powder in ½ liter of ordinary water. Pour this solution into a plastic bottle, apply a lid and place the bottle in a dark place. This reagent is good for about 3 months.
- Collect 10-15ml of milk from each teat in separate container like tea cups. If Surf Field Mastitis Test paddle is available, there is no need to collect milk samples into tea cups as the milk from individual quarters of cow and buffalo can be collected into individual receptacle of this paddle.
- Mix the milk from individual teat and Surf solution (3%) in approximately equal proportions (i.e. add 10-15 ml 3% surf solution).
- Rotate the mixture of milk and surf solution for about 15-20 seconds.
- Examine the mixture for thickening or any other change.
b) Interpretation
If the hidden form of mastitis (subclinical mastitis) is present in the quarter of udder, the mixture (milk + surf solution) will thicken (i.e. gel formation) within 15 seconds. The udder is free of subclinical mastitis if the mixture remains liquid and there is no thickening of mixture of milk and surf solution.
The milk from surf test positive quarters of udder is not wholesome for human consumption and should be discarded. As subclinical mastitis is antecedent to clinical mastitis, many surf test positive quarter (s) will develop clinical form of the disease in future.
Uses of the Surf Field Mastitis Test in mastitis treatment, control and public health
- All farmers should conduct Surf Field Mastitis Test on all quarters of all milch animals at fortnightly intervals. In the event of a positive test reaction in one or more udder quarter(s), immediately contact the local veterinarian for treatment and advice on mastitis treatment and control.
- Whenever there is reduction in quarter yield, Surf Field Mastitis Test should be conducted to rule out the possibility of mastitis as the cause of reduced milk yield.
- Lactating animals should be divided into Surf test positive and Surf test negative groups. The Surf test negative group (mastitis free animals) should be milked first because the germs, which cause mastitis are transmitted from mastitis-affected (surf test positive) to healthy animals through milkers’ hands at the time of milking.
- Always conduct Surf Field Mastitis Test when purchasing new cows and buffaloes. Purchase only surf test negative cows and buffaloes.
- Milk from surf test positive animals is unfit for human consumption because it contains a lot of germs, their toxins and pus cells (somatic cells) and abnormal milk constituents.
- The processing of milk by the milk processing plants which gives a positive surf test reaction results in sub-optimal and substandard finished products like yogurt, cheese, etc. The management of dairy industry (milk plant) should, therefore, train their field staff and farmers about the procedure and uses of this innovative and nifty mastitis detection test.
Reference-On request
