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Aim: To evaluate blood antioxidant profile and lipid peroxides in dairy cows with clinical mastitis. Materials and Methods: Twelve cases of clinical mastitis in cross-bred cows were selected based on physical examination of udder and milk, California Mastitis Test (CMT), Somatic Cell Count (SCC) and confirmation by bacteriological examination 5 of milk and requisite biochemical tests. Twelve lactating cows showing negative CMT reaction and SCC <2x10 cells/ml were considered as healthy control. Antioxidant parameters measured in blood were superoxide dismutase (SOD), catalase activities and reduced glutathione (GSH) concentration. Erythrocytic lipid peroxidation (LPO) was measured in terms of malondialdehyde (MDA) production. Results: Significant (P<0.05) decrease in blood SOD and catalase activities, GSH concentration and an increase in erythrocytic lipid peroxides was observed in cows with clinical mastitis. Conclusion: It is concluded that there is a compromise in antioxidant defense of the body in dairy cows with clinical mastitis resulting in oxidative damage, therefore, necessitate the use of antioxidants and other protective compounds along with conventional therapy for mastitis control.


Introduction
Therefore, the present study was carried out to evaluate blood antioxidant profile and lipid peroxides in dairy Cells living under aerobic environment are cows with clinical mastitis.continuously exposed to number of oxidants derived from various endogenous and exogenous sources [1].

Under normal physiological conditions, antioxidant
Selection of animals: The study was carried out in defense system within the body can effectively cross-bred dairy cows (Haryana x Jersey/Brown neutralize the oxidants produced.When the production Swiss/Holstein Friesian) maintained under identical of oxidants exceeds the capacity of antioxidant defense, feeding and management practices at the Cattle and a condition of oxidative stress is produced resulting in Buffalo farm, Livestock Production and Management oxidative damage to macromolecules such as lipids, section, Indian Veterinary Research Institute, DNA and proteins [2].The oxidative stress may be Izatnagar, India.Twelve cases of acute clinical mastitis involved in several pathological conditions including were selected based on physical examination of udder mastitis in dairy animals [3,4] which is characterized and milk collected in sterile glass vials.The udder and by an influx of somatic cells, primarily the neutrophils, teats of cows were examined for signs of inflammation into the mammary gland.These neutrophils destroy the i.e. redness, swelling, warmth, pain and depressed invading bacteria by oxygen-dependent and oxygenfunction.The quarters with any physical deformity like independent systems.Simultaneously, they potentially atrophy or fibrosis, blind or supranumerary teats etc. damage the secretory epithelium of mammary gland by were excluded from the study.The milk was examined reactive oxygen species and proteolytic enzymes, for the presence of discoloration, blood clots, flakes, resulting in decreased milk production [5].Although, purulent material etc.The milk samples were also there are evidences that inflammation of mammary examined for somatic cell count (SCC) indirectly by gland may alter the blood oxidative stress parameters California Mastitis Test (CMT) as per Schlam and in terms of lipid peroxides, reduced glutathione (GSH), Noorlander [8] and directly as per Schlam et al. showing negative CMT reaction and SCC <2x10 reactive oxygen species [2] in mastitis is still scanty.cells/ml were considered as healthy control.organism of the bovine mammary gland causing a lowgrade, persistent type of infection and does not have Measurement of blood antioxidant parameters and high self-healing rate [15,16].Therefore, its lipid peroxides: The blood samples were collected therapeutic management by antibiotics and other from each affected animal in centrifuge tube protective compounds is strongly recommended.containing anticoagulant.After centrifugation at 3000 Superoxide dismutase (SOD), a copper-zinc rpm for 10 min, the plasma and buffy coat were containing enzymatic antioxidant localized in the removed to harvest the red blood cells (RBC).Part of cytoplasm of eukaryotic cells, catalyze the dismutation RBC pellet was diluted with chilled distilled water in of superoxide radicals to hydrogen peroxide (H O ) 2 2 1:10 for the preparation of 10% stock hemolysate which can be removed by the activity of the catalase which was used for the estimation of SOD, CAT and glutathione peroxidase [17].The present study activities and lipid peroxidation (LPO) and rest of the revealed a significant decrease in SOD activity in RBC pellet was diluted with chilled normal saline in mastitic cows which might be related with low level of 1:1 to get 50% RBC suspension for GSH estimation.
zinc in blood from cows with mastitis [6].A significant SOD and CAT activities were measured as per Madesh decrease in catalase activity was also observed which and Balasubramanian, [11] and Bergmeyer [12] was similar to the finding observed by Sharma et al. respectively.Reduced glutathione was measured by [18] in bovine staphylococcal mastitis.The protective dithio-bis-2 nitro benzoic acid (DTNB) method [13].
effect of catalase has been demonstrated in bovine Lipid peroxidation was measured in terms of neutrophil-induced model of mammary cell damage malondialdehyde (MDA) production as per Placer et [19].Decrease in enzymatic antioxidant activities al. [14].might be attributed to increased consumption to Statistical analysis: Data were analyzed by one-way counteract reactive oxygen species produced from analysis of variance (ANOVA) using statistical inflamed gland, suggesting a compromise in software package SPSS 16.0.The comparison between antioxidant defense of the body.values was established at level of significance, P<0.05.
Glutathione, a thiol-containing tripeptide, in its reduced form (GSH) is present in living cells at high

concentrations [17]. Upon reaction with reactive
Mean CMT point score and SCC recorded in milk oxygen species, it gets oxidized to glutathione radical of healthy lactating cows were 0.00±0.00and 1.87± which can be regenerated to its reduced form by 5 0.06 x 10 per ml respectively.Mean CMT point score glutathione reductase [1,17].The present study and SCC recorded in milk of mastitic cows were 3.67 revealed a significant decrease in GSH concentration 5 ±0.13 and 83.12±1.17x 10 per ml respectively.Out of in mastitic cows which may be due to conversion of total 12 cases of clinical mastitis, 7 (58.33%)were reduced form to oxidized form (GSSH) by excessive found positive for Streptococcus agalactiae, 2 (16.66 production of reactive oxygen species from inflamed %) for Micrococci, 2 (16.66%) for Coliform and 1 gland.On contrary, an enhanced GSH concentration in (8.33%) showed no bacterial growth on culture media.plasma has been demonstrated in cows with mastitis by The blood antioxidant profile and lipid peroxides in Kizil et al.
[7] with the explanation that there might be dairy cows with clinical mastitis are depicted in table 1.
enhanced activities of GSH dependent enzymes There was observed a significant (P<0.05)decrease in leading to intense regeneration of reduced glutathione blood SOD, CAT activities and GSH concentration (GSH) from the oxidized form (GSSH). along with a significant (P<0.05)increase in erythrocytic The determination of lipid peroxidation status is among the most widely used methods for determinalipid peroxides in terms of malondialdehyde production tion of the oxidative stress [9]. vitamin A, C, E and trace elements [6,7] but the Further confirmation of intramammary infection was information on enzymatic antioxidants such as done by bacteriological examination of milk and superoxide dismutase (SOD), catalase (CAT) which requisite biochemical tests[10].Twelve lactating cows are the most efficient in directly catalyzing reduction of 5 of the lipid bilayer of the Mean CMT point score and SCC recorded in milk cellular membrane and are easily oxidized [20] leading of mastitic cows correlate with clinical mastitis [9]. to the creation of lipid peroxides which are decomposed The present study revealed the predominance of to aldehydes like malondialdehyde (MDA), detected Streptococcus agalactiae as cause of clinical mastitis by thiobarbituric acid [17].The present study revealed in dairy cows which is a highly contagious obligate a significant increase in erythrocytic MDA production doi:10.5455/vetworld.2013.271-273Table-1.Blood antioxidant profile and lipid peroxides in dairy cows with clinical mastitis (Mean±S.E.) Discussionare important constituents