Veterinary Archives, Vol. 87 No. 5, 2017.
Original scientific paper
https://doi.org/10.24099/vet.arhiv.160728
Evaluation of the relationship between milk glutathione peroxidase activity, milk composition and various parameters of subclinical mastitis under seasonal variations
Hatice E. Colakoglu
; Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, University of Ankara, Ankara, Turkey
Ozlem Kuplulu
; Department of Food Hygiene and Technology, Faculty of Veterinary Medicine, University of Ankara, Ankara, Turkey
Mehmet R. Vural
; Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, University of Ankara, Ankara, Turkey
Sukru Kuplulu
; Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, University of Ankara, Ankara, Turkey
Murat O. Yazlik
; Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, University of Ankara, Ankara, Turkey
Ibrahim M. Polat
; Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, University of Kirikkale, Kirikkale, Turkey
Burcu Oz
; Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, University of Ankara, Ankara, Turkey
Ufuk Kaya
; Department of Biostatistics, Faculty of Veterinary Medicine, University of Ankara, Ankara, Turkey
Rustem Bayramoglu
; Veterinary Medicine, Farm Animal Managament Practicer, Western Thrace, Greece
Abstract
The aims of this study were to evaluate the Glutathione peroxidase (GSH-Px) activity in milk, and various milk parameters [milk fat, milk protein, milk solids non-fat (SNF), somatic cell count (SCC), total bacteria count (TBC), electrical conductivity (EC)] in healthy dairy cows during lactation, and to demonstrate the significant correlations between GSH-Px activity, milk composition, SCC, TBC and EC under seasonal variations. The cows calving in January were assigned into the winter group (n = 30) while the other cows calving in August were assigned into the summer group (n = 30). Milk samples were collected weekly during lactation, and monthly average values of the parameters were determined. Although milk GSH-Px activity was variable during lactation, it was significantly higher in the winter group compared to the summer group of cows during the first five months of lactation (P<0.001). However, between the 6th and 10th months of lactation, GSH-Px activity was significantly higher in the summer group (P<0.001). In both groups of cows, GSH-Px activity was negatively correlated with SCC, TBC and EC during lactation. No correlation was found between GSH-Px activity and milk composition. In conclusion, the alteration of milk GSH-Px levels could be used as a diagnostic tool for monitoring udder health due to its relationship with the parameters of subclinical mastitis. Furthermore, cows calving in winter had higher GSH-Px activity than those calving in summer, especially during the first few months of lactation. These findings indicate that milk GSH-Px activity in cows during lactation could be influenced by seasonal variations.
Keywords
cow; milk; glutathione peroxidase; subclinical mastitis; season
Hrčak ID:
186218
URI
Publication date:
6.9.2017.
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