Evalution of the relationship between milk glutathione peroxidase activity, milk composition and various parameters of subclinical mastitis under seasonal variations
VETERINARSKI ARHIV, cilt.87, sa.5, ss.557-570, 2017 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 87 Sayı: 5
- Basım Tarihi: 2017
- Doi Numarası: 10.24099/vet.arhiv.160728
- Dergi Adı: VETERINARSKI ARHIV
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.557-570
- Anahtar Kelimeler: cow, milk, glutathione peroxidase, subclinical mastitis, season, LACTATING DAIRY-COWS, SOMATIC-CELL COUNTS, OXIDATIVE STRESS, VITAMIN-E, ANTIOXIDANT STATUS, HEAT-STRESS, SELENIUM, CATTLE, TEMPERATURE, MARKERS
- Ankara Üniversitesi Adresli: Evet
Özet
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-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.