3 research outputs found
Evaluation of the relationship between milk glutathione peroxidase activity, milk composition and various parameters of subclinical mastitis under seasonal variations
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.Ciljevi ovog istraživanja bili su, tijekom laktacje zdravih krava, procijeniti aktivnost glutation peroksidaze (GSH-Px) u mlijeku te odrediti razliÄite druge sastojke (mlijeÄnu masti, mlijeÄne bjelanÄevine, bezmasnu suhu tvar, broj somatskih stanica (SCC), ukupan broj bakterija (TBC), elektriÄnu provodljivost (EC) i prikazati znaÄajnost korelacija izmeÄu aktivnosti GSH-Px, sastava mlijeka, SCC, TBC i EC u uvjetima razliÄitih sezona. Krave oteljene u sijeÄnju rasporeÄene su u zimsku skupinu (n = 30), dok su ostale krave oteljene u kolovozu dodijeljene ljetnoj skupini (n = 30). Tijekom laktacije, uzorci mlijeka su prikupljani jednom tjedno i na temelju toga za svaki pokazatelj utvrÄene su prosjeÄne mjeseÄne vrijednosti. Iako je aktivnost GSH-Px u mlijeku tijekom laktacije bila varijabilna, krave iz zimske skupine imale su u prvih pet mjesci znaÄajno (P<0,001) viÅ”u aktivnost GSH-Px u odnosu na krave iz ljetne skupine. MeÄutim, izmeÄu 6. i 10. mjeseca laktacije, aktivnost GSH-Px bila je znatno viÅ”a u ljetnoj skupini krava (P<0,001). U obje skupine krava aktivnost GSH-Px bila je negativno povezana sa SCC, TBC i EC tijekom laktacije. Nije pronaÄena korelacija izmeÄu aktivnosti GSH-Px i sastava mlijeka. ZakljuÄno, na temelju njezinog odnosa s pokazateljima supkliniÄkog mastitisa, promjenjivost razine GSH-Px u mlijeku mogla bi se koristiti kao dijagnostiÄki alat u praÄenju zdravlja vimena. Nadalje, krave oteljene zimi imale su veÄu aktivnost GSH-Px od onih oteljenih ljeti, posebno tijekom prvih nekoliko mjeseci laktacije. Ovi rezultati upuÄuju na to da bi aktivnost GSH-Px u mlijeku krava tijekom laktacije mogla biti pod utjecajem sezonskih promjena
MDA and GSH-Px activity in transition dairy cows under seasonal variations and their relationship with reproductive performance
Introduction: The purpose of the current study was to evaluate the blood glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) levels under seasonal variations in dairy cows during transition period, and to assess the relationship between chosen reproductive parameters, GSH-Px, and MDA
Evalution of the relationship between milk glutathione peroxidase activity, milk composition and various parameters of subclinical mastitis under seasonal variations
YAZLIK, Murat Onur/0000-0002-0039-5597WOS: 000411813300003The 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