Identification of bacterial species in milk by MALDI-TOF and assessment of some oxidant-antioxidant parameters in blood and milk from cows with different health status of the udder.

This study aimed to identify bacterial pathogens in milk samples from dairy cows with subclinical and clinical mastitis as well as to assess the concentrations of oxidant-antioxidant parameters [malondialdehyde (MDA), reduced glutathione (GSH), and total GSH levels] in both blood and milk samples. From a total of 200 dairy cows in 8 farms, 800 quarter milk samples obtained from each udder were tested in the laboratory for the presence of udder pathogens. Cultivated bacteria causing intramammary infection from milk samples were identified by Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF). In addition, from tested animals 60 cows were selected including 20 healthy cows that were CMT negative, 20 cows with subclinical mastitis (SM), and 20 cows with clinical mastitis (CM) for detection of MDA, GSH, and total GSH levels in blood and milk samples. Three hundred and eighty (47.5%; 380/800), 300 (37.5%; 300/800), and 120 (15%; 120/800) of milk samples, respectively were CMT positive or SM and CM, and those positives were cows from different farms. We observed that 87.4% (332/380), 25.3% (76/300), and 34.2% (41/120) of cows with CMT positive, CMT negative, and CM had bacterial growth. The most predominantly identified bacteria were Staphylococcus chromogenes (18.7%) obtained mainly from SM and Staphylococcus aureus (16.7%) as the most frequent cause of CM. According to our results, dairy cows with CM had the highest MDA levels, the lowest GSH, and total GSH levels in both blood and milk samples however, high MDA levels and low GSH levels in milk samples with SM were observed. Based on our results, lipid oxidant MDA and antioxidant GSH could be excellent biomarkers of cow's milk for developing inflammation of the mammary gland. In addition, there was no link between nutrition and MDA and GSH levels.

Effects of sex, eye-side, diurnal variation on intraocular pressure in calves.

The aim of this study was to determine the effects of factors such as sex, eye-side and diurnal variation on intraocular pressure (IOP) values measured by Tono-Pen Vet® in healthy calves. Twenty four (12 males, 12 females) calves were used in this study. IOP measurements were per- formed in the morning (6:00 a.m.) and at night (8:00 p.m). Average IOP values in all calves were measured as 17.67±2.64 mmHg in the morning and 15.52±2.05 at night and the difference between these two time points was found to be statistically significant (p⟨0.0001). Average IOP values were measured as 16.04±2.82 mmHg in males and 17.15±2.23 mmHg in females with a statistically significant (p⟨0.05=0.023) difference between them. Average IOP values were 16.81±2.85 mmHg in right eyes and 16.37±2.23 mmHg in left eyes and the difference between these values were statistically insignificant (p>0.05). At the end of study, overall average IOP in all calves was measured as 16.59±2.59 mmHg. The present data showed a significant difference in terms of sex and diurnal variations and a non-significant difference in eye-side. In addition, this study is the first research article in which the intraocular pressure in calves was measured by Tono-Pen Vet®.