The relationship between milk progesterone and milk traits during estrus in dairy cows

The aim of this study was to evaluate relationship between milk progesterone concentration (P4) and milk traits at the start of estrus time and 12h after start of the estrus in dairy cows. The 96 milk samples of 48 Lithuanian dairy cows without reproduction disorders and 90–100 days after calving were evaluated. Cows were classified into two groups based on milk yield per day: <30 kg (n=20) and ?30 kg (n=28). Data were categorized by milk fat and protein content at the start estrus and 12h after start of estrus to evaluate relationship between P4 and milk traits examined. P4 at estrus time in dairy cows was significantly positively correlated with milk yield (P<0.001), whereas it was negatively correlated with milk protein (P<0.05-P<0.01) and fat at 12h after start of estrus. Dairy cows with F/P from 1.0 to 1.5 had the lowest P4 in milk. Results of the pregnancy in dairy cows were related with lower P4 and milk yield level (P<0.001), higher milk fat (P<0.05) and milk protein content (P<0.001). These cows had 1.90 times lower prevalence of the signs of subclinical ketosis (P<0.05) at estrus time when compared with non-pregnant cows. As a result, it was clearly demonstrated that P4 in dairy cows can help to evaluate and improve the reproductive properties of cows

The effect of different levels of teat-end hyperkeratosis on mammary infrared thermograph and mastitis in dairy cows

The object of this study was to assay different levels of teat hyperkeratosis and to determine the connections between teat thermographic characteristics, somatic cells count (SCC) and mastitis in dairy cows. A total of 920 teats of 230 Lithuanian Black and White cows were evaluated to assess teat-end conditions and the thermographic characteristics were determined before evening milking. Teats of the animals were grouped into four different classes of hyperkeratosis. Additionally, quarters of udder were divided into three different classes based on the California mastitis test (CMT) and clinical signs: group 1 (healthy), group 2 (subclinical mastitis), and group 3 (clinical mastitis). The 44.3% of the teats were given a score of N (No ring), 41.1% of the teats were scored S (smooth ring), 11.8% of teats were given a score R (rough ring) and 2.9% of teats were given a score VR (very rough skin). The N and S groups had more healthy udder quarters than R and VR groups (P<0.001). Analysis of thermographic images at the teat sinuses showed that group 1 had lower teat temperature (0.93-1.32 0C) than group 2 and group 3 (P<0.01). There was a significant positive correlation between milk SCC and temperature of the teats evaluated by hyperkeratosis scores N, S, and R. The results of the present study clearly showed that there was a significant connection between different levels of hyperkeratosis and teat temperature in all groups, indicating a greater risk to mastitis