The influence of milking on the teat canal of dairy cows determined by ultrasonographic measurements

The effect of milking on the length and diameter of the teat canal during teat regeneration immediately after milking was evaluated. The practical measurements of the teat canal were performed on 70 Holstein cows using ultrasound Aloka Prosound device 2. A special "bath method" of the teat ultrasonographic scanning was used at set time intervals - before milking, immediately after milking, and 30, 60, 90, and 120 min after milking. Before milking, the average length of the teat canal was 10.67 mm and 9.3 mm and the teat canal diameter was 1.11 mm and 1.09 mm for front and rear teats, respectively. The average length of the front and rear teat canal significantly increased by about 20.5 and 32.9% and the front and rear teat canal diameter increased by 9.0 and 9.1% on average immediately after milking compared to values detected before milking. After 120 min of regeneration the teat canal was by 3.56 and 14.95% longer than before milking for front and rear teats, respectively. Prolongation of the teat canal was significantly affected by teat position. Based on the present results, the time period of 120 min is not sufficient for the complete regeneration of the teat canal length to the pre-milking values. On the other hand, we recorded total regeneration of the teat diameter within 120 min after milking. The initial values of the front and rear teat diameter were equal to those measurd 120 min after milking.