Size changes in some ultrasound examined teat parameters during milking in different lactation stages

SUMMARY Background: The size of the teat of the cattle changes during milking. The degree of change in size depends on the breed, age, quantity of milk produced and the lactation stage, as well. Objectives: The authors wanted to determine how ultrasound-related teat parameters change during milking in Holstein-Friesian cows in different lactation stages. Materials and Methods: The study was carried out on a dairy-farm in Veszprém county of freshly calved cows (n = 40), in the 100-150th day in milk (n = 70) at the end of lactation (n = 40) and freshly calved heifers (n = 31) teats. The length of the teat canal, the 1 cm area of the paracle papillary and the teat end area were measured before milking, immediately and two hours after milking. The authors used SonoScape A6 ultrasound machine and 5-7 MHz linear transducer for the ultrasound examination and SPSS. 18. program for the statistics. Results and Discussion: Prior to milking, the length of the teat canal and the area of the teat end was measured significantly higher (p < 0.05) at cows at the end of lactation, the lowest in heifers. The area of the pars papillaris was significantly (p < 0.05) the smallest at the time of deflation, the highest after calving. Milking results in significantly (p < 0.05) lengthening the teat canal and the teat end area but the pars papillaris area is significantly reduced (p < 0.05). In a two hour measurement, the length of the teat canal and the teat end area at the heifers grow further at the cows in the middle of lactation, while in the other two groups they decreased. Only in cows at the end of lactation there were no significant differences (p < 0.05) between the two-hour and pre-milking results. The area of the pars papillaris increases in all four groups but is still significantly (p < 0.05) lower than the pre-milking value