The recovery of teat wall thickness and teat tissue density after machine milking

Abstract: Udder health has a strong effect on profitability in milk productions. Udder diseases, especially mastitis, are among the most costly diseases and has a major economic impact on dairy production as well as it is an animal welfare issue. Mastitis can occur if bacteria enters the teat canal causing an infection. The teat has different mechanisms to protect itself from bacteria but changes in the teat condition can impair the defense. Milking machines has been seen to cause temporary changes in the teats after milking. Different changes have been observed by many scientists and in this study, focus was pointed on teat wall and teat density thickness. Teat wall thickness and teat tissue density increased after milking which is assumed to be due to accumulation of fluids in the teat defined as congestion. Temporary changes in the teat caused by machine milking has been seen to impair udder health and significantly increase microbial colonization of the teat canal. The results from this study showed that with routine milking the teat recovers from congestion within 30 minutes. After the 30 minutes the teat wall kept decreasing until next milking due to the increase of intramammary pressure. Teat changes can be measured with different methods and in this study, the measurements from a cutimeter were compared to the measurements from an ultrasound machine. The conclusion is that ultrasonography appears to be more sensitive to small variations and was able to reveal teat wall changes caused by both congestion and intramammary pressure. The cutimeter method was more easily implemented but did in this study only reveal teat density changes caused by congestion after milking.