Influence of udder depth on cleaning teats and health of the mammary gland in robotic milking

ABSTRACT The aim of this study was to assess the influence of the depth of the udder on cleaning of teats and health of the mammary gland. The experiment was developed in the period spanning from March to June 2014, in Castro, PR. Twenty Holstein cows confined in free stall and milked in an automatic milking system (AMS) were used. The cows were divided into 4 groups with five animals (2 primiparous and 3 multiparous) based on the depth of the udder (udder depth: normal, small, and shallow). The electronically recorded data were collected monthly for four months, referring to the week of the official production milk control. To evaluate the effectiveness of cleaning teats, two contralateral teats were swabbed (right front quarter and left rear) before and after the automatic cleaning and once moistened towels were scrubbed around the other teats. A sample of milk was collected per cow to determine the somatic cell count (SCC). In the multivariate analysis relation of the udder depth with the teat cleaning was observed and evaluated through the teat cleaning with moistened towels score (TCTS). Udders slightly above the hocks (normal) had lower SCC and total bacterial count (TBC) of the teats. Shallow udders showed greater difference in TCTS. Cows with deep and shallow udders show less effective teat cleaning and health of the mammary gland. Cows with normal udders presented mammary gland conformation and health and contamination of teats most appropriate for robotic milking. On farms intending to introduce AMS it is recommended to select cows with udder depth which is a little above the hock. The impact of AMS on the TBC of the teats is related to the condition of cleaning of the teats pre-milking and housing conditions. Therefore, the condition of ambience of the cows is fundamental for the health of the mammary gland and obtaining high quality milk.