Changes in teat end condition following installation of an individual quarter pulsation system

The objective of this study, conducted at the University of Kentucky Coldstream Dairy, was to examine changes in teat end hyperkeratosis in a herd transitioning from a standard pulsation system to an individual quarter pulsation milking system. Teat end hyperkeratosis (HK) was evaluated immediately after cluster removal using the scoring system outlined by Mein et al. (2001) where N signifies no ring; S signifies a smooth, raised ring; R signifies a rough ring; and VR signifies a very rough ring. Scorings were classified for 69 cows (48 Holstein, 12 crossbred, and 9 Jersey) relative to installation (April 28, 2011) of the Milpro P4C (Milkline, Gariga di Podenzano, Italy) system as follows: PRE1-April 7; PRE2-April 21; POST1-May 12; POST2May 26; POST3-June 9. The Milpro P4C system stops milking individual quarters using a unique individual quarter pulsation system with four pulsation channels instead of two. Hyperkeratosis classifications were converted to numerical scores as follows: N = 1; S = 2; R = 3; VR = 4. The MIXED Procedure of SAS® (Cary, NC) was used to evaluate fixed effects of age, breed, parity, teat position and all interactions on teat end HK score with variables repeated by scoring with cow within breed as subject. The effects of teat position and scoring × breed on teat end HK score were significant (P < 0.01). Holstein HK scores improved from PRE1 to PRE2 (1.75 ± 0.10 and 1.63 ± 0.10, respectively, P = 0.04), PRE1 to POST1 (1.75 ± 0.10 and 1.59 ± 0.10, respectively, P = 0.02), PRE1 to POST2 (1.75 ± 0.10 and 1.53 ± 0.10, respectively, P < 0.01), PRE1 to POST3 (1.75 ± 0.10 and 1.42 ± 0.10, respectively, P < 0.01), PRE2 to POST3 (1.64 ± 0.09 and 1.42 ± 0.10, respectively, P < 0.01), POST1 to POST3 (1.59 ± 0.10 and 1.41 ± 0.10, respectively, P < 0.01), and POST2 to POST3 (1.53 ± 0.10 and 1.42 ± 0.10, respectively, P < 0.05). Crossbred HK did not differ among scorings (P > 0.05). Jersey HK scores increased from POST1 to POST3 (1.32 ± 0.21 and 1.63 ± 0.22, respectively, P = 0.04). Right front HK scores were higher than right rear or left rear HK scores (1.58 ± 0.09, 1.37 ± 0.09, and 1.36 ± 0.09, respectively, P < 0.01). Left front HK scores were higher than right rear and left rear HK scores (1.62 ± 0.09, 1.37 ± 0.09, and 1.36 ± 0.09, respectively, P < 0.01). Individual quarter pulsation systems may prevent overmilking and reduce HK.