Effects of switch trimming on fly avoidance behaviors, udder cleanliness, and milk quality in lactating Holstein and Jersey cows

Abstract

The objective of this study was to observe differences in fly avoidance behaviors, udder cleanliness, and milk quality in Holstein and Jersey dairy cows due to switch trimming. Both breeds (n=12 each; half trimmed, half intact) were divided into 3 groups of 8 and observed for 1 week. Cows were assigned an udder hygiene score (HS) using a multi-zone system for udder cleanliness (1=very clean to 4=very dirty; Cook, 2002). Fly counts (FC), foot stomps (FS), tail swings (TS), and panniculus reflexes (PR) were recorded during a 5-min period/cow twice daily. Composite milk samples were collected and somatic cell count (SCC) was determined using the DeLaval Cell Counter. Milk samples were cultured and incubated for 48-hr using a Tri-plate agar (University of Minnesota Easy Culture). Statistical analysis of FC, FS, TS, and PR, and SCC were conducted using the MIXED procedure, and HS and bacterial species counts (BSC) were evaluated using the FREQ procedure in SAS (v9.4). No differences in TS, FS, PR, FC, SCC, or BSC were observed among treatments. Cows with an intact switch exhibited improved HS compared to cows with trimmed switches (54.17% vs. 27.08% HS 2, P = 0.02; and 22.92% vs. 554.17% HS 3, P = 0.01 for trimmed vs. intact switches). No differences in FS, PR, or BSC were observed among breeds. Jerseys swung their tails more than Holsteins (12.44 vs. 9.59 ± 0.71, P = 0.005) and had lower FC (17.43 vs. 25.40 ± 2.9, P = 0.009). However, Jerseys had greater somatic cell scores than Holstein cows (14.65 vs. 12.39 ± 0.60, P = 0.02). These results indicate that cows with a trimmed switch are equally able to perform fly avoidance behaviors as cows with intact switches, and that Holstein cows had improved milk quality over Jerseys.