Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)

First Advisor

Robert W. Adkinson


Thirty lactating Holstein cows were divided into three groups of ten each and assigned to three treatments. The first treatment required using a gel teat sanitizer cleaner (GEL) and paper towels, no water to clean teats prior to milking. The second used only water (WASH) and paper towels, and the third used water, paper towels, and predipping (PREDIP) with 0.5% iodophor solution. Individual cow samples of milk were aseptically collected weekly from weigh jars for ten weeks. Bacteria counts were determined. Microorganism counts were also monitored from individual cow teat swabs. Treatment effects on daily milk yield, fat and protein percentages, udder health, milk iodine residue, and parlor efficiency were investigated. Raw milk microorganism counts were 1184, 2481 and 1119 organisms/ml for GEL, WASH and PREDIP. Teat swab counts were 10388, 28558, and 9205 organisms/ml for GEL, WASH and PREDIP. Preliminary incubation counts were 2048, 4583 and 2527 for GEL, WASH and PREDIP. The GEL and PREDIP counts were lower than WASH counts. No differences existed between all counts of GEL and PREDIP treatments. Treatment effects were similar for production traits: fat percent, protein percent, a.m. milk yield, p.m. milk yield, and daily milk yield. Milk iodine content in WASH was 0.002 and 0.001 ppm lower than GEL and PREDIP, but GEL and PREDIP treatments did not differ. The GEL group had lower SCC than WASH and PREDIP. There was no clinical mastitis in the GEL group while 17.24 and 10.34% of cows had clinical mastitis in WASH and PREDIP groups. Cultured organisms from the WASH group included Klebsiella specie, Staphylococcus aureus, Streptococcus bovis and Streptococcus dysgalactiae. Pathogens from PREDIP could not be identified in two cases and Escherichia coli was isolated in one case. Premilking udder preparation time least-squares means were 1.58, 1.10, and 1.77 min for GEL, WASH and PREDIP. Parlor throughputs were 55, 51, and 43 (cows/hr) for GEL, WASH, and PREDIP. Results showed the GEL procedure to be superior to WASH and PREDIP methods of premilking udder preparation.