Advances in dairy Research
Open Access

Abstract

Intramammary Infusion of Casein Hydrolysate for Involution of Single Mastitic Mammary Quarters Elevating Cow-Level Somatic Cell Count

Justine Britten, Kerry A Rood and David J Wilson

Mastitis in a single quarter can cause high somatic cell counts (SCC), clinical mastitis, and death in dairy cows. Currently, management of these mastitic quarters presents a problem for the dairy industry. Casein hydrolysate (CH) is an intramammary (IMM) infusion treatment reported to induce mammary involution. The primary objectives of this study were to investigate whether IMM CH treatment of single high SCC quarters, followed by cessation of quarter milk production for the remainder of lactation, was effective in reducing cow–level SCC and whether that quarter resumed milk production following calving. Three treatment groups were used: CH, non-hydrolyzed casein (NHC), and cessation of milking only (negative; N). Treatments were assigned in a 2:2:1 ratio for 40 cows enrolled in the study; 27 cows completed the entire protocol. Following IMM infusion and involution of the single mastitic quarter, decreases in cow–level SCC (-966,000/ml) and milk production (-11 lb (5 kg), -14%) with 3 remaining lactating quarters were significant for all 28 cows combined. Cows treated with CH (n=17) had a significant decrease in cow– level SCC (-1,150,000/ml) during remaining lactation. All treated quarters returned to milk production after calving, and their proportion of total–cow milk production (24%) was not different than before treatment (28%). After calving, treated quarters’ decrease in SCC was significant for CH (-2,763,000/ml; n=14) and N (–5,324,000/ml; n=5). Of 16 quarters with positive milk culture before treatment that completed the protocol, 88% (14/16) were cured (no isolation of the same bacteria for 3 weeks following calving). A new intramammary infection (IMI) was detected in 67% (18/27) of previously treated quarters post-calving. Infusing single mastitic quarters with casein hydrolysate to induce involution for the remainder of lactation may be a promising alternative to current methods.