The Use of Casein Hydrolysate as Intramammary Therapy to Cause Cessation of Lactation at the Quarter Level in Dairy Cows

摘要

This ongoing project is investigating the efficacy of infusing chronically inflamed mammary quarters with a casein hydrolysate to involute the affected quarter and allow cessation of milking. A persistent intramammary infection in a single quarter isan important possible negative outcome in dairy cows. This can result in poor milk quality, chronic clinical mastitis, or even the death of the cow. Previous research has evaluated the use of strong iodine or chlorhexidine solutions as intramammary infusions into mastitic quarters as a method to cease production in those quarters for the six week study period (Middleton et al., 2001). Results suggested some efficacy in ceasing production from the treated quarter. However, quarters infused with iodine did not produce milk again, while quarters infused with chlorhexidine displayed milk residues up to 42 days post-infusion (Middleton et al., 2003)! Accidental milking of the treated quarter poses a possible residue risk with the use of either of these chemicals. Casein hydrolysates are found naturally among milk-borne factors that trigger involution in dairy cows (Shamay et al., 2003). The study's objectives include: Objective 1. Cessation of lactation in a single quarter meeting the case definition: SCC> 1,000,000 cells/ml (target quarter) and <400,000 cells/ml (composite milk from other three), target quarter contributing 20-30% (front) or 25-35% (rear) of total cow, cow producing > 50 lbs. of milk per day, between 30-150 days until expected dry-off date and culture results mycoplasma-negative.