Effect of abraded intramammary device on milk yield, tissue damage, and cellular composition

The study was conducted to determine effects of an abraded intramammary device on milk yield, tissue damage, and milk somatic cells during late lactation. Abraded intramammary devices were inserted into diagonally opposed quarters of 20 cows. One group of 11 cows (devices inserted 30 wk of lactation) was quarter machine milked daily for 2 wk before and for 8 wk after insertion. Nine cows had devices inserted within 4 wk postpartum and were quarter milked at 20 and 40 wk of lactation. Aliquots of quarter bucket milk were obtained for determination of milk somatic cells, red blood cells, and NAGase activity. Stripping milk was obtained for milk somatic cell counts. For both groups, there was no significant effect of the abraded intramammary device on NAGase activity. There was a tendency for quarters with devices to produce less milk than control quarters, but the difference was not significant. Milk SCC were significantly elevated in quarter bucket and stripping milk from quarters containing intramammary devices. Red blood cells were higher in quarters containing intramammary devices when compared with controls. Results indicate that abraded intramammary devices increased concentrations of somatic cells and red blood cells in bucket milk, did not damage tissue as measured by NAGase activity, and loss in milk production was nonsignificant.