Innovative dry cow therapy

The ability of an internal teat sealer (ITS) administered at dry-off for the prevention of new intramammary infections (IMI) and for the cure of existing IMI during the dry period was examined. In addition, incidence of clinical mastitis (CM), pattern of somatic cell count (SCC), particulate matter recovery, and milk production during the subsequent lactation were measured. The California mastitis test (CMT) was evaluated for its ability to identify cows and quarters with IMI at dry-off.

The quarter-level CMT results, interpreted in parallel to form a cow-level test result, were an effective way to identify infected cows for treatment of DCT. Using an ITS in conjunction with DCT provided enhanced protection from the development of new IMI during the dry period when compared with DCT alone, although it had no additional benefit on the cure of existing IMI. An ITS alone provided enhanced protection against the development of new environmental IMI during the dry period when compared with DCT alone. There was no reduction in the incidence of CM during the subsequent lactation when an ITS was utilized either in combination with DCT or alone. Quarters treated with ITS have significantly more particulate matter recovered during the first day postpartum when compared with quarters treated with DCT. Internal teat sealers had a negative impact on milk production during the first six months of the subsequent lactation.

In summary, ITS are an efficacious addition to dry cow programs to aid in the prevention of new IMI. The effects of ITS on milk production need to be studied further to help clarify the effect found in the current study. Lastly, the CMT is an inexpensive, effective and efficient way to identify infected cows at dry-off. This finding will be useful to assist farmers in adopting selective dry cow programs.