Discussion
Of great concern was that 28% of the producers using intramammary therapy reported using products in multi-dose containers for treatment of clinical mastitis. There are potential problems with contamination of these products with yeast and fungi and then the concurrent contamination of mammary tissue with these organisms (Reid, 1990). Of concern also is that use of products in multidose containers or non-labeled medications may result in drug residues in milk and, in fact, may violate federal law, the Animal Drug Use Clarification Act (FDA, 1996).
The majority of the producers (78%) in our study did not record cases of clinical mastitis occurring on their farms. Hoblet et al. (1991) reported that, in nine herds in Ohio that effectively controlled mastitis caused by contagious pathogens, clinical mastitis still affected 16 to 64% of the cows. The value of keeping records of the cases of clinical mastitis occurring on the dairy herd has been documented (Morse, 1991). The fact that the majority of producers on our study did not keep these records could be an opportunity to explore for extension education programming.
From DHIA records, the mean number of cows in milk of the herds that responded to our survey was about twice that of the herds that did not respond (97 vs 49). This could be an indication that smaller herds were not as interested in participating in our survey, possibly because they were not keen on adopting any new information on dairy production. The latter group of herds could have been among the smaller herds that were on the verge of leaving the dairy industry as per the trend in the five-year period (1991 to 1996) reported (NAHMS, 1996).
Producers surveyed did not appear to recognize The Ohio State University Extension as a major resource in developing the Ohio Dairy Industry. The majority (62%) had not attended an Extension meeting on any topic during the previous year. This provides an indication of producers' perception of the role of Extension in developing the dairy industry in Ohio, and could serve as a yardstick of what impact Extension has made in the dairy industry, and of how much still needs to be done. Alternatively, producers may be receiving benefit from The Ohio State University Extension such as printed material but without recognizing the source of it. Extension probably did not "market" itself well enough to be recognized.