Behavior of the Holstein dairy farming system in Brazil between 1980 and 1992 (part 1)

The Holstein breed has been successfully used for milk production in many countries, because of its genetic potential for milk production. In Brazil, the Holstein breed performs well under good management practices. This study aimed at giving an overview of the development of the Holstein dairy system in Brazil by evaluating its structure and properties in terms of trends in milk yield from 1980 and 1992. This evaluation shows the persistence of the system in maintaining production over the long term, concerning routine fluctuations in response to disturbances.This research is a partial study on the sustainability of the Holstein dairy system in Brazil. Data provided by the National Dairy Database consist of lactation records from Holstein cows registered by milk recording services of theBrazilian Holstein Breeders Association from 1980 to 1992. There were154,053 lactation records available. The most representative system was selected: cows milked twice a day, from the South and Southeast regions which included 118,802 records from the states of Minas Gerais, Sao Paulo, Parana, Santa Catarina and Rio Grande do Sul. The analyses included the distribution of number of records, level and range of production. Milk yields were adjusted to 305 days.The development of the milk recording system is reflected by the increasing number of lactation records in the course of the period, independent of lactation number. However, in 1990 the system was evidently disturbed. Its resilience was shown by the capacity to recover in number of records as well as in production level, thus maintaining system stability. The results of the distribution analysis showed an increasing variation in the range of production values. The median showed little variation across years.