Date Published: July 17, 2006
Publisher: BioMed Central
Author(s): Cecilia Hamilton, Ulf Emanuelson, Kristina Forslund, Ingrid Hansson, Torkel Ekman.
Mastitis is one of the major threats to animal health, in organic farming as well as conventional. Preliminary studies of organic dairy herds have indicated better udder health in such herds, as compared to conventional herds. The aim of this paper was to further study mastitis and management related factors in certified organic dairy herds.
An observational study of 26 certified organic dairy herds in mid-eastern Sweden was conducted during one year. A large-animal practitioner visited the herds three times and clinically examined and sampled cows, and collected information about general health and management routines. Data on milk production and disorders treated by a veterinarian in the 26 herds, as well as in 1102 conventional herds, were retrieved from official records. Multivariable logistic regression was used to assess associations between herd type (organic vs. conventional) and incidence of disorders.
The organic herds that took part in the study ranged in size from 12 to 64 cows, in milk production from 3772 to 10334 kg per cow and year, and in bulk milk somatic cell counts from 83000 to 280000 cells/ml. The organic herds were found to have a lower incidence of clinical mastitis, teat injuries, and a lower proportion of cows with a high somatic cell count (as indicated by the UDS, Udder Disease Score) compared to conventional herds. The spectrum of udder pathogenic bacteria was similar to that found in other Swedish studies. Treatment of mastitis was found to be similar to what is practised in conventional herds. Homeopathic remedies were not widely used in the treatment of clinical mastitis.
Udder health in Swedish organic herds appears to be better than in conventional herds of comparable size and production. The major difference in management between the two types of farms is the proportion of concentrates fed. The mechanisms explaining the association between intensity of feeding and udder health in dairy cows require further research.
Mastitis is one of the major threats to animal health, in organic farming as well as conventional. Mastitis therapy accounts for a very large proportion of antibiotic drug use in dairy production [1-4] and one of the aims of organic production is to reduce the use of antibiotics . Thus, according to the standards of organic production, animals treated with such restricted substances are subject to doubled withdrawal periods before milk may be sold to the dairy. To be able to reduce use of antibiotics it is important to keep the animals healthy by providing optimal care, feed and housing. Concern about the well-being of cows on organic dairy farms because of dietary restrictions has, however, been voiced among veterinarians. Our preliminary studies of organic dairy farms indicated better udder health in such herds, as compared to conventional herds [6,7], although no differences in overall animal health and welfare could be identified in other studies . This paper will focus on aspects of udder health.
The mean herd size was 32 cows (range 13–64) for the organic herds and 33 cows (range 13–65) for the selected conventional herds. Mean milk yield per cow was 6213 kg (range 3772–10334) and 7572 kg (3802–11379) for the organic and conventional herds, respectively, while corresponding numbers for geometric mean BMSCC were 173000 cells/ml (range 83000–280000) and 191000 cells/ml (range 45000–540000).
Udder health in Swedish organic herds appears to be better than in conventional herds of comparable size and production. The major difference in management between the two types of farms is the proportion of concentrates fed. The mechanisms explaining the correlation between intensity of feeding and udder health in dairy cows require further research.
The author(s) declare that they have no competing interests.
CH carried out the field study, compiled the results and drafted the manuscript. UE participated in the design of the study, compiled and analysed the official data. KF initiated the study, participated in the design and coordination of the study. IH participated in the field study. TE initiated the study, participated in the design and coordination of the study. All authors read and approved the manuscript.