Characterization of dairy farm soils of córdoba province and its relationship with intramammary infections.

CERIOLI FLORENCIA; RAVIOLO, JOSÉ MARÍA; SAMBUCETI, NICOLÁS; MOLIVA, MELINA V.; PALMA LEOPOLDO; REINOSO, ELINA B.

Congreso; SAIB - SAMIGE Joint meeting 2021 on line; 2021

Bovine mastitis is an infectious disease that affects dairy cows causing a reduction in milk production. The habitat of theopportunistic agents that cause the disease is the environment where the cows live, and the soil is one of the environments withthe greatest microbiological complexity. Bacteria are transmitted to the animal through improper handling of animals, lack ofhygiene, and presence of wounds on the nipples, among others. Considering that the microorganisms are distributed accordingto the environmental conditions and the availability of food and that in the first centimeters of the soil there is the greatestamount of organic matter and O2, the development of microorganisms with aerobic metabolism in this section is allowed. Theaim of this work was to characterize dairy farm soils with different prevalence of intramammary infections. Two dairy farmslocated in the province of Córdoba were selected, one with a high prevalence of mastitis due to environmental pathogens (T1)and another with a high prevalence of mastitis caused by contagious pathogens (T2). Three independent soil samples werecollected for each dairy farm and physicochemical analysis of each sample, isolation and preliminary identification at themicrobiological level were carried out. The results showed that the soil with a pH lower than 7 (T2) presented a lower bacterialcount than the soil with a pH higher than 7 (T1). On the other hand, the availability of some elements such as P, Na, N, K, Mgand Ca influenced bacterial counts, considering that the greater amount of these minerals would contribute to the developmentof microorganisms. In the samples with greater availability of these elements, bacterial development was consequently greaterin some cases, even tripling the bacterial counts (T1). In both samples, presence of Gram-positive bacteria was greater than75% and Gram-negative bacteria did not reach more than 25%. These results were preserved despite the physicochemicaldifferences of the soils. Bacteriological results were concurrent with dairy farms reports regarding the prevalence ofmicroorganisms that cause mastitis. The present study showed that the development of bacteria in the soils of dairy farms isconditioned by their physicochemical characteristics, which may affect the incidence and prevalence of intramammaryinfections.