Resumen

NESCIER, I et al. Vías de contaminación de la leche con esporas generadoras de gas butírico (clostridium) a partir del silaje consumido por las vacas lecheras. FAVE. Secc. Cienc. agrar. [online]. 2015, vol.14, n.1. ISSN 1666-7719.

Routes of contamination of raw milk with butyric gas generating spores (Clostridium) from silage fed to dairy cows. Raw milk contamination with spores (Clostridium) generates defects in hard and semi-hard cheeses. One of the main causes is the consumption of contaminated silage by dairy cows. Alterations in animal health have also been associated with the consumption of poor quality silage. The aim of this paper is to analyze the degree of association between: quality, extraction and distribution of silage and dung contamination of lactating cows. Milk samples from bulk milk tanks were obtained in order to know the potential impact of the quality of the silages consumed by cows, as a risk factor on the milk delivered to the industry. The exploratory study was performed in nine dairy farms, located in the departments "Las Colonias" and "San Justo" (Province of Santa Fe), which used corn and sorghum silage (silo bags) most of the year. Samples were taken to determine fermentation quality of silage. Faecal samples from lactating cows were analyzed as indicators of contamination of silage consumed (NMP clostridium/g faeces). The determination of anaerobic spore-forming microorganisms fermenting lactate in raw milk (NMP sporulated/l milk) was performed on bulk tank milk samples. Information of the technology used for the extraction and distribution of silage, was collected. The sample period starts in autumn 2010, ending in the fall of 2011. The highest loads of spores were found in autumn and winter period, in which the use of silage is maximized. The data was analyzed using multivariate statistical INFOSTAT. The results indicate association between the variables: NMP spores/g of faeces and silage extraction, and NMP spores/g faeces and silage distribution, considering the dairy and time of year variables. Independence between the variables fermentative quality of silage and NMP of spores/g in faeces, was found. The silos generally were considered of good quality, leading to the conclusion that the greatest risk of contamination occurred during the extraction and distribution of silage. It would be necessary to improve the training of producers and operators in relation to these processes. When the values were higher in faeces (NMP> NMP 40.000 spores/g faeces), high levels of contamination in milk, was observed.

Palabras clave : Clostridium spores; Silage; Extraction and Distribution Technology.