animals
Article
Effect of Different Farming Practices on Lactic Acid Bacteria
Content in Cow Milk
Luciana Bava
1
, Maddalena Zucali
1,
* , Alberto Tamburini
1
, Stefano Morandi
2
and Milena Brasca
2
Citation: Bava, L.; Zucali, M.;
Tamburini, A.; Morandi, S.; Brasca, M.
Effect of Different Farming Practices
on Lactic Acid Bacteria Content in
Cow Milk. Animals 2021, 11, 522.
https://doi.org/10.3390/ani11020522
Academic Editor: Ton Baars
Received: 8 January 2021
Accepted: 15 February 2021
Published: 17 February 2021
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4.0/).
1
Department of Agricultural and Environmental Sciences, University of Milan, via Celoria 2,
20133 Milan, Italy; luciana.bava@unimi.it (L.B.); Alberto.tamburini@unimi.it (A.T.)
2
National Research Council, Institute of Sciences of Food Production, via Celoria 2, 20133 Milan, Italy;
stefano.morandi@ispa.cnr.it (S.M.); milena.brasca@ispa.cnr.it (M.B.)
* Correspondence: maddalena.zucali@unimi.it; Tel.: +39-02-5031-6452
Simple Summary: Lactic acid bacteria (LAB) are the most important players to guarantee a correct
cheesemaking process, and to define aroma profile and texture of the cheese. The natural prevalence
of LAB in milk is variable, thus, the aim of the study was to identify the relationship between
farm management practices, i.e., cow cleaning, bedding materials and management, ingredients in
the feed ration and the presence of LAB and different other important groups of bacteria in cow
bulk milk during different seasons. Information about farm management and milk bulk samples
were collected in 62 dairy farms located in Po plain (Lombardy, Italy), most of them destined as
milk for the production of Grana Padano Protected Denomination of Origin (PDO). Data from milk
analyses and farm management practices were processed using multi-factor analyses in order to look
for complex relations among variables, as in the farm environment. LAB content in milk did not
result significantly different between seasons. Large farm dimension, high milk production and the
application of a complete milking routine reduced microbial population in milk but promoted a high
percentage trend of LAB on total bacteria count. The study underlined that the different management
practices at the farm level could have an important effect on cheesemaking bacteria.
Abstract: The natural load of lactic acid bacteria (LAB) in milk is the basis of the production of
raw milk cheeses, such as Grana Padano PDO. In the last decades, improvements in livestock
hygiene management resulted in bulk cow milk with less than 20,000 colony forming units (CFU)
of bacterial count, unable to ensure a sufficient supply of LAB, with a negative impact on cheese
quality. This study investigated the relations between farm management practices and prevalence
of different groups of bacteria in cow milk. Sixty-two intensive dairy farms located in Lombardy
(Italy) where involved, most of them destined as milk for the production of Grana Padano. Season
had no significant effect on the content of most of the bacterial groups, except for coliforms. A
strong relation among standard plate count (SPC) and other bacterial groups was evidenced. Cluster
analysis showed that the most productive farms applied a complete milking routine and produced
milk with the lowest value of SPC, the lowest count of the other bacteria, including LAB, but the
highest LAB/SPC. The study suggests that complexity of farming practices can affect the microbial
population of milk.
Keywords: lactic acid bacteria; milk; farming practices; milk quality
1. Introduction
In Europe, raw milk must meet the legal requirements for the bacterial load (≤100,000
colony forming units (CFU)/mL) and it must be free of pathogenic microorganisms when
intended for human consumption (Regulation (EC) 853/2004), that means parameters
closely related to milk spoilage and safety. On the other hand, the bacterial load, which
constitutes an indicator of hygienic-sanitary quality, is not itself a parameter which guar-
antees the presence of lactic acid bacteria (LAB), which are the leading players in the
Animals 2021, 11, 522. https://doi.org/10.3390/ani11020522 https://www.mdpi.com/journal/animals