**1. Introduction**

The notion of fungus refers to a large array of eukaryotic structures, unicellular or multicellular, as they are regulated through ISO 21527–1 and 21,527–2, which cancel and replace ISO 7698:1990, ISO 7954:1987 and ISO 13681:1995.

Molds are free of chlorophyll, mesophilic aerobic filamentous microorganisms which, on the surface of mycological agar medium, under some conditions (0.7–0.9 water activity (aw) and usually 25 ± 1°C temperature), develop flat or fluffy spreading propagules/germs or colonies often with colored fruiting or sporing structures [1, 2].

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The majority of microfungi are saprobiotic organisms that can be seen in all-natural media – earth, water, air. In nature, fungi can grow and invade any type of food, at any moment, if the conditions favorable for their growth are created. The latter are in general represented by: substrate humidity higher than 11.5%, relative humidity of the air of over 70%, oxygen presence of 1–2%, temperatures between 5 and 40°C, substratum pH of 4–8, aw between 0.7 and 0.85, relatively low light intensity and plant stress under the action of unfavorable medium factors (action of damaging insects, climate factors etc.).

differences in the conditions of production for fungi and the mycotoxins associated to them

In general, the favoring factors for the development of fungi and the production of mycotox-

• Physical: relative humidity, substrata humidity, water activity, temperature, fodder integrity.

In general, with aw of 0.85 at 25°C which corresponds to approximately 14–16% humidity,

• Reduction in the reproductive performances until the entire reproductive system is affected.

The symptoms are most often nonspecific, which makes the diagnostic difficult or even impossible. The difficulty in diagnosing mycotoxicoses is given as well by the occurrence of multiple mycotoxins, their uneven distribution in the fodder mass, the influence of certain

Aflatoxins (AF) are mycotoxines produces in nature by fungi species of the *Aspergillus (A. flavus* and *A. parasiticus*) and more rarely *Penicillium* (*P. puberulum*, *P. citrinum, P. variable* and *Rhizopus* types. The notion of aflatoxin in common languages refers to all its four represen-

), AFG1

qualitative difference regarding the ability of the different fungi species of producing these

metabolites are hydroxylated derivatives of aflatoxins B1

in the animal milk following the consumption by the cows of food that has been contaminated

At present, the kinetics of the transformations and the risk associated with the consumption and absorption of aflatoxins is well known, both at animals and at humans. The main conjugation way of aflatoxins is glucurono-conjugation, the resulting complex being eliminated

(C17H12O7

. Aflatoxins B2

. From a mycologic point of view there is a large quantitative and

, M<sup>2</sup>

) and AFG2

and G2

, B2a, AFL, AFL-M1

(C17H14O6

Dairy Cows Health Risk: Mycotoxins http://dx.doi.org/10.5772/intechopen.72709 87

are dehydrogenated

, P<sup>1</sup> , Q<sup>1</sup> , H1

and B<sup>2</sup>

). *A. flavus*

secreted

• The reduction of the ingestion of food until it is completely refused y the animal.

• Reduction in the absorption of nutrients and the affliction of the metabolism.

are significantly different.

ins can be divided into three main categories:

fungi spores germinated within 5 to 12 days. Moreover, the effects of mycotoxins consist of:

• Alteration of the endocrine and exocrine systems.

factors linked to the animal, ration and climatic conditions.

), AFB2

mycotoxins, about half of the *A. flavus* species producing aflatoxins [4].

as well as AFB<sup>1</sup>

The AF group comprises around 20 mycotoxins (e.g. M1

(C17H14O6

and AFB<sup>2</sup>

(C17H12O6

and AFB<sup>2</sup>

, AFG2

and M<sup>2</sup>

• Suppression of the immune system.

**2.1. Aflatoxins**

tative forms: AFB1

derivatives of AFB<sup>1</sup>

produces AFG1

etc.). The M1

with these [5].

• Chemical: pH, substrata composition of nutritive substances.

• Biological: presence of some microorganisms and/or invertebrates.

The direct action of fungi over live organisms is of tissular destructive levels and can be limited or generalized, determining diseases named mycoses. In the pathology of ruminants, the following types of fungi are generally involved: *Absidia, Alternaria, Aspergillus, Candida, Cryptococcus, Fusarium, Mucor, Penicillium, Rhizopus, Rhodotorula, Sporothrix, Stachybotrys, Trichoderma, Trichophyton, Trichosporon*. Of these, there are certain types which are recognized as having mycotoxigen potential: *Aspergillus, Fusarium, Penicillium, Mucor* and *Rhizopus*. According to FAO/IAEA, mycotoxines are secondary metabolites of fungi, non-volatile, organic, developed by fungi in both food and fodder [3].

The optimal temperature and humidity for developing a species of fungi does not correspond to the optimal parameters mentioned to produce mycotoxins, which determines a disparity between the presence of a species of fungi and the mycotoxins developed at that moment in the respective substrate. Note that there can be situations in which we find in analyzed food or fodder either only fungi, fungi and the mycotoxin/mycotoxins they produce or only mycotoxins. Mycotoxins are developed through a secondary metabolic process, which differs to the primary metabolism through its random nature, the diversity of compounds developed and the specificity of the thalli involved. The metabolic chains involved in the production of mycotoxins respond to the signals received by the fungus from the outside medium, thus not being related to cellular growth.

The diseases resulting from the activity of mycotoxins are named mycotoxicoses. The acute forms have a rapid evolution and are produced due to the action of high doses of mycotoxin over an organism. The chronicle forms, much more common, imply a slow development of the infection.

In general, ruminants, compared to monogastric animals, are considered resistant to the action of most mycotoxins, attitude explained by the detoxifying role of ruminal microsymbionts and especially protozoa. Ruminal and intestinal microorganisms do not significantly degrade mycotoxins when the ruminant's food is rich in concentrated fodder, as an example, or when the quantity of mycotoxins ingested reaches over certain limits. Equally, rumen metabolites of the parent mycotoxins can become, after ruminal biodegradation, not just less toxic but, in some cases, also more aggressive than the initial substance. Even so, the clinical examination performed on the dairy cows from the studied farm did not reveal the presence of any symptom characteristic to mycoses or to mycotoxicoses at dairy cows. From this perspective, it is extremely useful the analysis of the quality of fodder in regards to their contamination with fungi and/or mycotoxins and the application of preventive measures for the health of the animals.
