Fusarium and Aspergillus mycotoxins contaminating wheat silage for dairy cattle feeding in Uruguay

Abstract

Wheat is one of the most important cultivated cereals in Uruguay for human consumption; however, when harvest yields are low, wheat is usually used in ensiling for animal feeding. Ensiling is a forage preservation method that allows for storage during extended periods of time while maintaining nutritional values comparable to fresh pastures. Silage is vulnerable to contamination by spoilage molds and mycotoxins because ensilage materials are excellent substrates for fungal growth. The aim of the study was to identify the mycobiota composition and occurrence of aflatoxins and DON from wheat silage. A total of 220 samples of wheat were collected from four farms in the southwest region of Uruguay were silage practices are developed. The main fungi isolated were Fusarium (43%) and Aspergillus (36%), with Fusarium graminearum sensu lato and Aspergillus section Flavi being the most prevalent species. Aflatoxin concentrations in silo bags ranged from 6.1 to 23.3 μg/kg, whereas DON levels ranged between 3000 μg/kg and 12,400 μg/kg. When evaluating aflatoxigenic capacity, 27.5% of Aspergillus section Flavi strains produced AFB1, 5% AFB2, 10% AFG1 and 17.5% AFG2. All isolates of F. graminearum sensu lato produced DON and 15-AcDON. The results from this study contribute to the knowledge of mycobiota and mycotoxins present in wheat silage.

The occurrence of aflatoxigenic Aspergillus spp. in dairy cattle feed in Southern Brazil

“…del Palacio et al reported lower values for water activity in wheat silage (around 0.70). 32 This could be attributed either to the different silage substrates or the methodology, wherein they evaluated the water activity by calculating the loss of mass after drying. 32 …”

Adverse Effects, Transformation and Channeling of Aflatoxins Into Food Raw Materials in Livestock

“…For example, del Palacio et al (2016) demonstrated that 27.5% of these strains produced AFB 1 , 17.5% of them aflatoxin G 2 (AFG 2 ) and 10% synthesized aflatoxin G 1 (AFG 1 ). Interestingly, only 5% of the strains produced AFB 2 (del Palacio et al, 2016). In another study concomitantly performed in Pakistan (Sultana et al, 2017), A. niger, A. flavus, A. fumigatus, A. ochraceous, and A. terrus were identified in both fresh fodder and corn silage.…”

Optimization of the extraction parameters of Aloe Vera polyphenols and study of antioxidant and antifungal activities: application to molds isolated from durum wheat

“…The metabolites produced by mushrooms at the time of their growth are major elements in the deterioration of the foodstuffs like the changes of the taste of the food product for example [8,9,10]. They also emerge into serious medical problems, such as the risks of intoxication by mycotoxins [11,12]. Because of its effectiveness and its easy and practical application, the use of the chemical products makes up for the present time the technique most used to fight against the harmful molds [12].…”