Effect of diatoms on the fermentation parameters and digestibility of contaminated diet with aflatoxin B1 by microorganisms isolated from rumen in vitro condition

The present study investigated the effect of different levels of diatoms on the in vitro fermentation parameters, dry matter and organic matter digestibility of contaminated diet with aflatoxin B1. This experiment was conducted in a completely randomized design with 5 treatments and 4 replicate per treatment. The treatments were: 1.Control, 2.Control with methanol 3. Contaminated diet with methanol solution containing aflatoxin B1 at 800 ng/ml, 4, 5 and 6. Contaminated diet treated with diatoms at 7, 75 and 150 mg/200mg, respectively. Glass bottles with a volume of 100 ml was used in a constant culture to measure gas production and digestibility. All bottles were purged with anaerobic CO2, sealed with rubber stoppers and incubated in a water bath for 96 h at 39 °C. Culture parameters were measured at different time of incubation. The results showed that the lowest organic and dry matter digestibility value and highest ammonia concentration were related to treatment containing aflatoxin B1 (p<0.05). Aflatoxin caused reduction of gas production parameters, metabolisable energy and VFA compared to control groups. Addition of diatoms at medium and low level (7 and 75 mg/200mg) improved digestibility of dry matter and organic matter compared to aflatoxin group (p<0.05). Cultures containing low level of diatoms also was improved partitioning factor, microbial mass production and efficiency of microbial mass (p <0.05). In conclusion diatoms as feed additive showed promising potential in vitro to improve detrimental effect of aflatoxin on rumen function, therefore more research is guaranteed to investigate their mode of action in the ruminal microbial ecosystem.