Bioavailability of aflatoxin B1 and ochratoxin A, but not fumonisin B1 or deoxynivalenol, is increased in starch-induced low ruminal pH in nonlactating dairy cows

Abstract

High-production dairy and beef systems require diets rich in starch. This practice may induce ruminal acidosis and also increase exposure to mycotoxins because starches in starch-rich diets are the main vehicles of mycotoxin contamination. The aim of this study was to investigate the effects of low ruminal pH on the bioavailability of 4 major mycotoxins [i.e., aflatoxin B (AFB1), ochratoxin A (OTA), deoxynivalenol (DON), and fumonisin B (FB1)]. Eight nonlactating dairy cows fitted with rumen cannulas were used in a double crossover experiment. The trial was divided into 4 periods with 2 periods per crossover. Cows were divided into 2 groups receiving a low (15% dry matter basis) and high-starch diet (30.8%) with and without live yeast supplementation (1×10 cfu per cow) in the first and second crossover, respectively. At the end of each period, cows received a single dose of mycotoxin-contaminated feed containing 0.05, 0.2, 0.24, and 0.56mg of AFB1, OTA, DON, and FB1 per kg of feed, respectively. The fecal and urinary excretion of mycotoxins and their metabolites was monitored for up to 48h postdosing. As expected, ruminal pH decreased in cows fed the high-starch diet. The high-starch diet increased the bioavailability of OTA and AFB1. Urinary excretion of OTA 24h after mycotoxin administration increased 3-fold in the high-starch diet, correlated with lower fecal excretion. Similarly, a decrease in fecal excretion of AFB1 was accompanied by an increase in urinary excretion of its major metabolite, aflatoxin M, 48h after mycotoxin administration. In contrast to AFB1 and OTA, the bioavailability of DON and FB1 remained unchanged. Yeast supplementation had no effect on the excretion balance of these 2 mycotoxins. In conclusion, these results show that high-starch diets increased the bioavailability of OTA and AFB1, most probably through the lowering effect on ruminal pH. This greater bioavailability potentially increases the toxic effects of these mycotoxins.

Mycotoxin mixtures in food and feed: holistic, innovative, flexible risk assessment modelling approach:

“…This practice may induce ruminal acidosis and also increase exposure to mycotoxins because starches in starchrich diets are the main vehicles of mycotoxin contamination (Pantaya et al, 2016). This practice may induce ruminal acidosis and also increase exposure to mycotoxins because starches in starchrich diets are the main vehicles of mycotoxin contamination (Pantaya et al, 2016).…”

DI/LC–MS/MS-Based Metabolome Analysis of Plasma Reveals the Effects of Sequestering Agents on the Metabolic Status of Dairy Cows Challenged with Aflatoxin B1

“…However, it represents a typical natural level of AFB1 in corn samples [23] and is within the range (20-100 µg/kg) used in previous studies [7,24]. The results of receiver-operator characteristic (ROC) analysis between C and T groups revealed five metabolites (arginine, alanine, methylhistidine, citrulline, and proline) with respective areas under the curve (AUC) of 0.88, 0.86, 0.86, 0.81, and 0.80.…”

“…Metabolite data were subjected to multivariate analysis using Metaboanalyst 4.0 software (www. metaboanalyst.ca) [24]. Prior to multivariate analysis, data were log-transformed and pareto-scaled.…”

Isolasi dan karakterisasi bakteri yang berpotensi mengikat aflatoksin di rumen sapi

“…and Van Soest, (1970) menggunakan 25 mL larutan buffer sitrat phosphate dan 15 m cairan rumen untuk analisis pengikatan aflatoksin. Adapun analisis VFA menggunakan 0,8 ml cairan rumen yang dicampur dengan 0,5 mL dari 0,4 mg/mL asam crotonic dan 20 mg/ ml asam metaphosphoric dalam 0,5 N HCl dan disimpan dalam suhu -20°C sampai dilakukan dianalisis (Pantaya et al, 2016). Larutan asam laktat sebanyak 2 mL diletakkan dalam tube, disimpan sampai dilakukan analisis Pakan yang digunakan dalam percobaan ini menggunakan formulasi rumput gajah (Pennisetum purpureum) 8%, konsentrat 14%, dan mineral 1%.…”

“…Gallo et al (2020) melaporkan terjadi degradasi sebanyak 42 % aflatoksin saat diinkubasi secara in vitro menggunakan cairan rumen. Pendapat berbeda disampaikan oleh Pantaya et al (2016) yang melaporkan bahwa mikroorganisme rumen mampu mendegradasi seluruh mikotoksin yang diuji kecuali AFB1.…”