Absorption, distribution and excretion of aflatoxin-derived ammoniation products in lactating cows

Abstract

Peanut meal naturally contaminated with 3.5 mg/kg aflatoxin B1 (AFB1) was spiked with radiolabelled AFB1 (meal 14C-I0) and decontaminated by a small-scale copy of an industrial ammoniation process (meal 14C-I1). During the process 15% of the radioactivity was lost, whereas 90% of the remaining radiolabel could not be extracted from the meal. In the extractable part, AFB1 accounted for 10% of the radiolabel, consistent with a total AFB1 reduction of more than 99%. No degradation products were observed in the extracts. Four lactating cows were fed with a diet containing 15% of either meal 14C-I0 or 14C-I1 for 10 days. On day 9 of this treatment, respectively 23 and 67% of the radiolabel was excreted in the urine and faeces of cows fed meal 14C-I0, as compared with 2 and 101% in the case of cows fed meal 14C-I1. Milk contained respectively 1.35 (meal 14C-I0) and 0.25% (meal 14C-I1) of the radiolabel. Milk samples taken during the equilibrium stage contained respectively 5 and 0.5 ng/ml of AFB1-derived compounds. Aflatoxin M1 (AFM1) accounted for 50-80% of these compounds in the case of milk from cows fed 14C-I0, as compared with 6-20% in the case of 14C-I1. AFB1 to AFM1 carry-over rates for 14C-I0 or 14C-I1 were estimated to be respectively 0.5 and 5.9%. Only liver and kidney samples contained detectable levels of the radiolabel, being respectively 260 and 37 micrograms/kg for cows fed meal 14C-I0, and 10 and 3 micrograms/kg for those fed meal 14C-I1. In the latter case, more than 55% of the radiolabel in the liver could not be extracted, as compared with 90% in the group fed meal 14C-I1. A small part of the extractable radiolabel in the livers of cows fed meal 14C-I0 could be attributed to AFB1 and AFM1 (less than 1% of total radioactivity). In the case of the animals fed 14C-I1 there were indications for the presence of AFB1 and AFM1 (6% of total radioactivity). Decontamination of the highly contaminated (non-radiolabelled) peanut meal by two different industrial ammoniation processes, resulted in a similar reduction of the initial AFB1 levels of 3.5 mg/kg to 15 micrograms/kg. Feeding of diets containing 15% of the non-treated and two treated peanut meals to cows for a period of 10 days, resulted in AFM1 levels in milk of respectively 2.1, 0.04 and 0.07 ng/ml. AFB1 to AFM1 carry-over rates were calculated to be respectively 0.5, 2.0, and 3.6%. It is concluded that the efficient reduction of aflatoxin levels by ammoniation of contaminated peanut meal results in a strong reduction of aflatoxin-related residues in milk and meat of cows, most likely caused by a decreased bioavailability of the degradation products.

Inhibitory effects of Thyme oils on growth and aflatoxin production by Aspergillus parasiticus

“…The results are also more promising than the effects of ammoniation reported by other investigators (Namazi et al, 2002). More recently, it has been shown that feeding lactating cows with ammoniated peanut meal can result in reduced levels of aflatoxin M1 in milk of cows (Hoogenboom et al, 2001). Examination of various concentrations of thyme essential oils on a potentially active fungal strain (A. parasiticus NRRL-2999) in this study shows promising prospectus on the utilization of natural plants or their oils and extracts.…”

Effects of clay after an aflatoxin challenge on aflatoxin clearance, milk production, and metabolism of Holstein cows

“…Few data have been reported on bodily excretions of AF. However, fecal concentrations of AFB 1 were measured by Hoogenboom et al (2001). To do this, 2 types of aflatoxin were fed to cows, one that was pure AFB 1 or known as unaltered and an AFB 1 that had been labeled with a radioactive agent that underwent decontamination so as to not cause harm to the animal and was intended to have reduced bioavailability to the cow so it would in fact be excreted through the digestive system.…”

“…Barrientos-Velazquez et al (2016) reported that when artificial gastric fluid was introduced to an in vitro system, the adsorption of AF was reduced by 60% using bentonite. The normal mechanism for adsorbents to bind with AF is by sequestration of AF in the gastrointestinal tract and chemisorption-tight bonding between the molecules (Kubena et al, 1998;Hoogenboom et al, 2001). This may explain why the rumen and fecal concentrations of AF were significantly decreased for cows fed clay in the diet.…”

Aflatoxins of type B and G affect porcine dendritic cell maturationin vitro

“…Although the exact proportion of AFB 1 , -B 2 , -G 1 , and -G 2 in Aspergilluscontaminated feed and foods is unclear, these molds predominantly produce AFB 1 and to a lesser extent the other three AF in feed (Cervino et al, 2008;Joubrane et al, 2011;Li et al, 2009). AFB 1 is the most immune-disruptive aflatoxin, as a lower bioavailability and less toxic nature for AFB 2 , -G 1 , and -G 2 have been reported (Cusumano et al, 1990;Hoogenboom et al, 2001;Mehrzad et al, 2011). Although the occurrence of AF-contaminated food/feed has decreased substantially in more affluent, but not in developing, countries due to the presence of extensive monitoring programs, the contamination of agricultural commodities by AF-producing fungi nevertheless remains a serious threat for animal and public health (Martins et al, 2007;Hernández Hierro et al, 2008;Pukkala et al, 2009).…”