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

Abstract

Oral supplementation of clay to dairy cattle has been reported to reduce toxicity of aflatoxin (AF) in contaminated feed. The objective of this study was to determine the effects of 3 concentrations of dietary clay supplementation in response to an AF challenge. Ten multiparous rumen-cannulated Holstein cows [body weight (mean ± SD) = 669 ± 20 kg and 146 ± 69 d in milk], were assigned to 1 of 5 treatments in a randomized replicated 5 × 5 Latin square design balanced to measure carryover effects. Periods (21 d) were divided in an adaptation phase (d 1 to 14) and a measurement phase (d 15 to 21). From d 15 to 17, cows received an AF challenge. The challenge consisted of 100 μg of aflatoxin B (AFB)/kg of dietary dry matter intake (DMI). The material was fitted into 10-mL gelatin capsules and administered into the rumen through a rumen-cannula based on the average DMI obtained on d 12 to 14. Treatments were no clay plus an AF challenge (POS); 3 different concentrations of clay (0.5, 1, or 2% of dietary DMI) plus an AF challenge; and a control consisting of no clay and no AF challenge (C). Statistical analysis was performed using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC). Two contrasts, CONT1 (POS vs. C) and CONT2 (POS vs. the average of 0.5, 1, and 2% clay), were compared along with the linear and quadratic treatment effects (POS, 0.5%, 1%, 2%). Cows supplemented with clay had lower AF excretion in milk as aflatoxin M (AFM; 0.5% = 20.83 μg/d, 1% = 22.82 μg/d, and 2% = 16.51 μg/d) and AF transfer from rumen fluid to milk (AFM 0.5% = 1.01%, 1% = 0.98%, and 2% = 0.74%) compared with cows in POS (AFM = 27.81 μg/d and AF transfer = 1.37%, CONT2). Similarly, concentrations of AFM in milk (0.5% = 0.35 μg/kg, 1% = 0.30 μg/kg, 2% = 0.25 μg/kg), AFB in feces (0.5% = 1.79 μg/g, 1% = 1.52 μg/kg, 2% = 1.48 μg/kg), and AFB in rumen fluid (0.5% = 0.05 μg/kg, 1% = 0.02 μg/kg, 2% = 0.02 μg/kg) were reduced in cows fed clay compared with POS (0.43 μg/kg, 2.78 μg/kg, and 0.10 μg/kg, respectively, CONT2). Cows supplemented with clay tended to have lower 3.5% fat-corrected milk [0.5% = 38.2 kg, 1% = 39.3 kg, 2% = 38.4 kg, standard error of the mean (SEM) = 1.8] than cows in POS (41.3 kg; SEM = 1.8; CONT2). Plasma superoxide dismutase (SOD) concentration tended to be lower for cows fed clay in the diet (0.5% = 2.16 U/mL, 1% = 1.90 U/mL, 2% = 2.3 U/mL; SEM = 0.3) than for cows in POS (2.72 U/mL; CONT2). Additionally, when cows were exposed to AF without clay in the diet, plasma concentrations of aspartate aminotransferase (AST) decreased from 84.23 (C) to 79.17 (POS) and glutamate dehydrogenase (GLDH) decreased from 91.02 (C) to 75.81 (POS). In conclusion, oral supplementation of clay reduced the transfer of AF from the rumen to milk and feces.

Feed additives containing sequestrant clay minerals and inactivated yeast reduce aflatoxin excretion in milk of dairy cows

“…We found that both additives markedly reduced the percentage of AF transferred into milk, from 2.7% in PC to 1.0 and 1.3 ± 0.2% for TN and UP, reductions of 63 and 52%, respectively (P < 0.001). The reduction in percentage transfer is similar to that reported for other mycotoxin-sequestering additives (transfers of 0.32 to 3.68%, reductions of 27-70%; Kutz et al, 2009;Sulzberger et al, 2017;Xiong et al, 2018), but is comparatively high, indicating the efficacy of TN or UP in reducing AF residues in milk.…”

“…On the other hand, the reductions in concentration of AFM 1 in urine of TN or UP, relative to PC, did not closely match the corresponding reductions in milk AFM 1 , perhaps because urine was only collected at a single time point. Few others have investigated urinary excretion of AFM 1 , but Sulzberger et al (2017) also found higher concentrations of AFM 1 in urine than milk and reported that, whereas dietary additives reduced AFM 1 in milk, there was no such effect on urinary concentrations. Similarly, Weatherly et al (2018) found higher concentrations of AFM 1 in urine compared with milk, although the dietary additives tested in that study were not effective in reducing concentrations of AFM 1 in milk or urine.…”

“…This conclusion is supported by the study of Phillips et al (1988) who reported that once radiolabeled AF was sorbed to a mycotoxin-sequestering additive (aluminosilicate), it remained bound to the additive even after a series of eluotropic solvents were used to extract the AF. Sulzberger et al (2017) reported that fecal concentrations of AF decreased with increasing dose of clays in the diet and suggested that clay-bound AF may be undetectable. Recently, Weatherly et al (2018) also reported that a yeast and bentonite clay-based adsorbent tended to reduce AF in feces.…”

Effects of lactic acid bacteria and smectite after aflatoxin B1 challenge on the growth performance, nutrient digestibility and blood parameters of broilers

“…Both LAB and smectite showed protective effects on the serum biochemical parameters in this study. These effects were evident because smectite as an adsorbing agent can effectively bind AFB 1 to lower or avoid these harms (Oguz et al, 2003;Raju & Devegowda, 2000;Sulzberger, Melnichenko, & Cardoso, 2017). In addition, LAB as probiotics were also shown to be capable of enhancing growth and health.…”

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

“…Oral supplementation of clay (at 0.5%, 1%, 2%) to dairy cattle has been reported to reduce toxicity of AFs in contaminated feed (100 μg of AFB1/kg of dietary dry matter intake) (Sulzberger et al, 2017). Concentrations of AFM1 in milk, AFB1 in faeces and AFB1 in rumen fluid were reduced in cows fed with clay compared with positive control with no clay.…”