Concentration Of Aflatoxin M1 In Milk Research Articles

Comparative Study of Aflatoxin M1 Carry-Over from Feed to Raw ‎Milk in Cow, Buffalo, Sheep, and Goats in Different Areas of ‎Baghdad Province

Mycotoxin aflatoxin B1 (AFB1) is a threat to food safety and human health because it is present in animal feed and is metabolized into aflatoxin M1 (AFM1), a more toxic form, during lactation. The aim of this study was to quantify AFM1 concentrations in raw milk of buffalos, cows, sheep, and goats sampled randomly from four regions within Baghdad ‎Province, Iraq, and to compare these levels with the maximum allowable levels set forth by the ‎European Commission (EC), the Iraqi Standard Specification (IQS), and the food and Drug Administration (FDA). The carry-over of AFB1 from feed to AFM1 in milk were also calculated for each of the ‎studied species. A total of 200 random samples, including 50 each from cows, buffaloes, ‎sheep, and goats, were collected from farms located in Zu'afraniya, Nahrawan, Abu Ghraib, and ‎Fedhalia regions. AFM1 and AFB1 concentrations were determined using the ‎enzyme-linked immunosorbent assay (ELISA). Raw milk samples from cows, sheep, buffaloes, and goats were all found to have AFM1 concentrations that were below the limits set by the EC, IQS, and FDA. Animal feed samples, on the other hand, had AFB1 concentrations of 10.08, 5.95, 4.27, and 7.10 ppb for ‎buffaloes, cows, sheep, and goats, respectively. The observed carry-over rates ranged from 0.36% ‎in goats to 0.78% in buffaloes to 0.66% in cows. Multiple factors, including animal species, ‎are considered, and it is determined that a universal carry-over equation cannot be applied to all cases. ‎Therefore, it is essential to regularly monitor AFM1 levels in milk from various animal species in order to ‎lessen potential health risks. Furthermore, the study suggests enhancing agricultural and veterinary ‎practices to better regulate feed quality for dairy animals‎‎‎‎.

Determination of Aflatoxin M1 in raw cow milk, raw camel milk, and heat-processed milk in the North region of Iran

ABSTRACT In this study, 40 milk samples (10 raw cow milk, 10 camel milk, 10 pasteurised milk, and 10 ultra-high temperature milk) were randomly collected from Golestan Province (including two cities, Gorgan and Gonbad-e Kavus) from December 2021 to March 2022. Aflatoxin M1(AFM1) level was determined by the high-performance chromatography method. AFM1 was found in all samples. The mean concentration of AFM1 in raw cow milk, camel milk, pasteurised milk, and ultra-high temperature milk were 72.81 ± 2.18, 57.10 ± 1.86, 34.73 ± 1.34, and 49.36 ± 1.78 ng/kg, respectively. The highest level of AFM1 was found in raw cow milk (p < 0.05). According to the EU standard of AFM1 level, pasteurised milk is the safest type of milk in Golestan Province.

A network meta-analysis on the efficacy of different mycotoxin binders to reduce aflatoxin M1 in milk after aflatoxin B1 challenge in dairy cows

The objective of this network meta-analysis was to determine the efficacy of different mycotoxin binders (MTB) to reduce aflatoxin M1 (AFM1) in milk. A literature search was conducted to identify in vivo research papers from different databases. Inclusion criteria were in vivo, dairy cows, description of the MTB used, doses of MTB, aflatoxin inclusion in the diet, and concentration of AFM1 in milk. Twenty-eight papers with 131 data points were selected. Binders used in the studies were hydrated sodium calcium aluminosilicate (HSCAS), yeast cell wall (YCW), bentonite, and mixes of several MTB (MX). The response variables were AFM1 concentration, AFM1 reduction in milk, total AFM1 excreted in milk, and transfer of aflatoxin from feed to AFM1 in milk. Data were analyzed with CINeMA and GLIMMIX procedures with the WEIGHT statement of SAS (SAS Inst. Inc.). The AFM1 concentration in milk decreased for bentonite (0.3 µg/L ± 0.05; mean ± SE) and HSCAS (0.4 µg/L ± 0.12), and tended to decrease for MX (0.6 µg/L ± 0.13) but was similar for YCW (0.6 µg/L ± 0.12), compared with control (0.7 µg/L ± 0.12). The percentage reduction of AFM1 in milk was similar for all MTB and different from control with a range of reduction from 25% for YCW to 40% for bentonite. The excretion of AFM1 in milk was lower in YCW (5.3 µg/L ± 2.37), HSCAS (13.8 µg/L ± 3.31), and MX (17.1 µg/L ± 5.64), and not affected by bentonite (16.8 µg/L ± 3.33) compared with control (22.1 µg/L ± 5.33). The transfer of aflatoxin B1 from feed into AFM1 in milk was lowest in bentonite (0.6% ± 0.12), MX (1.04% ± 0.27), and HSCAS (1.04% ± 0.21), and not affected in YCW (1.4% ± 0.10), compared with control (1.7% ± 0.35). The meta-analysis results indicate that all MTB reduced the AFM1 transfer into milk, where bentonite had the highest capacity and YCW the lowest.

Efficacy of Bentonite and Fumonisin Esterase in Mitigating the Effects of Aflatoxins and Fumonisins in Two Kenyan Cattle Breeds

The objective of the study was to investigate the efficacy of bentonite and fumonisin esterase, separately or combined, in mitigating the effects of aflatoxins (AF) and fumonisins (FUM) in Boran and Friesian-Boran crossbreed cattle. These effects were studied by measuring mycotoxins, their metabolites, and biomarkers that relate to animal health, productivity, and food safety. The study was divided into three experiments each lasting for 2 weeks. Cows in experiment 1 received in random order aflatoxin B1 (AFB1) [788 μg/cow/day (69.7 μg/kg dry matter intake (DMI)) for Borans and 2,310 μg/cow/day (154 μg/kg DMI) for crossbreeds], bentonite (60 g/cow/day), or both AFB1 and bentonite. Boran cows in experiment 2 received in random order FUM (12.4 mg/cow/day (1.1 mg/kg DMI)), fumonisin esterase (120 U/cow/day), or both FUM and fumonisin esterase. Boran cows in experiment 3 received in random order AFB1 (952 μg/cow/day (84.2 μg/kg DMI)) + FUM (30.4 mg/cow/day (2.7 mg/kg DMI)), bentonite (60 g/cow/day) + fumonisin esterase (120 U/cow/day), or both AFB1 + FUM and bentonite + fumonisin esterase. Feeding AFB1 and/or FUM contaminated feed with or without the addition of the detoxifiers for 14 days did not affect DMI, milk composition, hematology, and blood biochemical parameters. The addition of bentonite in a diet contaminated with AFB1 led to a decrease in milk aflatoxin M1 (AFM1) concentration of 30% and 43%, with the carry-over subsequently decreasing from 0.35% to 0.20% and 0.08% to 0.06% for crosses and Borans, respectively. No significant change was observed in the sphinganine/sphingosine (Sa/So) ratio following feeding with FUM alone or in combination with fumonisin esterase; however, the ability of fumonisin esterase to hydrolyze FUM into less toxic fully hydrolyzed FUM and partially hydrolyzed FUM was evident in the rumen fluid and feces. These results indicate bentonite was effective in decreasing AFM1 concentration in milk, and AFB1 and AFM1 in plasma, while fumonisin esterase can convert FUM into less toxic metabolites and can be a suitable addition to feed cocontaminated with AFB1 and FUM.

Aflatoxin M1 in milk does not contribute substantially to global liver cancer incidence

For 60 y, it has been known that aflatoxin B1 (AFB1), a mycotoxin produced by Aspergillus fungi in certain food and feed crops, causes hepatocellular carcinoma (liver cancer; HCC) in humans. The annual global burden of AFB1-related HCC has been estimated. However, much less is known about the potential carcinogenic impact of a metabolite of AFB1 called aflatoxin M1 (AFM1), which is secreted in milk when dairy animals consume AFB1-contaminated feed. The cancer risk of AFM1 to humans from milk consumption has not yet been evaluated. We sought to estimate the global risk of AFM1-related liver cancer through liquid milk consumption, accounting for possible synergies between AFM1 and chronic infection with hepatitis B virus (HBV) in increasing cancer risk. We conducted a quantitative cancer risk assessment by analyzing extensive datasets of national population sizes, dairy consumption patterns, AFM1 concentrations in milk in 40 nations, and chronic HBV prevalence. Two separate cancer risk assessments were conducted: assuming a possible synergy between AFM1 and HBV in increasing cancer risk in a manner similar to that of AFB1 and HBV, and assuming no such synergy. If there is no synergy between AFM1 and HBV, AFM1 may contribute ∼0.001% of total annual HCC cases globally. If there is synergy between AFM1 and HBV infection, AFM1 may contribute ∼0.003% of all HCC cases worldwide. In each case, the total expected AFM1-attributable cancer cases are ∼13-32 worldwide. AFM1 exposure through liquid milk consumption does not substantially increase liver cancer risk in humans. Policymakers should consider this low risk against the nutritional benefits of milk consumption, particularly to children, in a current global situation of milk being discarded because of AFM1 concentrations exceeding regulatory standards.

Decrease in Aflatoxin M1 Concentration in Milk during Cholesterol Removal by Application of β-Cyclodextrin.

Approximately one-third of humankind is chronically exposed to the carcinogenic aflatoxin M1 contained in milk. As β-cyclodextrin is frequently used in the food industry, its effect on aflatoxin M1 concentration was investigated during cholesterol removal from milk due to the similarity among the physicochemical properties of aflatoxin M1 and cholesterol. Moreover, the elimination of cholesterol using β-cyclodextrin has been successfully applied in many studies without any substantial effect on the quality of the treated milk. Therefore, milk samples were spiked with aflatoxin M1 within the range from 0.20 to 2.00 µg/kg, and cholesterol removal was carried out by 2.0% (w/w) β-cyclodextrin addition, as this concentration is enough for the sufficient removal of cholesterol. It was found that the mean cholesterol concentration decreased by 92.3%, while the aflatoxin M1 concentration decreased to 0.53 ± 0.04 µg/kg, i.e., by 39.1% after treatment (n = 2). This mitigation procedure itself is easy and inexpensive and thus is fully applicable with a high potential for complete decontamination of aflatoxin M1 milk. This method will therefore considerably improve the food safety issues associated with aflatoxin M1 presence in milk and dairy products.

Aflatoxin M1 in Raw Milk, Pasteurized Milk and Cottage Cheese Collected along Value Chain Actors from Three Regions of Ethiopia.

Milk is a highly nutritious and perfect natural food for humans. However, when lactating animals feed on Aflatoxin B1 (AFB1)-containing feed, the hydroxyl metabolite aflatoxin M1 (AFM1) contaminates the milk and dairy products. The objective of the current study was to assess the level of AFM1 in raw milk, normally pasteurized milk and Ethiopian cottage cheese collected from value chain actors (producers, collectors, processors and retailers). Cross-sectional study and simple random techniques were used to collect primary samples. A total of 160 composite samples was collected; raw milk (n = 64), pasteurized milk (n = 64) and cheese (n = 32) was analyzed. Quantitative analysis of AFM1 was conducted using enzyme-linked immunosorbent assay (ELISA). The results indicate that AFM1 was detected in all milk products. Results along value chains show that the concentration of AFM1 in raw milk from collectors was significantly higher than from producers, and in pasteurized milk from processors and retailers (p < 0.05). However, no significant (p > 0.05) difference was observed in cottage cheese value-chain actors in all regions. Comparison of AFM1 mean values among all dairy products shows that raw milk had a significantly higher concentration of AFM1 followed by pasteurized milk and cottage cheese. However, there was no significant difference between raw and pasteurized milk (p > 0.05). The mean AFM1 contamination in milk products ranged from 0.137 to 0.319 µg/L (mean value 0.285 µg/L). The contamination percentages of AFM1 in raw milk (62.50%), pasteurized milk (67.20%) and cottage cheese (25%) were above the regulatory limit set by the European Union (EU) (0.05 µg/L). According to USA/Ethiopian Standard (US/ES) (0.50 µg/L), 21.87%, 25% and 1% exceeded the regulatory limit for the above products, respectively. The overall prevalence (56.88%) was above the EU regulatory limit and 19.38% over US/ES regulations. Therefore, to provide accurate information about the health risk to consumers, there is a need to conduct risk assessment studies in consumers of milk and dairy products at different age groups.

Human health risk assessment of aflatoxin M1 in raw and pasteurized milk from the Kermanshah province, Iran

The principal purpose of this study was to investigate the amount and human health risk assessment by Monte Carlo simulation for aflatoxin M1 (AFM1) in milk in Kermanshah province, Iran. For this purpose, a total of 108 composite samples were analyzed for AFM1 levels using high-performance liquid chromatography with fluorescence detection (HPLC-FLD). Based on AFM1 in milk, aflatoxin B1 (AFB1) in animal feed, exposure, and human health risk were evaluated. The results showed that the total mean of AFM1 in raw milk in summer and winter was 49 ± 2 and 14 ± 1 ng/L, respectively, while in pasteurized milk was 6 ± 1 and 10 ± 1 ng/L, respectively, and in general, the mean amount of AFM1 in both raw and pasteurized milk is significantly different between summer and winter. Based on the results, it was found that 16.7% of all samples had AFM1 higher than the European Union (EU) limit (50 ng/L). Accordingly, the AFM1 level of raw milk in summer had health risks for all age groups of men and women. In conclusion, in Kermanshah province, AFM1 concentrations in milk produced by livestock should be reduced, especially during the summer seasons; basic procedures should be implemented to reduce AFB1 concentrations in lactating animals' foods.

Association between aflatoxin M1 excretion in milk and indicators of rumen fermentation in bovines.

Aflatoxins and its metabolites negatively impact the ruminant health and production. The present cross-sectional study was aimed to determine the effect of aflatoxins on rumen fermentation by deducing the correlation between the aflatoxin M1 (AFM1) excretion in milk and indicators of rumen fermentation in bovines. The indicators of rumen fermentation were taken into account and correlated with AFM1 concentration in milk of 120 bovines (cattle (n = 82) and buffalo (n = 38)). The AFM1 in milk samples (n = 120) was quantified by ELISA kit. The correlation analysis revealed that with increase in excretion of AFM1 in milk, the pH (r = 0.38), methylene blue reduction time (MBRT) (r = 0.43), sedimentation activity time (SAT) (r = 0.31) and ammonia nitrogen content (r = 0.34) of rumen liquor increase, whereas the total volatile fatty acid (TVFA) content (r = - 0.25), total bacterial count (TBC) (r = - 0.43) and total protozoal count (TPC) (r = - 0.14) of rumen liquor decrease. The results of the present study suggest that the presence of aflatoxins in rumen could have negative effect on the process of rumen fermentation. Therefore, the prevention of primary entry point(s) of AFB1 through the feed of bovines is important for the animal health as well as public health.

The use of the two different mycotoxin deactivators in the nutrition of dairy cows

The aim of this study was to investigate the effect of two different commercial products for mycotoxin deactivation in the dairy cows’ nutrition. The research was done on the 18 dairy cows in the different phase of lactation, with the average production of 14 L of milk per day. The diet contained in average 8 kg of concentrate feed, 10 kg of mixed peas and wheat forage, 4 kg hay of alfalfa and cereal straw ad libitum. Before starting the trials all components of the cows’ ration were analysed for the presence of aflatoxin B1, while cow’s milk was analysed for the presence of aflatoxin M1. In the first phase of the trial cows were fed diet containing aflatoxin B1 at level of 5±0.9 µg/kg, which resulted in the average aflatoxin M1concentration of 181±3.5 ng/kg in the milk. In the second phase of the trail 0.5% of the commercial product 1 (Neozel®) was added into the feed ration of cows and after the period of adaptation, the aflatoxin M1 concentration in milk was measured. In the third phase of the trail 0.3% of the commercial product 2 (miko-Stop 0.3®) was added into the feed ration of cows and also, after the period of adaptation, the concentration of aflatoxin M1 in milk was measured. The last phase was the control phase in which cows were fed diets with aflatoxin B1 (5 µg/kg) without added mycotoxin deactivators. The use of both commercial products for ten days resulted in the reduction of aflatoxin M1 levels for 35.9% and 53.6%, respectively.

Quantitative risk assessment for aflatoxin M1 associated with the consumption of milk and traditional dairy products in Argentina

A quantitative risk assessment for exposure to aflatoxin M1 (AFM1) related to the consumption of milk and traditional dairy products of Argentina was developed. The frequency and concentration of AFM1 was modelled at various stages through the milk processes, considering Argentinean practices. Concentration of AFM1 (0.046μg/l, 95%CI = 0.002-0.264μg/l) in raw milk was estimated. The AFM1 concentration in milk was sensitive to the carry-over rate (r = 0.80), and milk yield in the first third of lactation during the spring-summer season (r = 0.11). AFB1 levels in silage (r = 0.22), pasture during the spring-summer season (r = 0.11), concentrate (r = 0.08), and cotton seed (r = 0.05) were the factors most correlated with AFM1 concentrations. Although the results showed that MoE values for the mean and median exposure to AFM1 were < 10,000 in infants, toddlers, and other children, the additional cancer risk due to exposure to AFM1 in infants, toddlers, and other children was 0.007, 0.005, and 0.0009 additional cases per year per 100,000 individuals, respectively, which indicates no health concern. In addition, the percentages of the population exceeding HI values (HI > 1) for exposure to AFM1 for infants, toddlers, and other children were 45%, 49.1%, and 40.6%, respectively. Under this scenario, the most susceptible population at risk was children < 10years old; therefore, it is necessary to establish measures to prevent contamination of AFM1 in milk and milk products.

Detection of aflatoxin M1 in bovine milk from different agro-climatic zones of Chhattisgarh, India, using HPLC-FLD and assessment of human health risks.

Concerns regarding food safety and 'One Health' are increasing globally. Aflatoxin M1 (AFM1), a human carcinogenic toxin, is excreted by lactating animals in their milk after consumption of feed contaminated with aflatoxin B1. The present cross-sectional study aimed to determine the occurrence of AFM1 in cattle and buffalo milk produced in rural and peri-urban areas under different agro-climatic conditions of Chhattisgarh, India, and assesses human health risks. Analyses of 545 milk samples by validated high-performance liquid chromatography revealed high level of AFM1 contamination in 224 (41.1%) samples with mean concentration of 0.137 ± 0.029 μg/L. Statistically significant differences (p< 0.05) were observed in the levels and frequency of AFM1 occurrence among different agro-climatic zones. AFM1 was more frequently detected in milk samples from Northern hills (64%) followed by Bastar plateau (40.7%) and Chhattisgarh plain (27.3%), with mean concentration levels of 0.396 ± 0.099 μg/L, 0.081 ± 0.025 μg/L and 0.013 ± 0.002 μg/L, respectively. Species wise no significant difference was observed in the detection frequency and concentration of AFM1 in milk from cattle and buffalo. AFM1 contamination above maximum permissible limits established by European commission and Food Safety and Standard Authority of India was detected in 21.3% and 4.4% of samples, respectively. The estimated daily intakes for AFM1 were found to be higher than tolerable daily intakes for both adults and children, especially of Northern hills implying a potentially high risk to consumer's health. This study provides valuable information on the contamination status of milk in one of the fastest developing state of India. It also highlights the importance and need for continuous farmers' awareness on good animal husbandry practices, routine surveillance of mycotoxins in animal feeds and food commodities to safeguard human health.

The Presence of Aflatoxin M1 in Milk and Milk Products in Bangladesh.

As milk provides both micro- and macronutrients, it is an important component in the diet. However, the presence of aflatoxin B1 (AFB1) in the feed of dairy cattle results in contamination of milk and dairy products with aflatoxin M1 (AFM1), a toxic metabolite of the carcinogenic mycotoxin. With the aim to determine AFM1 concentrations in milk and milk products consumed in Bangladesh, in total, 145 samples were collected in four divisional regions (Sylhet, Dhaka, Chittagong, and Rajshahi). The samples comprised these categories: raw milk (n = 105), pasteurized milk (n = 15), ultra-high temperature (UHT)-treated milk (n = 15), fermented milk products such as yogurt (n = 5), and milk powder (n = 5). AFM1 levels in these samples were determined through competitive enzyme-linked immunosorbent assay (ELISA). Overall, AFM1 was present in 78.6% of milk and milk products in the range of 5.0 to 198.7 ng/L. AFM1 was detected in 71.4% of raw milk (mean 41.1, range 5.0–198.7 ng/L), and in all pasteurized milk (mean 106, range 17.2–187.7 ng/L) and UHT milk (mean 73, range 12.2–146.9 ng/L) samples. Lower AFM1 levels were found in yogurt (mean 16.9, range 8.3–41.1 ng/L) and milk powder samples (mean 6.6, range 5.9–7.0 ng/L). About one-third of the raw, pasteurized, and UHT milk samples exceeded the EU regulatory limit (50 ng/L) for AFM1 in milk, while AFM1 levels in yogurt and milk powder samples were well below this limit. Regarding regions, lower AFM1 contamination was observed in Chittagong (mean 6.6, max 10.6 ng/L), compared to Sylhet (mean 53.7, max 198.7 ng/L), Dhaka (mean 37.8, max 97.2 ng/L), and Rajshahi (mean 34.8, max 131.4 ng/L). Yet, no significant difference was observed in AFM1 levels between summer and winter season. In conclusion, the observed frequency and levels of aflatoxin contamination raise concern and must encourage further monitoring of AFM1 in milk and milk products in Bangladesh.

Aflatoxin M1 in pasteurized, ESL and UHT milk products from central China during summer and winter seasons: Prevalence and risk assessment of exposure in different age groups

This study aimed to investigate aflatoxin M1 (AFM1) contamination in pasteurized, extended shelf life (ESL) and ultra-high temperature (UHT) milk in central China in winter and summer, and to assess the risk of exposure to milk AFM1 in 10 different age groups. A total of 547 milk samples were collected in Henan, Hubei and Hunan provinces from 2019 to 2020, of which 142 pasteurized milk samples, 68 ESL milk samples and 69 UHT milk samples were collected in summer, and 161 pasteurized milk samples, 79 ESL milk samples and 28 UHT milk samples were collected in winter.The concentrations of AFM1 in these samples were determined by ELISA, with a recovery and relative standard deviation of 95.0–98.6% and 3.31–4.18%, respectively. AFM1 was detected in 431 samples (78.8%) with an average concentration of 19.6 ng/L in positive samples. The AFM1 concentrations in 29 samples (5.3%) were higher than the maximum residue level (MRL) of 50 ng/L set by the EU, but much lower than the value of 500 ng/L set by China. The average concentration of AFM1 (25.4 ng/L) in winter milk was 88.1% higher (p < 0.05) than that (13.5 ng/L) in summer. The concentration of AFM1 in UHT milk was lower (p < 0.05) than that in pasteurized and ESL milk in both winter and summer. Children aged 2–4 years had the highest risk of exposure to AFM1 in milk, with a mean estimated daily intake of 0.22 ng/kg bw/day. Therefore, it is necessary to strictly detect and prevent AFM1 contamination in milk, especially in winter, to reduce the risk of AFM1 exposure in humans.

An assessment of the occurrence and nutritional factors associated with aflatoxin M1, ochratoxin A, and zearalenone in the breast milk of nursing mothers in Hamadan, Iran

This research investigated the occurrence of aflatoxin M1 (AFM1), ochratoxin A (OTA), and zearalenone (ZEN) in human milk samples in the Hamadan city, Iran. The study was carried out using the milk of nursing mothers from ten governmental health care centers. Mycotoxin content of ninety milk samples measured using enzyme-linked immunosorbent assay (ELISA). All samples that tested positive for AFM1 with the ELISA test were subsequently analyzed by high-performance liquid chromatography (HPLC). The mean ± SD concentrations of AFM1, determined by ELISA and HPLC were 5.98 ± 1.47 and 4.36 ± 1.23 ng/L, respectively. OTA and ZEN levels were below the detection limit (<5 ng/L) in all samples. None of the contaminated samples exceeded the regulation limit set by the European Commission (25 ng/L) for AFM1 in infant formula. We found a significant correlation between the AFM1 concentration in breast milk and infant age and milk consumption by the nursing mother (p < 0.05). These findings revealed that infants are susceptible to AFM1 exposure from their mother's milk. The authors recommend that additional research be conducted on the analysis of foodstuff and biological fluids for various mycotoxins.

Effect of Supplemental Kluyveromyces marxianus and Pichia kudriavzevii on Aflatoxin M1 Excretion in Milk of Lactating Dairy Cows.

Simple SummaryA recent survey determining the occurrence of mycotoxins showed that almost all feedstuffs fed to dairy cattle contained aflatoxin, predominantly B1 type. The present study illustrated the potential application of aflatoxin-detoxifying yeast isolated from ruminal fluid of dairy cows to enhance the aflatoxin B1 detoxification in the rumen, to reduce the aflatoxin M1 contamination in milk and to improve dairy cattle performances. The inclusion of 2 g/day yeast into total mixed ration (TMR) diet reduced the transfer of aflatoxin B1 to aflatoxin M1 in raw milk by 72.08% and negative effects of aflatoxin B1 on dry matter intake (DMI) and milk compositions. Aflatoxin-detoxifying yeast isolates could potentially be developed for use as a feed additive to reduce aflatoxin contamination in milk and dairy products.The objective of this study was to determine the effect of supplementing Kluyveromyces marxianus CPY1, K. marxianus RSY5 and Pichia kudriavzevii YSY2 isolated from ruminal fluid of dairy cows on transfer of aflatoxin B1 (AFB1) from feed into aflatoxin M1 (AFM1) in milk, DMI, milk production and nutrient digestibility. Four multiparous Holsteins in mid-lactation were used in a 4 × 4 Latin square design trial consisting of 14 days in each experimental period for sample collection. Between each period, 14 clearance days prior to the next treatment were allowed to minimize carryover effects. In each treatment, subsequent supplementation of isolated yeast was compared, i.e., (1) control (without yeast supplementation), (2) K. marxianus CPY1 (K1Y), (3) K. marxianus RSY5 (K2Y) and (4) P. kudriavzevii YSY2 (PY). All diets contained 22.28 µg of AFB1/kg. Treatments were individually fed at the rate of 2 g/day (1 × 109 CFU/g) of yeast biomass or corn meal in the control group. Concentrations of AFM1 in milk was reduced with yeast and averaged 1.54, 0.36, 0.43 and 0.51 µg/L for control, K1Y, K2Y and PY, respectively (p < 0.01). The transfer of AFB1 from feed into AFM1 in milk was higher in control compared with K1Y, K2Y and PY (7.26% vs. 1.18%, 1.44% and 1.69% respectively, p < 0.01). Supplementation of yeast also improved DMI and milk compositions, but no differences were observed in nutrient digestibility or milk yield among treatments. Concentration and yield of milk protein, fat, lactose, solid-not-fat (SNF) and total solids were greater in cows fed yeast compared with the control (p < 0.01). These results indicate that K. marxianus CPY1, RSY5 and P. kudriavzevii YSY2 shows promise as a dietary supplementation to detoxify AFB1 and improve DMI and yield of milk components.

Effect of dietary supplementation of bentonite and yeast cell wall on serum endotoxin, inflammatory parameters, serum and milk aflatoxin in high-producing dairy cows during the transition period

Twenty-four Holstein cows were randomly allocated to four equal experimental groups containing a control (n = 6) and three treatment (n = 6) groups. Experimental animals were selected according to their average milk yield, weight, and body condition score. The experimental groups received basal diet + Saccharomyces Cerevisiae cell wall (SCW) (group 1), basal diet + bentonite + SCW (group 2), basal diet + bentonite (group 3), and basal diet (control), on a dry matter basis (group 4). Blood samples were taken 4, 3, and 1 week prior to and 1 and 3 weeks following parturition. Serum concentrations of haptoglobin (Hp), serum amyloid A (SAA), lipopolysaccharide (LPS), and concentration of aflatoxin B1 in ration and M1 in milk and blood were determined during the transition period. The results showed that LPS concentration in blood was in the normal range in all groups. The acute-phase proteins (Hp and SAA) were in the normal range as well. The concentration of aflatoxin M1 in the serum of the control group was higher than other groups, yet lower in the group receiving toxin binders (p < 0.05). The mean aflatoxin M1 concentration in milk was the lowest in the group receiving SCW (p < 0.05). Similarly, the concentration of aflatoxin M1 in milk was the highest in the control group (p < 0.05). The study also showed that the levels of endotoxin in ration of different groups resulted from our experimental diet were not high enough to stimulate APP response. It was further observed that SCW might be able to reduce the level of aflatoxin in serum and milk. The results obtained from our study may lead to a better understanding of using dietary supplements, such as bentonite and yeast cell wall, during the transitional period. Moreover, the study may contribute to our knowledge on simultaneous LPS and toxin binders for providing more safe food during the transition period in cattle.

Prevalence of aflatoxin M1 in raw milk and three types of liquid milk products in central-south China

The objective of this study was to survey the prevalence of aflatoxin M1 (AFM1) in raw, pasteurized, extended shelf life (ESL) and UHT milk from central-south China. A total of 734 milk samples, comprising raw milk (133 samples), pasteurized milk (410), ESL milk (93) and UHT milk (98), were obtained between Nov. 01, 2018 and Mar. 31, 2019.The AFM1 concentrations in milk samples were detected by ELISA and confirmed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Five hundred and ninety samples (80.4%) were positive for AFM1; the mean value was 23.7 ng/L, and the range was 5.1–104.4 ng/L. The percentages of AFM1 positive raw, pasteurized, ESL and UHT milk samples were 75.2, 82.2, 81.7 and 78.6%, respectively. The AFM1 concentration in raw milk was significantly lower (p < 0.05) than that in pasteurized and ESL milk, and the AFM1 level in UHT milk tended to be lower (p < 0.10) than that in pasteurized and ESL milk. The AFM1 levels exceeded the EU legal limit of 50 ng/L in 0, 11.5, 18.3 and 3.1% of raw, pasteurized, ESL and UHT milk samples, respectively. All milk samples tested had levels far below China's legal limit of 500 ng/L. Therefore, the AFM1 content in raw milk and milk products in central-south China does not pose a public health threat, but close attention should nonetheless be paid to milk AFM1, given the high positive rate of 80.4%.

Effects of aflatoxins on some reproductive hormones and composition of buffalo’s milk

The aim of this study was to assess the effects of feeding aflatoxins on some reproductive hormones and on the composition of buffalo milk. Forty lactating buffaloes fed total mixed rations (TMR), part of which was contaminated by fungi secreting aflatoxin. The animals were divided into two equal groups: aflatoxin high group (AHG), animals were fed TMR containing aflatoxin > 21.2 ppb, and aflatoxin low one (ACG), buffaloes were fed on TMR containing aflatoxin < 5 ppb. Blood concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), progesterone, estradiol 17s, cortisol, and prolactin were assayed. The physiochemical indices of milk samples including fat%, solid not fat (SNF%), Slats%, protein%, total solids%, and pH were measured. The aflatoxins detected in dietary ration and milk of the buffaloes were aflatoxin B1 (AFB1) and aflatoxin M1 (AFM1) respectively. The mean concentration of AFM1 in raw buffalo milk was (0.42 ± 0.043 ppb) in AHG, while there was (0.04 ± 0.002 ppb) in the ACG; the difference was significant (P < 0.05). Animals in AG, revealed a highly significant (P < 0.001) decrease in FSH, LH, and progesterone concentration compared with control animals. In contrast, estradiol 17 s and cortisol increased significantly (P < 0.01) in AHG compared with ACG. Prolactin concentration showed a slight elevation with a non-significant difference. There were no significant differences in the milk parameters between the two groups. Aflatoxins disturb some endocrine functions of the reproductive organs, which could adversely affect buffalo’s productivity.

Reduction of aflatoxin transfer into milk of lactating dairy cows with addition of a dietary clay adsorbent

Twenty-four lactating Holstein cows were used in a randomized complete block design to test the efficacy of clay at reducing aflatoxin M1 (AFM1) in milk. Cows were blocked by parity and stage of lactation and were adapted to individual feed gates prior to treatment. Cows were randomly assigned 1 of 4 dietary treatments (n=6): 1) control (CON) total mixed ration (TMR); 2) aflatoxin control (AFC) TMR with 300 ppb aflatoxin B1 (AFB1); 3) adsorbent diet (CLY) TMR with 1.76 oz (50 g) of clay; 4) AFC diet with clay (CLY+AF) with 300ppb AFB1 and 1.76 oz (50 g) of clay. Data were analyzed using the GLM procedure of SAS. Main effects were treatment, days-inmilk, parity, and day. Significance was declared at P&lt;0.05. Dry matter intake was similar across treatments; however, cows consuming CON diets had reduced milk yield. Milk from AFC cows had the greatest concentration of AFM1, and cows fed CLY+AF averaged 1.47 ± 0.186 ppb AFM1 less than cows fed AFC, resulting in a 60.0% reduction. Results from this study show that adding clay to contaminated diets was effective at reducing AFM1 concentrations in milk of cows fed AFB1 without negatively affecting production.