Omics analysis revealed the intestinal toxicity induced by aflatoxin B1 and aflatoxin M1.

Aflatoxin B1 (AFB1), a common mycotoxin, can occur in agricultural products. As a metabolite of AFB1, aflatoxin M1 (AFM1) mainly exist in dairy products. These two mycotoxins threaten human health, although it is unclear how they affect the function of the intestinal barrier. In this study, mice were exposed to AFB1 (0.3 mg/kg body b.w.) and AFM1(3.0 mg/kg b.w.) either individually or in combination for 28 days to explore the main differentially expressed proteins (DEPs) and the associated enriched pathways. These findings were preliminarily verified by the transcriptomic and proteomic analyses in differentiated Caco-2 cells. The results revealed that AFB1 and AFM1 exposure in mice disrupted the function of the intestinal barrier, and the combined toxicity was greater than that of each toxin alone. Further proteomic analysis in mice demonstrated that the mechanisms underlying these differences could be explained as follows: (i) lipid metabolism was enriched by AFB1-induced DEPs. (ii) protein export pathway was stimulated by AFM1-induced DEPs. (iii) cell metabolic ability was inhibited (as evidenced by changes in UDP-GT1, UDP-GT2, and Gatm6), apoptosis was induced (MAP4K3), and epithelial cell integrity was disrupted (Claudin7 and IQGAP2), resulting in more extensive intestinal damage after combined treatment. In conclusion, the hazardous impact of co-exposure to AFB1 and AFM1 from proteomic perspectives was demonstrated in the present study.

Effect of the Replacement of Maize Silage and Soyabean Meal with Mulberry Silage in the Diet of Hu Lambs on Growth Performance, Serum Biochemical Indices, Slaughter Performance, and Meat Quality.

Maize silage has a high demand for fertilizer and water. As an unconventional feed resource, mulberry silage has the potential to replace most maize silage and to alleviate the shortage of roughage in the mutton sheep industry in China. The purpose of this experiment was to study the effect of the replacement of maize silage and soyabean meal with mulberry silage in the diet of Hu lambs on growth performance, serum biochemical indices, slaughter performance, and meat quality. Ninety-six healthy Hu lambs were randomly divided into four groups with six replicates per group and four lambs per replicate. The amounts of 0, 20, 40, and 60% of maize silage were replaced by mulberry silage in each group (denoted as CON, L, M, and H, respectively). The results showed that replacing maize silage with mulberry silage had no significant effect on the growth performance or the slaughter performance of Hu lambs (p > 0.05). Feeding Hu lambs with mulberry silage significantly reduced serum glucose (GLU) and the blood urea nitrogen (BUN) content (p < 0.05), and it increased the content of ether extract (EE) in the longissimus dorsi muscle (p < 0.05). Meanwhile, the percentage of EAA in the M and H groups was significantly lower than that in the CON and L groups (p < 0.05). In addition, in the fatty acid profile, the percentage of C16:1 in the M group was significantly increased, while the percentage of C18:0 and C20:0 were significantly decreased (p < 0.05). Based on these findings, it was recommended that 20−40% of maize silage be replaced by mulberry silage in the diet of Hu lambs.

Effects of Heavy Metal Exposure from Leather Processing Plants on Serum Oxidative Stress and the Milk Fatty Acid Composition of Dairy Cows: A Preliminary Study.

This study investigated whether unsaturated fatty acids in milk and the oxidative status of cows are affected by heavy metal exposure due to leather processing. The blood lead (Pb) concentrations in cows from two farms in the polluted area were 16.27 ± 8.63 µg/L, respectively, which were significantly (p < 0.05) higher than the blood Pb concentrations in cows from an unpolluted farm (6.25 ± 3.04 µg/L). There were significantly (p < 0.05) lower levels of glutathione S-transferase (GST), glutathione peroxidase (GPX), and glutathione (GSH) in the serum of cows from the polluted area compared to the levels in cows from an unpolluted area. The linoleic acid (C18:2n6c) content in milk from the polluted area was 15% lower than in the control area. There was a significant correlation between linoleic acid in milk with the blood Pb and serum GSH levels. Heavy metals can alter fatty acid synthesis through oxidative stress, which may be the mechanism by which heavy metals affect fatty acid synthesis in milk.

Replacement of Maize Silage and Soyabean Meal with Mulberry Silage in the Diet of Hu Lambs on Growth, Gastrointestinal Tissue Morphology, Rumen Fermentation Parameters and Microbial Diversity.

Maize silage has a significant environmental impact on livestock due to its high requirement for fertilizer and water. Mulberry has the potential to replace much of the large amount of maize silage grown in China, but its feeding value in the conserved form needs to be evaluated. We fed Hu lambs diets with 20-60% of the maize silage replaced by mulberry silage, adjusting the soybean meal content when increasing the mulberry silage inclusion rate in an attempt to balance the crude protein content of the diets. Mulberry silage had higher crude protein and lower acidic and neutral detergent fiber contents compared to maize silage. Replacing maize silage and soyabean meal with mulberry silage had no effect on the feed intake and growth rate of Hu lambs. However, the rumen pH increased, the acetate to propionate in rumen fluid increased, and the rumen ammonia concentration decreased as mulberry replaced maize silage and soyabean meal. This was associated with an increase in norank_f__F082 bacteria in the rumen. Rumen papillae were shorter when mulberry silage replaced maize silage, which may reflect the reduced neutral detergent fiber (NDF) content of the original silage. In conclusion, mulberry silage can successfully replace maize silage and soyabeans in the diet of Hu lambs without loss of production potential, which could have significant environmental benefits.

The Occurrence, Pathways, and Risk Assessment of Heavy Metals in Raw Milk from Industrial Areas in China.

This study evaluated chromium (Cr), arsenic (As), cadmium (Cd), and lead (Pb) contamination in raw milk from industrial areas in China, identified the possible pathways of heavy metals from the environment to raw milk, and made a risk assessment of the consumption of heavy metals from milk consumption. The Cr, As, Cd, and Pb concentrations in raw milk, water and silage were analyzed using inductively coupled plasma mass spectrometry. The Cr and As in soil were analyzed by flame atomic absorption spectrometry and atomic fluorescence spectrometry, respectively. Cd and Pb in soil were determined by a Graphite furnace atomic absorption spectrophotometer. The Cr and As concentrations in milk from industrial areas were 2.41 ± 2.12 and 0.44 ± 0.31 µg/kg, respectively, which were significantly higher (p < 0.01) than those from non-industrial areas, which had levels of 1.10 ± 0.15 and 0.25 ± 0.09 µg/kg, respectively. Chromium was mainly transferred through the soil-silage-milk pathway, As was transferred through the water-silage-milk pathway, while Cd was mainly transferred through the soil (water)-silage-milk pathway. The contributions of each metal to the overall hazard index (HI) followed a descending order of As, Cr, Pb, and Cd, with values of 46.64%, 25.54%, 24.30%, and 3.52%, respectively. Children were at higher risk than adults.

Whole transcriptome-based ceRNA network analysis revealed ochratoxin A-induced compromised intestinal tight junction proteins through WNT/Ca2+ signaling pathway.

Ochratoxin A (OTA) is a widespread environmental pollutant that is a threat to humans and livestock and remains a global concern to public health. It has negative effects on both humans and animals that are in a continuously exposed environment. The compromised intestinal barrier caused by OTA has aroused widespread concern. This study aimed to investigate the mechanism of OTA-induced tight junction (TJ) protein damage and the relevant components of the intestinal barrier through in vivo whole transcriptome analysis combined with in vitro functional verification. Bioinformatics analysis in OTA-treated Balb/c mice demonstrated that regulated TJ protein related mRNAs were perturbed, and activated the WNT/Ca2+ signaling pathway possibly regulated by key lncRNAs and miRNAs. Competing endogenous RNA (ceRNA) network analysis revealed that lncRNA Zeb1 regulated FZD4 binding with WNT5a to release Ca2+ by targeting miR-1258-x and reduced the expression of TJ proteins, thus damaging the function of the intestinal barrier. An in vitro experiment with Caco-2 cells verified that an increase in Ca2+ level was involved in OTA-induced decreases in the expression of TJ proteins. Taken together, these results will help to identify targets in the intestinal barrier that are compromised by OTA, and will provide the basis for preventing the associated hazard and risk.

Heavy Metals in Raw Milk and Dietary Exposure Assessment in the Vicinity of Leather-Processing Plants.

The objective of this study was to assess the contamination levels of arsenic (As), lead (Pb), chromium (Cr), and cadmium (Cd) in raw milk and the subsequent potential health risk to local consumers close to leather-processing plants in China. The As and Pb concentrations in milk from contaminated areas were 0.43 ± 0.21 and 2.86 ± 0.96 µg/L, respectively, which were significantly higher than in milk from unpolluted farm, with values of 0.20 ± 0.05 and 2.32 ± 0.78 µg/L, respectively. The Cr and Cd levels in milk from contaminated areas were 1.21 ± 1.57 and 0.15 ± 0.04 µg/L, respectively, which were slightly higher than in milk from unpolluted farm, with values of 0.87 ± 0.61 and 0.13 ± 0.04 µg/L, respectively, (P > 0.05). Target hazard quotient (THQ) and hazard index (HI) values for As, Pb, Cr, and Cd from milk consumption were calculated for individuals aged 3 to 69. The THQ followed a descending order of As > Pb > Cr > Cd, with values of 0.0066-0.0441, 0.0033-0.0220, 0.0019-0.0124, and 0.0007-0.0046, respectively. The HI values (0.0124-0.0832) were far below the threshold of 1.

Content and Dietary Exposure Assessment of Toxic Elements in Infant Formulas from the Chinese Market.

In this study, the content of chromium (Cr), arsenic (As), cadmium (Cd) and lead (Pb) in domestic and imported infant formulas from Beijing, China were analyzed using inductively coupled plasma mass spectrometry. The content of Cr, As, Cd and Pb was 2.51-83.80, 0.89-7.87, 0.13-3.58 and 0.36-5.57 µg/kg, respectively. Even though there were no significant differences in toxic elements content between domestic and imported infant formulas, Cd content was slightly lower in domestic samples. The estimated daily intake (EDI), target hazard quotient (THQ) and hazard index (HI) were calculated for infants between 0.5 and 5 y of age. The EDIs were lower than the oral reference doses. THQ of As, Cr, Cd and Pb was 0.027-0.103, 0.024-0.093, 0.0025-0.0090 and 0.0015-0.0046, respectively. HI values were 0.055-0.192 for boys and 0.056-0.209 for girls and were inversely associated with age with a threshold < 1. The non-carcinogenic risk value were in the safe range, indicating that exposure of As, Pb, Cr and Cd from infant formulas do not represent a health risk in China.

Relationships between Pb, As, Cr, and Cd in individual cows' milk and milk composition and heavy metal contents in water, silage, and soil.

Various industrial activities lead to environmental pollution by heavy metals. Toxic heavy metals enter the food chain of dairy cows through feed and water, then transferred into milk. This study investigated the correlations of heavy metal contents between individual cows' milk, water, silage and soil. The relationships between heavy metal contents in individual cows' milk with milk protein, fat, lactose, solid nonfat (SNF), and total solids (TS) were analysed. Concentrations of Pb, As, Cr, and Cd in milk, silage and water were measured by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Lead, Cr, and Cd in soil were measured by Atomic Absorption Spectrometry (AAS), and As was detected by Atomic Fluorescence Spectrometry (AFS). One-way non-parametric tests and Spearman correlation analyses were performed using SAS 9.4 software. Levels of Pb and Cd in milk from the unpolluted area were significantly lower (P < 0.01) than those from industrial area. Significantly higher (P < 0.01) As residue was recorded in milk from unpolluted area. Positive correlation of Pb was observed between milk and silage, and As in milk was positively correlated with As in water. Content of As in milk was slightly (r = 0.09) correlated with As in silage, even though strong positive correlation (r = 0.78) was observed between silage and water. Positive correlations were observed for Cr and Cd between milk and silage, as well as milk and soil. Positive correlations were observed in Pb-protein, Cr-protein, and Cd-lactose; other positive correlation coefficients were nearly equal to zero. The results suggest that industrial activities lead to possible Pb and Cd contamination in milk. Drinking water could be the main source of As contamination in cows. No clear relationship was found between milk composition and heavy metals contents in milk. Water and soil on the farm had a partial contribution to heavy metal contamination in milk.

Large scale study of the within and between spatial variability of lead, arsenic, and cadmium contamination of cow milk in China.

This large scale study investigated the spatial variability of Pb, As, and Cd contents in raw milk within and between the 10 main milk producing areas in China. A total of 997 raw milk samples were analysed by inductively coupled plasma mass spectrometry (ICP-MS). Mean values of Pb, As, and Cd in milk were 1.75 µg/L, 0.31 µg/L, and 0.05 µg/L, respectively. The highest level of Pb and As was present in area C, and Cd was highest in area J. The standard deviation suggested a higher heterogeneity of milk heavy metal contamination within area than between areas. Levels of Pb, As, and Cd showed significant differences between studied areas. The estimated root mean squared standardised error obtained by the cross-validation suggested a differentiated quality of Pb, As, and Cd modelling between areas: the predictions obtained were sometimes overestimated or underestimated. These results can be used to define a more appropriate sampling procedure for heavy metal contaminate distribution in raw milk for improved future control of milk contamination by heavy metals in the studied areas. The significant positive correlations between concentrations of Pb-Cd, As-Cd, and Pb-As were observed in nine, six and five areas, respectively. No significant negative correlations were observed. The observed variability of correlation values suggested a different pollution source for Pb, As, and Cd in milk between areas. Further studies are required to clarify the relationships between the contamination of raw milk by heavy metals and the herd environment.

A Survey of Naturally-Occurring Steroid Hormones in Raw Milk and the Associated Health Risks in Tangshan City, Hebei Province, China.

In recent years, high levels of hormone residue in food, capable of damaging the health of consumers, have been recorded frequently. In this study, 195 raw milk samples were obtained from Tangshan City, China, and the concentrations of 22 steroid hormones were measured by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Cortisol was detected in 12.5% of raw milk samples (mean 0.61 µg/kg; range:

Accumulation and Depletion of Cadmium in the Blood, Milk, Hair, Feces, and Urine of Cows During and After Treatment.

The objective of this study was to assess the accumulation and depletion of cadmium in the blood, milk, hair, feces, and urine of Holstein cows during and after treatment. Three Holstein cows received daily oral cadmium administrations (as cadmium chloride) of 0.182 mg/kg body weight/day for 21 days followed by a 63-day withdrawal period. Blood, milk, hair, feces, and urine were collected during treatment and withdrawal periods. Cadmium concentrations were measured by inductively coupled plasma mass spectrometry (ICP-MS). Cadmium concentrations in blood (0.61-1.12 µg/L), milk (0.39-1.04 µg/L), and urine (0.41-2.05 µg/L) were low. Comparatively, cadmium concentrations in feces were higher, especially on treatment day 14 (20.11 mg/kg dry matter). Fecal cadmium concentrations decreased to baseline levels (0.12 mg/kg dry matter) on withdrawal day 21. Hair cadmium concentrations increased with treatment, reaching the highest levels on withdrawal day 7 (24.33 µg/kg). Most of the cadmium was excreted via the feces and very little was present in urine or milk. Cadmium residues were detected in blood and milk more than 63 days after cadmium withdrawal. Hair cadmium concentrations may reflect exposure to the metal.

Hair Analysis to Monitor the Illegal Use of Salbutamol in Beef Cattle.

This study measured the concentrations of salbutamol residues in red and white hair of cattle during and after salbutamol administration. Three Chinese Simmental beef cattle received an oral administration of 150 µg/kg body weight/d salbutamol for 21 consecutive days. Salbutamol concentrations were determined on Days 1, 7, 14, and 21 of administration and on Days 7, 14, 28, 42, and 70 following the last administration dose using ultra-performance liquid chromatography-tandem mass spectrometry. The concentrations of salbutamol that eluted from hair were determined. The results revealed that salbutamol concentrations were higher in red hair than in white hair on the same sampling day (P < 0.01). In red hair, salbutamol concentrations increased from 29.82 ± 1.8 ng/g on Day 1 of administration to 442.55 ± 250.29 ng/g on Day 21 of administration, and decreased to 33.36 ± 19.22 ng/g on Day 70 after the last administration. In white hair, salbutamol concentrations changed from 4.25 ± 0.32 ng/g on Day 1 of administration to 33.81 ± 6.44 ng/g and 12.25 ± 2.51 ng/g on Days 14 and 70, respectively, after the last administration. The concentrations of salbutamol that eluted from white hair on Days 1 and 7 were 22.94 ± 2.00 ng/g and 92.94 ± 22.49 ng/g, respectively. Our findings revealed that hair is an appropriate biological matrix for assessing the illegal use of salbutamol in animal husbandry.

Salbutamol Residues in Plasma, Urine and Hair of Heifers After a Single Dose and Throughout.

The objective of this study was to evaluate the salbutamol residues in the plasma, urine and hair of heifers after a single dose. Three heifers were given a single oral dose of salbutamol hydrochloride (150 µg/kg bodyweight). The salbutamol concentrations were measured in the plasma, urine (before and after hydrolysis with ß-glucuronidase/arylsulfatase) and hair samples with ultra-performance liquid chromatography-tandem mass spectrometry. In the unhydrolyzed samples, the peak concentrations of salbutamol occurred in the plasma and urine at 12 and 8 h after drug administration, respectively, but were below the limit of quantification (LOQ = 0.2 ng/mL) at 48 and 120 h after administration, respectively. However, in the hydrolyzed samples, the salbutamol concentration was 1.1 ng/mL in the plasma 72 h after its administration and 0.7 ng/mL in the urine 168 h after its administration. Thus, the concentrations of salbutamol were significantly higher in the hydrolyzed samples than that in the unhydrolyzed samples (P < 0.01). The concentrations of salbutamol in the black and white hair 24 h after its administration were 1.7 and 1.0 ng/g, respectively. These results indicate that hair may be a target tissue for detecting the misuse of salbutamol after a single dose and that the primary forms of salbutamol in the plasma and urine samples from heifers are its sulfate and glucuronide conjugates.