Chronic Effects of Fusarium Mycotoxins in Rations with or without Increased Concentrate Proportion on the Insulin Sensitivity in Lactating Dairy Cows

Effects of Supplementation of a Mycotoxin Mitigation Feed Additive in Lactating Dairy Cows Fed Fusarium Mycotoxin-Contaminated Diet for an Extended Period

Fusarium mycotoxins are inactivated by rumen flora; however, a certain amount can pass the rumen and reticulum or be converted into biological active metabolites. Limited scientific evidence is available on the impact and mitigation of Fusarium mycotoxins on dairy cows' performance and health, particularly when cows are exposed for an extended period (more than 2 months). The available information related to these mycotoxin effects on milk cheese-making parameters is also very poor. The objective of this study was to evaluate a commercially available mycotoxin mitigation product (MMP, i.e., TOXO® HP-R, Selko, Tilburg, The Netherlands) in lactating dairy cows fed a Fusarium mycotoxin-contaminated diet, and the repercussions on the dry matter intake, milk yield, milk quality, cheese-making traits and health status of cows. The MMP contains smectite clays, yeast cell walls and antioxidants. In the study, 36 lactating Holstein cows were grouped based on the number of days of producing milk, milk yield, body condition score and those randomly assigned to specific treatments. The study ran over 2 periods (March/May-May/July 2022). In each period, six animals/treatment were considered. The experimental periods consisted of 9 days of adaptation and 54 days of exposure. The physical activity, rumination time, daily milk production and milk quality were measured. The cows were fed once daily with the same total mixed ration (TMR) composition. The experimental groups consisted of a control (CTR) diet, with a TMR with low contamination, high moisture corn (HMC), and beet pulp; a mycotoxins (MTX) diet, with a TMR with highly contaminated HMC, and beet pulp; and an MTX diet supplemented with 100 g/cow/day of the mycotoxin mitigation product (MMP). The trial has shown that the use of MMP reduced the mycotoxin's negative effects on the milk yield and quality (protein, casein and lactose). The MTX diet had a lower milk yield and feed efficiency than the CTR and MMP HP-R diets. The MMP limited the negative effect of mycotoxin contamination on clotting parameters, mitigating the variations on some coagulation properties; however, the MMP inclusion tended to decrease the protein and apparent starch digestibility of the diet. These results provide a better understanding of mycotoxin risk on dairy cows' performances and milk quality. The inclusion of an MMP product mitigated some negative effects of the Fusarium mycotoxin contamination during this trial. The major effects were on the milk yield and quality in both the experimental periods. These results provide better insight on the effects of mycotoxins on the performance and quality of milk, as well as the cheese-making traits. Further analyses should be carried out to evaluate MMP's outcome on immune-metabolic responses and diet digestibility.

Effects of climate change on the distribution of Fusarium spp. in Italy

This work studies the incidence of Fusarium spp. on wheat kernels about current and future climatic conditions in Italy. Epidemiological analyses were performed from 2007 to 2013 and the resulting dataset was used to find correlations between the disease incidence of five important Fusarium species monitored in Italy (Fusarium graminearum, F. langsethiae, F. sporotrichioides, F. poae and F. avenaceum) and climatic and geographical parameters. Probabilistic-based modelling of the actual distribution of Fusarium spp. was achieved by using the Zero-inflated Poisson regression. The probabilistic geographical distribution of the Fusarium species was assessed by applying future climatic scenarios (RCPs 4.5 and 8.5). The shift from current to future climatic scenarios highlighted changes on a national and regional scale. The tightening of environmental conditions from the RCP4.5 to 8.5 scenarios resulted in a sporadic presence of F. avenaceum only in the northern region of Italy. Fusarium graminearum was plentifully present in the current climate, but the tightening of minimum and maximum temperatures and the decrease of precipitation between May-June in the RCP8.5 no longer represents the optimum conditions for it. Fusarium langsethiae was currently distributed in all of Italy, showing an increase in the probability of detecting it by moving from high to low latitudes and from low to high longitudes in the RCP8.5. Fusarium poae, unlike other Fusarium species, grows and develops in arid climatic conditions. High values of F. poae were recorded at low latitudes and longitudes. Under the RCP scenarios, it showed high incidence probabilities in the southeast and northeast areas of Italy. Fusarium sporotrichioides is scarcely present in Italy, found at high latitudes and in the central areas. Climate change altered this distribution, and the chances of discovering it increased significantly moving to southern Italy. Overall, the study shows that climate change conditions are likely to lead to an increase in the incidence of Fusarium species on wheat kernels in Italy, highlighting the importance of developing strategies to mitigate the effects of climate change on wheat production, quality, and safety.

Inhibitory Effect Mediated by Deoxynivalenol on Rumen Fermentation under High-Forage Substrate

Deoxynivalenol (DON) is a type B trichothecene mycotoxin produced by Fusarium fungi. To investigate its ruminal degradability and its effect on rumen fermentation, a 2 × 5 factorial experiment was conducted in vitro with two feed substrates with different forage levels (high forage (HF), forage-to-concentrate = 4:1; low forage (LF), forage-to-concentrate = 1:4) and five DON additions per substrate (0, 5, 10, 15, and 20 mg/kg of dry matter). After 48 h incubation, the DON degradability in the HF group was higher than in the LF group (p < 0.01), and it decreased along with the increase in DON concentrations (p < 0.01), which varied from 57.18% to 29.01% at 48 h. In addition, the gas production rate, total VFA production and microbial crude protein decreased linearly against the increase in DON additions (p < 0.05). Meanwhile, the proportion of CH4 in the fermentation gas end-products increased linearly, especially in the HF group (p < 0.01). In brief, rumen microorganisms presented 29–57% of the DON degradation ability and were particularly significant under a high-forage substrate. Along with the increasing DON addition, the toxin degradability decreased, showing a dose-dependent response. However, DON inhibited rumen fermentation and increased methane production when it exceeded 5 mg/kg of dry matter.

Deoxynivalenol triggers porcine intestinal tight junction disorder through hijacking SLC5A1 and PGC1α-mediated mitochondrial function

Deoxynivalenol (DON) is a mycotoxin frequently occurring in human and animal food worldwide, which raises increasing public health concerns. Growing evidence suggests that mitochondria is a pivotal molecular target for DON. However, the contribution of mitochondrial dysfunction to the pathogenesis of DON-induced gut epithelial barrier disruption remains poorly understood. In an animal experiment, piglets exposed to 2.89 mg DON/kg feed for 4 weeks showed altered metabolomic profiling in the serum and compromised transcriptome in the jejunum. DON exposure also impaired mitochondrial structure in the jejunal mucosa, corresponding with dysfunction of the tight junctions. In IPEC-J2 cells, metabolomic and transcriptomic analyses revealed that DON exposure perturbed biological processes occurring in the mitochondria and disordered the expression of genes involved in mitochondrial energy metabolism. Fuel utilization from glucose was affected by DON exposure, as were mitochondrial morphological dynamics leading to increased fragmentation. A marked loss of Na⁺/glucose cotransporter (SLC5A1) and peroxisome proliferator activated receptor-γ co-activator 1α (PGC1α) was observed in DON-treated cells. Taken together, our data highlight the critical role of impaired mitochondrial energy metabolism and mitochondrial biogenesis in abnormal intestinal tight junction upon DON exposure, and provide a potential mitochondrial target for intestinal mucosal restoration following DON exposure.

Fighting Fusarium Pathogens in the Era of Climate Change: A Conceptual Approach

Fusarium head blight (FHB) caused by Fusarium pathogens is one of the most devastating fungal diseases of small grain cereals worldwide, substantially reducing yield quality and food safety. Its severity is increasing due to the climate change caused by weather fluctuations. Intensive research on FHB control methods has been initiated more than a decade ago. Since then, the environment has been rapidly changing at regional to global scales due to increasing anthropogenic emissions enhanced fertilizer application and substantial changes in land use. It is known that environmental factors affect both the pathogen virulence as well as plant resistance mechanisms. Changes in CO₂ concentration, temperature, and water availability can have positive, neutral, or negative effects on pathogen spread depending on the environmental optima of the pathosystem. Hence, there is a need for studies of plant–pathogen interactions in current and future environmental context. Long-term monitoring data are needed in order to understand the complex nature of plants and its microbiome interactions. We suggest an holobiotic approach, integrating plant phyllosphere microbiome research on the ecological background. This will enable the development of efficient strategies based on ecological know-how to fight Fusarium pathogens and maintain sustainable agricultural systems.

Do mycotoxin contaminated diets and yeast cell wall adsorbent affect meat quality of Nellore bulls finished in feedlot? - A short communication

Ninety-six Nellore bulls (430 ± 13 kg and 24 months) were assigned to a completely randomized block design (2 × 2 factorial arrangement of treatments) to evaluate meat quality. Dietary treatments consisted of natural or exogenous contamination with mycotoxins (Factor 1), with or without yeast cell wall adsorbent (10 g/animal/d; Factor 2). The diets were provided during 97 d. The meat chemical composition was unaffected (P ≥ .37) by the factors and the averages of variables were 74.2% moisture, 22.7% protein, 1.04% ether extract, and 2.10% ash. The L*, a*, b*, E*, C* (P ≥ .11), cooking loss (P ≥ .24) and Warner-Bratzler shear force (P ≥ .17) were also similar among factors. In conclusion, low mycotoxin contamination and yeast cell wall based adsorbent do not affect meat quality of Nellore bulls finished in feedlot.

Mycotoxins at the Start of the Food Chain in Costa Rica: Analysis of Six Fusarium Toxins and Ochratoxin A between 2013 and 2017 in Animal Feed and Aflatoxin M1 in Dairy Products

Mycotoxins are secondary metabolites, produced by fungi of genera Aspergillus, Penicillium and Fusarium (among others), which produce adverse health effects on humans and animals (carcinogenic, teratogenic and immunosuppressive). In addition, mycotoxins negatively affect the productive parameters of livestock (e.g., weight, food consumption, and food conversion). Epidemiological studies are considered necessary to assist stakeholders with the process of decision-making regarding the control of mycotoxins in processing environments. This study addressed the prevalence in feed ingredients and compound feed of eight different types of toxins, including metabolites produced by Fusarium spp. (Deoxynivalenol/3-acetyldeoxynivalenol, T-2/HT-2 toxins, zearalenone and fumonisins) and two additional toxins (i.e., ochratoxin A (OTA) and aflatoxin M1 (AFM1)) from different fungal species, for over a period of five years. On the subject of Fusarium toxins, higher prevalences were observed for fumonisins (n = 80/113, 70.8%) and DON (n = 212/363, 58.4%), whereas, for OTA, a prevalence of 40.56% was found (n = 146/360). In the case of raw material, mycotoxin contamination exceeding recommended values were observed in cornmeal for HT-2 toxin (n = 3/24, 12.5%), T-2 toxin (n = 3/61, 4.9%), and ZEA (n = 2/45, 4.4%). In contrast, many compound feed samples exceeded recommended values; in dairy cattle feed toxins such as DON (n = 5/147, 3.4%), ZEA (n = 6/150, 4.0%), T-2 toxin (n = 10/171, 5.9%), and HT-2 toxin (n = 13/132, 9.8%) were observed in high amounts. OTA was the most common compound accompanying Fusarium toxins (i.e., 16.67% of co-occurrence with ZEA). This study also provided epidemiological data for AFM1 in liquid milk. The outcomes unveiled a high prevalence of contamination (i.e., 29.6-71.1%) and several samples exceeding the regulatory threshold. Statistical analysis exposed no significant climate effect connected to the prevalence of diverse types of mycotoxins.

The effects of post-partum drops in body condition on indices of energy metabolism in mid-lactation Holstein cows

BACKGROUND

Evaluation of energy metabolism indices in mid-lactation Holstein cows is critical to monitor health status. Aims: The objective of this study was to assess the effects of low (≤0.75) vs. high (>0.75) drops in body condition score (BCS) until day 60 post-partum on energy metabolism indices during mid-lactation in Holstein cows.

METHODS

Twenty-eight Holstein cows were included in the study from the day of calving to day 120 of lactation. Whole blood samples were taken on 60, 90, and 120 days in milk (DIM). Serum was analyzed for insulin, glucose, non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHB) levels.

RESULTS

In cows with low BCS drop (LoD group), insulin did not change significantly through days 60 to 120 of lactation, but increased in high drop cows (HiD group) (P<0.001). Glucose concentrations decreased linearly in the LoD cows (P=0.039) and showed a quadratic increase in the HiD group on day 90 (P=0.028). Concentrations of non-esterified fatty acids showed both linear (P=0.04) and quadratic (P=0.002) changes in the HiD group. The HiD cows had significantly higher concentrations of insulin on day 120 (P=0.017) compared to the LoD group. Glucose concentration was lower (P<0.01) in HiD cows on 60 DIM. The concentration of non-esterified fatty acids was higher in HiD cows on day 90 (P<0.01). Surrogate indices of insulin resistance (calculated based on the concentrations of the measured metabolites) were different between the groups on day 90, indicating decreased insulin sensitivity in the HiD cows.

CONCLUSION

Greater depletion of body reserves during early lactation may result in some inconsistencies in energy metabolism during mid-lactation periods. Controlling BCS loss during early lactation may help alleviate such alterations possibly through modifying insulin sensitivity of the tissues.