Moldy Silage Research Articles

Forage selection behavior of sheep with visually moldy or nonmoldy grass silage

Baled silage can be contaminated with several mycotoxins, which cause health and economic problems for farm animals. We investigated the relationship between the visible mold area and deoxynivalenol (DON) concentration of Italian ryegrass baled silage. We subjected the sheep offered with three types of silage (moldy, nonmoldy, and visually nonmoldy part within the mold silage) to a feeding experiment. We assayed silage degradability in vitro by using the rumen liquid of the sheep before and after the feeding experiments. Results revealed no significant relationships among the visible mold area and the outer, inner, and total DON concentration in the silage. In the feeding experiment, the relative forage intake of sheep for each silage type significantly differed between experimental days. The visiting frequency of sheep for the silage varied between experimental days, but relative frequency for each silage type did not significantly differ between experimental days. The in vitro rumen degradability of the silage remained unchanged after the feeding experiment. The intake amount of the visually nonmoldy part and the nonmoldy silages increased at the latter half of the feeding experiment compared with that of the moldy silage, indicating that sheep could determine the silage quality and gradually shift from contaminated silage to noncontaminated silage. Therefore, their intake amount would be reduced if visually moldy silage was fed even though its toxin concentration was low. Conversely, they would prefer silage without visible mold even though its toxin concentration was possibly high because visible mold in the silage did not reflect its toxin concentration.

305 Awardee Talk: Application of on-Animal Sensors and Precision Livestock Management on Extensive Cattle and Sheep Ranches

Abstract Monitoring livestock and forage conditions on extensive rangelands is labor intensive and expensive, and often observations occur infrequently. Technological advancements have made real-time remote monitoring more feasible and less costly. Global positioning system (GPS) tracking data can be transferred from livestock to the internet using cellular phone technologies, low range wide area networks (LoRaWan) and satellite transmissions. With good coverage, cellular-based real time tracking systems work well. Rugged terrain and extensive pastures increase the cost of LoRaWan. Additional LoRaWan gateway towers are needed for data transmission, because these systems rely upon line-of-sight signals. Satellite systems are expensive but hold great potential for rugged terrain. Accelerometers can be used to monitor animal activity, and after on-device summarization the data summary can be transmitted to the internet. Changes in behavior from normal patterns are useful for detecting illness and wellbeing. Bovine ephemeral fever in heifers and perennial ryegrass staggers in sheep were identified by a decrease in activity during the morning and evening grazing bouts using accelerometers. In pen settings, accelerometers were able to detect the timing of lambing and illness associated with unexpected feeding of moldy silage. Continued congregation of livestock at water tanks may indicate water system failures. Normally, animals move away from water to rest after drinking. Tracking is a valuable tool to identify locations where new water developments can improve distribution. Tracking also has potential to notify managers where livestock are congregating and potentially overgrazing, but prediction of forage utilization at light levels is not exact. Tracking systems would also facilitate genetic selection for grazing distribution by providing terrain use phenotypes. Improvements in technology and associated cost reductions of sensors as well as development of algorithms and software potentially gives ranchers mechanisms to remotely monitor livestock wellbeing and rangeland conditions and allow them to respond promptly.

Fungal species and mycotoxins in mouldy spots of grass and maize silages in Austria

Fungi and mycotoxins in silage can have detrimental consequences for both cattle and human health. This pilot study identified, via the routinary direct plating method, the dominant cultivable fungi in mouldy grass silages (GS) (n = 19) and maize silages (MS) (n = 28) from Austria. The profiles of regulated, modified, and emerging mycotoxins together with other fungal metabolites were analysed via LC-(ESI)MS/MS. Penicillium roqueforti, Saccharomyces spp., Geotrichum candidum, Aspergillus fumigatus and Monascus ruber were the most frequent fungal organisms identified. Other species including Mucor circinelloides, Fusarium spp. and Paecilomyces niveus were detected at lower frequencies. The presence of complex mixtures of toxic and potentially toxic compounds was evidenced by high levels and occurrences (≥ 50%) of Penicillium-produced compounds such as mycophenolic acid (MPA), roquefortines (ROCs), andrastins (ANDs) and marcfortine A. Mouldy silages contained toxins commonly produced by genus Fusarium (e.g. zearalenone (ZEN) and trichothecenes), Alternaria (like tenuazonic acid (TeA) and alternariol (AHO)) and Aspergillus (such as sterigmatocystin (STC)). Compared to those in GS, mouldy spots in MS presented significantly higher fungal counts and more diverse toxin profiles, in addition to superior levels of Fusarium spp., Penicillium spp. and total fungal metabolites. Generally, no correlation between mould counts and corresponding metabolites was detected, except for the counts of P. roqueforti, which were positively correlated with Penicillium spp. metabolites in mouldy MS. This study represents a first assessment of the fungal diversity in mouldy silage in Austria and highlights its potential role as a substantial contributor to contamination with complex mycotoxin mixtures in cattle diets.

Dairy farm management practices and the risk of contamination of tank milk from Clostridium spp. and Paenibacillus spp. spores in silage, total mixed ration, dairy cow feces, and raw milk

The occurrence of Paenibacillus and Clostridium spores in silage is of great concern for dairy producers because their spores can contaminate milk and damage processed milk and semi-hard cheeses. Spoiled silage is considered to be the main contamination source of the total mixed ration (TMR), feces of dairy cows, and consequently bulk tank milk via the contamination of cow teats by dirt during milking. The presence of an anaerobic and facultative anaerobic sporeformer population in different matrices (soil, corn silage, other feeds, TMR, feces, and milk) and its transmission pathway has been studied on 49 dairy farms by coupling plate count data with 16S-DNA identification. The different matrices have shown a high variability in the anaerobic and facultative anaerobic spore count, with the highest values being found in the aerobically deteriorated areas of corn silages. Clostridium tyrobutyricum, Paenibacillus macerans, and Paenibacillus thermophilus were detected in all the matrices. The TMR spore count was influenced by the amount of spoiled corn silage in the TMR and by the care taken when cleaning the spoiled silage before feed-out. Most of the farms that prevent the presence of visible moldy silage in the silo and carefully clean to remove molded spots were able to maintain their TMR spore counts below 4.0 log spores/g. When a level of 4.5 log spores/g of TMR was exceeded, the feces presented a greater contamination than 3.0 log spores/g. Moreover, the higher the number of spores in the feces was, the higher the number of spores in the milk. Most of the farms that presented a feces contamination greater than 5.0 log spores/g had a higher milk spore contamination than 1,000 spores/L. Careful animal cleaning and good milking practices have been found to be essential to maintain low levels of contamination in bulk tank milk, but it has emerged that only by coupling these practices with a correct silage management and cleaning during TMR preparation can the contamination of milk by spores be kept at a low level. It has been found that aerobically deteriorated silage has a great capacity to contaminate TMR and consequently to increase the risk of milk spore contamination, even when routine milking practices are adopted correctly.

Neurotoxicity of mycotoxins produced in vitro by Penicillium roqueforti isolated from maize and grass silage.

Fungal growth in human foods and animal feeds causes profound damage indicating a general spoilage, nutritional losses, and the formation of mycotoxins. Thirty apparently contaminated maize and grass silage samples were analyzed for the presence of total fungi. Penicillium roqueforti were isolated from all (100%) moldy silage samples on general and selective culture media. Furthermore, P. roqueforti-positive samples culture media subjected to the toxin extraction and toxins of patulin, penicillic acid, mycophenolic acid, and roquefortin-C (ROQ-C) were identified by means of high-performance liquid chromatography method. Cytotoxicity of identified toxins was investigated on neuro-2a cells. Alamar blue reduction, neutral red uptake, and intracellular adenosine triphosphate (ATP) content assays indicated that patulin and ROQ-C exert the strongest and weakest toxicity, respectively. Reactive oxygen species (ROS) generation by the toxins-exposed cells was measured, and the results supported the mitochondrial and lysosomal dysfunction and ATP depletion in exposed cells. Our data suggest that P. roqueforti is the widely present mold in analyzed maize and grass silage samples, which is able to produce toxins that cause neurotoxicity. This finding may explain in part some neuronal disorders in animals, which are fed contaminated feedstuffs with mentioned fungus. Moreover, mitochondrial and lysosomal dysfunction, intracellular ATP depletion, and the excessive ROS generation were found as the mechanisms of cytotoxicity for P. roqueforti-produced toxins.

Hooked! Seductive Details in Soil Science

Hooked! Seductive Details in Soil Science

Mycotoxin syndrome in dairy cattle: characterisation and intervention results

In daily practice, dairy cattle may be exposed to complex mixtures of mycotoxins originating from pre- and postharvest contamination of roughages, silage and concentrates. In particular silage has been identified as a source of different microbial toxins, which may impair animal health and productivity. The aim of the current study was to identify functional and descriptive biomarkers for the mouldy silage syndrome in dairy cattle. Such biomarkers should also serve as indicators of the beneficial effects of intervention strategies. In a field trial, a total of 87 cows from three different farms were enrolled in the study. From these animals blood samples were collected at three different time points and subjected to multiple biochemical analyses. Within this group, fine needle liver biopsies were obtained from 43 animals and subjected to biochemical analyses and targeted gene expression profiles. The measured parameters represent biomarkers of inflammation, oxidative stress, gluconeogenesis and lipids. In the affected animals, oxidative stress and a dysfunction in lipid metabolism were observed, marked by significantly decreased levels of glutathione peroxidase (GSH-Px) activity, glucose-6-phosphate-dehydrogenase (G6PD) concentrations and trolox equivalent antioxidant capacity (TEAC) and significantly increased concentrations of free cholesterol in plasma, together with a decreased activity of phospholipid transfer protein (PLTP) and lecithin-cholesterol acyltransferase (LCAT). When a glucomannan mycotoxin absorbent was added to the daily ration for a period of 8 weeks most of these biochemical markers gradually improved to normal levels, and body condition and milk yield improved. The obtained results contribute to the understanding of the pathophysiological changes associated with multiple mycotoxin exposure in dairy cows and allow a refined assessment of intervention strategies under field conditions.

Study of animal welfare status in dairy cow herds in Hungary

Animal welfare is a hot topic among consumers, producers and researches nowadays. The major welfare problems of dairy cows are mastitis, lameness, and any conditions which lead to impaired reproduction, inability to express normal behaviour, emergency physiological responses or injury. This paper summarizes preliminary results of project taken in 27 Hungarian dairy farms evaluating general animal welfare. The most important areas for improving animals? wellbeing are related to facilities and comfort of resting. Findings include slippery floors, cows struggling laying and standing in cubicles. Other measures include hair loss, hocks, neck rail injuries and number of thin cows (Body Condition Score 1 and 2). Mouldy silage and low quality of other feedstuff was also found. In conclusion, preliminary results confirm strong demand for monitoring farms and discussions with managers and farmers about welfare measures needed to be taken on farms immediately.

Isolation of cellulolytic enzymes from moldy silage by new culture-independent strategy

A culture-independent strategy has been developed for investigation of cellulases in moldy silage. By the qualitative differences in the adsorption of cellulases on lingo-cellulosics, a new cellobiohydrolase (CBH) with apparent molecular mass of 194 kDa was isolated and characterized. The entire extracellular proteins of silage were separated by two-dimensional gel electrophoresis, and five potential endoglucanases were identified by activity staining. These results demonstrate the feasibility of direct screening cellulases from environment without microorganism cultivation and this strategy could be expected to facilitate the research of uncultured microorganisms.

Influence of Oral Application of Mycophenolic Acid on the Clinical Health Status of Sheep

Mycophenolic acid (MPA) is an immunosuppressive metabolite of various fungi, especially of Penicillium roqueforti, and can be found in considerable amounts in mouldy silage. The aim of this study was to investigate the effect of MPA on sheep. Thirty-six castrated male sheep aged 7 +/- 1 months were randomly divided into four groups of nine sheep. Different dosages of MPA were administered orally to all groups (group 1/2/3/4: 0/10/70/300 mg MPA/animal daily) for a period of 44 days. Throughout the trial, the sheep were examined daily. Jugular vein blood was taken twice weekly to analyse haematological and biochemical parameters. No significant influence was observed on the number of erythrocytes, thrombocytes, leucocytes (including differentiation), packed cell volume, haemoglobin-, glucose- and bilirubin-concentration, activity of alanine amino transferase, aspartate amino transferase and glutamate dehydrogenase. Even an oral application of up to 300 mg MPA/animal daily, which is equivalent to 5.4 mg/kg body weight, did not affect the sheep's general state of health and weight gain significantly. Mycophenolic acid and its glucuronide were analysed in plasma samples of groups treatments from day 1 on with mean concentrations up to 0.29 +/- 0.13 microg/ml (MPA) and 11.0 +/- 2.9 microg/ml (MPA glucuronide) respectively (group 4). There were no indications for a ruminal reduction of MPA. The postmortem dissection revealed minor alterations in lung, spleen, liver and kidneys, unrelated to the MPA dosage. The results of the study indicate that MPA concentrations occurring naturally in silage have no obvious impact on sheep health.

Warfarin: almost 60 years old and still causing problems

Warfarin: almost 60 years old and still causing problems

Isolation and toxigenicity of Aspergillus fumigatus from moldy silage.

Thirty-nine silage samples were collected from various silos on Terceira Island in the Azores. Samples were examined for the presence of total fungi, and isolates of Aspergillus fumigatus were analyzed for their ability to produce fumitremorgens B and C, fumigaclavines B and C, and gliotoxin. Thirty-four silage samples (87%) were contaminated with fungi, and A. fumigatus was isolated from 27 samples (69%). Samples that were taken from the surface of silos had significantly higher populations of both total fungi and A. fumigatus than did samples taken from the middle of silos. Analysis of 27 A. fumigatus isolates (one representing each positive sample) showed that 59.3% produced fumitremorgen B; 33.3% produced fumitremorgen C; 29.6% produced fumigaclavine B; 7.4% produced fumigaclavine C; and 11.1% produced gliotoxin. Fifty-two percent of the isolates produced multiple toxins, and 25.9% did not produce any of these toxins. Gliotoxin and fumigaclavine C were always produced in combination with other toxins. Because of the demonstrated potential of these A. fumigatus isolates to produce mycotoxins, it is important to properly construct and manage silos to prevent their contamination with A. fumigatus.

Tremorogenic Toxic Encephalopathy

A 16 year old boy who developed tremorogenic toxic encephalopathy as a result of inhalation and/or ingestion of mouldy silage containing aspergillus fumigatus, flavus and clavitus is reported from Halifax, Nova Scotia and Kingston, Ontario, Canada.

Practical aspects of sampling for organic dusts and microorganisms

Air sampling for organic dusts and microorganisms was carried out in silos when moldy silage was discarded through the discharge chute. Concentrations of respirable dust and airborne viable microorganisms exceeded 20 mg/m3 and 1 x 10(9)/m3, respectively, when dry silage was removed from silos. Much lower concentrations of dust and microorganisms were present when wet silage was discarded. Impinger and filter cassette samplers were equally effective in collecting the hardy spores present in silage dusts.

Isolation and possible relevance of Thermoactinomyces candidus proteinases in farmer's lung disease.

The thermophilic actinomycetes are the most common etiological agents causing hypersensitivity pneumonitis. Antigen preparations of these organisms contain proteolytic activity. Further investigation of the proteinases of the thermophilic actinomycetes was undertaken to determine whether this activity may contribute directly to the pathogenesis of hypersensitivity pneumonitis and pulmonary mycotoxicosis. The presence of proteolytic activity in aerosolized dust from moldy silage was demonstrated, and antibodies to two proteolytic enzymes from Thermoactinomyces candidus were found in the blood of farmer's lung patients who had been sensitized to this organism. These two enzymes were isolated from culture filtrate antigen preparations that had been partially characterized with respect to the proteolytic activities and their interaction with human serum proteinase inhibitors. Both proteinases belonged to the serine class of endopeptidases. Neither proteinase was inhibited by alpha 1-proteinase inhibitor or alpha 1-antichymotrypsin. Both proteinases were inhibited by alpha 2-macroglobulin. One of the proteinases had elastase activity. Inhalation of these proteinases apparently does occur, and they may induce an inflammatory response in the lungs since they are not inhibited by the main proteinase inhibitors protecting the lung.

The Pathogenetic Role of Inhaled Microbial Material in Pulmonary Mycotoxicosis as Demonstrated in an Animal Model

Pulmonary mycotoxicosis (PM) is an acute systemic reaction to the inhalation of massive amounts of dust generated from moldy silage in a filled silo.1 The clinical presentation of these patients is frequently confused with farmer's lung disease, but is not related to silo gas. Less than half of these individuals have antibodies to the organisms which cause farmer's lung.

Thin Layer Chromatographic Determination of Aflatoxin B1 in Corn Silage

A procedure is described for the purification and quantitation of aflatoxin B1 in corn silage. The toxin is extracted and partially purified using parts of the AOAC minicolumn detection method. The extract is further cleaned up on a 2-step minicolumn and is then analyzed by using thin layer chromatography. Essentially all interferences are removed when the procedure is applied to moldy and non-moldy corn silage. The estimated limit of detection is 5 microgram aflatoxin B1/kg corn silage, and 73 +/- 8% of the added aflatoxin B1 (20 and 85 microgram/kg) was recovered. No aflatoxin B1 was detected in 270 samples collected from 19 silage piles in late fall 1976 and early spring 1977. This procedure also removes interferences associated with moldy corn and mixed feeds.

Allergic alveolar diseases problems in diagnosis and management.

One of the diagnostic possibilities to consider when a patient presents with cough, fever, dyspnea, or pulmonary infiltrates is hypersensitivity pneumonitis. Some of the problems encountered in diagnosis of diffuse lung disease are illustrated in two case reports. In one of the cases, interstitial pneumonitis of insidious onset was attributed to inhalation of thermophilic organisms in moldy silage. In the other, the outstanding pathologic feature was bronchiolitis obliterans, and circumstantial evidence pointed to a home humidifier as the source of the problem.

Aspergillus Fumigatus in Samples of Moldy Silage

Samples of moldy and unmoldy corn silage submitted after several beef cows fed the moldy silage died were cultured for identification of fungi. Colonies of Aspergillus fumigatus were identified on dilution plates up to dilutions of 5×106. Large numbers of A. fumigatus spores were in the samples of moldy corn silage. A. fumigatus is a pathogen of animals and man. Special precautions in handling of moldy silage are recommended. Analysis for aflatoxin by thin layer chromatography was negative.

Título en español.

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