Rumen and Serum Metabolomes in Response to Endophyte-Infected Tall Fescue Seed and Isoflavone Supplementation in Beef Steers.

Fescue toxicosis impacts beef cattle production via reductions in weight gain and muscle development. Isoflavone supplementation has displayed potential for mitigating these effects. The objective of the current study was to evaluate isoflavone supplementation with fescue seed consumption on rumen and serum metabolomes. Angus steers (n = 36) were allocated randomly in a 2 × 2 factorial arrangement of treatments including endophyte-infected (E+) or endophyte-free (E-) tall fescue seed, with (P+) or without (P-) isoflavones. Steers were provided a basal diet with fescue seed for 21 days, while isoflavones were orally administered daily. Following the trial, blood and rumen fluid were collected for metabolite analysis. Metabolites were extracted and then analyzed by UPLC-MS. The MAVEN program was implemented to identify metabolites for MetaboAnalyst 4.0 and SAS 9.4 statistical analysis. Seven differentially abundant metabolites were identified in serum by isoflavone treatment, and eleven metabolites in the rumen due to seed type (p < 0.05). Pathways affected by treatments were related to amino acid and nucleic acid metabolism in both rumen fluid and serum (p < 0.05). Therefore, metabolism was altered by fescue seed in the rumen; however, isoflavones altered metabolism systemically to potentially mitigate detrimental effects of seed and improve animal performance.

Selenosis in Ruminants.

Selenium (Se) is a metalloid that exists as a red amorphous powder, reddish crystal, silver-gray crystal, or brown-black solid. Its potency as a nutrient and a toxicant is such that few people have seen the pure element. It is easy to lose sight of the narrow margin between too little and too much. The most common cause of selenosis is accidental or intentional overuse of supplements. Many target organs and effects of Se toxicity are similar to those of Se deficiency, so laboratory confirmation is necessary. Prevention consists of minimizing exposure to seleniferous feedstuffs and optimizing dietary factors that might aggravate selenosis.

Effects of a diet containing dried grape pomace on blood metabolites and milk composition of dairy cows.

BACKGROUND: The effect of a diet containing 15% grape pomace (GP) on the general health status and milk quality of dairy cows was assessed by plasma biochemistry and total polyphenol (TP) content, milk polyphenols, milk composition and milk protein fractions. RESULTS: Among the polyphenols measured by liquid chromatography-mass spectroscopy in GP, in feed containing GP (GP+) or not containing GP (GP-), gallic acid and epicatechin were present in the highest concentrations (67.58 and 19.23 µg mL-1 , respectively). Higher amounts of TP were also detected in the blood plasma of GP+ cows (114.06 and 83.93 mg GAE L-1 , respectively) but not in their milk (233.17 and 245.75 mg GAE L-1 , respectively). Also a significant increase was found for lactose and ß-lactoglobulin, although there was no effect on α-lactalbumin, albumin, secretory components and caseins. CONCLUSION: Inclusion of 15% GP in the diets of dairy cows is beneficial for overall normal blood constituent metabolism and helps to maintain cow health. The milk of cows fed with a GP diet preserves the normal levels of fat, protein and caseins, and has increased levels of components that make this milk a versatile ingredient material for the food industry (e.g. model whey powders, stability of lactose-rich powders). © 2016 Society of Chemical Industry.

[Feed-related selenium poisoning in swine]. / Fütterungsbedingte Selen-Vergiftung beim Schwein.

The following case report describes a selenium toxicosis in a pig-fattening farm of two finisher groups. The diseased animals partly showed ataxia and paresis or intense lameness in connection with band-like ablation of the epidermis at the coronary band. Some of them suffered from alopecia. Foot-and-mouth disease and swine vesicular disease were excluded by serological tests. Dissection revealed a multifocal bilateral symmetric poliomyelomalacia. Histological changes in the claws ranged from severe cell-decay in the germinative layer to distinctive decay of the stratum corneum. Due to damage of the claw epidermis the corium was partly exposed. Feed analysis revealed 100-fold increased selenium content in the finishing premix from the feed mill and as a result 20- to 60-fold increased selenium values in feed samples from the farm-made finisher mixture. Selenium concentration in the blood of diseased animals was 4- to 10-fold higher than normal values, which confirmed the tentative diagnosis of a selenium toxicosis.

Effect of feeding T-2 toxin contaminated feed on the utilisation of vitamin E in chickens.

The purpose of the present study was to investigate the effect of experimental T-2 toxin load (2.35 mg/kg of feed) and vitamin E supply in the drinking water (10.5 mg/bird/day) on vitamin E levels of the blood plasma and liver in broiler chickens in a 14-day experiment. It was found that T-2 toxin load did not influence vitamin E content of the blood plasma except at day 3 after the toxin load when a moderate increase was detected in plasma vitamin E. No significant changes were found in vitamin E content of the liver. The simultaneous use of high-dose vitamin E supplementation and T-2 toxin load caused a significantly higher plasma vitamin E content but the changes were less expressed in the group subjected to T-2 toxin load. Vitamin E supply also resulted in a marked and significant increase in vitamin E concentrations of the liver on days 3 and 7 even in the T-2 loaded group, but this concentration significantly decreased thereafter. The results show that T-2 contamination of the diet has an adverse effect on the utilisation of vitamin E in broiler chickens.

Toxic effects in dairy cattle following the ingestion of a large volume of canola oil.

The clinical and laboratory findings of a group of 9 dairy cattle that accidentally ingested large volumes of canola oil are described. Four of the animals died, and 3 were necropsied. No specific cause of death was found, although a number of theories are advanced. This is the first report of such an occurrence.

Drought associated poisoning of cattle in South Texas by the high quality forage legume Leucaena leucocephala.

Approximately 80 head of yearling cattle grazing on 680 acres exhibited signs of Leucaena leucocephala toxicosis, which was confirmed in 3 animals by detection of 3-hydroxy-4 (IH)-pyridone, the metabolite of the poisonous principle mimosine, in their urine. The animals had grazed leucaena almost exclusively due to lack of alternative forage resulting from drought conditions. Toxicosis from this otherwise high quality forage would likely not have occurred had animals consumed lower amounts of leucaena and could probably have been prevented, as it has been elsewhere, had the animals been colonized with Synergistes jonesii, a beneficial ruminal bacterium capable of degrading the toxic metabolites.

Selenosis.

Despite more than six decades of research, some aspects of the natural history of selenosis remain confused in modern texts. The primary targets of acute Se toxicity in food animal species are the cardiovascular, gastrointestinal, and possibly hematopoietic systems. Swine may develop neurologic lesions; however, the signs of poliomyelomalacia are quite distinct from those described as "blind staggers" by early workers. The most characteristic signs of chronic selenosis are hair and hoof loss; however, other, less specific, damage to the immune system and reproduction are economically more important. Given the numerous interactions of chronic Se with other dietary factors, it is very important to examine the whole environment when dealing with a potential selenosis case.

[Animal nutrition in veterinary medicine--actual cases: copper intoxication in piglets]. / Tierernährung für Tierärzte--aktuelle Fälle: Kupferintoxikation bei Ferkeln.

A case is described where piglets reacted with severely reduced feed intake, watery and dark faeces, poor growth and rough hair coat after delivery of a new charge of a commercial pelleted diet. Body temperature was normal, the behaviour appeared depressed. The diet contained 860 mg copper/kg, which was highly above the labelled concentration (160 mg/kg) and the concentration allowed by feed legislation (175 mg/kg for pigs up to 16 weeks of age). After changing to a new mixed feed the general condition of the piglets improved and faecal consistency and colour normalised within a few days.

Chronic gypsum fertiliser ingestion as a significant contributor to a multifactorial cattle mortality.

OBJECTIVE: To assess the validity of claims that heavy metal contamination from an open-cut mine caused the death of 226 cattle on a nearby farm over a period of 18 months, and to investigate other possible contributing factors. PROCEDURE: A retrospective assessment of previous investigations combined with additional chemical analyses. RESULTS: Extensive chemical analyses produced no evidence of heavy metal contamination associated with the mine. Analysis of bones indicated exposure to fluoride in greater than normal amounts. The main source of fluoride seems to have been gypsum that was included in a feed supplement and also ingested from fertiliser dumps on paddocks. The gypsum itself may have contributed significantly to the ill health. Other factors probably affected some classes of animals, notably the young calves. CONCLUSIONS: What originally seemed to be a disease problem of single aetiology probably was an expression of interacting multifactorial causes. This investigation has highlighted the potential toxicity of gypsum to livestock and the need for further studies to establish its basis.

Dietary vitamin D toxicity in a household of pot-bellied pigs (Sus scrofa).

Vitamin D intoxication developed in Vietnamese Pot-Bellied Pigs (Sus scrofa) fed 2 commercially available swine rations. Pronounced hypercalcemia and a history incompatible with other causes of hypercalcemia led to confirmation of this diagnosis by plasma vitamin D metabolite analysis in 2 affected animals as compared to a control animal. Feed sample analysis suggested the diet as the likely source of toxicity.

Selenium toxicosis with focal symmetrical poliomyelomalacia in postweaning pigs in South Africa.

An outbreak of paralysis in finisher pigs in South Africa after ingestion of feed containing 54,581 mg/kg of selenium is described. The main and entirely consistent lesion was bilaterally symmetrical focal poliomalacia of the ventral horns of the spinal cord, which was most severe and consistent in the lumbar intumescence. Acute and subacute lesions were characterized by malacia with large numbers of gitter cells. The main features of chronic lesions were loss of neurons and gliosis. Focal degeneration and necrosis of the myocardium and skeletal muscles were also consistent, but there were fewer specific changes. Endothelial swelling, mild fibrinoid degeneration and perivascular leukocytic infiltration were present in the acute stage. Dermatitis, coronitis and hoof sloughing, usually present in more chronic cases of intoxication, were not a feature of the present outbreak, although alopecia and crusting were evident on the backs of a few pigs several weeks after the episode of intoxication. Serum-and tissue-selenium levels were elevated in the early stages after intoxication. Serum levels were nearly normal in chronic cases two months after the episode, while liver and kidney levels were still higher than normal. Higher levels were found in liver, kidney and serum than in muscle, with the highest levels in the kidney. Less than 20% of affected pigs recovered sufficiently to be marketed.

Leucaena toxicosis and its control in ruminants.

Leucaena (Leucaena spp., especially L. leucocephala) is an arboreal, tropical legume that ranges into the cool subtropics and equatorial elevations up to 1,000 m. One of its uses includes forage for livestock, but introduction of leucaena outside its indigenous range often has led to acute and chronic toxicosis. The major toxic constituents of leucaena are the nonprotein free amino acid mimosine and its ruminal degradation product, 3-hydroxy-4(1H)-pyridone (3,4-dihydroxypyridine; 3,4-DHP). Leucaena also contains appreciable quantities of condensed tannins. In ruminants, mimosine is a depilatory agent and 3,4-DHP is a potent goitrogen. In the 1980s, Australian workers demonstrated that the geographical limits of leucaena toxicosis were due to the absence of ruminal bacteria capable of degrading 3,4-DHP, and successfully introduced 3,4-DHP degrading ruminal bacteria from a Hawaiian goat into goats and cattle in Australia. Simple in vitro screening methods have been developed for detection of 3,4-DHP degraders in ruminal samples and feces. Also, several strains of 3,4-DHP degrading ruminal bacteria have been characterized and have been given the genus and species designation, Synergistes jonesii. Ruminal inoculation with ruminal contents from adapted animals, enriched cultures of 3,4-DHP-degrading ruminal bacteria, and pure cultures of S. jonesii have all been used successfully to establish ruminal populations that are capable of degrading 3,4-DHP and preventing leucaena toxicosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Nutritional toxicology of tannins and related polyphenols in forage legumes.

Proanthocyanidins (PA) (condensed tannins) and hydrolyzable tannins (HT) are the two major classes of tannins. Proanthocyanidins are flavonoid polymers. Hydrolyzable tannins are polymers of gallic or ellagic acid esterified to a core molecule, commonly glucose or a polyphenol such as catechin. Proanthocyanidins are the most common type of tannin found in forage legumes. Problems in the analysis of tannins are that sample processing and drying decrease extraction and reactivity, suitable standards are unavailable, and quantitative analytical methods are poorly correlated with enzyme inhibition, protein precipitation, and nutritional effects. Hydrolyzable tannins are potentially toxic to ruminants. Pyrogallol, a hepatotoxin and nephrotoxin, is a product of HT degradation by ruminal microbes. Proanthocyanidins are considered to be non-toxic because they are not absorbed, but they are associated with lesions of the gut mucosa. Research on tannins in forage legumes has determined their effects on protein digestion and metabolism but more research on tannin structure in relation to digestion of specific proteins is needed. The widely accepted explanation for positive effects of PA on protein digestion and metabolism is that PA-protein complexes escape ruminal degradation and the protein is available in the lower tract. This proposed mechanism may be incorrect because PA also complex carbohydrates, endogenous proteins, and microbial products and the degradability of PA-protein complexes by ruminal microbes has not been adequately studied. Several alternative hypotheses (to escape protein) that explain the effect of PA on protein digestion and metabolism in ruminants are also consistent with experimental results on forage legumes. These include increased microbial protein synthesis, increased use of endogenous nitrogen in the rumen, and increased secretion of salivary glycoproteins. Research on manipulating the content and type of PA in forage legumes is justified because they are associated with non-bloating legumes, lower soluble non-protein nitrogen in silage, and improved efficiency of protein utilization. Research on the biosynthesis, molecular genetics, and cell biology of PA in forage legumes needs to be integrated with research on toxicology and nutrition.

Equine fescue toxicosis: signs and solutions.

Gravid mares grazing endophyte-infested (E+) tall fescue exhibit increased gestation lengths, agalactia, foal and mare mortality, tough and thickened placentas, weak and dysmature foals, increased sweating during warm weather, reduced serum prolactin and progesterone, and increased serum estradiol-17 beta levels. Also, E+ tall fescue hay is less digestible than endophyte-free (E-) hay. Unlike many other species, horses consuming E+ tall fescue do not exhibit increased body temperature. Young horses consuming only E+ pasture do not gain as well as those consuming E- pasture. There is little difference in gain when the pasture is supplemented with enough concentrate to meet NRC requirements for growth. Neither selenium injections nor supplementing with corn at 50% of the NRC requirements for energy reduces the effects of toxic tall fescue on reproduction and lactation in gravid mares. It seems that the alkaloids of E+ tall fescue are serving as D2 dopamine receptor agonists. This activity would explain their prolactin-lowering effect. Domperidone, a dopamine receptor antagonist, is effective in preventing the signs of tall fescue toxicosis in horses without neuroleptic side effects.

Apparent gossypol-induced toxicosis in adult dairy goats.

Consumption of a cotton-seed meal-based mineral supplement (cattle label) and a concentrate dairy mix (goat label) resulted in gossypol toxicosis in 3 adult dairy goats. The primary clinical signs were limb swelling and stiffness, ventral abdominal edema, and anorexia. All does died within a few days of the onset of illness. Necropsy revealed generalized subcutaneous edema, acute centrilobular necrosis of the liver, and myocardial fibrosis, consistent with a diagnosis of gossypol toxicosis. It was estimated that the does had consumed from 348 to 414 mg of free gossypol/d for at least 3 months. Apparent gossypol toxicosis in goats consuming this amount of free gossypol indicates that goats may be more susceptible than cattle to this substance.

Chronic selenosis in horses fed locally produced alfalfa hay.

Chronic selenosis (alkali disease) was diagnosed in horses of western Iowa, a region associated with marginal to adequate soil selenium. Two locally produced alfalfa hays (Medicago sativa L) were identified as the primary source. Difficulty in selecting diagnostic specimens to evaluate potential chronic selenosis cases is complicated by the wide range of tissue concentrations reported in previous cases, conflicting correlation of sample selenium concentrations in the literature, and different recommendations on specimen selection and diagnostic value. These problems arise form the similarity in clinical signs for mild and severe chronic selenosis cases, and inability to establish the disease time course. Therefore, collection of multiple samples to confirm high selenium concentration in various tissues and identify selenium sources is recommended. Value of samples believed to reflect historical exposure vs current status may be questionable. Interpretation of results by practitioners and diagnosticians should consider selenium exposure level and duration, antagonistic or ameliorating factors, and postexposure excretion.

Selenium toxicosis in feeder pigs.

Selenium toxicosis was diagnosed in feeder pigs on a central Michigan farm. Use of a commercial supplement, found to contain approximately 20 times the intended Se concentration, resulted in a Se concentration of 8.1 mg/kg of the complete feed. This was fed for 34 days during which daily feed consumption decreased approximately 35%, several pigs developed weakness and forelimb paresis, and 1 pig died. The highest serum Se concentration measured was 1,550 ng/ml (normal range, 140 to 190 ng/ml). Normal feed consumption returned when an alternative feed was provided. Mean serum Se concentrations of representative pigs, monitored over the subsequent 26 days, decreased from 905 to 258 ng/ml. Histologic examination of a recovering pig revealed skeletal and cardiac myopathy and bilaterally symmetric malacia of the gray matter of the ventral horns of the spinal cord. During the developing toxicosis, the pigs consumed an estimated 11.4 mg of Se/pig/d.