Effects of dietary supplementation with butylated hydroxyanisole, cysteine, and vitamins B on tansy ragwort (Senecio jacobaea) toxicosis in ponies

Dried tansy ragwort, which contains pyrrolizidine alkaloids, was fed as 10% of a complete diet to ponies, with and without a mixture of additives. The additives provided a dietary supplement equivalent to 1% cysteine, 0.75% butylated hydroxyanisole, 200 micrograms of vitamin B12/kg of feed, and 5 mg of folic acid/kg of feed. The additives did not alter tansy ragwort toxicity, as assessed by survival time, liver changes, sulfobromophthalein (BSP) clearance rate, serum gamma-glutamyl transpeptidase activity, and plasma amino acid patterns. In ponies fed tansy ragwort, BSP clearance rate was a sensitive indicator of liver damage, and decreased to about 20% of control values. gamma-Glutamyl transpeptidase activities showed considerable variability, but generally were elevated in animals fed tansy ragwort. Liver iron and copper concentrations increased, and liver zinc concentrations decreased in tansy ragwort-fed ponies. Plasma amino acid patterns in tansy ragwort-fed ponies showed changes typical of those observed in liver disease.     

Failure of mineral-vitamin supplements to prevent tansy ragwort (Senecio jacobaea) toxicosis in cattle

The efficacy of 2 mineral-vitamin supplements in preventing or alleviating initial pyrrolizidine alkaloid (PA) toxicosis in cattle was tested. Three groups of calves were fed 1 of the 2 supplements plus tansy ragwort (Senecio jacobaea) containing PA and 2 groups of calves were fed tansy ragwort without the supplement. Toxicity comparisons were based on differences in observed clinical signs, serum enzyme changes, survival time of calves, and histopathologic examination of hepatic tissue. Typical tansy ragwort toxicosis terminating in death developed in all calves. There were no marked differences in responses of the groups of calves. Seemingly, the supplements did not afford protection or alleviate tansy ragwort-related PA toxicosis in calves.     

Milk transfer of pyrrolizidine alkoloids in cattle.

A study was conducted to determine if pyrrolizidine alkaloids from Senecio jacobaea (tansy ragwort) are passed into milk of lactating cows. Four cows were given dried tansy ragwort via rumen cannula at a dosage of 10 g/kg/day for 2 weeks. Chemical assay of pyrrolizidine alkaloid content in the dried plants averaged 0.16% by weight. By use of thin-layer chromatography, 5 alkaloids were isolated from the plant materials. The only alkaloid isolated from the milk was jacoline. Condition of the cows and nursing calves was monitored via measurement of blood leukocyte count, and serum protein, albumin, and globulin content. Sorbitol dehydrogenase values and liver biopsy specimens were used to assess liver function. In the cows, marked changes were observed in blood leukocyte count, sorbitol dehydrogenase values, and liver biopsy findings. No changes of any type were observed in the calves. Pyrrolizidine alkaloid content of the milk ranged from 9.4 to 16.7 mug/100 ml of milk.     

Effects on cattle and their calves of tansy ragwort (Senecio jacobaea) fed in early gestation

Tansy ragwort (Senecio jacobaea) fed to pregnant cows on gestation days 15 through 30 in lethal and near-lethal doses did not cause detectable damage to 100-day-old or to full-term fetuses as determined by gross examinations, serum enzyme tests chosen to detect hepatic changes, and by histopathologic examinations. Some cows that appeared normal during gestation expired soon after parturition from typical seneciosis apparently triggered by parturition stress. Pregnant cows fed 12% smaller tansy ragwort doses on gestation days 30 through 45 had only minimal serum enzyme changes and gave birth to normal calves that had normal serum enzymes up to 64 days after parturition.     

Effects of dietary copper and molybdenum on tansy ragwort (Senecio jacobaea) toxicity in sheep

Dried tansy ragwort (Senecio jacobaea), which contains pyrrolizidine alkaloids (PA), was fed to sheep to determine whether PA consumption influenced liver Cu concentrations. Nine Polypay wether lambs were allotted to 3 groups according to the diets: control diet + 50 micrograms of Cu/g of feed (control + Cu); tansy ragwort (TR) diet + 50 micrograms of Cu/g of feed (TR + Cu); and TR diet + 50 micrograms of Cu/g of feed and 10 micrograms of Mo/g of feed (TR + Cu + Mo). Liver Cu concentrations were sharply increased (13-fold) after 8 weeks of feeding the diets, and then decreased slightly. There were no significant differences in concentrations of liver Cu among treatment groups. All lambs in the group fed TR + Cu + Mo died by the end of 23 weeks, with the usual signs of PA poisoning, including liver necrosis, hepatic megalocytosis, and biliary hyperplasia. The TR intake was about 2.7 to 3.0 kg/kg of their initial body weight. All lambs in the group fed the control + Cu diet survived. The results indicated that sheep fed TR do not preferentially accumulate liver Cu. There was an indication that dietary Mo increased susceptibility to TR intoxication.     

Effects of dietary supplementation with ethoxyquin, magnesium oxide, methionine hydroxy analog, and B vitamins on tansy ragwort (Senecio jacobaea) toxicosis in beef cattle

Dried tansy ragwort containing pyrrolizidine alkaloids was fed as 2.5% of a complete (control) diet to Hereford steers, with and without (basal) a mixture of additives. The additives provided a dietary supplement equivalent to 0.1% ethoxyquin, 1% methionine hydroxy analog, 2% MgO, 2.7 mg of vitamin B6/kg of diet, 50 micrograms of vitamin B12/kg of diet, 0.45 g of folic acid/kg of diet, and 0.2 g of cobalt/kg of diet. The additives did not alter tansy ragwort toxicity substantially, as assessed by liver histologic changes, sulfobromophthalein clearance rate, and serum gamma-glutamyl transpeptidase activity. After 281 days, 1 of 4 steers fed the basal diet was alive, whereas 3 of 4 steers in the basal plus additives group were alive, suggesting some protective activity. The chronic lethal dose of tansy ragwort in steers was 3.6% of initial body weight.     

Evaluation of amino acids, B vitamins and butylated hydroxyanisole as protective agents against pyrrolizidine alkaloid toxicity in rats

Supplementation of the diets of rats with branched chain amino acids (BCAA: leucine, isoleucine, valine) did not alter their susceptibility to chronic poisoning by tansy ragwort (Senecio jacobaea), which contains hepatotoxic pyrrolizidine alkaloids (PA). Phenobarbital in the diet, which alters liver microsomal enzyme activity, also did not alter susceptibility to PA poisoning. A combination of butylated hydroxyanisole (BHA), cysteine and BCAA did increase (P less than .05) survival time of rats fed tansy ragwort. Dietary BHA and cysteine increased the survival time of rats injected with the PA monocrotaline, with evidence that addition of vitamin B12 and folic acid improved the effectiveness of this treatment. In a chronic feeding trial with tansy ragwort, a combination of BHA and cysteine increased (P less than .05) the survival times of rats, showing protective activity against PA poisoning. A mixture of B-complex vitamins, or vitamin B12-folic acid, was not effective in improving the response.     

Clinical manifestations of tansy ragwort poisoning

The clinical signs of tansy ragwort poisoning are variable and in 5 cases included diarrhea, tenesmus, ascites, bloody feces, icterus, paresis, CNS involvement, rectal prolapse, poor appetite and weight loss. It is thus apparent that the disease can be confused clinically with many others, and tansy ragwort poisoning should be considered in animals exhibiting ascites, diarrhea and rectal prolapse. Several cases of tansy ragwort (Senecio jacobaea) poisoning occurring from 1969 to 1976 are reported to illustrate the numerous clinical pictures that might confront a practitioner. The disease is sporadic in this area. The poisonous principles in tansy ragwort are pyrrolizidine alkaloids, which cause gradual alteration and necrosis of liver cells with replacement by fibrous tissue. The development of signs in all of these cases could be attributed to failure of one or more liver functions.     

Senecio jacobaea: deceiving beauty. Senecio jacobaea poisoning

In a cattle herd problems were noticed during 1.5 years, characterised by emaciation and loss of milk production with lower fat- and protein%, tenesmus, central nervous symptoms (aggression, circling and blindness), diarrhoea, eczema solare and death. Clinical, laboratory and post mortem examinations did not reveal a specific cause at first. An intoxication was suspected based on the clinical symptoms, the course of the disease in sick animals and severe liver cirrhosis found in a sudden death cow: The animals were fed grassilage derived from an air force base on which an overwhelming amount of tansy ragwort (Senecio jacobaea) was present. On subsequent microscopic examination of the livers of 11 slaughtered clinically healthy animals all of these showed fibrosis in varying extension. Cirrhosis and fibrosis of the liver and the clinical symptoms are all features of chronic pyrrolyzidine alkaloidosis. Tansy ragwort poisoning has not been diagnosed in the Netherlands for years. The rise in cases is due to more extensive use of land.     

Activities of gamma-glutamyltransferase, alkaline phosphatase and aspartate-aminotransferase in colostrum, milk and blood plasma of calves fed first colostrum at 0-2, 6-7, 12-13 and 24-25 h after birth

Enzyme activities of gamma-glutamyltransferase (gamma-GT), alkaline phosphatase (AP) and aspartate-aminotransferase (AST) were measured from birth to the age of 28 days in calves which were fed colostrum at 0-2, 6-7, 12-13, or 24-25 h after birth. Enzyme activities were also measured in colostrum (first to fifth milking) and in mature milk. Activities were highest in the first colostrum milking and decreased to the lowest activities in mature milk. Plasma gamma-GT activity transiently increased after first colostrum intake and was greater in calves fed first colostrum within less than 6-7 h than in those fed first colostrum later than 12 h after birth. Activity of gamma-GT reflected the absorption of colostral gamma-GT, which decreased with time after birth. The AP activity transiently increased after colostrum intake and was higher in calves fed colostrum within the first 12 h of life than in those fed later after birth. The transient rise of plasma AP activity also indicated absorption of colostral AP, although endogenous sources of AP could not be excluded. The activity of AST also transiently increased after colostrum intake but there was no association with time of first colostrum feeding, indicating that the rise of plasma AST activity was the consequence of enhanced endogenous production and was independent of colostrum intake. In conclusion, there are different causes leading to postnatal changes in enzyme activities.     

Changes in plasma enzyme activities and other blood components in response to acute and chronic liver damage in cattle

Three calves were dosed orally with carbon tetrachloride at 0.05, 0.1 or 0.3 ml/kg body-weight. Plasma enzyme activities, clotting times, bilirubin concentrations and bromsulphthalein elimination times increased. These changes are associated with damage to the liver and are discussed in relation to the clinical syndrome. Three groups of seven calves were infected weekly with 10, 50 or 100 Fasciola hepatica metacercariae for 12 consecutive weeks. Maximum glutamate dehydrogenase and gamma glutamyltransferase activities in the plasma were greater with the larger infecting doses but there was no change in plasma clotting times.     

Changes in the profile of liver enzymes in newborn calves induced by experimental,subclinical acidosis in pregnant cows and osmotic diarrhoea

Experimental, subclinical acidosis was induced by oral administration of sacharose during the last 2 months of pregnancy in 15 cows. Seven cows and their newborn calves were used as a control group. The liver enzyme activities in the serum and the blood acid-base status were determined in the 15 calves from the cows in the experimental group. Mannitol was administered orally to 8 calves from the experimental group to induce osmotic diarrhoea. It was concluded that subclinical acidosis in pregnant cows alters the biochemical liver profile of their newborn calves, affecting the aspartate aminotransferase, alanine transaminase, beta glucuronidase, glutamate dehydrogenase and bilirubin activities in the serum, which are associated with oedematous changes to the hepatocytes. Diarrhoea was accompanied by an increase in the alkaline phosphatase and gammaglutamyl transferase activities and a decrease in the total protein concentration in the serum. These changes were apparently related to the numerous necrotic foci in the liver and the proliferation of the Kuppfer cells. It would appear from these results that the liver damage in the newborn calves was associated with the subclinical, metabolic acidosis in their dams and that osmotic diarrhoea occurring in the neonatal period additionally impaired the liver function.Abbreviations ALP alkaline phosphatase - ALT alanine transaminase - AST aspartate aminotransferase - GR betaglucuronidase - bw body weight - ELISA enzyme-linked immunosorbent assay - GD glutamate dehydrogenase - GGT gammaglutamyl transferase - IU international unit     

Dietary magnesium and urolithiasis in growing calves

The effect of high levels of dietary magnesium (1.4%) alone or in combination with elevated calcium (1.8%) or phosphorus (1.6%) on growth and health of male calves was evaluated during a nine week feeding trial after weaning. Twenty calves were randomly divided into 4 feeding groups consisting of controls, high magnesium, high magnesium and calcium or high magnesium and phosphorus. Elevated dietary minerals caused decreased feed intake and growth rate. Blood urea nitrogen and serum creatinine levels were greatly elevated in calves fed high magnesium or magnesium and phosphorus and serum urea nitrogen was moderately elevated in calves fed high magnesium and calcium. These elevations suggested the occurrence of renal damage as a result of microcrystalline obstruction of renal tubules. Serum magnesium levels were three times normal in calves fed high magnesium or magnesium and phosphorus, but only twice normal in calves fed high magnesium and calcium. High dietary magnesium resulted in a significant depression in blood calcium level. This effect was somewhat overcome by additional dietary calcium Three calves fed the high magnesium diet and two calves fed the high magnesium and phosphorus diet developed urinary tract obstruction. The chemical composition of uroliths recovered from these calves was calcium apatite. Elevated dietary magnesium has been shown to be a cause of urolithiasis in growing male calves. Additional dietary calcium, but not phosphorus, appears to protect calves against urolithiasis induced by elevated dietary magnesium.     

Effects of feeding a blend of grains naturally contaminated with Fusarium mycotoxins on feed intake,serum chemistry,and hematology of horses,and the efficacy of a polymeric glucomannan mycotoxin adsorbent

The feeding of Fusarium mycotoxin-contaminated grains adversely affects the performance of swine and poultry. Very little information is available, however, on adverse effects associated with feeding these mycotoxin-contaminated grains on the performance of horses. An experiment was conducted to investigate the effects of feeding a blend of grains naturally contaminated with Fusarium mycotoxins on feed intake, serum immunoglobulin (Ig) concentrations, serum chemistry, and hematology of horses. A polymeric glucomannan mycotoxin adsorbent (GM polymer) was also tested for efficacy in preventing Fusarium mycotoxicoses. Nine mature, nonexercising, light, mixed-breed mares were assigned randomly to one of three dietary treatments for 21 d. The horses were randomly reassigned and the experiment was subsequently replicated in time following a 14-d washout interval. Feed consumed each day was a combination of up to 2.8 kg of concentrates and 5 kg of mixed timothy/alfalfa hay. The concentrates fed included the following: 1) control, 2) blend of contaminated grains (36% contaminated wheat and 53% contaminated corn), and 3) blend of contaminated grains + 0.2% GM polymer. Diets containing contaminated grains averaged 15.0 ppm of deoxynivalenol, 0.8 ppm of 15-acetyldeoxynivalenol, 9.7 ppm of fusaric acid, and 2.0 ppm of zearalenone. Feed intake by all horses fed contaminated grains was reduced (P < 0.001) compared with controls throughout the experiment. Supplementation of 0.2% GM polymer to the contaminated diet increased (P = 0.004) feed intake of horses compared with those fed the unsupplemented contaminated diet. Serum activities of gamma-glutamyltransferase were higher (P = 0.047 and 0.027) in horses fed the diet containing contaminated grain compared with those fed the control diet on d 7 and 14, but not on d 21 (P = 0.273). Supplementation of GM polymer to the contaminated diet decreased (P < 0.05) serum gamma-glutamyltransferase activities of horses compared with those fed unsupplemented contaminated diet on d 7 and 14. Other hematology and serum chemistry measurements including serum IgM, IgG, and IgA, were not affected by diet. It was concluded that the feeding of grains naturally contaminated with Fusarium mycotoxins caused a decrease in feed intake and altered serum gamma glutamyltransferase activities. The supplementation of GM polymer prevented these mycotoxin-induced adverse effects.     

The effects of Dictyocaulus viviparus infection on energy metabolism of calves

To determine the effects of lungworm infection on energy metabolism and rate of weight gain, five 3-mo-old male Friesian calves were infected orally twice each week with 640, third-stage larvae of Dictyocaulus viviparus (D.v.) over an 8-wk period. Infected calves were matched with uninfected controls on the basis of similar rates of feed consumption and weight gain during the acclimation period before infection. Infected calves were fed 2 kg of concentrates daily (88% DM), about 8.5 Mcal/d. Controls each received approximately 250 g less, about 7.5 Mcal/d. Similar amounts of hay (5.6 to 5.8 Mcal/d) were provided to all calves. Clinical, serum chemical, hematological and parasitological criteria, weight gain and utilization of energy were monitored on a weekly basis. Serum chemical and hematological analyses and clinical examinations of infected animals revealed signs typical of lungworm infection. Fecal and sputum sample examinations for infected calves were positive for D.v. larvae and ova, respectively. Control animals gained approximately 80 g.animal-1.d-1 more than infected calves. Lungworm infection had no significant effect on digestibility of energy or protein. Metabolizability of energy ingested was somewhat higher in the infected calves due to a higher dietary concentrate to roughage ratio. Utilization of metabolizable energy and protein tended to be less efficient for infected animals. Results showed that D.v.-infected calves need more feed for gain than do uninfected animals. This extra requirement is due to an increased maintenance requirement and probably to a reduced protein retention from digested protein.     

不同饲喂模式对犊牛小肠及胰腺内消化酶活性的影响

为研究饲喂模式对犊牛肠道及胰腺内消化酶活性的影响。试验选择24头体重和出生日期相近的犊牛,随机分成2组,每组12头,其中Ⅰ组采用传统饲喂模式(干草+粉状开食料),4 d开始补充开食料,10 d开始补充苜蓿干草,干草自由采食。Ⅱ组采用现代饲喂模式(颗粒型开食料)犊牛于4 d开始补充开食料。60 d断奶。各组分别在0、15、30、60 d屠宰3头犊牛。结果表明:Ⅰ组犊牛中性洗涤纤维以及酸性洗涤纤维日均摄入量均显著高于Ⅱ组(P<0.05),粗蛋白、消化能、粗脂肪、钙和磷的日均摄入量差异均不显著(P>0.05)。Ⅱ组犊牛小肠以及胰腺内淀粉酶、糜蛋白酶、胰蛋白酶、脂肪酶均高于Ⅰ组,尤其是胰蛋白酶以及糜蛋白酶在60 d时显著高于Ⅰ组(P<0.05)。结果提示,断奶前饲喂颗粒开食料有利于促进犊牛小肠以及胰腺内消化酶的分泌,利于提高犊牛对饲料的消化利用率。     

Influence of dietary forage and feed intake on carbohydrase activities and small intestinal morphology of calves.

Twenty (12 Holstein, 8 Longhorn cross) calves (198 kg and 7 mo old) were used in a randomized complete block design to evaluate the effects of dietary forage concentration and feed intake on carbohydrase activities and small intestinal (SI) morphology. Calves were individually fed 90% forage (alfalfa) or a 90% concentrate (50% sorghum: 50% wheat) diet at either one or two times NEm for 140 d and slaughtered; tissues and small intestinal digesta were collected. Increased feed intake increased (P less than .05) pancreatic weight, alpha-amylase and glucoamylase activities in the pancreas, SI length and SI digesta weight. Forage-fed calves gained faster (P less than .01) and had greater (P less than .05) pancreatic protein concentrations, alpha-amylase and glucoamylase activities in the pancreas and greater SI digesta alpha-amylase activities than grain-fed calves did. Increased feed intake increased (P less than .01) mucosal weight/cm small intestine only in forage-fed calves and increased (P less than .05) SI surface/volume only in grain-fed calves. Mucosal weight was greatest (P less than .05) at the terminal ileum, surface/volume was greatest (P less than .05) in the duodenum, and mucosal protein concentration was highest (P less than .05) in the SI mid-section. Mucosal lactase was higher (P less than .05) in proximal segments, whereas mucosal isomaltase was higher in middle and distal segments of the small intestine. For mucosal maltase activity, there was a feed intake x SI sampling site interaction (P less than .05) and for trehalase, a diet x feed intake x SI sampling site interaction (P less than .05). The SI distribution patterns of maltase and isomaltase were similar, as were those of trehalase and lactase. The alpha-amylase activity in the pancreas and SI morphology were influenced greatly by diet composition and feed intake by calves.     

Copper toxicosis in a dairy goat herd

CASE DESCRIPTION: A closed herd of 400 mixed-breed dairy goats was examined because of a decrease in milk production and increase in mortality rate. Nine animals had died within a 1-month period. CLINICAL FINDINGS: Clinical signs were evident only in lactating goats and included anorexia and recumbency. In the most severely affected goats, signs progressed to neurologic abnormalities and death. Serum aspartate aminotransferase activity, gamma-glutamyltransferase activity, and total bilirubin concentration were high in clinically affected does, but no evidence of hemolysis was found. A diagnosis of copper toxicosis was made on the basis of high liver and kidney copper concentrations and histologic evidence of hepatic necrosis. Goats were found to have been fed a mineral mix containing 3,050 ppm copper for 9 months prior to the onset of copper toxicosis. Overall, there was no consistent relationship between serum hepatic enzyme activities, serum copper concentration, and liver copper concentration. TREATMENT AND OUTCOME: Clinically affected goats were treated with penicillamine, ammonium molybdate, sodium thiosulfate, and vitamin E. Penicillamine increased urine copper excretion in treated does versus untreated control animals. An increased incidence of infectious disease was identified in the herd 9 months later. Liver vitamin E concentration was low in 10 of the 12 goats that underwent necropsy. CLINICAL RELEVANCE: Findings suggested that penicillamine may be an effective treatment for goats with copper toxicosis. Production losses months after the diagnosis was made suggested that the intoxication had a prolonged animal welfare and economic impacts.     

Tansy ragwort poisoning in a horse in southern Ontario

Bizarre behavior, apparent lameness, and colic were noticed in 1 of 3 horses on a pasture overgrown by weeds during a drought. Liver failure and hepatoencephalopathy were diagnosed, caused by pyrrolizidine alkaloid toxicosis associated with consumption of tansy ragwort. The horse made a full recovery when removed from the pasture.     

Differences in monocarboxylic acid transporter type 1 expression in rumen epithelium of newborn calves due to age and milk or milk replacer feeding

The aim of the present study was to investigate whether besides age and solid feed intake, monocarboxylic acid transporter type 1 (MCT1) expression in the rumen epithelium of calves is affected by liquid feed type [whole milk (WM) or milk replacer (MR)]. Thirty bull calves at the mean age of 5 days were randomly allocated to five experimental groups (six calves/group). Six calves were slaughtered immediately after allocation to the trial (5 days of life), eighteen calves were fed MR and slaughtered at week intervals (on 12, 19, 26 days of life respectively), and six calves were fed WM and slaughtered at the 26 days of life. MCT1 protein abundance and the MCT1 mRNA level were investigated in the dorsal and ventral sack of the rumen. Solid feed intake and short‐chain fatty acids (SCFA) concentration in the rumen fluid increased linearly with calves' age. The amount of the MCT1 protein and mRNA in the dorsal sac of rumen as well as the amount of MCT1 protein in the cranial ventral sac of rumen also increased linearly with calves' age. Calves fed WM had greater solid feed intake in the last week of the study as compared to calves fed MR, but SCFA concentration in the rumen fluid was not different. MCT1 mRNA expression in the cranial dorsal sac of rumen and protein MCT1 expression in both dorsal and ventral cranial sack of the rumen were higher in calves fed WM as compared to calves fed MR. This study confirmed age‐dependent changes of MCT1 expression in the rumen epithelium of newborn calves and showed that its expression might be affected by liquid feed type.