Mycotoxins in corn and wheat silage in Israel.

Silage is an important feed source for intensive dairy herds worldwide. Fungal growth and mycotoxin production before and during silage storage is a well-known phenomenon, resulting in reduced nutritional value and a possible risk factor for animal health. With this in mind, a survey was conducted to determine for the first time the occurrence of mycotoxins in corn and wheat silage in Israel. A total of 30 corn and wheat silage samples were collected from many sources and analysed using a multi-mycotoxin method based on LC-MS/MS. Most mycotoxins recorded in the present study have not been reported before in Israel. Overall, 23 mycotoxins were found in corn silage; while wheat silage showed a similar pattern of mycotoxin occurrence comprising 20 mycotoxins. The most common post-harvest mycotoxins produced by the Penicillium roqueforti complex were not found in any tested samples, indicative of high-quality preparation and use of silage. Moreover, none of the European Union-regulated mycotoxins--aflatoxin B1, ochratoxin, T-2 toxin, diacetoxyscirpenol and deoxynivalenol--were found above their limits of detection (LODs). The Alternaria mycotoxins--macrosporin, tentoxin and alternariol methyl ether--were highly prevalent in both corn and wheat silage (>80%), but at low concentrations. The most prominent (>80%) Fusarium mycotoxins in corn silage were fusaric acid, fumonisins, beauvericin, monilifomin, equisetin, zearalenone and enniatins, whereas in wheat silage only beauvericin, zearalenone and enniatins occurred in more than 80% of the samples. The high prevalence and concentration of fusaric acid (mean = 765 µg kg⁻¹) in Israeli corn silage indicates that this may be the toxin of highest potential concern to dairy cow performance. However, more data from different harvest years and seasons are needed in order to establish a more precise evaluation of the mycotoxin burden in Israeli silage.

Physiological parameters in broiler lines divergently selected for the incidence of ascites.

Ascites syndrome (AS) is manifested in flocks of contemporary broilers that are allowed to fully manifest their genetic potential for rapid growth. After successful selection, a pair of divergent lines was established, AS-susceptible (AS-S) and AS-resistant (AS-R). These lines facilitate comparisons between genetically resistant and susceptible healthy young broilers when reared under standard brooding conditions (SBC). The aim of the present study was to look for predictive indicators for AS susceptibility by comparing relevant physiological parameters in the AS-S and AS-R lines under SBC and after exposure to extreme ascites-inducing conditions (AIC). In this design, a trait differing significantly between the 2 lines under SBC is expected to be a reliable indicator for selection against AS susceptibility in breeding stocks when reared under noninducing conditions. Males from the AS-S and AS-R lines were reared together under SBC to 19 d of age, then under the AIC protocol. Cumulative incidence of AS mortality was 93.2% in the AS-S line and only 9% in the AS-R line, confirming the genetic divergence between the lines. Exposure to AIC enhanced the imbalance between oxygen demands and supply in the AS-S birds and induced differences in blood parameter level between the 2 lines. The AS-S birds exhibited elevated hematocrit and red blood cell counts and a decline in oxygen saturation in the arterial blood. No difference in hemoglobin concentration was found, but calculation of hemoglobin content per 1,000 red blood cells revealed a significant reduction in hemoglobin content in the AS-S birds. Under SBC, there were no significant differences between the lines for hematocrit, red blood cell count, hemoglobin concentration, hemoglobin count per 1,000 red cells, and blood oxygen saturation. However, heart rate during the first week of life was significantly higher in the AS-S birds than in the AS-R birds on d 1 and 7, suggesting that high heart rate may potentially serve as an early criterion for selection against AS susceptibility.

Evaluation of growth rate, body weight, heart rate, and blood parameters as potential indicators for selection against susceptibility to the ascites syndrome in young broilers.

The continuous selection for rapid growth has been accompanied by an increasing occurrence of ascites syndrome (AS), which develops in broilers failing to supply the increasing demand for O(2) in their bodies. Moderate heritability has been reported for AS in broiler populations, suggesting that selection against AS is feasible. However, direct selection based on AS mortality requires exposure of candidate birds to AS-inducing conditions (AIC), which hinder selection for performance traits. Noninvasive indicators of AS, expressed under standard husbandry, may facilitate the integration of selection against AS into breeding programs. This study was designed to look for differences in heart rate, hematocrit, O(2) saturation of hemoglobin in arterial blood (SaO(2)), BW, and weight gain, all measured at early ages under standard brooding conditions, between birds that later developed AS and those that remained healthy under AIC, and to estimate the heritability of these AS-related parameters and their genetic correlation with the tendency of broilers to develop AS. The experimental population was derived from a broiler dam line. Male progeny of 34 half-sib sire families were reared under standard brooding conditions to 19 d of age, then under an AIC protocol consisting of housing in individual cages, cool air high-speed ventilation, and growth enhancement using high-energy pelleted feed and 23 h/d of light. Birds were necropsied upon mortality or at the end of the trials and were recorded as being susceptible, with manifestations of AS (SUS), or resistant and healthy (RES). About 44% developed AS, confirming the efficacy of the novel AIC protocol. The SUS and RES chicks did not differ in BW and weight gain up to 19 d of age, suggesting that there was no association between AS susceptibility and rapid early growth. The SUS chicks exhibited lower SaO(2) and heart rate than the RES chicks. Moderate heritability was estimated for all traits, but only SaO(2) exhibited consistently significant genetic correlation (-0.5) with AS, suggesting that it may serve as an early indicator for selection against AS, albeit with a limited efficacy.

Natural Clostridium botulinum type C toxicosis in a group of cats.

Clinical signs of botulism were observed in a group of eight cats, four of which died, after being fed pelican carrion. Clostridium botulinum type C was isolated from one cat. The microorganism and its toxin were found in the pelican. This is apparently the first report of natural botulism in cats.

Accidental poisoning of 17 dogs with lasalocid.

Over a period of 10 days, 17 dogs became weak and developed neurological deficits of different degrees of severity. About 12 hours before these clinical signs appeared they had all eaten a particular brand of commercial dog food from a recently opened bag. They were all quadriparetic and hyporeflexic, and some of them also showed additional systemic or neurological signs, including dyspnoea, a high body temperature, tongue laxity, hyperaesthesia and anisochoria. Serum biochemical abnormalities included high activities of creatine kinase, lactate dehydrogenase and aspartate aminotransferase. Analysis of the suspect food revealed high concentrations of the ionophore lasalocid. Fifteen of the dogs were given supportive treatment at home and two were hospitalised. Five of the dogs died, but the others improved gradually and had fully recovered by one to four days after the appearance of the clinical signs.

Poisonous plants in the eastern Mediterranean basin.

Plants found in the eastern Mediterranean are discussed by their toxic principles and poisonous effects. Nitrate- and oxalate-containing plants, those with alkaloids and glycosides, plants inducing photosensitization and carrying tannins, and selected miscellaneous species of toxic plants are reviewed and their poisonous properties described.

Genotype-by-environment interaction with broiler genotypes differing in growth rate. 4. Association between responses to heat stress and to cold-induced ascites.

Males and females, selected from a commercial line to represent its phenotypic variation for BW, were mated with similarly ranked mates to produce sire families representing a wide genetic variation in potential growth rate (GR). Following 5 wk of rearing at normal ambient temperatures, birds representing all sire families were exposed to cold (Days 37 to 47, Trial 1) or hot (Days 43 to 48, Trial 2) environments. Birds exhibiting ascites syndrome (AS) in the cold environment (Trial 1) were counted, and the incidence of AS (%AS) per family was calculated. Sire families' least-square means of BW at 37 d of age in Trial 1 and BW at 43 d of age in Trial 2 represented the families' potential GR (i.e., GR under normal conditions). A significant positive correlation was found between potential GR and %AS (r = 0.479, Trial 1), indicating that families with higher potential GR under normal conditions are more likely to suffer from AS under cold stress, compared to families with lower GR. Heat stress markedly reduced weight gain in all families (Trial 2); however, the genetic potential GR was negatively correlated with actual GR under heat stress (r = -0.411, Trial 2). Since offspring of the same sire families were exposed to the two stressful environmental conditions, correlations between sire families' means under the two environments could be calculated. A negative correlation was found between growth under heat stress (Trial 2) and %AS (Trial 1) (r = -0.439), indicating that families whose GR is more depressed under heat stress are more likely to suffer from AS under cold stress. These results suggest that the two stress responses may share similar control of the genetic variation in each trait and their negative genetic correlation with potential GR.

An unusual outbreak of malignant catarrhal fever in a beef herd in Israel.

Malignant catarrhal fever (MCF. corrizza contagiosa) is an invariably fatal communicable disease in cattle, whose causative agent is the ovine herpes virus-2, or the alcelaphine herpes virus-1. In one feed-lot family farm, 34 calves out of 100 became ill at the rate of one to four calves per week, and all of them subsequently died over a period of 4 months. Most of the initial cases were manifested clinically as the head and eye form, but most of the entire clinical spectrum of forms (the respiratory, intestinal and nervous forms) characteristic for MCF were observed as this epidemic progressed. Very few calves died without showing any specific signs of MCF. Pathological examinations revealed characteristic obliterative arteriovasculitis in the brain of calves with nervous signs, typical of MCF. Polymerase chain reaction (PCR) testing revealed 100% homology between the 238 bp hemi-nested PCR fragment and the ovine herpes virus-2 sequences. Based on the clinical signs, epidemiological data, pathological, and histopathological findings, and the PCR results, it was concluded that MCF occurred on the farm. The fact that sheep and goats were housed in close proximity on the same farm reinforced this diagnosis.

Interaction of fluoroquinolones and certain ionophores in broilers: effect on blood levels and hepatic cytochrome p450 monooxygenase activity.

The concomitant administration to broilers of ionophore coccidiostats and certain chemotherapeutic agents may cause deleterious interactions, with toxicosis and death as possible sequelae. In this study, co-administration of the ionophore monensin was not shown to alter blood levels of enrofloxacin or norfloxacin. In addition, exposure to lasalocid was not shown to change blood levels of enrofloxacin. However, norfloxacin + lasalocid co-administration induced aminopyrine N-demethylase (AD) activity by day 5 after the last administration of norfloxacin, and induced a rise of norfloxacin levels in the blood. This rise of blood norfloxacin levels after co-administration of norfloxacin + lasalocid implies that lower levels of norfloxacin could be administered in birds also receiving lasalocid.

Interaction of monensin and sulfadimethoxine in broilers, as mediated by hepatic microsomal cytochrome P-450 monooxygenases.

The influence of monensin + sulfadimethoxine on cytochrome P-450 monooxygenase activity in broilers, and the possible consequences of modification of this system, including changes in blood levels of sulfadimethoxine, influence on the duration of xylazine-ketamine anesthesia, total antioxidant status and superoxide dismutase activity were studied. The results indicate that the combination of monensin + sulfadimethoxine gave a short-term inhibition of microsomal cytochrome P-450 monooxygenase activity but apparently did not influence the metabolism of other (exogenic) substances (ketamine, xylazine), and did not change the state of antioxidant systems or the relative liver weight. There was a rise in blood sulfadimethoxine levels.

Isolation of Corynebacterium pilosum and Actinomyces pyogenes from cystitis and vulvovaginitis infection in a 2-month-old female calf.

Cystitis and vulvovaginitits, due to Corynebacterium pilosum and Actinomyces pyogenes infection in a 2-month-old female calf, is described. The prominent clinical signs were urinary incontinence, adherence of triple phosphate crystals to the vulvar hair and ulceration on the vulva, the ventral side of the tail skin and the perineum. Only a mild inflammation of the bladder mucosa and submucosa was seen on histological examination.

Probable toxicosis in cattle in Israel caused by the oak Quercus calliprinos.

A probable outbreak of oak (Quercus calliprinos) toxicosis in a herd of beef cattle--heifers and first-calving cows--grazing in the Judean foothills of Israel is described. Toxicosis probably occurred because of the consumption of oak leaves and buds during a period of pasture scarcity without any feed supplementation. A progressive syndrome of wasting, dullness, anorexia, polyuria, nephrosis, constipation and recumbency, culminating in death, was seen. A high mortality rate of 83% (38/46 animals) was noted. The clinical-pathological findings revealed increases in blood urea, creatinine, aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), creatine kinase (CK), lactate dehydrogenase (LDH) and inorganic phosphorus. Decreases were found in alkaline phosphatase (ALP), total serum protein, albumin (ALB), triglyceride (TG), calcium (Ca), magnesium (Mg), sodium (Na) and chloride (CI). The main pathological findings were severe nephrosis, chronic interstitial nephritis, and occasional intestinal ulceration. On the basis of epidemiology, clinical signs, clinical-pathological and pathological findings and renal histology, a tentative diagnosis of oak toxicosis was made.

Comparative effects of added sodium chloride, ammonium chloride, or potassium bicarbonate in the drinking water of broilers, and feed restriction, on the development of the ascites syndrome.

A hypothesis that the ionic composition of drinking water might affect development of the ascites syndrome in broilers was investigated in two trials. The first trial comprised four groups of 650 male chicks. A control treatment was normal tap water and the other three treatments comprised the addition to the tap water of 1,000 mg/L sodium as NaCl, 5,000 mg/L NH4Cl, or 5,000 mg/L KHCO3, supplied from age 2 to 47 d. At Day 28, equally sized subsets of these groups were moved to individual cages, where they received a severe exposure to ambient cold. The development of the ascites syndrome was monitored by measurements of hematocrit and arterial blood oxygen saturation (PaO2) by oximetry, body weight, and examination of dead birds for cause of death. Mortality from ascites in cold-exposed birds from Days 28 to 47 was 28, 48, 40, and 16% in the tap water, NaCl, NH4Cl, and KHCO3 groups, respectively; only the NaCl mortality was significantly different from the tap water mortality. The KHCO3 treatment increased PaO2 (compared with tap water treatment) at Day 28 by 5.5% and at Day 35 by 10.5%, but not at Day 42. The KHCO3 caused a reduction in body weight, which was 13% less than the tap water group at Day 42, probably due to a chronic toxicity. The second trial specifically examined the same parameters with lower water levels of KHCO3 (3,000 and 1,000 mg/L), in comparison to a 10% feed restriction protocol, in order to clarify whether the increased PaO2 was due to a specific effect of the KHCO3 or was a metabolic manifestation of a reduced growth rate. The 3,000 mg/L KHCO3 treatment had no effect on PaO2, but the 1,000 mg/L treatment augmented PaO2 by 5.3% at Day 35 (but not at Days 28 or 42), without reducing the final body weight. The feed restriction group showed an elevated PaO2 of 5.4% at Day 35 (but not at Days 28 or 42), with no reduction in the final body weight. The inclusion of 1,000 mg/L of KHCO3 into the drinking water of broilers or a temporary 10% feed restriction may be means to augment PaO2.

Relationship between broiler chicken haematocrit-selected parents and their progeny, with regard to haematocrit, mortality from ascites and bodyweight.

A previous work of this group demonstrated that the relative haematocrit value of broilers is inherited and may serve as an indicator to susceptibility to the ascites syndrome in cold-stressed broilers. In this study, a full-pedigreed population was produced from male and female grandparent breeding stock that was selected by haematocrit and by normal selection parameters. Matings were made between low (L), medium (M) and high (H) haematocrit parents: L x L, M x M, and H x H. In their progeny, both before and after cold exposure, there was a statistically linear relationship between actual haematocrit and their H, M and L grouping (P<0.0001); heritability of the haematocrit was high (0.46-0.81). Both the low haematocrit parent and progeny groups showed an increased bodyweight. Exposure of the progeny from all the parental groups to an ascites-predisposing cold environment caused similar losses from ascites in the progeny of all three groups. Although this finding was not the same as in the previous trial where the H haematocrit group was associated with high ascites mortality, it is hypothesized that other factors, such as arterial blood saturation with oxygen, interacted in these birds at genetic or environmental levels.

New treatment regimens in organophosphate (diazinon) and carbamate (methomyl) insecticide-induced toxicosis in fowl.

The objective of this work was to determine optimal treatment regimens for organophosphate (OP) or carbamate insecticide toxicoses in fowl using the antidotes atropine sulfate and pralidoxime chloride (2-PAM). Broiler chicks in treatment groups, each comprising 3 replicates of 6-7 birds/replicate, were gavaged on a body weight (BW) basis with the OP and carbamate insecticides, diazinon and methomyl, respectively, at lethal dosages. Treatment groups were injected with either or both of the antidotes at various dosages as soon as clinical signs appeared. Birds appearing healthy 24 h thereafter were regarded as having been treated successfully. At a dosage of 100 mg/kg BW, atropine was mildly toxic and at 200 mg/kg 2-PAM was severely toxic (but not lethal), whereas at dosages of 50 and 100 mg/kg BW, respectively, the antidotes were at their most effective. With diazinon, atropine alone was only partially effective (12/20 survivors), whereas 2-PAM was extremely efficacious. (20/20 survivors); the combination of the 2 antidotes at 2 dosages was slightly less effective (19/20 survivors) than 2-PAM alone. For methomyl toxicity, atropine was largely successful (18/20 survivors), whereas 2-PAM was mostly unsuccessful (10/20 survivors); the combination at high dosage was less effective (15/20 survivors) than atropine alone, but at a low dosage the combination was the most successful (20/20 survivors). The results indicate that anticholinesterase insecticide toxicoses in fowl should not be treated according to textbook recommendations, and antidotal dosage with atropine should be up to 100 times greater than is commonly recommended. The specific cause of the toxicoses should ideally be determined before treatment is given, but as this is often unknown, a combination of antidotes may be the optimal treatment protocol.

Nitrate toxicosis in beef and dairy cattle herds due to contamination of drinking water and whey.

Four cases of rarely reported nitrate toxicosis due to contamination of drinking water or whey were recorded in 2 beef and 2 dairy cattle herds. In the cases associated with water contamination, water containing ammonium nitrate as a fertilizer for irrigating orchards accidentally entered drinking water troughs for cattle through malfunctioning 1-way valves. The whey contamination in 1 instance was caused by transportation in containers which contained traces of concentrated ammonium nitrate; the 2nd case was induced by whey derived from the production of a specialty cheese produced by the incorporation of nitrate. Mortality occurred in 2 herds and abortions in the 2 other herds. Affected cows responded well to treatment, but some animals remained in a deteriorated physical condition for several months.

Acute maduramicin toxicity in calves.

A herd of 277 beef-breed calves in three age groups was mistakenly given the poultry coccidiostat maduramicin in a total mixed ration. It caused an acute toxicosis in which sudden death was the sole clinical finding in most cases. One group of 212 calves aged five to eight months suffered a mortality of 51 per cent in eight days and a total mortality of 56 per cent during the 40 days in which mortality was recorded. Mortality of only 3 per cent was recorded in two other groups of calves aged nine to 16 months in eight days and a total mortality of 11 per cent over the 40-day period.

Lead toxicosis in a captive bottlenose dolphin (Tursiops truncatus) consequent to ingestion of air gun pellets.

A captive bottlenose dolphin (Tursiops truncatus) in a dolphinarium in Tel Aviv, Israel, had signs of anorexia, weight loss and a reluctance to train over a 4-week period in June 1995 and died shortly thereafter. On necropsy, it had an enlarged, yellow discolored liver, and about 55 air gun pellets in the second stomach. The pellets were composed of 40% lead. Samples of liver and kidney cortex contained 3.6 and 4.2 micrograms/g lead, respectively. There was hemosiderosis in the liver and kidneys, status spongiosus in the brain, and vacuolization in the optic nerve; acid-fast intranuclear inclusion bodies were seen in the kidneys. We propose that chronic lead toxicosis had been induced after the gradual dissolution of the lead-based pellets in the acid environment of the stomach.

The inhibitory effects of the fluoroquinolone antimicrobials norfloxacin and enrofloxacin on hepatic microsomal cytochrome P-450 monooxygenases in broiler chickens.

The fluoroquinolone antimicrobials norfloxacin and enrofloxacin were found to inhibit hepatic microsomal cytochrome P-450 monooxygenases in the livers of broiler chickens using dosages as given in commercial flocks. Norfloxacin inhibited the process of N-demethylation of aminopyrine to a greater degree, while enrofloxacin more markedly inhibited hydroxylation of aniline.