Fatal metaldehyde poisoning in a dog confirmed by gas chromatography

BACKGROUND

Metaldehyde is a toxic pesticide used mainly as a molluscicide, responsible for intoxication and deaths in both humans and animals. Accidental exposure to metaldehyde in dogs is considered rare, but severe. Data concerning clinical and veterinary forensic toxicology are largely incomplete, especially regarding case reports in dogs. The present work reports a complete and detailed description of a case from the history, clinical evolution, pathological exams and toxicological diagnosis in an accidental case of metaldehyde poisoning in dog.

CASE PRESENTATION

An eleven-month-old, 3.0 kg, male German Spitz was presented for emergency care with acute vomiting and seizures 3 hours after suspected accidental ingestion of commercial molluscicide containing 3% metaldehyde (Lesmax®). The animal was in lateral recumbency and showed stuporous mentation, salivation, tonic-clonic status epilepticus, systemic tremors, bilateral miosis, absent palpebral, corneal, oculovestibular and gag reflexes, severely depressed spinal reflexes, dyspnea and tachycardia. Despite treatment, the patient progressed to comatose mentation and died. Necropsy examination revealed discrete lesions in the liver and central nervous system, while stomach examination revealed content of feed, activated charcoal and blue-green granules, compatible to the commercial formula of metaldehyde. Histology examination revealed extensive hemorrhage and severe centrolobular necrosis of the liver and tumefaction of Kupfer cells. Brain samples showed discrete hemorrhage and hyperemia. In order to confirm the diagnosis, samples from feces, stomach content, spleen, liver, heart, kidneys and brain were submitted gas chromatography analysis. Results confirmed the presence of metaldehyde in all samples. We describe clinicopathological abnormalities of a fatal case of metaldehyde poisoning in a dog, as well as postmortem diagnosis using gas chromatography.

CONCLUSION

Metaldehyde poisoning is rarely reported, since the diagnosis is often difficult and the notifications scarce. To our knowledge, this is the first report describing clinical signs, pathological findings and chromatographic diagnosis. This report aims to contribute to the understanding of the pathogenesis of metaldehyde intoxication, to further explore veterinary forensic toxicology diagnosis.

Identification of differentially expressed proteins of brain tissue in response to methamidophos in flounder (Paralichthys olivaceus)

Methamidophos (MAP), an organophosphorus pesticide used around the world, has been associated with a wide spectrum of toxic effects on organisms in the environment. In this study, the flounder Paralichthys olivaceus was subjected to 10 mg/L MAP for 72 h and 144 h, and the morphological and proteomic changes in the brain were observed, analyzed and compared with those in the non-exposed control group. Under the light microscope and transmission electron microscope, MAP had evidently induced changes in or damage to the flounder tissues. Gas chromatography analysis demonstrated that the MAP residues were significantly accumulated in the flounder brain tissues. Proteomic changes in the brain tissue were revealed using two-dimensional gel electrophoresis and 27 protein spots were observed to be significantly changed by MAP exposure. The results indicated that the regulated proteins were involved in immune and stress responses, protein biosynthesis and modification, signal transduction, organismal development, and 50% of them are protease. qRT-PCR was used to further detect the corresponding change of transcription. These data may be beneficial to understand the molecular mechanism of MAP toxicity in flounder, be very useful for MAP-resistance screening in flounder culture. According to our results and analyzing, heat shock protein 90 (HSP90) and granzyme K (GzmK) had taken important part in immune response to MAP-stress and could be biomarkers for MAP-stress in flounder.

Dietary lipid levels impact lipoprotein lipase, hormone-sensitive lipase, and fatty acid synthetase gene expression in three tissues of adult GIFT strain of Nile tilapia, Oreochromis niloticus

The objective of this study was to assess the effects of dietary lipids on growth performance, body composition, serum parameters, and expression of genes involved in lipid metabolism in adult genetically improved farmed tilapia (GIFT strain) of Nile tilapia, Oreochromis niloticus. We randomly assigned adult male Nile tilapia (average initial body weight = 220.00 ± 9.54 g) into six groups consisting of four replicates (20 fish per replicate). Fish in each group were hand-fed a semi-purified diets containing different lipid levels [3.3 (the control group), 28.4, 51.4, 75.4, 101.9, and 124.1 g kg(-1)] for 8 weeks. The results indicated that there was no obvious effect in feeding rate among all groups (P > 0.05). The highest weight gain, specific growth rate, and protein efficiency ratio in 75.4 g kg(-1) diet group were increased by 23.31, 16.17, and 22.02 % than that of fish in the control group (P < 0.05). Protein retention ratio was highest in 51.4 g kg(-1) diet group. The results revealed that the optimum dietary lipid level for maximum growth performance is 76.6-87.9 g kg(-1). Increasing dietary lipid levels contributed to increased tissue and whole body lipid levels. Saturated and monounsaturated fatty acids (MUFAs) decreased, and polyunsaturated fatty acids increased with increasing dietary lipid levels. With the exception of MUFAs, the fatty acid profiles of liver and muscle were similar. Dietary lipid levels were negatively correlated with low-density lipoprotein- cholesterol content and positively with triacylglycerol and glucose contents. In the lipid-fed groups, there was a significant down-regulation of fatty acid synthase (FAS) mRNA in liver, muscle, and visceral adipose tissues. There was a rapid up-regulation of lipoprotein lipase (LPL) mRNA in muscle and liver with increasing dietary lipid levels. In visceral adipose tissue, LPL mRNA was significantly down-regulated in the lipid-fed groups. Dietary lipids increased hormone-sensitive lipase (HSL) mRNA expression levels in the three tissues. These results strongly suggested that moderate dietary lipid levels were beneficial for adult tilapia growth performance and feed efficiency. However, excessive dietary lipid levels contributed to lipid deposition. Additionally, excessive dietary lipids may induce a competition between lipolysis and lipogenesis. FAS did not have tissue-specific regulation; however, the regulation of dietary lipids on LPL expression is tissue specific. FAS was a negative feedback regulator on fat deposition, and HSL was an indicator of fat content in tilapia.

Iodine-129 in animal thyroids from Argentina

(129)I and (127)I concentrations in animal thyroids coming from several regions of Argentina were determined by accelerator mass spectrometry (AMS) and gas chromatography (GC), respectively. The measured (129)I/(127)I ratios, ranging from 3 × 10(-12) to 4 × 10(-10), are significantly lower than those typical for areas in the northern hemisphere (10(-10)-10(-7)). The (129)I concentrations show a clear dependence with latitude and season, which can be understood considering tropospheric circulation patterns, possible (129)I sources and regional precipitation rates.

Physical and chemical effects of ingested plastic debris on short-tailed shearwaters, Puffinus tenuirostris, in the North Pacific Ocean

We investigated the plastics ingested by short-tailed shearwaters, Puffinus tenuirostris, that were accidentally caught during experimental fishing in the North Pacific Ocean in 2003 and 2005. The mean mass of plastics found in the stomach was 0.23 g per bird (n=99). Plastic mass did not correlate with body weight. Total PCB (sum of 24 congeners) concentrations in the abdominal adipose tissue of 12 birds ranged from 45 to 529 ng/g-lipid. Although total PCBs or higher-chlorinated congeners, the mass of ingested plastic correlated positively with concentrations of lower-chlorinated congeners. The effects of toxic chemicals present in plastic debris on bird physiology should be investigated.

Mitochondrial phospholipids of rat skeletal muscle are less polyunsaturated than whole tissue phospholipids: implications for protection against oxidative stress

The fatty acid composition of phospholipids is an important determinant of membrane function. Although the mitochondria play a pivotal role in skeletal muscle function, the fatty acid composition of their individual phospholipids has not been examined. The purpose of this study was to determine the fatty acid profile of each phospholipid in rat skeletal muscle mitochondria and compare it with that of the whole muscle. Lipids were extracted from the gastrocnemius muscles of 10 Wistar rats, and phospholipids were separated by thin-layer chromatography. The fatty acid composition of each phospholipid was then determined by gas chromatography. The same procedure was applied to a mitochondrial preparation from these muscles. We found that the fatty acid composition of the individual mitochondrial phospholipids (phosphatidyl choline, phosphatidyl ethanolamine, cardiolipin, phosphatidyl inositol, phosphatidyl serine, sphingomyelin, and lysophosphatidyl choline) and of the total mitochondrial phospholipids differed markedly (P < 0.05) from the fatty acid composition of the corresponding whole muscle phospholipids. Notably, the mitochondrial phospholipids had higher percentages of MUFA [13.9 (2.1) vs. 10.3 (0.9)] and lower percentages of PUFA [34.8 (4.3) vs. 39.5 (5.2)] and n6 fatty acids [25.0 (2.5) vs. 27.6 (2.5)]. Overall, the mitochondrial phospholipids had a lower unsaturation index than whole muscle phospholipids [135 (20) vs. 161 (26)]. Because PUFA are susceptible to peroxidation, unlike saturated fatty acids and MUFA, we propose that the low polyunsaturation of mitochondrial phospholipids is the result of selective pressure toward membranes that are more resistant to oxidative damage by reactive oxygen species produced in their vicinity. The negative effect of the low polyunsaturation on membrane fluidity may be counterbalanced by the higher percentage of MUFA and the known low cholesterol content of mitochondrial membranes.

Effects of a commercial dose of L-tryptophan on plasma tryptophan concentrations and behaviour in horses

REASON FOR PERFORMING STUDY

L-tryptophan is a common ingredient in equine calmative products, but its effectiveness has not been demonstrated in horses.

HYPOTHESIS

To determine whether a commercial dose of L-tryptophan increases plasma tryptophan and alters behaviour in horses fed a roughage or concentrate meal.

METHODS

L-tryptophan (6.3 g) or placebo (water) was administered per os in a cross-over design, to 12 Thoroughbred horses (503 +/- 12.1 kg bwt), just before a meal of lucerne hay or oats. Plasma tryptophan was measured by gas chromatography. Horse behaviour was observed in an empty enclosure, then in the presence of an unfamiliar person and a novel object.

RESULTS

Total plasma tryptophan increased 3-fold in both studies, peaking 1.5-2 h after dosing. After the peak, tryptophan remained high for several hours if the horses had been fed hay, but fell sharply if fed oats, consistent with the glycaemic responses to these meals. However, the ratio of tryptophan to 4 large neutral amino acids (phenylalanine, tyrosine, leucine and isoleucine) increased in the tryptophan-treated horses to a similar extent and for a similar duration, with both diets. The presence of a stranger or novel object increased heart rate (P<0.05), but caused no behavioural effects that were altered by tryptophan, regardless of the diet.

CONCLUSIONS

Plasma tryptophan increases when tryptophan is administered at a dose used in some commercial products, but this is not reflected by marked behavioural changes in the horse.

POTENTIAL RELEVANCE

Further work is required to refine behavioural tests and identify an effective dose of L-tryptophan in the horse.

Profiles of Fatty Acids in Different Bone Structures of Growing Chicks

This study was concerned with the dynamics of fatty acids in tissues involved in the growth and mineralization of the femur of Starbro chicks from 1 to 50 days of age. Four chickens that died of suffocation were obtained each day. Altogether, 400 femoral bones were studied in five age groups (I-V). Compact bone, spongy bone and articular cartilage were sampled. Lipids were extracted according to Folch and fatty acids were separated using gas chromatography. The fatty acid profile was found to change with age. Fatty acids with the highest content in bone were C(18:1), C(16:0), C(18:2) and C(18:0). The highest content of fatty acids was found in spongy bone and the lowest in articular cartilage. Several correlations were revealed between individual fatty acids. The following conclusions were drawn. (1) Fatty acid profiles in compact bone, spongy bone and articular cartilage change with age of chicks. (2) Oleic (C(18:1)), palmitic (C(16:0)), linoleic (C(18:2)), stearic (C(18:0)) and arachidonic (C(20:4)) acids accounted for most of the fatty acid pool. (3) Correlations in the content of fatty acids were noted between bone structures.

Erythrocyte and plasma fatty acid patterns in dogs with atopic dermatitis and healthy dogs in the same household

Recent studies have indicated that dogs with canine atopic dermatitis (CAD) may have a disorder of fatty acid metabolism: possibly low or absent activity of delta6-desaturase or delta5-desaturase, or both. To clarify this possibility, we examined the erythrocyte and plasma fatty acid patterns of 8 dogs with CAD and their 8 healthy housemates. Atopic dermatitis was diagnosed according to the criteria proposed by Willemse; other causes of dermatitis were excluded clinically and by appropriate tests. Erythrocyte ghosts were prepared from blood samples. Membrane lipids were extracted and separated by thin-layer chromatography. From plasma and lipid fractions, fatty acid content was determined by gas chromatography. In erythrocytes, but not in plasma, we observed significant differences in the fatty acid pattern that suggested a reduction in the n6 fatty acid products of the delta6- and delta5-desaturases in dogs with atopic dermatitis when compared with healthy housemates.

The content and composition of lipids in the digital cushion of the bovine claw with respect to age and location – A preliminary report

The pads of the bovine digital cushion, which serves as a shock absorber, have specific anatomical structures to cope with the substantial forces acting within the claw. To gain more information on the lipid composition and content of the pads, horn shoes from 12 slaughtered heifers and cows were removed and different samples of the pads excised with a scalpel. Pad lipids were extracted and the fatty acid composition determined by gas chromatography. Fat from perirenal and subcutaneous adipose tissues served as a comparison. Overall, this fat contained a higher quantity of extracted lipids than that of the claw pads and did not differ between heifers and cows. In contrast, lipid content in the pads was significantly higher in the cows than in the heifers. In both groups, the lipid content of the middle and abaxial pads, which are situated directly under the distal phalanx, was lower than in the pads of the other locations. The lipids in all pads contained >77% monounsaturated fatty acids (MUFA), differing sharply from the adipose tissue with values <51%. Among the polyunsaturated fatty acids (PUFA) a significantly higher proportion of arachidonic acid (AA) was found in the heifer pads than in those of the cows, whereas the proportion of AA was similar in the adipose tissue of all animals. The proportion of AA in the pad lipids also varied between the defined locations with the highest proportion found in locations that showed the lowest lipid content and was related to the age of the animal.

The effect of transdermal delivery of fentanyl on activity in growing pigs

Recently, decreased activity levels have been observed in pigs treated postoperatively with transdermal delivery of fentanyl (TD-fentanyl) after isoflurane anaesthesia. Whether the change in behaviour is related to opioid-induced sedation or to insufficient pain relief remains to be investigated. This study was therefore undertaken to evaluate the effect of TD-fentanyl 50 μg h^-1 on the activity level with and without isoflurane anaesthesia. Eight pigs (25.4 ± 5.2 kg) were submitted to a cross-over study and given two treatments; 1) fentanyl patch applied after 30 minutes of anaesthesia (treatment A/F) and 2) fentanyl patch without anaesthesia (treatment F). The pigs' behaviour was observed from a video recording instantaneously every 10 minutes for 24 h before treatments and up to 72 h after the patch attachment. Venous blood samples were taken 1, 6, 12, 24, 48 and 72 h after the patch application. The behaviour recordings showed that TD-fentanyl did not produce sedation in any pig. No differences were found between the two treatments in activity level, weight gain or serum fentanyl concentration. This concentration measured after 24 h was 0.27 ± 0.11 ng ml^-1 and 0.47 ± 0.40 ng ml^-1 in the A/F and F group, respectively.

In conclusion, transdermal delivery of 50 μg h^-1 fentanyl did not cause inactivity in growing pigs. However, the large variations in serum fentanyl concentration indicate that drug absorption from transdermal patches is unpredictable and sometimes deficient.

Myocardial concentrations of fatty acids in dogs with dilated cardiomyopathy

OBJECTIVE

To compare myocardial concentrations of fatty acids in dogs with dilated cardiomyopathy (DCM) with concentrations in control dogs.

SAMPLE POPULATION

Myocardial tissues from 7 dogs with DCM and 16 control dogs.

PROCEDURE

Myocardial tissues were homogenized, and total fatty acids were extracted and converted to methyl esters. Myocardial concentrations of fatty acids were analyzed by use of gas chromatography and reported as corrected percentages.

RESULTS

The amount of docosatetraenoic acid (C22:4 n-6) was significantly higher in myocardial samples from dogs with DCM (range, 0.223% to 0.774%; median, 0.451%), compared with the amount in samples obtained from control dogs (range, 0.166% to 0.621%; median, 0.280%). There were no significant differences between DCM and control dogs for concentrations of any other myocardial fatty acids.

CONCLUSIONS AND CLINICAL RELEVANCE

Although concentrations of most myocardial fatty acids did not differ significantly between dogs with DCM and control dogs, the concentration of docosatetraenoic acid was significantly higher in dogs with DCM. Additional investigation in a larger population is warranted to determine whether this is a primary or secondary effect of the underlying disease and whether alterations in fatty acids may be a target for intervention in dogs with DCM.

The fatty acid composition of muscle fat and subcutaneous adipose tissue of pasture-fed beef heifers: Influence of the duration of grazing

Our objective was to determine the effect of the duration of grazing before slaughter on the fatty acid composition of muscle fat and s.c. adipose tissue (SAT) of beef heifers. Sixty crossbred Charolais heifers (n = 15 per treatment) were assigned randomly to one of four dietary treatments: 45 animals (Treatments 1, 2, and 3, respectively) were housed at the beginning of the experiment, and 15 (Treatment 4) were fed at pasture. Two groups of 15 heifers were moved to pasture 40 d (Treatment 2) and 99 d (Treatment 3) before slaughter, respectively, resulting in preslaughter grazing periods of 0, 40, 99, or 158 d for Treatments 1, 2, 3, and 4, respectively. Before grazing the predominantly perennial ryegrass pasture, animals were housed and offered grass silage ad libitum and 3 kg of concentrate diet (650 g of grass silage/kg of total DMI). After slaughter, the fatty acid profile of the neutral (NL) and polar lipid (PL) fractions of muscle fat from the LM and the total lipids from SAT were analyzed by gas chromatography. Duration of grazing showed a quadratic tendency on mean carcass weight (P = 0.08), but did not affect growth (P = 0.27) or the lipid content (P = 0.13) of the LM. Increasing the duration of grazing led to a linear increase (P < 0.001) in the concentration (on fresh-tissue basis) of CLA in muscle fat (from 11.80 to 17.75 mg/100 g of muscle in NL, and from 0.52 to 0.82 mg/100 of g muscle in PL) and in SAT (from 3.98 to 10.23 mg/g of SAT; P < 0.001), and increased the concentration of C18:1trans-11 in both muscle fat fractions (P < 0.001) and in SAT (P < 0.001). In the total muscle lipids, the polyunsaturated to saturated fatty acid ratio (P:S) increased from 0.12 to 0.15 with increased duration of grazing following a linear (P < 0.05) and cubic pattern (P < 0.05). Increasing the duration of grazing led to a linear decrease in the n-6:n-3 ratio of muscle fat from 2.00 to 1.32 (P < 0.001), and from 2.64 to 1.65 in the SAT lipids (P < 0.001), mainly as a consequence of the increased concentration of C18:3n-3. It is concluded that muscle fat and SAT fatty acid profile was improved from a human health perspective by pasture feeding, and that this improvement depended on the duration of grazing.

Technical Note: A Rapid Lipid Separation Method for Determining Fatty Acid Composition of Milk

A rapid method for milk lipid separation followed by transmethylation to produce fatty acid methyl esters from bovine milk samples is presented. Fat is separated by a nonsolvent method using centrifugation. The method was compared with the popular hexane:isopropanol solvent extraction method, and fatty acid proportions were statistically identical for both methods. In 108 replicates, variance accounted for by using the 2 methods was of a similar magnitude to variance due to repeat separations or repeat injections onto the gas chromatography column. It is concluded that the proposed method is accurate, simple, rapid, safe, economical, and especially suitable for large numbers of samples.

Validation of a method for collection and assay of pentane in the exhaled breath of the horse

Oxidative stress refers to an imbalance between the production of oxidising free radicals and the antioxidant defenses of the cell, and is associated with many pathogenic processes. Oxidative damage to cellular lipids results in the evolution of pentane and ethane gas, and detection of these hydrocarbons in the exhaled breath can be used to monitor in vivo oxidative stress. The aim of this study was to validate a gas chromatography (GC) method for measurement of breath pentane in the horse. The GC-system developed showed good specificity for discrimination of pentane from other breath hydrocarbons, and was sensitive to 0.5 ppb pentane. Pentane was detected in the exhaled breath of five horses investigated on two occasions. The results of this preliminary study demonstrate that breath pentane can be measured in the horse, and further work is now justified to investigate the feasibility of applying this method for monitoring in vivo oxidative stress in the horse.

Challenges with fats and fatty acid methods

The content and chemical nature of lipids in feedstuffs is heterogeneous. It has long been known that ether extraction by the Weende procedure inadequately characterizes the fat content of feedstuffs, yet it remains the official method. Diethyl ether (or hexanes that are often used) extracts significant amounts of nonnutritive, nonsaponifiable lipids from forages, and often incompletely extracts lipids of nutritional value, especially fatty acids present as salts of divalent cations. Preextraction hydrolysis of insoluble fatty acid salts with acid releases these fatty acids, and this step is included in the official procedure for certain feedstuffs in the United Kingdom; however, acid hydrolysis increases analysis time and decreases precision. Acid hydrolysis also causes confusion as to the proper definition of the fat content of feedstuffs. A preferred method of fat analysis determines the total fatty acid concentration in feed samples by converting fatty acid salts, as well as the acyl components in all lipid classes, such as triacylglycerols, phospholipids, and sphingolipids, to methyl esters using a simple, direct one-step esterification procedure. Fatty acid methyl esters are then quantified by GLC, which provides information on both fatty acid quantity and profile in a single analysis. Adjustments in conditions and reagents may be necessary to overcome difficulty in quantitatively preparing esters from certain types of fatty acids and their derivatives in commercial fat supplements. After correction for glycerol content, analysis of oils by this procedure provides information on the content of nonsaponifiable material, such as chlorophyll, waxes, and indigestible polymers formed from heat- or oxidatively damaged fats. The correct description of feedstuffs for energy value of fats is the content of total fatty acids.

Preen gland function in layer fowls: factors affecting preen oil fatty acid composition

1. Preen oil derived from the preen gland has previously been shown to differ in its composition between birds of different ages, sex and diet. As a part of a larger study on preening behaviour and its components, the relative percentages of fatty acids in preen oil were examined in laying hens that differed in age, beak trimmed status, feather pecking status (pecker and pecked) and method of sampling (either direct from the preen gland or from lipid extracted from feathers). 2. Five experiments are described. Fatty acids extracted from lipid were analysed by gas chromatography (GC). Fatty acid composition was affected by age, by whether or not a bird was feather pecked (but not if it was a feather pecker) and by lipid source. 3. Changes in preen oil composition with age (shown here) may be due to changes in circulating concentrations of hormones. Differences in preen oil composition between feather pecked and non-pecked birds may influence plumage odour and therefore taste, making the plumage of some birds more attractive to pecking than others. 4. The proportions of some fatty acids derived from feathers differed to those extracted from the preen gland. Lipid found on feathers is most likely a combination of that from the preen gland and from sebaceous secretions from the skin.

[Pathophysiological significance of steatorrhea as well as of hydroxystearic acids in the feces of calves with diarrhea]

The objective of this study was to determine the digestibility of milk lipids in calves with diarrhoea, the pathophysiological effects of fat intake on the course of the disease and the conversion of malabsorbed longchain fatty acids to secretory effective hydroxy fatty acids by the intestinal flora.

ANIMALS

32 male calves of the breed "Deutsches Fleckvieh" with spontaneous occurring diarrhoea, age 3-14 days. Reference group: 6 clinically healthy calves of the same age group. Feed: whole milk, daily ration corresponding to 10% of the BM, divided into 3 meals; supplementary oral rehydration solution as required.

METHODS

Quantitative collection of the faeces excreted over a period of at least 72 hours, determination of fatty acids and glycerides, identification and quantification of hydroxystearic acids in the faeces by gas chromatography; calculation of the apparent digestibility of the milk lipids.

RESULTS

The apparent digestibility of the milk lipids was in part considerably reduced in direct relation (r = 0.8) to the severity of the diarrhoea. In the case of daily fecal outputs of over 50 g/kg BM (watery diarrhoea), the apparent fat digestibility was reduced below 50%. Even so, the apparent digestibility correlated positively with the milk intake (r = 0.5). The fat excretion in the patients showed an average of 1.4 g/kg BM/24 h and was thus nearly nine times higher in comparison to the reference group (0.16 g/kg BM/24 h). In the case of severe diarrhoea, fat excretion rates of over 2 (up to max. 5.8) g/kg BM in 24 hours were recorded. However, in the main (approx. 70%) it was not glycerides but nonesterified fatty acids. A part of the longchain fatty acids were converted to hydroxy fatty acids by the intestinal flora. It was possible to quantify alpha-, 10(9)- and 12-hydroxystearic acids individually in the faeces of both healthy calves and those with diarrhoea. However, the total concentration of hydroxystearic acids in the faces of 26 out of 32 patients was considerably under the secretory effective concentration of 2 mmol/kg (mean = 1.5 mmol/kg), the other six lay between 2.9 and 11.6 mmol/kg. Only a weakly positive correlation (r = 0.23 or 0.24) existed between the amount of milk intake and the fecal concentration resp. excretion of hydroxystearic acids.

CONCLUSIONS

There was no evidence that the consumption of milk lipids influenced the diarrhoea negatively. In individual cases, it could not be completely excluded that fluid and electrolyte absorption was affected by hydroxystearic acids produced in the intestine, but the quantitative effects of this process are of minor significance in comparison to other diarrhoea inducing factors.

Effects of transcutaneous electrical nerve stimulation on the fatty acid profile of rabbit longissimus dorsi muscle (preliminary report)

This study was designed to investigate whether transcutaneous electrical nerve stimulation (TENS) of the longissimus dorsi muscle (MLD) of rabbits induces specific proportional changes in the muscle fatty acid composition. Ten 4-week-old Pannon White rabbits were exposed to TENS treatment two times a day, with the following settings: 30 Hz, 20 micros impulse length, 10 mA, 2 x 20 min. After a treatment period of 50 days rabbits were slaughtered and the fatty acid composition of the MLD was determined by gas chromatography. The TENS treatment increased the proportions of linoleic (C18:2 n-6), linolenic (C18:3 n-3) and gondoic acids (C20:1 n-9), compared with the control group. The level of palmitic (C16:0), stearic (C18:0), oleic (C18:1 n-9) and eicosapentaenoic (C20:5 n-3) acids significantly decreased. The proportion of total unsaturated fatty acids significantly increased. On the basis of the results obtained, TENS may have similar effects on the muscle fatty acid profile like physical training. Based on the supposal that the composition of membrane structure was also affected, the electrical stimulation of muscles may have further consequences, e.g. on membrane properties.

The influence of dietary fish oil vs. sunflower oil on the fatty acid composition of plasma cholesteryl-esters in healthy, adult cats

The question addressed was whether the fatty acid composition of plasma cholesteryl esters (CEs) in cats reflects the intake of fatty acids. Diets containing either fish oil or sunflower oil were fed to six healthy, adult cats in a cross-over trial. The dry cat foods contained approximately 18.5% crude fat, of which two-third was in the form of the variable oil. Blood samples were collected at the end of each 4-week feeding period, and the fatty acid composition of plasma CEs and plasma concentrations of lipoproteins were determined. Consumption of the diet with fish oil was associated with significantly greater proportions of eicosapentaenoic acid, arachidonic acid, alpha-linolenic acid, oleic acid, palmitic acid and myristic acid in plasma CEs. The intake of fish oil instead of sunflower oil reduced the percentage of linoleic acid in CEs. The plasma concentrations of total cholesterol, high-density lipoprotein cholesterol, phospholipids and triglycerides were not affected by fish oil vs. sunflower oil feeding.

Effectiveness of short-term feeding strategies for altering conjugated linoleic acid content of beef

A steer finishing trial was performed to determine the effect of short-term dietary regimens on conjugated linoleic acid (CLA) content of muscle tissues. The experimental design was an incomplete 3 x 2 factorial, with three levels of soybean oil (SBO; 0, 4, and 8% of diet DM) and two levels of forage (20 vs. 40% of diet DM). Forty Angus x Hereford steers averaging 504 +/- 29.0 kg were allotted randomly to one of four treatments for the last 6 wk of the finishing period. Treatments were: 80:20 concentrate:forage control diet (C); 80:20 concentrate:forage + 4% SBO (C4); 60:40 concentrate:forage + 4% SBO (F4); and 60:40 concentrate:forage + 8% SBO (F8). After 42 d on the experimental diets, steers were sacrificed and samples were collected from the chuck, loin, and round muscle groups. Fatty acid (FA; mg/100 mg of FA) composition was determined by gas-liquid chromatography. Data were statistically analyzed with mixed models procedures. The performance and carcass quality model included the effects of SBO and forage. The model for FA composition included the effects of SBO, forage, muscle group, and interactions. Orthogonal contrasts were used to determine linear effects of SBO. There were no differences in growth performance among treatments (P > 0.05). Increasing dietary SBO linearly decreased dressing percent (P = 0.04), and tended to linearly decrease marbling score (P = 0.12) and quality grade (P = 0.08). The only CLA isomer detected in tissue samples was cis-9,trans-11. Addition of SBO to diets linearly increased linoleic acid (18:2n-6; P = 0.04) and tended to linearly increase linolenic acid (18:3n-3; P = 0.10) in muscle tissues. The CLA in lean tissues was decreased (P = 0.005) with SBO-containing diets. These findings suggest that increased PUFA may limit ruminal production of CLA and trans-vaccenic acid (VA) and/or may depress stearoyl-CoA desaturase expression or activity in lean tissues, which in turn limits CLA formation and accretion in tissues. Increasing dietary forage tended to increase 18:0, 18:2n-6, CLA, and 18:3n-3 (P < 0.15), suggesting that increased forage may mitigate toxic effects of PUFA on ruminal biohydrogenation, thereby increasing the pool of CLA and VA available for CLA formation and accretion in tissues. Short-term feeding of elevated SBO and forage levels can alter FA profiles in muscle tissues.

Relationship between concentration of citrate and ketone bodies in cow's milk

The authors' hypothesis is that the members of the tricarboxylic acid cycle (TCA cycle) such as citrate decrease in association with increased ketone body formation. To prove this hypothesis the connection between ketone bodies and citrate formation of milk was studied. A fluorimetric method was used to determine citrate and a headspace sampling gas chromatographic (GC) method was developed for determination of ketone bodies. Under real conditions of milk sampling, transport and storage, preserved milk samples of 119 clinically healthy dairy cows obtained in the 48 hours after milking were investigated. A low level of acetoacetate (ACAC) was found in all samples. This fact can be explained by the spontaneous decarboxylation of acetoacetate during sample storage (previously decarboxylised acetoacetate = pdACAC) and, consequently, the majority of the amount of acetoacetate in the samples (AC + pdACAC) appeared in the measured acetone concentrations. Based on the measured acetone concentration of milk samples two groups were formed retrospectively: HA (high-acetone) group (n = 41) with an AC + pdACAC concentration of > 0.4 mmol/l and a LA (low-acetone) group (n = 78) with an AC + pdACAC level of < or = 0.4 mmol/l. In the milk of cows of Group HA a positive correlation (r = +0.623) and linear connection between acetone (AC + pdACAC) and beta-hydroxybutyrate (BOHB) levels was found [BOHB = 2.491 + 0.586 x (pdAC + ACAC)]. Furthermore, in this group a negative correlation between citrate and BOHB and AC + pdACAC was also established (r = -0.579). Focusing on the results of this group the authors found a significant drop of AC + pdACAC and citrate during the metabolically critical first 1-4 weeks of lactation. For this reason they suggest that simple, easy, automated methods (i.e. flow injection analysis, Fourier transformation infrared analysis) should be introduced for the simultaneous determination of acetone and citrate concentration in milk to make the evaluation of the energy status of high-producing dairy cows easier and more certain.

High trimethylamine concentration in milk from cows on standard diets is expressed as fishy off-flavour

To establish whether fishy off-flavour observed in cows' milk in Sweden is due to abnormal concentrations of trimethylamine (TMA) in milk, 15 milk samples from 13 cows of the Swedish Red and White breed (SRB) were analysed for this compound using dynamic headspace (DHS) gas chromatography (GC). A mass selective detector (MSD) was used for the qualitative and a flame ionization detector (FID) for the quantitative analyses. Further confirmation was obtained using a solid phase microextraction (SPME) followed by GC-olfactometry (GC-O) and GC-NPD (nitrogen and phosphorus detector). Samples were also evaluated by a two-person organoleptic panel for the presence of fishy off-flavour. Results showed that the seven milk samples with a fish-like taint contained > 1 mg TMA/kg milk, whereas, with a single exception, the seven samples that were judged to be normal did not contain this compound. Furthermore, there were indications of a dose-dependent relationship between TMA concentration and fishy off-flavour score.

Further survey of the occurrence of Fusarium toxins in wheat grown in southwest Germany

A total of 53, 54, 57, 52 and 60 wheat samples for feed use were collected randomly after the 1989, 1990, 1991, 1992 and 1993 crops, respectively, from farms in an area of southwest Germany. Deoxynivalenol (DON), 3- and 15-acetyldeoxynivalenol (3-, 15-ADON), nivalenol (NIV), HT-2 toxin (HT-2), T-2 toxin (T-2), diacetoxyscirpenol (DAS), and fusarenon-X (FUS-X) were determined by gas chromatography, combined with mass selective detection (GC-MS), zearalenone (ZEA), alpha- and beta-zearalenol (alpha-beta-ZOL) were determined by HPLC. DON was the major toxin, with incidences at 77 to 93% and mean contents at 167 to 735 micrograms/kg. In contrast, incidences of ZEA, 3-ADON, NIV, HT-2, and T-2 were at 13 to 37%, 10 to 44%, 15 to 67%, 0 to 11%, and 0 to 12%, respectively, with mean contents in positive samples between 2 and 73 micrograms/kg, except for 948 micrograms/kg 3-ADON in samples from 1993. 15-ADON and FUS-X were assayed in samples from 1991, 1992 and 1993. 15-ADON was found in 0 to 11% of samples at mean levels < or = 17 mu/kg, DAS, alpha- and beta-ZOL, and FUS-X were not detected in any sample. Over the years, incidences and levels of toxins remained constant, decreased or increased, with most differences between years being slight and insignificant. The risk for livestock due to DON, HT-2 and ZEA was estimated based on maximum tolerated levels recommended for these toxins in some countries.

The biohydrogenation of linoleamide in vitro and its effects on linoleic acid concentration in duodenal contents of sheep

Previous studies showed that oleamide was protected from ruminal biohydrogenation and increased 18:1(n-9) concentration in milk when fed to lactating dairy cows. To appraise whether this protection extended to linoleamide, a rumen in vitro experiment was conducted to determine biohydrogenation of linoleamide followed by two sheep experiments to evaluate whether linoleamide could increase 18:2 (n-6) concentration in duodenal contents. Treatments for the in vitro and sheep studies consisted of three diets containing no added lipid (control), linoleic acid, or linoleamide. Lipids were added at 10% (DM basis) of the in vitro substrate (ground grass hay). The three substrates were incubated with mixed ruminal microbes in triplicate, and 5 mL of culture contents was taken at 0, 24, and 48 h for analysis of 18:2 (n-6) concentration by gas chromatography. The concentrations of 18:2 (n-6) (corrected for 18:2 (n-6) in the control cultures) at 0, 24, and 48 h were 2.51, 0.38, and 0.11 mg/5 mL for the linoleic acid cultures compared to 2.10, 1.35, and 1.08 mg/5 mL for the linoleamide cultures. Compared to linoleic acid, the cultures containing linoleamide had higher 18:1 (n-9) and lower concentrations of biohydrogenation products including trans-18:1 and 18:0. Three sheep with duodenal cannulas were fed the three diets in two separate 3 x 3 Latin squares each with 2-wk periods. The two squares only differed in the amount of added lipid (1.5 vs 5% of the ration DM). When the lipids were added at 1.5% of the ration DM, they had little effect on duodenal 18:2 (n-6) concentration (2.8, 3.6, and 4.3 mg/g DM for the control, linoleic acid, and linoleamide treatments, respectively). At 5% of the ration DM, both lipid supplements increased duodenal 18:2 (n-6) concentration over the control diet with a greater response observed for linoleamide (2.5, 12.2, and 16.8 mg/g DM for the control, linoleic acid, and linoleamide treatments, respectively). This study demonstrates reduced biohydrogenation of linoleamide based on its ability to maintain a higher concentration of 18:2 (n-6) in ruminal cultures and in duodenal contents of sheep compared to free linoleic acid.

The composition of bovine milk lipids: January 1995 to December 2000

Data from recent publications on bovine milk lipids are presented and discussed. This includes extraction of lipids, triacylglycerols, phospholipids, other complex lipids, sterols, isoflavones, and fatty acids. Improved gas-liquid and high performance liquid chromatography were used. Data on the trans and cis isomers of fatty acid and of conjugated linoleic acids are given, and the analyses are described. Papers about the lipids in milks and dairy products from the United States are few; where with the exception of trans-fatty acid isomers and conjugated linoleic acids, almost no research has been reported.

Fatty acid composition and egg components of specialty eggs

Egg components, total fat, and fatty acid content of specialty eggs were compared. One dozen eggs were collected and analyzed from each of five different brands from hens fed a diet free of animal fat (SP1), certified organic free-range brown eggs (SP2), uncaged unmedicated brown eggs (SP3), cage-free vegetarian diet brown eggs (SP4), or naturally nested uncaged (SP5). Regular white-shelled eggs were the control. A significant (P < 0.05) difference was observed in the egg components and fatty acid content in different brands. The percentage of yolk was lower (P < 0.05) in SP2 and SP4 with a concomitant increase (P < 0.05) in the percentage of white. The percentage of shell was lower (P < 0.05) in SP4 and SP5. The total edible portion was greater in SP4 and SP5. The yolk:white ratio was greater (P < 0.05) in SP3. The total lipid content was lower in SP4 eggs. The content of palmitic (C16:0), stearic (C18:0), and total saturated fatty acids were lower (P < 0.05) in SP1. No difference was observed in the content of palmitoleic (C16:1), oleic (C18:1), or total monounsaturated fatty acids. The content of n-3 fatty acids in SP2, SP4, and SP5 were similar to control eggs. The ratio of total n-6:n-3 polyunsaturated fatty acids ranged from 39.2 for SP5 to 11.5 for SP1 (P < 0.05). No difference was observed in the total polyunsaturated fatty acid content of eggs (P > 0.05).

Morphine, pethidine and buprenorphine disposition in the cat

Pharmacokinetics of morphine, buprenorphine and pethidine were determined in 10 cats. Six cats received morphine (0.2 mg/kg) intravenously and four intramuscularly. Five received buprenorphine (0.01 mg/kg) intravenously and six intramuscularly. Six received pethidine (5 mg/kg) intramuscularly. Jugular venous blood samples were collected at time points to 24 h, and plasma morphine concentrations were measured by high performance liquid chromatograpy (HPLC), buprenorphine by radioimmunoassay (RIA) and pethidine by gas chromatography. Our data for morphine show elimination half-life (t1/2el) 76.3 min intravenous (i.v.) and 93.6 min intramuscular (i.m.); mean residence time (MRT) 105.0 and 120.5 min; clearance (Clp) 24.1 and 13.9 mL/kg/min; and volume of distribution (V(dss)) 2.6 and 1.7 L/kg, respectively. Comparable data for buprenorphine are t1/2el 416.8 and 380.2 min; MRT 417.6 and 409.8 min; Clp 16.7 and 23.7 mL/kg/min; and V(dss) 7.1 and 8.9 L/kg. For i.m. pethidine, t1/2el 216.4 min; MRT 307.5 min; Clp 20.8 mL/kg/min and V(dss) 5.2 L/kg. For i.m. dosing, the tmax for morphine, buprenorphine and pethidine were 15, 3 and 10 min, respectively. The pharmacokinetics of the three opioids in cats are broadly comparable with those of the dog, although there is a suggestion that the cat may clear morphine more slowly.

Fermentation of liquid coproducts and liquid compound diets: Part 2. Effects on pH, acid-binding capacity, organic acids and ethanol during a 6-day storage period

The effects of a 6-day storage period on changes in pH, acid-binding capacity, level of organic acids and ethanol of three liquid coproducts [liquid wheat starch (LWS), mashed potato steam peel (PSP) and cheese whey (CW)] and two liquid compound diets [liquid grower diet (LGD) and liquid finisher diet (LFD)] were studied. All products, except LWS, showed a significant decrease in pH and acid-binding capacity during storage. At the end of the storage period, all products reached a pH of between 3.5 and 3.9. In general, it can be concluded that the lactic acid content, and to a lesser extent the acetic acid content, increased dramatically during storage. In contrast, the ethanol content increased significantly in the liquid compound diets only. The pattern of changes in pH and organic acids during the 6-day storage period was different between the liquid coproducts and the liquid compound diets. At the start of storage, liquid coproducts are already in the 'middle' of the fermentation process, while liquid compound diets need approximately 24-36 h before fermentation begins. Consequently, in practice a different approach to obtain fermented diets is needed for liquid coproducts and liquid compound diets.

Immunochemical and catalytic characterization of hepatic microsomal cytochrome P450 in the sperm whale (Physeter macrocephalus)

Liver samples from three live-stranded adult male sperm whales, that could be sampled and frozen in liquid nitrogen within 18 h post mortem, provided an opportunity to learn more about the basic properties of their cytochrome P450 (CYP) system. All samples were catalytically active and showed sharp bands of the different CYP enzymes after Western blotting, indicating that degradation of the proteins was negligible. All three sperm whales showed a similar immunochemical CYP pattern: bands of CYP1A1/2, CYP3A and CYP4A were present, but CYP2B1/2 was not detected. Significant biotransformation of the polychlorinated aromatic hydrocarbons 4, 4'-dichlorobiphenyl (CB-15), 2,7-dichlorodibenzodioxin and 1,2,3,4,8-pentadibenzofuran was measured in an in vitro biotransformation assay. In contrast, 3,3',4,4'-tetrachlorobiphenyl (CB-77) and two chlorobornanes (CHB-32 and CHB-62) occurring in the insectide toxaphene(R), were not metabolised.

Effect of Various Dairy Packaging Materials on the Headspace Analysis of Ultrapasteurized Milk

Milk from three different dairies (each a separate trial: 1, 2, and 3) was standardized to 2% fat and processed at 140.6, 129.4, 118.3, and 107.2 degrees C (temperatures 1, 2, 3, and 4, respectively) for 2 s and packaged into six different packaging boards [standard (A) milk boards with standard seam, juice boards with standard (B) and J- bottom (D) seams, barrier boards with standard (C) and J-bottom (E) seams, and foil (F) boards with J-bottom seam] resulting in 24 different treatments. A Shimadzu 15A series chromatograph equipped with a Porapak-P column was used to measure the headspace of the milk stored at 6.7 degrees C for 1, 2, 3, 5, 10, and 15 wk of storage. Gas chromatographic headspace analysis for sulfur compounds showed that hydrogen sulfide, methanethiol, and dimethyl sulfide were detected in milk processed at 140.6, 129.4, 118.3, and 107.2 degrees C. In addition, dimethyl disulfide was detected in milk processed at 140.6 and 129.4 degrees C, and dimethyl trisulfide was detected at 140.6 degrees C. Milk processed at 140.6 degrees C contained the most sulfur compounds. Samples C1, E1, and F1 retained the most hydrogen sulfide and methanethiol at 6 d of storage. Methanethiol appeared to be heat-induced. At wk 6, a slightly hammy or cardboardy flavor was detected for milk packaged in boards with standard seams (A, B, and C), and a slightly cooked flavor was detected for milk packaged in barrier and foil boards with J-bottom (E and F) seams. The hammy or cardboardy flavor intensified with storage time, and all of the cooked flavor dissipated at wk 10.

Species, tissue and gender-related organochlorine bioaccumulation in white-sided dolphins, pilot whales and their common prey in the northwest Atlantic

Organochlorine concentrations were measured in white-sided dolphins, pilot whales, and their prey from the Gulf of Maine and used to identify species, tissue, and gender differences, and trophic transfer trends, in bioaccumulation. Polychlorinated biphenyl concentrations ([PCB]) in dolphin blubber (13 +/- 7.1 micrograms/g fresh wt.) were twice those in pilot whales, but pesticide concentrations (20 +/- 13 micrograms/g fresh) were similar between species. 4,4'-DDE, trans-non-achlor, Cl6(153) and Cl6(138) concentrations were highest. Skin tissues had more recalcitrant organochlorines than the internal organs. Male dolphins bioaccumulated higher concentrations of nonmetabolizable PCBs and hexachlorocyclohexane (HCH) isomers, whereas pilot whales had no gender-related differences in bioaccumulation. Pilot whales, mackerel, and herring had proportionately higher concentrations of DDTs, whereas [PCB] were higher in dolphins and squid. Although these odontocetes feed at the same trophic level and store a similar suite of contaminants, dolphins bioaccumulated higher and potentially hazardous 4,4'-DDE and PCB concentrations from food in their more geographically restricted range.

In vitro metabolism of fumonisin B1 by ruminal microflora

Fumonisin B1 (FB1) is a mycotoxin produced by Fusarium moniliforme and F. proliferatum. Little is known of its metabolic fate after oral ingestion in ruminants, but these animals are reported to be tolerant towards FB1. The metabolism of this mycotoxin was evaluated following incubation (1 microg/ml) in ruminal fluid for up to 72 h, in the presence or absence of alfalfa as a substrate for microbial growth, using a model rumen (sealed flask, anaerobic conditions, exclusion of light, gentle agitation, 39 degrees C). The decrease in FB1 concentration and the production of short-chain fatty acids were determined. FB1 had no effect on SCFA production. After 72 h incubation, FB1 depletion was 12% and 18% in samples with and without alfalfa, respectively. No hydrolysed metabolites (aminopolyols or aminopentol) were detected. These results indicate that FB1 is poorly metabolized in the rumen and suggest that such metabolism is not the cause of the tolerance to this toxin displayed by ruminants.

Influence of bacitracin on microbial functions in the gastrointestinal tract of horses

This study investigated the influence of zinc bacitracin on the intestinal flora of horses. The functionally active intestinal flora was examined in 6 horses during treatment with zinc bacitracin. Utilising gas chromatography, spectrophotometry, gel electrophoresis and paper chromatography, samples were analysed on biochemical markers reflecting the action of parts of the intestinal flora. The following 5 flora-related functions were studied in faecal samples and intestinal samples from different sections of the hindgut: conversion of cholesterol to coprostanol and of bilirubin to urobilinogens, degradation of mucin and of beta-aspartylglycine and inactivation of tryptic activity. Conversion to coprostanol, conversion to urobilinogens and degradation of mucin were affected by treatment of zinc bacitracin and conversion to coprostanol was most sensitive. All functions were normalised in a short time, in contrast to man and rats. Differences in environmental exposures are probably the reason for a more rapid normalisation of the intestinal flora functions in horses.

Exposure to environmentally relevant concentrations of different nonylphenol formulations in Japanese medaka

The time course of exposure to p-nonylphenol (NP) from two different sources was compared to equivalent exposures of 17-beta-estradiol (E2) and a solvent control (ethanol; EtOH). Japanese medaka were exposed for 4 days to a nominal concentration of 20 micrograms/l of either NP-I (Schenectady International, Inc.), NP-II (Aldrich), or E2, and were then placed in untreated water for 5 days. Tissue samples were taken at two time points during the 4-day exposure and two time points during the 5 days following exposure. Liver homogenates were analyzed using a western blot to detect vitellogenin (VTG) and quantified by measuring the optical density for each lane. Preliminary results indicate that E2 significantly increased VTG staining above the level observed in EtOH-treated controls for both males and females. A two-way analysis of variance (ANOVA) indicates that NP from both sources, as well as E2, significantly increased VTG staining in males (ANOVA, n = 48, P < 0.001; Tukey pairwise tests, all P < 0.008). A significant increase in VTG was observed in E2-treated males and females the first day following transfer into toxicant-free water (two-way ANOVAs, both n = 48, P < 0.003; Tukey pairwise tests, all P < 0.019). If confirmed, this extended response observed for low-level exposures may represent a significant factor for sampling scenarios following pulsitile exposure.

Evaluation of diet as a cause of gastric ulcers in horses

OBJECTIVE

To measure pH, volatile fatty acid (VFA) concentrations, and lactate concentrations in stomach contents and determine number and severity of gastric lesions in horses fed bromegrass hay and alfalfa hay-grain diets.

ANIMALS

Six 7-year-old horses.

PROCEDURE

A gastric cannula was inserted in each horse. Horses were fed each diet, using a randomized crossover design. Stomach contents were collected immediately after feeding and 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, and 24 hours after feeding on day 14. The pH and VFA and lactate concentrations were measured in gastric juice Number and severity of gastric lesions were scored during endoscopic examinations.

RESULTS

The alfalfa hay-grain diet caused significantly higher pH in gastric juice during the first 5 hours after feeding, compared with that for bromegrass hay. Concentrations of acetic, propionic, and isovaleric acid were significantly higher in gastric juice, and number and severity of nonglandular squamous gastric lesions were significantly lower in horses fed alfalfa hay-grain. Valeric acid, butyric acid, and propionic acid concentrations and pH were useful in predicting severity of nonglandular squamous gastric lesions in horses fed alfalfa hay-grain, whereas valeric acid concentrations and butyric acid were useful in predicting severity of those lesions in horses fed bromegrass hay.

CONCLUSIONS AND CLINICAL RELEVANCE

An alfalfa hay-grain diet induced significantly higher pH and VFA concentrations in gastric juice than did bromegrass hay. However, number and severity of nonglandular squamous gastric lesions were significantly lower in horses fed alfalfa hay-grain. An alfalfa hay-grain diet may buffer stomach acid in horses.

Comparative evaluation of rumen-protected fat, coconut oil and various oilseeds supplemented to fattening bulls. 1. Effects on growth, carcass and meat quality

Growth performance, carcass and meat quality were determined in 36 fattening Brown Swiss bulls fed with maize silage-hay-concentrate based rations supplemented with fats and various oilseeds. The concentrate diet in the control group contained only barley and soybean meal, while the treated groups included, as partial replacement of the concentrate, rumen-protected crystalline fat, coconut oil, whole crushed rapeseed, sunflower seed or linseed, providing additional 3% fat of total ration dry matter. Animals were housed in groups of six with one representative of each treatment in a monofactorial design and feed was offered using transponder controlled equipment. Daily gains were similar for control, protected fat, rapeseed and linseed treatments (1240 g/d on average), but were lower (P < 0.05) with sunflower seed (1135 g/d) and coconut oil (1038 g/d). Corresponding differences (P < 0.05) in carcass weights were observed. All fat supplemented groups had reduced rumen fluid protozoa counts (P < 0.05). Carcasses tended to be leaner with the fat supplements. Mostly no significant effects on other carcass quality (dressing percentage, conformation score) and meat quality traits (final pH, cooking loss, shear forces) as well as composition (dry matter, fat, collagen) occurred. Consequently, rumen protected fat and some oilseeds can be recommended to be fed to growing cattle as energy sources.

Six intestinal microflora-associated characteristics in sport horses

The aim of this study was to investigate 6 microflora-associated characteristics (MACs) in faecal samples from horses and to compare the results with baselines previously established in other mammals. A MAC is defined as any anatomical structure, physiological, biochemical or immunological characteristic in a host, which has been acted on by microorganisms. When the active microbes are absent, as in germ-free animals and healthy newborn organisms, the corresponding characteristic is defined as germ-free animal characteristic (GAC). The MACs studied were degradation of mucin, conversion of cholesterol to coprostanol and bilirubin to urobilinogens, inactivation of tryptic activity, degradation of beta-aspartylglycine and excretion of short-chain fatty acids. Five MACs were studied in 19 sport horses and the mucin pattern investigated in 25 other sport horses. Our results show that conversion of cholesterol to coprostanol was present in all horses, irrespective of diet. All horses also demonstrated excretion of urobilinogens; however, the values varied depending on diet. Mucin and beta-aspartylglycine were totally degraded, as occurs similarly in other animal species. Excretion of short-chain fatty acids was lower than values previously found in man, rats and pigs, and the level of faecal tryptic activity was low. Our results show that the MAC/GAC concept is as good in monogastric herbivores as in omnivores for investigations of endogenous and exogenous factors influencing the intestinal ecosystem(s). Therefore, use of the MAC/GAC concept has a potential significance for future studies on functions related to the microflora.

Dietary levels of chia: influence on yolk cholesterol, lipid content and fatty acid composition for two strains of hens

Four hundred fifty H&N laying hens, half white and half brown, were fed for 90 d to compare a control diet to diets containing 7, 14, 21, and 28% chia (Salvia hispanica L.) seed. Cholesterol content, total fat content, and fatty acid composition of the yolks were determined 30, 43, 58, 72, and 90 d from the start of the trial. Significantly less cholesterol was found in the egg yolks produced by the hens fed the diets with 14, 21, and 28% chia compared with the control, except at Day 90. Palmitic fatty acid content and total saturated fatty acid content decreased as chia percentage increased and as the trial progressed. Total omega-3 fatty acid content was significantly greater (P < 0.05) for both strains for all chia diets compared with the control diet. Total polyunsaturated fatty acid (PUFA) content of the yolks from the chia diets was significantly greater (P < 0.05) than from the control diet. Generally, total PUFA content tended to be highest in the yolks of the white hens.

Effect of food enzymes on utilisation of lupin carbohydrates by broilers

1. The effects of 3 commercial enzyme products on the nutritive value of 2 lupin species were investigated with the emphasis on changes in composition of non-starch polysaccharides (NSPs) along the digestive tract. Enzyme A contained primarily cellulase, beta-glucanase and xylanase activities, enzyme B primarily hemicellulase, pentosanase and xylanase activities, and enzyme C primarily hemicellulase, pectinase and beta-glucanase activities. 2. The enzymes were added to semi-purified diets based on sorghum and casein containing 35% whole seed lupins (Lupinus angustifolius cv Gungurru or Lupinus albus cv Kiev mutant). Control diets contained no lupins. 3. Food conversion ratio (FCR), excreta moisture content and apparent metabolisable energy (AME) were affected by lupin species but not by enzyme supplementation. 4. In diets with L. angustifolius, enzyme C significantly increased digesta viscosity and increased the concentration of soluble NSPs in all sections of the intestine. 5. Digestibility of protein and NSPs in the ileum and microbial fermentation in the ileum and caeca were not affected by adding enzymes to diets containing L. angustifolius. 6. Enzyme addition to diets with L. albus did not affect digesta viscosity nor concentration of soluble NSPs but caused a significantly (P<0.05) reduced concentration of insoluble NSP in the ileum. 7. Enzyme addition to L. albus significantly (P<0.05) increased NSP digestibility in the ileum but had no effects on protein digestibility and fermentation in the ileum and caeca.

The metabolic use of energy from dietary fat in broilers is affected by fatty acid saturation

1. Two experiments were performed to evaluate the effect of dietary fat on performance and fat and protein accretion in broiler chickens according to the degree of saturation. 2. The first experiment was designed to test 2 sources of dietary fat and 3 levels of dietary energy using a factorial (2x3) experimental design. The foods were formulated to maintain a constant ratio of energy to protein (and other nutrients). There were no significant differences in weight gain, intake, final body weight or food to gain ratio between broilers fed on diets differing solely in the degree of fat saturation. Broilers fed on diets containing animal fat showed higher whole-body fat retention (P=0.02) and lower protein accretion (P=0.03) than those fed on diets containing vegetable oils. 3. In the second experiment, only 1 concentration of fat (tallow, lard or sunflower oil) was incorporated into the experimental diets, providing different energy to protein ratios. The carcase protein content was not affected by dietary fat source, while total fat accretion (P=0.01) and energy retention (P=0.14) were highest in broilers fed on a diet containing tallow. 4. The findings suggest that the degree of saturation of dietary fats affects their metabolic use and fat accumulation in broiler chickens.

Periodicity of sex pheromone biosynthesis, release and degradation in the lightbrown apple moth, Epiphyas postvittana (Walker)

Pheromone titer in moths is a product of three processes occurring in or at the surface of the pheromone gland: biosynthesis, release, and intraglandular degradation, of pheromone. Changes in titers of sex pheromone, the fatty acyl pheromone analog (FAPA), and tetradecanoate, a pheromone biosynthetic intermediate, were studied in detail in the lightbrown apple moth, Epiphyas postvittana (Walker). Although changes in the pheromone titers in a day were relatively small, with the peak titer being 2-3 times greater than that at the trough, pheromone titer did show a distinct diel periodicity. Titer of the FAPA showed a similar, but less variable, diel pattern, but tetradecanoate titer showed little or no diel pattern. The pattern of pheromone titer suggested that females biosynthesize pheromone at two different rates during the photoperiod: a high rate during the latter half of the photophase and most of the scotophase, which is associated with a high pheromone titer, and a low rate throughout the first half of the photophase, which is associated with a low titer. Consistent with data on commencement of copulation, pheromone was released from the second hour of the scotophase through to the eighth hour. Pheromone release rate during this period appeared to be similar to the rate of pheromone biosynthesis. In contrast to the other two processes, pheromone degradation did not appear to have a diel pattern. Females decapitated at different times of the photoperiod showed a similar decline in pheromone titer, consistent with the reaction kinetics being first order in pheromone titer.

Identification of cuticular hydrocarbons and the alkene precursor to the pheromone in hemolymph of the female gypsy moth, Lymantria dispar

Hydrocarbons were extracted from the surface of the cuticle and from the hemolymph of adult female gypsy moths. GC and GC/MS analysis indicated that the cuticular hydrocarbons with chain lengths >21 carbons were the same as those found in the hemolymph. These consisted of mostly saturated straight chain hydrocarbons with heptacosane the major component. Methyl branched hydrocarbons were also identified including a series of tetramethylalkanes with chain lengths of 30, 32, and 34 carbons. In addition to those found on the cuticle surface, the hemolymph contained the alkene pheromone precursor, 2-methyl-Z7-octadecene and two saturated analogues, 2-methyl-octadecane and 2-methyl-hexadecane. No evidence was obtained for the presence of the pheromone 2-methyl-7, 8-epoxy-octadecane in the hemolymph. Pheromone gland extracts indicated that small amounts (<1 ng) of the alkene precursor were also present in the gland. Relatively larger amounts of the alkene precursor were found in the hemolymph at the time when pheromone titers were higher on the gland. The presence of the hydrocarbon pheromone precursor in the hemolymph is discussed in relation to possible biosynthetic pathways for producing the gypsy moth pheromone.

Short-term dietary effects on reproductive wastage after induced ovulation and artificial insemination in primiparous lactating Sarda ewes

Short-term effects of nutrition on conception rate (CR), ovulation rate (OR), ova and embryo losses (OEL) during the first 50 days following insemination and total reproductive wastage after ovulation (TRW), were investigated in primiparous lactating Sarda ewes after oestrous synchronisation and cervical [corrected] artificial insemination (AI). Eighty ewes grazing a green high-quality pasture were offered one of three iso-energetic supplements from day 14 before to day 2 after AI: whole maize grain (M); soyabean meal (S); maize gluten meal (G); or served as controls (C). Supplements G and S were iso-nitrogenous but provided different amounts of rumen undegradable digestible protein. The intake of herbage and digestible dry matter, measured by the n560 mg/l was associated with lower CR. Ranking by ovulation groups of CR was single Collapse

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MESH Headings

• Alkanes/analysis
• Animal Feed
• Animal Husbandry
• Animal Nutritional Physiological Phenomena
• Animals
• Blood Glucose/analysis
• Chromatography, Gas/veterinary
• Corpus Luteum/diagnostic imaging
• Feces/chemistry
• Female
• Glutens/metabolism
• Insemination, Artificial/veterinary
• Insulin/analysis
• Lactation
• Male
• Milk/chemistry
• Milk/metabolism
• Pregnancy
• Radioimmunoassay/veterinary
• Reproduction/physiology
• Sheep/physiology
• Glycine max/metabolism
• Ultrasonography
• Zea mays/metabolism

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Grants Collapse

Affiliation(s)

A Branca Istituto Zootecnico e Caseario per la Sardegna, 07040 Olmedo, Italy
G Molle
M Sitzia
M Decandia
S Landau

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Viability, susceptibility to peroxidation and fatty acid composition of boar semen during liquid storage

The changes in viability, susceptibility to peroxidation and fatty acid composition of total phospholipid were studied in boar spermatozoa during 5 day liquid storage in a standard or alpha-tocopherol (alphaT) enriched diluent. The sperm rich fraction of the ejaculates was collected from 6-month old boars. Sperm viability progressively decreased during storage and alphaT inclusion into the diluent significantly inhibited this trend. alphaT inclusion also decreased significantly peroxidation (TBARS production of spermatozoa). Spermatozoa stored in the treatment diluent became rapidly enriched in alphaT with a concomitant decrease of alphaT content in the medium. The proportion of polyunsaturates, mainly 22:6n-3, decreased with a complementary increase in the content of the saturates, mainly 18:0. The inclusion of alphaT into the diluent was effective in totally preventing the significant decrease of 22:6n-3 observed in sperm phospholipid in the control samples during the storage period. It is concluded that the alphaT inclusion in the boar semen diluent increased cell viability through its prevention of an oxidative reduction in the levels of the major polyunsaturated fatty acids, namely 22:6n-3.

Effects of starch source and level of forage neutral detergent fiber on performance by dairy cows

The effectiveness of neutral detergent fiber (NDF) from soyhulls and whole cottonseed for replacing NDF from forage was evaluated in a lactation trial during wk 10 to 25 of lactation. Forty-eight cows were blocked and randomly assigned within a block to one of four diets: 1) 21% forage NDF with corn 2) 16% forage NDF with corn, 3) 16% forage NDF with corn and wheat (1:1) and, 4) 11% forage NDF with cottonseed and corn. Soybean hulls were added at approximately 23.0% of dry matter (DM) for the 16 and 11% forage NDF diets to replace forage and formulate diets with 35% nonfiber carbohydrates. Actual forage NDF concentration were 17.8, 14.0, 13.9, and 9.4%, respectively. Dry matter intake and milk yield were highest for cows fed 11% forage NDF with cottonseed. Milk fat percentage was higher for cows consuming 21% forage NDF and 16% forage NDF with corn than for cows fed the two other diets. Cows fed 16% forage NDF with corn and wheat experienced milk fat-protein inversion, but ruminal acetate:propionate was lower for cows fed 11% forage NDF than cows fed 16% forage NDF. Body weight (BW) and BW change were not different among treatments. Time spent chewing was similar among all diets. For cows in midlactation, forage NDF may be reduced to 9 to 11% when cottonseed is at 11% of DM and dietary nonstructural carbohydrates are at 30% of DM. Forage NDF may be reduced to 14 to 16% without cottonseed when nonstructural carbohydrates are at 30% of DM.

Feeding oleamide to lactating Jersey cows 1. Effects on lactation performance and milk fatty acid composition

Oleamide was previously reported to resist ruminal biohydrogenation and elevate milk oleic acid concentration when fed to lactating Holstein cows. To determine if Jersey cows responded similarly to oleamide, four lactating Jersey cows (mean 417 kg of body weight and 64 days in milk) were fed four diets in a 4x4 Latin square with 2-wk periods. Diets were total mixed ration containing 47% corn silage and 53% concentrate (dry matter basis) and were supplemented with no added fat (control), or with 3.5% added fat from either higholeic canola oil, a commercial source of oleamide, or oleamide synthesized from oleic acid and urea. The canola oil supplement had no effect on milk yield or composition. Compared to canola oil, the oleamide supplements reduced milk yield, dry matter intake, and milk fat and protein contents. Milk oleic acid concentration increased from 17.4% of total fatty acids for the control diet to 22.1% for the canola oil diet. Both oleamides further increased milk oleic acid to 30.0 and 27.1% of total fatty acids for the commercial and synthesized oleamides, respectively. Milk palmitic acid was reduced and stearic acid was increased by all fat supplements but more so by the oleamides than by the canola oil. Consistent with previous reports that fatty acyl amides resist ruminal biohydrogenation, feeding oleamide to Jersey cows in this study increased milk oleic acid concentration but had negative effects on feed intake and milk yield.

Pharmacokinetics of clomipramine in dogs following single-dose intravenous and oral administration

OBJECTIVE

To determine pharmacokinetics of clomipramine and its principle metabolite (desmethylclomipramine) in the plasma of dogs after IV or oral administration of a single dose.

ANIMALS

6 male and 6 female Beagles.

PROCEDURES

Clomipramine was administered IV (2 mg/kg), PO (4 mg/kg) after food was withheld for 15 hours, and PO (4 mg/kg) within 25 minutes after dogs were fed. Plasma clomipramine and desmethylclomipramine concentrations were measured by use of a gas chromatography with mass-selection method.

RESULTS

Time to peak plasma concentrations of clomipramine and desmethylclomipramine following oral administration was 1.2 hours. For clomipramine, after IV administration, elimination half-life was 5 hours, mean residence time was 3 hours, and plasma clearance was 1.4 L/h/kg. Values for mean residence time and terminal half-life following oral administration were similar to values obtained following IV administration, and systemic bioavailability was approximately 20% for clomipramine and 140% for desmethylclomipramine, indicating fast absorption of clomipramine from the gastrointestinal tract and extensive first-pass metabolism. Administration of clomipramine with food did not alter the area under the concentration versus time curve for desmethylclomipramine but resulted in a 25% increase for clomipramine. Clomipramine and desmethylclomipramine were extensively bound (> 96%) to serum proteins. There were no significant differences in area under the concentration versus time curve between male and female dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicate that there should not be any clinically important differences in efficacy regardless of whether clomipramine is administered with or without food.

Pharmacokinetics of clomipramine in dogs following single-dose and repeated-dose oral administration

OBJECTIVE

To determine pharmacokinetics of clomipramine and its principle metabolite (desmethylclomipramine) in the plasma of dogs following single-dose and repeated-dose oral administration at various dosages.

ANIMALS

9 male and 9 female Beagles.

PROCEDURES

Clomipramine was administered orally at a dose of 1, 2, or 4 mg/kg to 3 male and 3 female dogs, first as a single dose and then, after an interval of 14 days, twice daily for 10 days. Plasma clomipramine and desmethylclomipramine concentrations were measured by use of a gas chromatography with mass-selection method.

RESULTS

Dose-related accumulation was detected following repeated-dose administration. Accumulation ratios after administration of clomipramine at dosages of 1, 2, and 4 mg/kg twice daily were 1.4, 1.6, and 3.8, respectively, for clomipramine and 2.1, 3.7, and 7.6, respectively, for desmethylclomipramine. Terminal half-life increased slightly (1.6-fold for clomipramine and 1.2-fold for desmethylclomipramine) with repeated-dose administration but remained short in all groups (< or = 4 hours). Steady state was reached within 4 days in all animals. Ratios of the areas under the concentration versus time curves from time 0 to 12 hours for clomipramine and desmethylclomipramine were 3.9, 3.1, and 1.5 after repeated administration at dosages of 1, 2, and 4 mg/kg every 12 hours, respectively. Areas under the concentration versus time curve, mean residence times, and terminal half-lives were not significantly different between male and female dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Repeated administration of clomipramine results in higher concentrations of clomipramine than desmethylclomipramine in dogs.