Significance for exercise capacity of some electrocardiographic findings in racehorses

Summary Various cardiorespiratory and metabolic indices were assessed during treadmill exercise in Thoroughbred and Standardbred racehorses with T wave changes in 4 or more leads on the electrocardiogram or second-degree atrio-ventricular (AV) block, and in horses that had no abnormalities on clinical examination, resting electrocardiography or upper respiratory tract endoscopy. No significant differences in heart rate, plasma lactate concentration, arterial blood gases, oxygen uptake, run time, peak velocity, or blood and red cell volumes were found between normal horses and horses with T wave changes or second-degree AV block. These results indicate that some electrocardiographic findings that are considered by some clinicians to indicate cardiac dysfunction, may have little effect on exercise capacity.     

Evaluation of ear tags impregnated with cypermethrin for the control of sheep body lice (Damalinia ovis)

The application of polymer matrix ear tags impregnated with 8.5% w/w cypermethrin to 6 wethers following shearing reduced lice to non-detectable levels on 4 of them at 29 weeks after tagging. At the conclusion of the study at 45 weeks the mean count of lice on tagged wethers was 3 per sheep compared to 158 on untreated wethers. In a second experiment, 6 non-infected sheep were treated at shearing with cypermethrin tags, 6 with 25 g/l cypermethrin backline formulation, 6 with tags plus backline and 6 were left untreated. Each group was exposed to 6 sheep with moderate to heavy infestations of lice. Compared to controls, all treatments delayed infestation, but cypermethrin tags gave no longer protection than backline treatment. All sheep were infested by 17 weeks after commencement of the study. At 45 weeks mean counts of lice were 38, 27, 20 and 74 respectively for sheep treated with tags, backline formulation, backline plus tags and untreated. Possible reasons for the better effect observed from applying tags to infested sheep than to sheep which were not infected at application but which were subsequently exposed to infested sheep are discussed.     

Nutrient intake of horses in Thoroughbred and Standardbred stables

SUMMARY Twenty-five Thoroughbred (TB) and 25 Standardbred (SB) stables were visited to determine their feeding practices. The ingredients of the main feed of the day for a mature gelding of average size in full training were weighed at each stable. Nutrient content of diets was calculated using published data for the individual ingredients. Results are expressed as mean±sd. The estimated body weight of TB horses was 493±34 kg and 437±32 kg for SB horses. There was considerable variation in diet composition and nutrient intake between stables. The TB trainers fed 11.0±2.4 kg and SB trainers 11.8±2.5 kg per day. The concentrate component of the diet weighed 7.8±1.6 and 7.7±2.3 kg for TB and SB stables, respectively, and the roughage component for TB horses 3.3±1.4 and SB horses 4.1±1.4 kg per day. The digestible energy intake of horses at TB stables was 129±29 MJ per day and at SB stables 132±31 MJ per day. Crude protein intake of TB horses was 1452±363 g and SB horses 1442±338 g per day. There were differences in some feeding practices at TB and SB stables. Standardbred trainers fed more roughage than TB trainers. Standardbred trainers fed chaffed lucerne (alfalfa) and cereal hays as the major roughage, whereas TB trainers fed more hay. The major hay type fed by TB trainers was lucerne, whereas many SB trainers preferred clover hay. Both trainers fed oats as the major grain, but TB trainers fed slightly more maize (corn) than SB trainers. The SB trainers fed barley as part of the concentrate component of the diet, whereas TB trainers usually fed boiled barley and linseed oil in winter only. Although many trainers used vitamin and mineral supplements, this appeared unnecessary in many Instances, especially with respect to Iron. Calcium and NaCI supplementation was necessary for some diets. We concluded that while there was a wide range in feed intake and diet composition for both TB and SB horses, average nutrient intakes were similar to National Research Council (1989) recommendations for horses performing intense work.     

Alpha-amylase/subtilisin Inhibitor Levels in Australian Barleys

An enzyme-linked immunosorbent assay (ELISA) was used to determine the bifunctional alpha-amylase/subtilisin inhibitor (BASI) content of barley grain from 11 cultivars grown in six diverse locations in Australia. The inhibitor ranged from 119 to 254 μg/g in 57 barley samples. Genotype had a significant (P<0·05) effect on BASI content but there was no effect due to environment. Total protein varied independently of BASI and was influenced by environment and genotype. BASI content was higher (P<0·05) in malting barley than in feed barley and was correlated positively (r=0·29;P<0·05) with alpha-amylase activity in corresponding malts. The ELISA used monoclonal and polyclonal antibodies raised against purified BASI. In immunoblot analysis the monoclonal antibody showed high specificity for the inhibitor in barley and also detected the inhibitor in wheat. Low levels of inhibitor (mean 3·2 μg/g) were found in 12 Australian wheat cultivars using the ELISA developed for barley. The assay had a linear working range of 5–50 ng/mL with a detection limit of 2 ng/mL. Reproducibility between assays was good (CV=4·9%) but mean recoveries were high, ranging from 116–129% when purified inhibitor was added to barley extracts. The ELISA may have useful applications in brewing research and barley breeding programmes.     

Development of a forest certification standard compatible with PEFC and FSC's management requirements. A case study from Greece

Greece currently has no national forest certification standard.This paper explains how a draft forest management standard forGreece was developed to be compatible with both the Forest StewardshipCouncil and the Programme for the Endorsement of Forest Certificationschemes requirements. The draft standard was tested in two contrastingforest areas to investigate its ease of operation, to indicatenecessary refinements to the standard and to reveal major areasof weakness in current forest management practices. Field testingshowed that the standard was operationally efficient and thatrelatively few changes to the standard were necessary. Majorweaknesses in current management practices were identified asbreaches of health and safety, poor training of forest workersand inadequate consultation with stakeholders.     

Physiological and biochemical consequences of electroimobilisation in conscious sheep

An electroimmobilisation device has been developed to facilitate the automated shearing of sheep, but there is little information on its effects on the body. We have studied its effects on the cardiovascular system and on intermediary metabolism in sheep. Electroimmobilisation caused statistically significant increases in mean arterial pressure, heart rate, cardiac output, renal and hepatic and hindquarter glucose and lactate flux, organ and whole body oxygen flux, hindquarter blood flow and core temperature and decreases in arterial and posterior vena cava blood pH, renal and hepatic blood flow and PaCO2. Notably, no change occurred in PaO2. The metabolic changes demonstrated the capacity of sheep to respond to the increased muscular and cardiovascular work induced by electroimmobilisation. Pulmonary function was not compromised during electroimmobilisation as judged from blood gas changes, and the acid/base changes were rapidly reversed after electroimmobilisation. The recovery to control conditions for all perturbations generally took no longer than 30 min, consistent with a rapid and physiologically adequate reversal by the animal's homeostatic mechanisms.