Blood lactate responses to submaximal field exercise tests in thoroughbred horses

The associations between velocity during a standardized, submaximal 800-m exercise test and blood lactate concentration after exercise were investigated in Thoroughbred racehorses on sand and grass racetracks. Predicted lactate concentrations for each horse's exercise test velocity were calculated from the line of best fit derived from results at each racetrack. The repeatability of the differences between the measured and predicted blood lactate response to exercise was also investigated. Exercise tests were conducted at speeds ranging from 12.8 to 16.6 m/s. The variability of velocity within the exercise test was expressed as the coefficient of variation (CV) of the times for the four 200-m sections.On the sand track, the coefficient of determination for the lactate-speed relationship was highest for an exponential regression equation [lactate (mmol/L) = 0.08e(0.33x)(m/s);r(2)= 0.58, P< 0.05;n = 21]. Similar coefficients of determination were calculated for linear (r(2)= 0.56) and second order polynomial equations (r(2)= 0. 57). On the grass racetrack, the relationship was best described by a second order polynomial equation [lactate (mmol/L) = -0.87x(2)+ 28. 17x - 211.41;r(2)= 0.57, P< 0.05;n = 25]. The mean differences between the measured and predicted blood lactate concentrations in repeated tests were 1.9 +/- 1.8 (SD) and 1.8 +/- 1.7 ( SD) on the sand and grass racetracks. There were no significant associations between the velocity of the exercise and the CV on either racetrack. Differences between measured and predicted blood lactate concentrations, based on track-specific lines of best fit, have potential application in field studies of fitness in Thoroughbred horses.     

Relative Flow-Time Relationships in Single Breaths Recorded After Treadmill Exercise in Thoroughbred Horses

Analysis of individual breaths after exercise has potential for pulmonary function testing. The aims of this study were to investigate the dependence of measurements of pulmonary function in single breaths on time postexercise and tidal volume (V_T) after treadmill exercise. Five Thoroughbred horses without evidence of airway disease were used. Horses had been previously acclimated to treadmill exercise and to wearing a face mask. A Quadflow spirometer recorded airflow rates continuously during 90 seconds after intense treadmill exercise to fatigue. Indices of function were based on ratios of times within each breath and analyses of the shape of relative flow–time curves within inspiration and expiration. Restricted maximum likelihood, general linear regression, repeated-measures one-way analysis of variance (ANOVA), and two sample t-tests were used, with statistical significance at P < .05. Time postexercise had no effect on several ratios based on time for inspiration (T_I) and expiration (T_E), and times to peak flows (T_I/T_T, T_E/T_T, T_E/T_I, Tpef [peak expiratory flow]/T_E, and Tpif [peak inspiratory flow]/T_I). Many variables were significantly dependent on V_T. Occasional big respiratory cycles with V_T more than 10% greater than in the previous breath had significantly different means for relative flow (Rf)/(T_E/T_I), epz_50% (50% of the time from Tpef to end of expiration), epz_75% (75% of the time from Tpef to end of expiration), and ipz_75% (75% of the time from Tpif to end of inspiration). Predicted means for these variables differed by 10–20%. This study establishes guidelines for the selection of breaths after exercise, and describes a new approach to measurement of relative flow and time relationships. It was concluded that several time-based ratios have potential for measuring pulmonary function. However, care is needed when selecting breaths for calculation of most of the new relative flow–time variables.     

C-reactive protein, tumor necrosis factor α, and interleukin-6 in dogs with pyometra and SIRS

Objective: To determine the frequency of the systemic inflammatory response syndrome (SIRS) in canine pyometra and to evaluate the relationship between C‐reactive protein (CRP), tumor necrosis factor α (TNFα), interleukin‐6 (IL‐6), and SIRS. Design: Prospective clinical study. Setting: Veterinary teaching hospital. Animals: Fifty‐three clinical cases of canine pyometra and 19 healthy control bitches. Interventions: Upon admission to the veterinary hospital, history and physical examination findings, including previously defined clinical SIRS parameters, were documented. Blood samples were obtained for hematology and biochemical tests and for CRP, TNFα, and IL‐6 analysis. The diagnosis of pyometra was confirmed by histopathology of the uterus after ovariohysterectomy. After surgery, clinical SIRS parameters, length of hospitalization, and mortality were recorded. Measurements and main results: Pyometra dogs were grouped as SIRS positive (30/53; 57%) or SIRS negative (23/53; 43%). Logistic regression showed that CRP was the only parameter that significantly related to SIRS apart from the clinical criteria that define this syndrome. The mortality rate was low (2/53; 3.8%), and conclusions regarding association with SIRS could not be drawn. A positive SIRS status, high plasma CRP concentration, and high body temperature were variables that related to increased morbidity reflected by the length of hospitalization. Conclusions: SIRS was seen in 57% of canine pyometra cases and a positive SIRS status showed a positive association with prolonged hospitalization. The mortality rate was low (3.3%) among SIRS positive dogs, indicating that progression to multiple organ dysfunction syndrome (MODS) rarely occurs in surgically treated cases of pyometra. CRP was associated with SIRS and with prolonged hospitalization. Further studies of plasma CRP may be warranted in canine intensive care cases susceptible to development of SIRS and MODS.     

Gross Anatomy of the Pancreatic Lobes and Ducts in Six Breeds of Domestic Ducks and Six Species of Wild Ducks in China

A previously unreported pancreatic duct was found by Liu (1989) in Pekin ducks. This duct has now been consistently found in six breeds of domestic ducks and six species of wild ducks in China. For purposes of Nomina Anatomica Avium it is hereby called the ‘first pancreatic duct’(Ducius pancreaticus primus) since it enters the duodenum at or near the flexure where the descending duodenum becomes the ascending duodenum. All other pancreatic ducts enter the duodenum later, closer to where it joins the jejunum. This first pancreatic duct drains the caudal extremity of the dorsal lobe of the pancreas and can be easily exteriorized for experimental purposes. Within the parenchyma of the dorsal lobe of the pancreas this duct communicates with the dorsal pancreatic duct. In the present study of the gross anatomy of the pancreatic lobes of domestic and wild Chinese ducks we describe and illustrate variations in position and number of all biliary and pancreatic ducts.     

The effect of applying cobalt sulphate to soil on the cobalt content of herbage

Abstract. Two hill pastures in north Dyfed, Wales, were each treated at reseeding in 1971 with 2.25, 4.5 and 9.0 kg ha⁻¹ cobalt sulphate. Herbage samples for analysis of Co content were taken in summer at each site from 1971 to 1976 and also at site 1 from 1977 to 1983. Acetic acid extractable Co was measured in soil samples taken each winter for the same period at both sites. At site 1, on a peat, the treatments continued to give worthwhile increases in herbage and soil Co after 13 years. At site 2, on a mineral soil, the residual effects were small and lasted no more than four years. It is suggested that me lower response and residual value at site 2 is due to higher levels of exchangeable and easily reducible manganese.     

Distribution of 5'-nucleotidase in the tissues of sheep and the effect of kidney and liver lesions on the activity of the enzyme in plasma and urine

The distribution of 5'-nucleotidase (5'-NT) activity in the tissues of the sheep differs from that of gamma glutamyl transferase (GGT). Nevertheless, both enzymes are released into the plasma of sheep which have been infected with Fasciola hepatica or in which the bile duct has been ligated. In a sheep dosed with sporidesmin, a fungal toxin which damages the biliary tract, there was an increase in GGT activity in the plasma and urine but no change in 5'-NT activity. Neither enzyme was released into the plasma or urine of sheep dosed with carbon tetrachloride. In sheep with renal tubular necrosis and hepatocellular necrosis caused by dosage with hexachlorobutadiene, both enzymes were released into the plasma, and GGT, but not 5'-NT activity was found in urine. In sheep with tubular necrosis of the kidney caused by the administration of mercuric chloride, GGT activity, but not 5'-NT, increased in the plasma and urine.     

Contribution of White Clover Varieties in High-Productivity Systems under Grazing and Cutting

Two medium leaf size varieties of white clover (Trifolium repens L.) were grown in mixture with a range of grass species and varieties in a field experiment conducted over 4 years. The clovers were grown singly or as a blend in swards with a tetraploid perennial ryegrass (Lolium perenne L.), a diploid Italian ryegrass (Lolium multiflorum L.) or tetraploid hybrids between these two species (Lolium x boucheanum Kunth). These grasses were also grown in monoculture. Swards were managed in a regime involving two periods of sheep grazing, two periods of cattle grazing and a silage cut in the same year for 4 years. The objectives of this experiment were 3‐fold: (1) to examine the yield and persistency of white clover in highly productive systems with modern perennial, hybrid and Italian ryegrasses; (2) to compare the performance of white clover varieties grown singly in mixture with grasses with their performance together as a blend, and (3) to examine the persistency of new Italian ryegrass varieties, exemplified by AberComo. The clover content of the sward remained high throughout the experiment, with a mean of 31 % overall. Differences in clover yield between plots were largely attributable to the effects of companion grasses. Total yields were very similar in plots containing different clover varieties and in plots where these varieties had been grown singly or as a blend. Grass yields in mixture were greater than those in monoculture but showed similar relative rankings. The diploid Italian ryegrass variety AberComo showed an unexpectedly high yield in the 4th year of the experiment. The implications of these results for strategies for productive, sustainable agriculture using modern white clover and ryegrass varieties are discussed.     

Field efficacy of a morantel sustained release bolus for control of gastrointestinal nematodes in yearling steers

The efficacy of a morantel sustained release bolus (MSRB) for control of gastrointestinal nematodes in yearling steers was evaluated over a 6-month grazing period commencing on 26 March 1982. Three groups of 15 steers were allotted to the following treatments: Group 1 -- one MSRB at start of trial; Group 2 -- one therapeutic dose of thiabendazole at start of trial; Group 3 -- untreated control. The treatment groups were grazed separately. Parasite egg counts (EPG), herbage larval counts, pepsinogen levels and weight gains were monitored. Every other month, sets of 2 parasite-free tracer calves were placed in the pasture grazed by each treatment group and allowed to graze for 3 weeks before being subsequently necropsied for worm counts. At the end of the trial, 6 animals from each group were also necropsied for worm counts. The MSRB treatment resulted in significantly lower egg counts, fewer infective larvae on pasture, lower pepsinogen levels and lower worm burdens in tracer calves than was the case for the untreated group, but generally the levels were not significantly different from those associated with the thiabendazole treatment. The mean weight gain for the MSRB treated steers showed a significant advantage (70.9 lb) over the untreated animals, but was not significantly different from those which received thiabendazole. Total worm counts at the end of the trial were not different from any treatment group.     

Management of inappetant sheep during export by sea

In the first of 2 experiments, a simulated voyage was conducted to examine the effects of various treatments on bodyweight change and feeding frequency of inappetant sheep at the end of lot-feeding (non-feeders). The treatments, applied during simulated shipping, were: normal quantities of feed and length of troughs; extra trough length; extra feed. Adult Merino wethers (n = 108) were used in each treatment. A voyage to the Middle East was then conducted to establish whether shipboard mortality could be reduced by separating non-feeders (n = 305) from feeders (n = 5,620) late in the feedlot hase and housing the groups separately aboard ship. A control group of non-feeders (n = 215) mixed with feeders (n = 5,732) was used for comparison. Bars (marker bars), containing a coloured dye, were attached to feed troughs to mark sheep that fed. Most non-feeders (82%) began eating when placed in shipping pens in both studies. However, there was no significant difference in percentage of sheep that fed between non-feeders given extra trough length or extra feed compared with non-feeders given standard management at any stage of simulated shipping. There was no significant difference in mean bodyweights between treatment groups on days 1, 8 and 15 of simulated shipping. Differences in bodyweight on d 22 were probably associated with different levels of gut fill. Death rates were not significantly different in separated and control groups (1.1%, 0.9%, P = 0.6) in the voyage of 14 d to the Middle East.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of zinc sulfate concentration and feeding frequency on ruminal protozoal numbers, fermentation patterns and amino acid passage in steers

Effects of zinc sulfate (0 vs 1,142 ppm supplemental zinc from zinc sulfate) and feeding frequency (1 x vs 12x daily) on ruminal protozoa numbers, fermentation patterns and amino acid passage were investigated using four ruminally and abomasally cannulated mature Jersey steers in a 4 x 4 Latin square experiment. Steers (530 kg) were fed a 50:50 roughage:concentrate diet at 1.5 times their NEm requirement. Experimental periods were 14 d in duration; ruminal, abomasal and fecal samples were collected at 6-h intervals during the last 3 d of each period. Protozoa numbers tended to be lowest (1.82 x 10(6)/ml) in steers fed zinc 1 x and tended to be highest (3.83 x 10(6)/ml) in steers fed zinc 12 x daily (P less than .10). Frequent feeding decreased ruminal pH .24 units and increased total VFA 20.7%, ammonia 22.7% and ruminal digestion of dietary amino acids (AA) 61.6% (P less than .05). Zinc supplementation decreased ruminal digestion of dietary AA 35.8% (P less than .05) and the abomasal passage of bacterial OM and AA 21.2% (P less than .05) and increased ruminal output of amino acids as a percentage of intake 15.1% (P less than .05). Although it increased escape of dietary AA, zinc sulfate decreased postruminal passage of bacterial AA and resulted in a net negative effect on total postruminal AA passage as a percentage of intake. The effects of zinc on ruminal AA digestion may be more closely related to an interaction of zinc with dietary CP rather than to an effect of Zn on ruminal microbial populations.