ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01461.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01462.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01463.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01464.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01465.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryNine reproductively normal mares, 25 infertile mares and one set of heterosexual twins were examined cytogenetically using conventional giemsa staining, C‐banding and G‐banding. It was concluded that G‐banding was necessary to identify even gross anomalies. Three (12 per cent) of the infertile mares, but none of the controls, had a chromosomal anomaly. One was 63,XO, one a 63,XO/64,XX mixoploid and one a 64,XY sex reversed male. It is argued that a cytogenetic examination is a useful diagnostic technique but that routine screening of the whole population would be uneco

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01466.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryA rapid incremental treadmill exercise test was used to determine the repeatability of the following measurements in exercising horses: maximal oxygen consumption (V̇o2max), maximal heart rate (HRmax), velocity at a heart rate of 200 beats/min (V̇‐200), oxygen consumption at a heart rate of 200 beats/min (V̇o2‐200), oxygen consumption at HRmax (V̇o2‐HRmax), work rate at a heart rate of 200 beats/min (W‐200), work rate at HRmax (W‐HRmax) and treadmill velocity at HRmax (V‐HRmax). Six Standardbred geldings were exercised on three separate occasions on a treadmill set at an inclination of 6°. The exercise protocol was that each horse was exercised for 2 mins at 3 m/sec, after which the treadmill speed was increased by 1 m/sec every 60 secs, until the horse could no longer maintain its speed. A minimum of 24 h was allowed between repeated tests. No significant differences were found between the three means of any of the eight cardiorespiratory variables with repeated measurement. Variables with high coefficients of variation (>10 per cent) included V‐HRmax, W‐HRmax and V̇o2‐HRmax. The V‐200, W‐200 and V̇o2‐200 showed less variation. The V̇o2max showed good reproducibility, there being coefficients of variation ranging from 1.4 to 9.0 per cent. The individual horse values for V̇o2max ranged from 104 to 169 ml/kg bodyweight/min. Maximal heart rate was also highly reproducible and the coefficients of variation were less than or equal to 2.7 per cent in all horses. It is concluded that the measurement of V̇o2max has good reproducibility, but other estimates of maximal

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01467.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryAn analysis was made of the causes of death in horses and ponies over one year of age which died suddenly (Group 1) or were found dead but were considered normal when last seen (Group 2). There were 49 animals in Group 1. Thoroughbreds were overrepresented, but there were no ponies in this group. No cause of death was found in 30.6 per cent of cases and 16.3 per cent died from each of the following causes: haemorrhage in the respiratory system, central nervous system, and adverse drug reactions. Cardiovascular lesions were the cause of death in 14.4 per cent and the remaining 3.1 per cent had lesions of the gastrointestinal system. Racehorses mostly died suddenly from severe haemorrhage in various sites, particularly the thorax. In Group 2 there were 151 animals, and in 33.1 per cent no cause of death was determined. Gastrointestinal lesions were considered the cause of death in 39.2 per cent of cases and respiratory lesions killed 8.6 per cent. Lesions of both the central nervous system and cardiovascular system were considered the cause in 4.6 per cent of cases. The remaining 9.9 per cent of animals had miscellaneous lesions. Toxicological studies were performed in 46 of the total 200 cases, and only two had positive results; lead in one and nicotine in the other.

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01468.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryLengths of small intestine, caecum, ascending colon and descending colon were measured in intestinal tracts from 103 foetuses, foals and adult horses. Intestinal tracts from 21 of the horses were measured at varying intervals after death. Total intestinal length increased markedly from mid‐gestation to one year of age, then showed little increment up to 35 years. Small intestinal length increased most rapidly in the first month of life. Caecal length increased most rapidly from one to six months and length of ascending colon increased most rapidly between one week and one year. Descending colon length increased gradually after birth. Periods of rapid increase in length of various intestinal segments and alterations in the percentage of total intestinal length were associated with periods of rapid body growth and changes in dietary compositon. Sex and post mortem interval did not affect intestinal length significantl

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01469.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryTo study the effect of short term high intensity exercise on plasma lactate, potassium, sodium and chloride concentrations, five Thoroughbred horses were galloped on a treadmill at a 5° incline. Following a standardised warm‐up period, they were galloped at 8, 10, or 12 metres/sec for 2 mins. One horse also galloped at 14 metres/sec for 1.5 mins. Sequential arterial and/or venous blood samples were collected during exercise and recovery. At 12 metres/sec, the effect of different recovery modes, ie, standing, walking or trotting, on the electrolytes was also examined. There was a progressive rise in plasma potassium concentration during galloping, with peak values occurring at the end of the exercise bout. In some cases, values above 10 mmol/litre were recorded at the highest workloads. Plasma lactate concentrations peaked during early recovery, with values up to 32 mmol/litre. A high correlation existed between peak potassium and lactate concentrations (venous r=0.923, and arterial r=0.989). Following exercise there was a rapid return to baseline plasma potassium concentrations, but by 12 mins recovery there was still an elevated lactate concentration, the extent depending on the intensity of the exercise bout and the recovery mode. There was a small rise in plasma sodium but no significant change in plasma chloride concentrations during exercise. However, when adjusted for the decrease in plasma volume, as determined from total plasma protein concentration, there was a decrease in circulating amounts of both electrolyt

ISSN:0425-1644    

DOI:10.1111/j.2042-3306.1988.tb01470.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY