Incidence of swallowing during exercise in horses with dorsal displacement of the soft palate

Reasons for performing study: The relationship between dorsal displacement of the soft palate (DDSP) and swallowing is unclear. Objective: To quantify the relationship between DDSP and swallowing in horses at exercise. Hypotheses: The frequency of swallowing increases immediately prior to DDSP in horses at exercise. Methods: Videoendoscopic and upper airway pressure data were collated from horses with a definitive diagnosis of DDSP at exercise. Horses with no upper airway abnormalities were matched by age, breed and sex and used as controls. Sixty‐nine horses were identified with a definitive diagnosis of DDSP during the study interval. Airway pressure data were available for 42 horses. Results: The majority of horses displaced at high exercising speeds while accelerating; a smaller number displaced during deceleration after peak speed had been reached. Horses swallowed significantly more frequently in the 1 min immediately preceding DDSP than in the control horses at equivalent speeds. DDSP at exercise results in a significant increase in tracheal expiratory pressure, a significant decrease in pharyngeal expiratory pressure and a significantly less negative pharyngeal inspiratory pressure compared to matched controls and compared to the pressures during the 1 min interval prior to DDSP. There was no significant difference between any measure of airway pressure before or after a swallow when examined at each time interval in the DDSP population. Conclusions: The frequency of swallowing decreases with increasing speed in normal horses. In contrast, the frequency of swallowing increases immediately prior to onset of DDSP. This is not a result of pharyngeal and tracheal pressure changes. Potential relevance: The increased frequency of swallowing observed prior to DDSP may be related to the aetiology of the disease.     

Effects of food withdrawal and transport on 5- to 10-day-old calves

The effects of food withdrawal for 30 hours and transport for up to 12 hours on 5- to 10-day-old calves were determined by monitoring plasma concentrations of glucose, beta-hydroxybutyrate, urea, lactate and creatine phosphokinase. In addition gamma-glutamyl transferase activity, packed cell volume, total plasma protein concentration, bodyweight and rectal temperature were recorded. Food withdrawal for 30 hours caused hypoglycemia but calves maintained normothermia and although their beta-hydroxybutyrate level increased indicating lipid mobilisation, the changes in blood urea level were minimal indicating low amino acid catabolism. When calves were transported for 12 hours in addition to having food withdrawn for 30 hours, they remained normoglycemic for six hours longer than non-transported calves, probably due to an effect of muscular activity during bracing against truck movements. Stocking calves at a lower density during transport apparently had a beneficial effect, as calves were able to lie down throughout the journey and therefore produced a similar metabolic profile to resting, non-transported animals. Transport and food withdrawal had no obvious effects on calf hydration. The results of this study suggest that food withdrawal for up to 30 hours and transport for up to 12 hours had no detrimental effects on the metabolism of healthy and clinically normal calves. With correct feeding regimes and transport protocols, welfare compromise in young, healthy calves being transported for up to 12 hours can be minimised when they are slaughtered within 30 hours of the start of transport.     

Evaluation of single-nucleotide polymorphisms in CAPN1 for association with meat tenderness in cattle

Micromolar calcium activated neutral protease (CAPN1) was evaluated as a candidate gene for a quantitative trait locus (QTL) on BTA29 affecting meat tenderness by characterization of nucleotide sequence variation in the gene. Single-nucleotide polymorphisms (SNP) were identified by sequencing all 22 exons and 19 of the 21 introns in two sires (Piedmontese x Angus located at the U.S. Meat Animal Research Center in Clay Center, NE; Jersey x Limousin located at AgResearch in New Zealand) of independent resource populations previously shown to be segregating meat tenderness QTL on BTA29. The majority of the 38 SNP were found in introns or were synonymous substitutions in the coding regions, with two exceptions. Exons 14 and 9 contained SNP that were predicted to alter the protein sequence by the substitution of isoleucine for valine in Domain III of the protein, and alanine for glycine in Domain II of the protein. The resource populations were genotyped for these two SNP in addition to six intronic polymorphisms and two silent substitutions. Analysis of genotypes and shear force values in both populations revealed a difference between paternal CAPN1 alleles in which the allele encoding isoleucine at position 530 and glycine at position 316 associated with decreased meat tenderness (increased shear force values) relative to the allele encoding valine at position 530 and alanine at position 316 (P < 0.05). The association of maternal alleles with meat tenderness phenotypes is consistent with the hypothesis of CAPN1 as the gene underlying the QTL effect in two independent resource populations and presents the possibility of using these markers for selective breeding to reduce the numbers of animals with unfavorable meat tenderness traits.     

Aspects of future animal health: the Animal Health Foresight Project

Against a background of social, political, and environmental change, the challenge to provide the most appropriate education for future veterinarians is daunting. A consideration of the multiple roles of veterinarians in our future society indicates that a different perspective is essential for progress to be made. One example of an approach to reach such a perspective is the Animal Health Foresight Project, which was jointly sponsored in 2005 by the Canadian Food Inspection Agency and the US Department of Agriculture. A new paradigm emerged from this study. This article explores the conclusions of this project and their potential implications for the future of animal health and for veterinary medical education. Outcomes of the Foresight Project led to the development of a new paradigm. The implications for and the possible influence on future animal health and on veterinary medical education are contemplated.     

A comparison of laryngoplasty and modified partial arytenoidectomy as treatments for laryngeal hemiplegia in exercising horses

OBJECTIVE: To compare upper airway mechanics, arterial blood gases, and tracheal contamination in horses with induced left laryngeal hemiplegia (recurrent laryngeal neuropathy [RLN]) treated by laryngoplasty/vocal cordectomy (LPVC) or modified partial arytenoidectomy (MPA). STUDY DESIGN: Repeated measures under the following conditions: Control, RLN, LPVC, and MPA. ANIMALS: Six horses. METHODS: Two trials were conducted under all conditions at 80% and 100% of maximal heart rate (HR(max)). In Trial 1, arterial blood gases, tracheal and pharyngeal pressures, and laryngeal videoendoscopy were recorded. In Trial 2, upper airway pressure and airflow were determined. Tracheobronchial aspirates were performed after exercise to quantify airway contamination. RESULTS: Compared with control, RLN significantly increased inspiratory impedance and worsened exercise-induced hypoxemia. At 80% HR(max), LPVC restored most variables to control values. At 100% HR(max), LPVC improved all variables, but did not restore minute volume, arterial pH, and PaCO(2). At 80% HR(max), MPA restored all variables except bicarbonate to control values. At 100% HR(max), MPA improved all variables, but did not statistically restore minute ventilation or bicarbonate level. Only minor differences were noted between LPVC and MPA. Both resulted in equivalent tracheal contamination. CONCLUSIONS: Airway mechanics and arterial blood gas values were not restored to normal after either LPVC or MPA in horses exercising at HR(max). This does not affect ventilation at sub-maximal exercise, but has clinical implications at HR(max). Both procedures diminish normal laryngeal protective mechanisms. CLINICAL RELEVANCE: At sub-maximal exercise intensities both LPVC and MPA restore airway ventilation to normal. At maximal exercise the superiority of LPVC over MPA is slight.     

Changes in antimicrobial susceptibility of Actinobacillus pleuropneumoniae isolated from pigs in Spain during the last decade

A total of 229 Spanish Actinobacillus pleuropneumoniae isolates recovered from diseased pigs with pleuropneumonia from 1997 to 2004 was tested for their susceptibility to 11 antimicrobials in a broth microdilution method. All the isolates were susceptible to florfenicol and most of them to cephalothin; however, a high rate of resistance was observed to tetracycline. A bimodal or multimodal distribution of isolates over the MIC range were observed for penicillins, tetracycline, trimethoprim, sulfisoxazole and nalidixic acid, suggesting the development of acquired resistance. Eight resistance patterns were established, and 21.1% of the isolates were resistant to at least two antimicrobials. In addition, a considerable increase in the resistance to tetracyclines was observed during the last decade in Spain, when compared with other A. pleuropneumoniae strains isolated during 1987-1988 (Gutiérrez, C.B., Píriz, S., Vadillo, S., Rodríguez Ferri, E.F., 1993. In vitro susceptibility of Actinobacillus pleuropneumoniae strains to 42 antimicrobial agents. Am. J. Vet. Res. 54, 546-550); this finding was also observed for gentamicin in minor percentage.     

Ectopic ureter in the horse: Three cases and a review of the literature

Ureterovesicular anastomosis resulted in resolution of the clinical signs of urinary incontinence in three horses with unilateral ectopic ureter. Follow-up of two of the horses ten months and three years later indicated no further urinary tract problems; the third horse died four days after surgery from intestinal infarction.

Diagnosis can be readily confirmed by antegrade or retrograde ureterography, or endoscopic visualization of the ectopic ureteral openings. Nephrectomy appears indicated in cases of unilateral ectopic ureter with associated ipsilateral urinary tract infection or hydronephrosis, providing the contralateral kidney has normal function. Ureterovesicular anastomosis appears to be indicated in the management of unilateral ectopic ureters in the absence of ascending urinary tract infection or hydronephrosis, and in cases of bilateral ectopic ureters.

     

海南州草地类型的基本特征

1996年,以实施海南州国际农发基金农业综合开发项目为目的,对草地和牲畜资源进行了全面调查。据调查资料,全州有天然草地334．43万hm’（不包括人工草地面积2．79万hmz）,其中可利用草地面积316．25万hm’,占全州天然草地面积的94．56％,天然草地生产干物质总量2．40亿xg,占全州饲草资源总量的91．29％。天然草地的理论载畜量为328．91万羊单位,占全州饲草资源总载畜量的88．64％。海南州天然草地按中国草地分类标准可分为6个草地类,2个亚类,16个草地组,53个草地型。现将各草地类的基本特征描述如下：1高寒草甸类1·l地理环境高…