Heritability of foot conformation and its relationship to sports performance in a Dutch Warmblood horse population

Reasons for performing study: Warmblood horse studbooks aim to breed horses with a conformation that will enable elite future performance, but reduce the risk of injuries and lameness. Negative conformational traits, such as asymmetrical or ‘uneven’ forefeet would possibly diminish performance. Objectives: To assess the prevalence and heritability of uneven feet and its genetic relationship to other conformation traits as well as to sporting performance later in life in Warmblood riding horses. Methods: The databases of the Royal Dutch Warmblood Studbook (KWPN, n = 44,840 horses) and Royal Dutch Equestrian Sports Federation (KNHS, n = 33,459 horses in dressage and n = 30,474 horses in showjumping) were linked through the unique number of each registered horse. Therefore, heritabilities and genetic and phenotypic correlations could be estimated from the scores of the jury at studbook admission and the sports performance of that population in dressage and jumping over the period 1990–2002. Results: The prevalence of uneven feet was 5.3% on average, and increased from under 4.5% during the first 3 years of recording to over 8% in the years from 2000 onwards. Heritability estimates of foot conformation traits were moderate and ranged from 0.16 for heel height to 0.27 for hoof shape. The genetic correlation between the trait of uneven feet and performance in competition was negative but weak: ?0.09 with dressage and ?0.12 with showjumping. Conclusions: Predisposition to uneven feet can be reduced by selection. Because of weak genetic correlations, the increased prevalence is not directly associated with selection for better sports performance or higher conformation grade. If the trait ‘uneven feet’ arises from a disproportionate relationship between height at the withers and neck length, then selection on conformation grade might result in development of uneven feet. In general, limb conformation has a moderate genetic relationship to conformation grade and foot conformation traits have a genetic relationship to sporting performance. Reducing occurrence of uneven feet by selection is possible, without limiting progress in sport performance.     

No easy solution for the fractionation of faecal nitrogen in captive wild herbivores: results of a pilot study

Faecal nitrogen (FN) concentration is used as a marker for habitat quality and digestive efficiency in free‐ranging herbivores. In herbivores, FN can be separated into undigested plant N (analysed as the N concentration of the neutral detergent residue) and metabolic faecal N (MFN). It has been suggested that by differential analysis of the faecal fibre‐bound N, the MFN fraction can be further split into a bacterial N and an endogenous N fraction [Hesta et al., Br. J. Nutr. 90 (2003) 1007]. We applied these methods to 96 faecal samples of 48 mammalian herbivore species from zoos. Species were grouped into coprophageous and non‐coprophageous hindgut fermenters and ruminating and non‐ruminating foregut fermenters. Diet was not controlled. The FN decreased with body mass, possibly reflecting higher proportions of concentrates in diets of smaller animals. The proportion of MFN increased with FN, indicating that higher quality food might enhance the gastrointestinal bacterial flora. The only outlier to this pattern was the lesser panda (Ailurus fulgens), confirming the low relevance of fermentative digestion in this herbivorous ‘carnivore’. No relevant differences between the four digestion types were noted. The proportion of endogenous faecal N (32–80% of FN) was always higher than that of bacterial faecal N (7–30%), which contradicts basal understanding of herbivore digestive physiology. Thus, the method of Hesta et al. (2003) does not appear applicable to herbivores. While the results do not exclude the possibility that detailed differences might occur between digestion types, they indicate a high degree of similarity between herbivores that rely on bacterial fermentation, regardless of their digestion type, with respect to metabolic faecal losses.     

The role of lectures in veterinary education

OBJECTIVE: To study the role of lectures from the perspective of staff and students involved in the veterinary course at The University of Queensland. METHODS: The Nominal Group Technique of Delbecq et al, which provides the maximum opportunity for group members to put forward points, was used to help develop a questionnaire which was completed by 351 students (a response rate of 84%) and 35 staff (76%) from the five years of the veterinary course, and was analysed using the SAS System for Windows. RESULTS: Almost all the staff and students agreed that lectures should fulfil many roles including stimulating and motivating students and encouraging them to think, as well as presenting ideas and concepts and an indication of the structure and relevance of the material. They should provide a guide for effective deep learning, but not encourage rote (or superficial) learning. A smaller percentage of staff and even fewer students agreed that lectures did fulfil these roles, especially those directed at encouraging students to look beyond simple memorisation of facts. The perceived disparity between reality and the ideal was greater amongst the older, clinical students than amongst their more junior colleagues. CONCLUSIONS: The focus of attention in lectures needs to change from the superficial, rote learning of information to deep, active learning directed at using information to solve problems that are perceived by the students to be relevant. If done in a stimulating and interesting way, this should develop skills in reasoning and critical analysis as well as providing a framework for storage and recall. It should also increase the motivation towards learning both during the veterinary course, and over the professional lifetime. Furthermore, the place of the lecture in veterinary education needs to be reassessed regularly in the face of newly-emerging educational technology.     

Metabolic and mitogenic activities of insulin-like growth factor-1 in interleukin-1-conditioned equine cartilage

OBJECTIVE: To determine response of interleukin-1alpha (IL-1alpha)-conditioned equine articular cartilage explants to insulin-like growth factor-1 (IGF-1). Sample Population-Cartilage from the trochlea and condyles of the femur of a clinically normal 4-year-old horse. PROCEDURE: Effects of IGF-1 (0 to 500 ng/ml) after addition of IL-1alpha were evaluated by assessing matrix responses, using a sulfated glycosaminoglycan (GAG) assay, matrix 35SO4 GAG incorporation, and release of GAG. Mitogenic response was assessed by 3H-thymidine incorporation into DNA and fluorometric assay of total DNA concentration. RESULTS: Human recombinant IL-1alpha (40 ng/ml) increased the amount of labeled GAG released and decreased labeled and total GAG remaining in explants, and IL-1alpha decreased mitogenic response. Addition of IGF-1 counteracted effects seen with IL-1alpha alone. In general, IGF-1 decreased total and labeled GAG released into the medium, compared with IL-1alpha-treated explants (positive-control sample). Values for these variables did not differ significantly from those for negative-control explants. A significant increase in total and newly synthesized GAG in the explants at termination of the experiment was observed with 500 ng of IGF-1/ml. Labeled GAG remaining in explants was greater with treatment at 50 ng of IGF-1/ml, compared with treatment with IL-1alpha alone. Concentrations of 200 ng of IGF-1/ml abolished actions of IL-1alpha and restored DNA synthesis to values similar to those of negative-control explants. CONCLUSIONS AND CLINICAL RELEVANCE: IGF-1 at 500 ng/ml was best at overcoming detrimental effects associated with IL-1alpha in in vitro explants. These beneficial effects may be useful in horses with osteoarthritis.     

Evaluation of intratesticular injection of glycerol for nonsurgical sterilization of dogs

OBJECTIVE: To determine efficacy of intratesticular injection of glycerol as a means to sterilize dogs. ANIMALS: Six 2- to 4-year-old sexually intact male dogs. PROCEDURE: Testicular volume, serum testosterone concentration, and number of sperm in ejaculate were determined before and at weekly intervals for 12 weeks following intratesticular injection of a 70% glycerol solution (1 ml/testis). Testicular tissue specimens for histologic evaluation were obtained 4, 8, and 12 weeks following injection. RESULTS: Number of sperm in ejaculate following glycerol injection was not significantly different from number before injection. Compared with preinjection values, serum testosterone concentrations were significantly less 5, 9, and 10 weeks following injection, although libido and ejaculate characteristics were unchanged. Testicular swelling was evident 24 to 48 hours following injection, and testicular volume decreased starting on week 5 following treatment. Seminiferous tubules and evidence of normal spermatogenesis were detected in testicular biopsy specimens obtained from all dogs 12 weeks following injection. CONCLUSION AND CLINICAL RELEVANCE: Intratesticular injection of a 70% glycerol solution did not result in azoospermia and sterility in dogs.     

Stress and feather pecking in laying hens in relation to housing conditions

1. Possible association between high rates of feather pecking and increased stress were investigated in laying hens. 2. From week 19 to week 30 after hatching, 16 groups of 11 hens (white Lohman Selected Leghorn hybrids) were kept in pens with or without long-cut straw as foraging material and provided with food in the form of pellets or mash. 3. Stress was assessed by egg production, weight gain, tonic immobility (TI), heterophil/lymphocyte (H/L) ratio and antibody titres to sheep red blood cells (SRBC), tetanus toxoid (TT) and human serum albumin (HSA). 4. Provision of foraging material and food form influenced feather pecking. Rates of feather pecking were highest in groups housed without straw and fed on pellets. 5. Egg production was reduced in pens without straw but not affected by food form. Both the duration of TI and H/L ratios were influenced by provision of foraging material and food form. TI was longer and H/L ratios were increased in hens housed without straw and in those fed on pellets. Antibody titers to SRBC and TT were lower in pens without straw than with straw but not influenced by food form. 6. In conclusion, foraging material and food form affected both feather pecking and indicators of stress, suggesting that feather pecking in laying hens is associated with stress.     

Pheasant ataxia: a new condition in pheasant poults

Between 1995 and 1997 a neurological condition in pheasant poults from 24 sites in England and Scotland was investigated. Affected birds showed varying degrees of ataxia and incoordinated movements and, in severe cases, recumbency, but generally remained alert with their heads held upright. The condition characteristically affected poults from seven weeks of age and the incidence on any one site was low. No significant bacteria were isolated consistently from brain tissue. The condition was characterised histologically by a non-suppurative meningoencephalitis, in which lesions were found predominantly in the cerebellum in 61 of 81 samples examined (75.3 per cent). A non-suppurative myelitis was recorded in 16 of 20 spinal cords examined. No lesions were recorded in peripheral neural tissue and lesions were rare in other tissues. The condition appeared not to have been recorded previously in pheasants. A viral aetiology was suspected but Newcastle disease virus was not involved.     

Normal bacterial flora from vaginas of Criollo Limonero cows

In order to describe the normal bacterial flora in vaginas of Criollo Limonero cows, 51 healthy multiparous cows, at least 90-day postpartum, were selected. Duplicated swabs (N = 102) were taken from the vaginal fornix of cows to perform aerobic and anaerobic cultures as well as conventional biochemical tests. Out of 102 swabs, bacterial growth was obtained in 55 (53.9%) while the remaining 47 (46.1%) did not exhibited any bacterial growth. Of the 55 bacterial growths, 23 (41.8%) were aerobic whereas 32 (58.1%) were anaerobic. Likewise, 29 (52.72%) of bacterial growths were pure and 26 (47.27%) were mixed. Under both aerobic and anaerobic conditions, Gram positive bacteria were predominant (81.82% and 73.08%, respectively) over Gram negative bacteria (18.18% and 26.92%, respectively). Isolated bacteria were Arcanobacterium pyogenes (22.92%), Staphylococcus aureus (15.63%), Staphylococcus coagulase negative (17.71%), Erysipelothrix rhusiopathiae (6.25%), Bacteroides spp. (13.54%), and Peptostreptococcus spp. (7.29%). In conclusion, normal vaginal bacterial flora of Criollo Limonero cows was predominantly Gram positive and included A. pyogenes, S. aureus, coagulase negative Staphylococcus, E. rhusiopathiae, Bacteroides spp., and Peptostreptococcus spp. In Criollo Limonero cattle, adaptive aspects such as development of humoral and physical mechanisms for defense, and bacterial adaptation to host deserve research attention.     

Lack of glucokinase regulatory protein expression may contribute to low glucokinase activity in feline liver

In most mammals, glucokinase (GK) acts as a hepatic “glucose sensor” that permits hepatic metabolism to respond appropriately to changes in plasma glucose concentrations. GK activity is potently regulated by the glucokinase regulatory protein (GKRP), which is encoded by the GCKR gene. GKRP binds GK in the nucleus and inhibits its activity. GK becomes active when it is released from GKRP and translocates to the cytosol. Low glucokinase (GK) activity is reported to be a principal feature of feline hepatic carbohydrate metabolism but the molecular pathways that regulate GK activity are not known. This study examined the hypothesis that species-specific differences in GKRP expression parallel the low GK activity observed in feline liver. Hepatic GKRP expression was examined using RT-PCR, immunoblot, and confocal immunomicroscopy. The results show that the GCKR gene is present in the feline genome but GCKR mRNA and the GKRP protein were absent in feline liver. The lack of GKRP expression in feline liver indicates that the low GK activity cannot be the result of GKRP-mediated inhibition of the GK enzyme. However, the absence of the permissive effects of GCKR expression on GK expression and activity may contribute to reduced GK enzyme activity in feline liver. The study results show that the cat is a natural model for GCKR knockout and may be useful to study regulation of GCKR expression and its role in hepatic glucose-sensing and carbohydrate metabolism.