Massey Research Online - Browsing by Author "Bolwell CF"

Browsing by Author "Bolwell CF"

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An imaging investigation of in situ uroliths in hospitalized cats in New Zealand and in the United States
(John Wiley & Sons, 6/07/2016) Wightman PF; Hill KE; Cohen EB; Bridges J; Bolwell CF; French J; Adler BA; Green R
The submission rates of feline uroliths to laboratories and the composition of uroliths have been reported in studies. The prevalence of uroliths reported on imaging findings has not been published. The objective of this retrospective study was to use imaging data to investigate the anatomical location and the prevalence of macroscopic in situ uroliths in cats. Radiographs, sonograms and imaging reports from two cohorts of cats (from New Zealand (n = 497) and the United States (n = 693)) from 2004-2013 were reviewed for the presence of in situ uroliths. Uroliths were categorized by their location in the lower or upper urinary tract. Radiographic studies were performed on 43% (212/497) of the cats from New Zealand and 50% (349/693) of the cats from the USA. Sonographic studies were performed on 57% (285/497) of the cats from New Zealand and 50% (344/693) of the cats from the USA. The total prevalence of uroliths was 3% in the New Zealand cohort and 13% in the USA cohort. Lower tract urolith prevalence in the New Zealand cohort was 2.4% (5/212) in cats ≤ 6y and 1.1% (3/285) in cats >6y. Upper tract urolith prevalence in the New Zealand cohort was 0.5% (1/212) in cats ≤ 6y and 1.8% (5/285) in cats >6y. Lower tract urolith prevalence in the United States cohort was 6.0% (11/183) in cats ≤ 6y and 2.9% (15/510) in cats >6y. Upper tract urolith prevalence in the United States cohort was 2.7% (5/183) in cats ≤ 6y and 10.2% (52/510) in cats >6y. The prevalence of uroliths in the upper tract or lower tract was low in the New Zealand cohort compared to that of cats in the USA cohort, irrespective of age category. Geographical location may be important when evaluating risk factors for feline urolithiasis.
Comparison of gastrointestinal transit times in stabled Thoroughbred horses fed freshly cut pasture and three conserved forage-based diets
(CSIRO Publishing, 2022-07) Fernandes KA; Rogers CW; Gee EK; Fitch G; Bolwell CF; Kittelmann S; Bermingham EN; Thomas DG
Context: The type of forage offered to horses varies in physical form, moisture content and nutrient quality, and these variables could affect the intake, passage rate and digestibility of the forage consumed. Aims: To investigate the changes in passage rate of digesta through the gastrointestinal tract in horses fed four different forage-based diets (diet effect). Methods: Thoroughbred mares (n = 6) were stabled in loose boxes for 6 weeks. During Weeks 1, 3 and 5 (washout periods), all horses were fed freshly cut pasture, either in restricted quantities (Week 1) or ad libitum (Weeks 3 and 5). Using a 3 × 3 Latin square design during Weeks 2, 4 and 6, each pair of horses was abruptly transitioned to one of three conserved forage-based diets (chopped ensiled forage fed exclusively or with oats, or perennial ryegrass hay with oats) fed ad libitum. At the beginning of each week, indigestible polyethylene markers (n = 200) were administered to the horses via a nasogastric tube, followed immediately by transition to the new diet. Key results: There was a significant diet effect on the daily dry-matter intake of feed (P < 0.0001), percentage of time spent eating (P < 0.001), frequency of voiding faeces (P < 0.05) and quantity of faeces voided (P < 0.0001). There was a significant horse effect on the daily dry-matter intake of feed (P < 0.0001) and quantity of faeces voided (P < 0.0001), but no differences in the percentage of time spent eating or the frequency of voiding faeces. There were significant diet and horse effects on the time to recovery of the first marker in the faeces (P < 0.01 and P < 0.01 respectively) and the mean retention time of markers in the gastrointestinal tract (P < 0.05 and P < 0.001 respectively). Mean retention time was negatively correlated with feed intake and quantity of faeces voided (r2 =-0.51 and r2 =-0.64 respectively). Conclusions: Longer mean retention time was associated with a greater fibre content in the diet and a restricted feed supply, thus supporting the hypothesis that horses alter mean retention time on the basis of a nutrient absorption optimisation model. Implications: Feed composition, but also the quantities offered, may alter measurement of apparent feed digestibility in horses.
Race-Level Reporting of Incidents during Two Seasons (2015/16 to 2016/17) of Harness Racing in New Zealand
(MDPI (Basel, Switzerland), 2022-02-11) Gibson MJ; Roca Fraga FJ; Bolwell CF; Gee EK; Rogers CW; McDonnell SM
The objective of this study was to describe the incident and non-incident reporting of harness racing in New Zealand, the primary injury and reporting outcomes, and to examine horse- and race-level variables associated with the odds of these outcomes. Retrospective stipendiary stewards' reports of race day events during the 2015/16 to 2016/17 racing seasons were examined. The number of incident and non-incident events and binomial exact 95% confidence intervals (CI) were calculated per 1000 horse starts. Most reports were for non-incidents and an examination was requested for poor performance (11.06 per 1000 starts (95% CI = 10.23-11.89). Races with more than eight participants were 1.9 (95% CI = 1.13-3.4) times more likely to have an incident than races with eight or less participants. The low incidence of significant injuries such as fractures (0.13 per 1000 starts (95% CI = 0.03-0.23) reflects the lower risk of injury in harness racing compared to Thoroughbred racing. The high incidence of poor performance reports highlights the steward's role in maintaining animal welfare to a high standard.
Race-Level Reporting of Incidents during Two Seasons (2015/16 to 2016/17) of Thoroughbred Flat Racing in New Zealand.
(MDPI (Basel, Switzerland), 2022-04-15) Gibson MJ; Bolwell CF; Gee EK; Legg KA; Rogers CW; McDonnell SM
The objective of this study was to describe the incident and non-incident reports of Thoroughbred flat racing in New Zealand. Retrospective stipendiary stewards' reports of race day events during the 2015/2016 and 2016/2017 racing season were examined. The primary injury and reporting outcomes were analysed to assess the horse- and race-level risk factors associated with the occurrence of incident and non-incident reports. The number of incident and non-incident events and binomial exact 95% confidence intervals were calculated per 1000 horse starts. Most reports were for non-incidents and examinations were requested for poor performance (10.3 per 1000 races, 95% CI = 9.5-11.1). Horses running in open-class races had greater odds of having an incident than horses in lower-rating classes. The incidence of musculoskeletal injuries (1.3 per 1000 races, 95% CI = 1.13-1.40) and fractures (0.6 per 1000 races, 95% CI = 0.39-0.74) were low and similar to previous New Zealand reports. There was a low incidence of epistaxis (0.8 per 1000 races, 95% CI = 0.69-0.92) possibly due to trainers screening susceptible horses before entering them in races, due to the regulatory consequences of an episode of epistaxis during a race.
Reproductive production constraints within the New Zealand racing industry
(2016) Rogers CWW; Gee EK; Bolwell CF
The New Zealand Thoroughbred industry has seen rationalisation in response to changes in the domestic market and more recently the Global Financial Crisis (GFC). To quantify changes in production, end-of-season reproductive data for active Thoroughbred sires were extracted for the 1989/90 to 2011/12 breeding seasons. There were reductions in the numbers of mares bred and foals produced (10,176 mares & 5,882 foals vs. 5,826 mares & 3,927 foals, respectively in 1989/90 and 2011/12 seasons) resulting in a greater relative proportion of foals registrations (57% vs. 67%). During this period, the number of active sires decreased (265 vs. 94) and number of mares per sire increased (33 IQR 18-53 vs. 49 29-91). The 2007/08 season (GFC) was associated with an acute reduction in the number of shuttle stallions imported for breeding (from 23% in 2006/07 to 11% of active sires in 2007/08), and a temporary increase in number of mares bred (13%), in response to the 2007 Equine Influenza outbreak in Australia. The proportion of sires covering >100 mares per season increased from 6% (1989/90) to 25% (2011/12). Despite the reduction in active broodmares during the same period (43%), there has not been a proportional decrease in export numbers (24%) or domestic numbers of horses racing (6.5%).
Resilience of Faecal Microbiota in Stabled Thoroughbred Horses Following Abrupt Dietary Transition between Freshly Cut Pasture and Three Forage-Based Diets
(MDPI (Basel, Switzerland), 2021-09-06) Fernandes KA; Rogers CW; Gee EK; Kittelmann S; Bolwell CF; Bermingham EN; Biggs PJ; Thomas DG; Costa M
The management of competition horses in New Zealand often involves rotations of short periods of stall confinement and concentrate feeding, with periods of time at pasture. Under these systems, horses may undergo abrupt dietary changes, with the incorporation of grains or concentrate feeds to the diet to meet performance needs, or sudden changes in the type of forage fed in response to a lack of fresh or conserved forage. Abrupt changes in dietary management are a risk factor for gastrointestinal (GI) disturbances, potentially due to the negative effects observed on the population of GI microbiota. In the present study, the faecal microbiota of horses was investigated to determine how quickly the bacterial communities; (1) responded to dietary change, and (2) stabilised following abrupt dietary transition. Six Thoroughbred mares were stabled for six weeks, consuming freshly cut pasture (weeks 1, 3 and 5), before being abruptly transitioned to conserved forage-based diets, both offered ad libitum. Intestinal markers were administered to measure digesta transit time immediately before each diet change. The conserved forage-based diets were fed according to a 3 × 3 Latin square design (weeks 2, 4 and 6), and comprised a chopped ensiled forage fed exclusively (Diet FE) or with whole oats (Diet FE + O), and perennial ryegrass hay fed with whole oats (Diet H + O). Faecal samples were collected at regular intervals from each horse following the diet changes. High throughput 16S rRNA gene sequencing was used to evaluate the faecal microbiota. There were significant differences in alpha diversity across diets (p < 0.001), and a significant effect of diet on the beta diversity (ANOSIM, p = 0.001), with clustering of samples observed by diet group. There were differences in the bacterial phyla across diets (p < 0.003), with the highest relative abundances observed for Firmicutes (62 - 64%) in the two diets containing chopped ensiled forage, Bacteroidetes (32-38%) in the pasture diets, and Spirochaetes (17%) in the diet containing hay. Major changes in relative abundances of faecal bacteria appeared to correspond with the cumulative percentage of intestinal markers retrieved in the faeces as the increasing amounts of digesta from each new diet transited the animals. A stable faecal microbiota profile was observed in the samples from 96 h after abrupt transition to the treatment diets containing ensiled chopped forage. The present study confirmed that the diversity and community structure of the faecal bacteria in horses is diet-specific and resilient following dietary transition and emphasised the need to have modern horse feeding management that reflects the ecological niche, particularly by incorporating large proportions of forage into equine diets.
Risk-Factors for Soft-Tissue Injuries, Lacerations and Fractures During Racing in Greyhounds in New Zealand
(Frontiers Media S.A., 2021-12-03) Palmer AL; Rogers CW; Stafford KJ; Gal A; Bolwell CF; Bruyette D
Recognition of injuries in racing animals is essential to identify potential risk factors so actions can be taken to reduce or mitigate the cause of the injury to safeguard the animal. Racing greyhounds are subject to musculoskeletal injuries associated with athletic pursuit, in particular soft-tissue injuries, lacerations, and fractures. The objective of this study was therefore to determine risk factors for soft-tissue injuries, lacerations and fractures occurring during racing, using a cohort of greyhounds racing in New Zealand between 10th September 2014 and 31st July 2020. Dog-level, race-level and track-level risk factors for each outcome were assessed using mixed-effects multivariable logistic regression including trainer as a random effect. Throughout the study period there were 218,700 race starts by 4,914 greyhounds, with a total of 4,385 injuries. Of these, 3,067 (69.94%) were classed as soft-tissue injuries, 641 (14.62%) were reported as lacerations, and 458 (10.44%) were fractures. Greyhounds with a low racing frequency (racing more than 7 days apart) had 1.33 [95% confidence interval (CI): 1.06-1.67] times the odds of fracture compared to those racing more frequently. Older greyhounds had a greater odds of fracture compared with younger greyhounds. Racing every 7 days had a lower odds of soft-tissue injury compared with racing more than once a week. Dogs over 39 months had 1.53 (95% CI: 1.35-1.73) times the odds of sustaining a soft-tissue injury compared to the younger dogs. Greyhounds originating from Australia had a higher odds of fracture and laceration compared with New Zealand dogs. Better performing dogs (higher class) had a greater odds of fracture and laceration whilst maiden dogs had a higher odds of soft-tissue injury. Greyhounds starting from the outside box had a higher odds of fracture. There was considerable variation in the odds of soft-tissue injury at different racetracks. In conclusion, although the incidence of soft-tissue injuries was higher than other injury types, the repercussion of such injuries was less than those for fractures. The results from this study will help to inform intervention strategies aimed at reducing the rate of injuries in racing greyhounds, enhancing racing safety and greyhound welfare.
Seasonal Variation in the Faecal Microbiota of Mature Adult Horses Maintained on Pasture in New Zealand
(MDPI (Basel, Switzerland), 2021-08-04) Fernandes KA; Gee EK; Rogers CW; Kittelmann S; Biggs PJ; Bermingham EN; Bolwell CF; Thomas DG; Costa M
Seasonal variation in the faecal microbiota of forage-fed horses was investigated over a 12-month period to determine whether the bacterial diversity fluctuated over time. Horses (n = 10) were maintained on pasture for one year, with hay supplemented from June to October. At monthly intervals, data were recorded on pasture availability and climate (collected continuously and averaged on monthly basis), pasture and hay samples were collected for nutrient analysis, and faecal samples were collected from all horses to investigate the diversity of faecal microbiota using next-generation sequencing on the Illumina MiSeq platform. The alpha diversity of bacterial genera was high in all samples (n = 118), with significantly higher Simpson's (p < 0.001) and Shannon-Wiener (p < 0.001) diversity indices observed during the months when horses were kept exclusively on pasture compared to the months when pasture was supplemented with hay. There were significant effects of diet, season, and month (ANOSIM, p < 0.01 for each comparison) on the beta diversity of bacterial genera identified in the faeces. While there was some inter-horse variation, hierarchical clustering of beta diversity indices showed separate clades originating for samples obtained during May, June, and July (late-autumn to winter period), and January, February, and March (a period of drought), with a strong association between bacterial taxa and specific nutrients (dry matter, protein, and structural carbohydrates) and climate variables (rainfall and temperature). Our study supports the hypothesis that the diversity and community structure of the faecal microbiota of horses kept on pasture varied over a 12-month period, and this variation reflects changes in the nutrient composition of the pasture, which in turn is influenced by climatic conditions. The findings of this study may have implications for grazing management and the preparation of conserved forages for those horses susceptible to perturbations of the hindgut microbiota.
Transforming a Didactic Lecture into a Student-Centered Active Learning Exercise—Teaching Equine Diarrhea to Fourth-Year Veterinary Students
(MDPI (Basel, Switzerland), 2022-02) Gordon SJG; Bolwell CF; Raney JL; Zepke N; Albright J
Problem-solving abilities, creative and critical thinking, communication skills, and teamwork are now recognized as fundamental determinants of professional success, especially in vocational professions, such as veterinary science. Tertiary education is now obliged to provide opportunities for students to become proficient in these qualities. With this in mind, the principal author, an equine science senior lecturer, attempted to increase student engagement by developing a new active learning, student-centered one-hour teaching episode on ‘equine diarrhea’, to replace the traditional didactic lecture format. The aim of the study, therefore, was to share the principal author’s journey in the development and implementation of this active learning episode and to explain why it represents a simple but effective method of promoting student engagement. In addition, the adaptation of this method into an online teaching and learning format is briefly discussed. The effectiveness of this active learning method is also explored by comparing it with the traditional didactic method of delivery. Students in the active learning class reported that the learning activity had enhanced their skills in clinical reasoning, problem-solving, and communication. They also described themselves as active participants in the learning process. Students in the traditional didactic class reported that they were satisfied with the time allocated to the lecture, felt that the lecture was well organized and managed, and subsequently felt adequately prepared to answer conventional examination questions relating to equine diarrhea. Other issues, such as student resistance to changes in teaching formats, the effectiveness of group work or teamwork, levels of student confidence within an active learning environment, and the importance of high-quality facilitation during active learning activities, are also discussed in this paper. Although the active learning method described is not novel, the authors hope that fellow educators, across any tertiary discipline, might find that the method described represents a quick and simple method of transforming a single didactic lecture into an enjoyable and engaging learning activity.
Validation of a combined approach-avoidance and conditioned stimulus aversion paradigm for evaluating aversion in chickens.
(PLOS, 2021-02-25) Du Plessis EW; Beausoleil NJ; Bolwell CF; Stafford KJ; Olsson IAS
Understanding animals' aversion is important to improving their welfare. Aversion is often assessed using an approach-avoidance (AA) test in which animals have to forfeit a reward if they want to avoid an event or environment presented in the same place. However, sometimes the event/environment suspected to be aversive may physically impair the animal's ability to withdraw from that place (i.e. its ability to express aversion), leading to incorrect interpretations. Combining AA with a Conditioned-Stimulus that predicts the event/environment may overcome this problem by allowing animals to demonstrate aversion without exposure to the stimulus. We aimed to validate this paradigm for testing aversion in chickens. Seven Hyline-Brown chickens were trained to obtain a food reward from a coloured bowl located in the test chamber (TC) of a two-chambered box; the reward was presented in a green bowl with an inactivated air canister or a red bowl with the canister activated to deliver an air puff. Two 5-minute tests were conducted, one with each bowl colour and both with the canister inactivated. All chickens entered TC with the green bowl. With the red bowl, two chickens entered on their first attempt, one fully entered after a partial entry (3/7 fully entered), two made only partial entries and two made no attempts to enter. Chickens spent less time in the TC with the red bowl (median 31s, IQR 7-252) compared to the green bowl (293s, IQR 290-294; p = 0.008). The higher ratio of partial to full entries, failure to enter the TC and less time spent in TC reflected chickens' aversion to the air puff, signalled by the red bowl. The paradigm allowed chickens to demonstrate aversion without exposure to the aversive stimulus during testing.

Browsing by Author "Bolwell CF"

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