The equine breeding industry continues to be somewhat inefficient, even with existing technology. On average, foaling rates are low when compared with that of other livestock. One major contributor is the inability to accurately predict ovulation in mares, which ovulate before the end of estrus, leaving much variability in coordinating insemination. A more efficient, less invasive method that could replace or reduce the need for constant teasing and ultrasonography to evaluate follicular activity is needed. In both dairy cattle and women, a change in body temperature has been shown to occur immediately prior to ovulation. Research on horses has been limited, although one study reported no useable relationship between body temperature and ovulation in mares (Ammons, 1989). The current study utilized thirty-eight mature cycling American Quarter Horse mares, and was conducted from March-August 2004. Each mare was implanted in the nuchal ligament with a microchip that can be used for identification purposes, but is also capable of reporting body temperature. Once an ovulatory follicle (>35mm) was detected using ultrasonography and the mare was exhibiting signs of estrus, the mare's follicle size and temperature were recorded approximately every six hours until ovulation. Not only was the temperature collected using the microchips, but the corresponding rectal temperature was also recorded using a digital thermometer. A significant effect (p<0.05) on body temperature was noted in relation to the presence or absence of an ovulatory follicle (>35mm) under different circumstances. When evaluating the rectal temperatures, no significant difference was found in temperature in relation to the presence or absence of a follicle. However, in the temperatures obtained using the microchip, temperature was higher (p<0.05) with the presence of a follicle of greater than 35mm. This may be due to the extreme sensitivity of the microchip implant and its ability to more closely reflect minute changes in body temperature.

Studies in other species indicate high protein diets increase urinary calcium (Ca) excretion and may lead to negative calcium balance and reduced bone density. As overfeeding of protein is commonplace in the horse industry, this study was undertaken to determine the effects of excess dietary protein on growth, physiologic response, mineral balance, bone density, and bone geometry in immature horses. Sixteen 10-month-old American Quarter Horses were blocked by age and sex into two dietary treatments. The control diet was formulated to provide the NRC (1989) recommended concentration of crude protein, while the high protein diet provided 130% of NRC (1989) recommendations. All other nutrients were formulated at or slightly above NRC (1989) recommendations. Blood samples, feces, and urine were collected during the 116-day study to determine any diet effect on pH and mineral balance. Radiographs were made of the left third metacarpal (MCIII) to determine bone density via radiographic bone aluminum equivalence (RBAE), and bone geometry was determined metrically from the radiographs. Urine pH decreased over time (p < 0.001), but there were no diet effects on blood pH or urine pH. Conversely, when normalized to day 0 values, fecal pH was reduced by feeding the high protein treatment (p < 0.02). Density of dorsal and palmar cortices increased over time (p < 0.001), but no differences were observed between diets. But, normalized total medial-lateral (ML) width of the MCIII was higher in the control diet (p < 0.05). Fecal Ca loss was greater in horses fed the high protein diet (p < 0.005), while Ca absorption and retention were lower for horses on the high protein treatment (p < 0.02). Phosphorus (P) balance was not different between diets, although feeding the high protein diet resulted in higher P intake overall (p < 0.001). While excess dietary protein may decrease fecal pH, increase fecal Ca excretion, and decrease Ca absorption and retention, there was no consistent effect of the high protein diet on bone density over the course of this study. Further research is necessary to determine if feeding high-protein diets is detrimental to bone quality in the growing horse.

Centrifugation of stallion semen is an integral part of the cryopreservation procedure, primarily allowing for the concentration of sperm and removal of seminal plasma. In addition, centrifugation is required for maximizing spermatozoal quality in semen from some stallions subjected to cooled transport, because of the detrimental effects of long-term exposure to high levels of seminal plasma. The centrifugation process, however, has potential deleterious effects, including reduction in sperm quality as well as loss of sperm numbers. Since centrifugation plays such a crucial role in semen processing, two experiments were designed to evaluate more efficient centrifugation methods to meet the demands of the equine industry. In Experiment 1, semen was centrifuged in two different tube types (nipple- or conical-bottom), using a cushioned technique (Eqcellsire® Component B) with two different extenders (opaque-INRA96 or clear-HGLL). For Experiment 2, nipple-tube centrifugation was conducted at two different g forces (400 or 600) for 20 min, using three different iodixanol cushion media, Eqcellsire® Component B, OptiPrep[TM], or Cushion Fluid[TM]. Regardless of tube or extender types, centrifugation of semen resulted in sperm recovery rates ≥90%; however, centrifugation in INRA 96 extender yielded higher sperm motility values than did centrifugation in HGLL extender (P < 0.05). Cushion type or g force did not impact post-centrifugation semen quality, based on the laboratory values measured (P > 0.05). These results indicate that cushioned centrifugation of stallion semen in either conical-bottom or nipple-bottom tubes can yield a high sperm harvest, while maintaining sperm function. An optically opaque extender, as is typically used in the equine breeding industry, can be used to achieve this goal. The fertility rate (94%; 131/140) following cushioned semen centrifugation in a commercial program this past year indicates that these laboratory results are transferable to the clinical setting.

The aim of this proposed study is to explore whether participation in a three day intervention involving horseback riding in nature– a program specifically designed for autistic children and their families called “Horse Boy Camps” – leads to improved outcomes for participants. It is hypothesized that children will demonstrate significant increases in language and communication skills after camp participation, as well as enhanced social, cognitive and sensory functioning. It is also hypothesized that attendance at a Horse Boy Camp will have an impact on the parents and siblings of the child with autism. Specifically, it is anticipated that camp participation will significantly decrease the anxiety, stress, depression and social isolation experienced by parents. It will also result in significant improvements in the relationship between the autistic and their siblings as well as family functioning in general. Participants will include 20 families attending a three-day Horse Boy Camp. There will be one autistic child per family who attends the camp, and at least one parent. The proposed study will help determine if Horse Boy Camps appear to be a promising intervention for children with autism and their families. / text

The influences of loading cholesterol into stallion spermatozoa membranes prior to cold storage or cryopreservation were determined using cholesterol loaded cyclodextrin (CLC) before preservation, followed by the unloading of cholesterol after preservation using methyl beta cyclodextrin (MBCD). Experiment I: dose response trials determining optimal amounts of CLC and MBCD based on percentages of progressively motile spermatozoa (PMS) following preservation. Experiment II: influences of CLC and MBCD on PMS, the percentages of live intact (LI) and live non-intact (LNI) spermatozoa following cold storage. Experiment III: influences of CLC before cryopreservation and MBCD on PMS, LI, and LNI post-thaw. Addition of CLC improved (P&lt;0.05) PMS and LI following preservation when compared to the control. Unloading cholesterol using MBCD does not alter PMS, LI nor LNI. Addition of CLC is beneficial to survival of spermatozoa following preservation and addition of MBCD in small amounts does not negatively influence PMS, LI or LNI.

In 2005 an equine rhinitis A virus (ERAV) isolate was recovered from a febrile horse during a respiratory outbreak in Ontario. This isolate (ERAV/ON/05) was propagated in cell culture and used to study its genomic characteristics and to investigate the clinical features in experimentally infected ponies. The fulllength genome of this isolate was sequenced and compared with other ERAV available in GenBank. The isolate genome is 7839 nucleotides (nts) in length with a variable 5’UTR and a more conserved 3’UTR. When the isolate was compared to other reported ERAV, an insertion of 13 nts in the 5’UTR was identified. Phylogenetic analysis demonstrated that ERAV/ON/05 was closely related to the ERAV/PERV isolate, which was recovered in 1962 in the United Kingdom. An experimental model was developed to study the clinical infection in naïve healthy ponies (ERAV/ON/05 n=4 and placebo n=4). ERAV/ON/05 induced clinical respiratory disease compared to placebo. The clinical signs consisted of pyrexia, nasal discharge, increased and abnormal lung sounds, increased size of submandibular lymph nodes and persistent mucopus in the trachea (up to 21 days post-infection). The virus was isolated from the lower and upper airways up to day 7 post-infection, corresponding with the detection of neutralizing ERAV antibodies. Assessment of the cytokine profile from bronchoalveolar lavage (BAL) cells demonstrated that this infection induced down-regulation of the mRNA expression of IL-4. One year later, four previously infected ponies with neutralizing antibodies to ERAV were assigned to a reinfection trial. None of the re-infected ponies developed clinical disease, and only one animal had a four-fold increase in antibody titres to ERAV. Attempts to recover the virus from the re-infected ponies using cell culture were negative; however, a down-regulation of the mRNA expression of IL-4 and IFN-β was identified in BAL cells. In conclusion, this study shows that the genome of ERAV has not significantly changed in the last 50 years and more importantly the virus induces clinical respiratory disease similar to other common equine respiratory viruses.

This thesis is concerned with equine attachment as a form of interspecies fictive kinship, in relation to the practices, social relations, and motivations of participant groups within the Canterbury thoroughbred racing industry. Exploring the interconnections between intimacy and investment, as both financial and emotional commitments, the different sectors of the industry are analyzed as actor-network assemblages in which boundaries between professional, economic, and social relations are porous. The thesis argues that the parameters of a distinct equine community are delineated through regulated forms of haptic access. Distinctions regarding those who are and are not permitted to touch horses, articulates with a regime of risk regulation, which is more broadly explored in its physical, social, financial, and emotional dimensions. Also integral to the character of this networked community of practitioners is the symbolism of naming and branding thoroughbreds, as well as the secular rituals of the auction and the race-day. Conceived as a naturalcultural phenomenon, the race is analyzed in terms of the cross-species meanings and experiences of jockeys and apprentices, who are understood as representatives of an occupational sub-culture. Finally, this thesis also explores the preponderance of women in South Island racing; charting the path by which they have successfully adopted traditionally male-dominated roles.

Many factors influence the reproductive efficiency of thoroughbred mares. This thesisestimated two separate models for 13 farms in the 2004 breeding season. One model isestimated for pregnancy outcomes, the other is estimated for breeding intervals.Statistically significant variables include age of the mare, number of breedings, certainmedications, farm size, last date of breeding for the first model. Statistically significantvariables for the second model include age, status of mare, number of breedings, certainmedication, and farm size. The model has implication to achieve an optimal breedingschedule and associated management decisions

No description available.

To fully understand the mechanisms of lower airway inflammation associated with many equine diseases such as heaves or Rhodococcus equi infection, which are age specific, we must first identify baseline “normal” structural characteristics of the horse lung. To develop a detailed understanding of the morphology of the horse lung, stereological methods were adapted and applied to the lungs from healthy adult horses (n=4) and one day (n=5) and 30 day (n=5) old foals. The left lung from each animal was fixed in situ and was then removed from the body cavity and remained in fixative overnight before beginning an unbiased sampling procedure. The tissue samples were fixed in plastic and paraffin blocks for stereological evaluation and immunohistochemistry, respectively. The lung was characterised into parenchyma and non-parenchyma, where median parenchymal density (alveolar airspace, ductal airspace and tissue) was 81.0% in one day old foals, 84.4% in 30 day old foals and 93.7% in adult lungs. The median volume density of alveolar airspace per lung was 45.9% in one day old, 55.5% in 30 day and 66.9% in adult horse lungs. Ductal airspace and alveolar tissue volume density was unchanged between the age groups. The median alveolar surface area (m^2) seemed to increase with age, from about 205.3m^2, 258.2m^2 and 629.9m^2 in one day old foals, 30 day old foals, and adults, respectively. While the median alveolar surface density decreased with age, the mean linear intercept increased with age. Alveolar surface area was consistently greater than endothelial surface area (m^2) within each lung, however the ratio between alveolar and endothelial surface density remains unchanged with age. The median endothelium surface area was 106.2m^2 in one day, 147.5m^2 in 30 day and 430m^2 in adult lungs. The data show that the foal is born with a functionally developed lung and its basic architecture changes with age. Foal lung development and remodelling postnatally is a result of alveolar expansion paralleled with angiogenesis.