Ascorbic Acid,Catalase and Chlorpromazine Reduce Cryopreservation‐induced Damages to Crossbred Bull Spermatozoaa

The present study evaluated the effectiveness of ascorbic acid, catalase, chlorpromazine and their combinations in reducing the cryodamages to crossbred bull (Bos taurus × Bos indicus) spermatozoa. A total of 32 ejaculates (eight each from four bulls) were diluted in Tris–citric acid–fructose–egg yolk–glycerol extender. Each ejaculate was split into six parts (five treatment and one control). Treatment groups included 10 mm ascorbic acid, 0.1 mm chlorpromazine, 200 IU/ml catalase, 10 mm ascorbic acid + 0.1 mm chlorpromazine or 200 IU/ml catalase + 0.1 mm chlorpromazine in the extender. Fluorescent probes (Fluorescein isothiocyanate–Pisum sativum agglutinin + Propidium iodide) were used for the assessment of spermatozoa viability and acrosomal status. The proportion of acrosome intact live (AIL), acrosome intact dead, acrosome reacted live and acrosome reacted dead sperm was assessed in fresh, equilibrated and frozen‐thawed semen. The functional status of the sperm was assessed using hypo‐osmotic sperm swelling test (HOSST). Activities of acrosin and hyaluronidase enzyme were also determined. Lipid peroxidation level was assayed based on the melonaldehyde (MDA) production. In cryopreserved semen, the values of AIL spermatozoa, HOSST response, hyaluronidase and acrosin activity were reduced by 53%, 47%, 34% and 54%, respectively from their initial values in fresh semen. However, MDA level was threefold higher in the frozen‐thawed sperm compared with fresh sperm. Significant (p < 0.05) improvement in motility, viability, HOSST response, retention of hyaluonidase and acrosin and reduction in MDA was recorded in ascorbic acid, catalase, ascorbic acid + chlorpromazine and catalase + chlorpromazine incorporated groups. The percentage of AIL sperm was significantly (p < 0.05) higher in ascorbic acid, catalase and ascorbic acid + chlorpromazine incorporated groups compared with the control. Chlorpromazine alone did not improve the post‐thaw semen quality but when combined with either ascorbic acid or catalse, improvement in semen quality was noticed. It was inferred that incorporation of ascorbic acid, catalase and ascorbic acid + chlorpromazine in semen extender improved the post‐thaw semen quality in crossbred bulls.     

Assessment of DNA Damage during In Vitro Development of Buffalo (Bubalus bubalis) Embryos: Effect of Cysteamine

Comet assay was used in the present study to examine DNA damage to buffalo oocytes and embryos during in vitro culture. Embryos were produced in vitro from oocytes obtained from slaughterhouse ovaries in presence of cysteamine (IVM and IVC media supplemented with 50 and 100 μm , respectively) or in its absence (controls). Compared to controls, cysteamine supplementation increased (p < 0.01) cleavage rate and proportion of oocytes that developed to 8‐ to 16‐cell stage. The incidence of DNA damage was lower (p < 0.01) in cysteamine group than that in controls at 8‐ to 16‐ (19.3 ± 4.24 vs 72.0 ± 5.22%) but not in 2‐cell stage embryos (11.7 ± 5.63 vs 20.8 ± 5.49%) or in mature oocytes (5.3 ± 3.43 vs 10.3 ± 4.73%). The tail length, which indicates magnitude of DNA damage, was shorter (p < 0.01) in cysteamine group than in controls in mature oocytes (25.5 ± 0.5 vs 36.0 ± 0.71 pixels) and 8‐ to 16‐cell stage (49.2 ± 1.64 vs 152.7 ± 1.28 pixels) but not in 2‐cell stage embryos (36.3 ± 1.54 vs 36.4 ± 0.75 pixels). Also, exposure of oocytes/embryos to UV radiation or H₂O₂ caused extensive DNA damage. In conclusion, these results suggest that oocytes/embryos suffer from DNA damage during progress of in vitro culture, which can be partly ameliorated by cysteamine supplementation of culture media.     

Effect of dental floating on weight gain, body condition score, feed digestibility, and fecal particle size in pregnant mares

OBJECTIVE: To investigate the effect of routine dental floating on weight gain, body condition score, feed digestibility, and fecal particle size in pregnant mares fed various diets. DESIGN: Randomized controlled clinical trial. ANIMALS: 56 pregnant mares. PROCEDURE: Mares were randomly allocated to 1 of 4 feed groups (n = 14 mares/group). All horses were sedated and an oral examination was performed, after which dental floating was performed on 7 horses in each group. Body weight was measured, and a body condition score was assigned before and at various times for 24 weeks after dental floating. Feed digestibility and fecal particle size were analyzed 7 and 19 weeks after dental floating. RESULTS: Weight gain, change in body condition score, feed digestibility, and fecal particle size were not significantly different between horses that underwent dental floating and untreated control horses. In contrast, weight gain was significantly associated with feed group. In the control horses, neither the number of dental lesions nor the presence of any particular type of lesion at the time of the initial oral examination was significantly associated with subsequent feed digestibility. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that dental floating does not result in significant short-term changes in body weight, body condition score, feed digestibility, or fecal particle size in healthy pregnant mares. Further studies are necessary to determine the clinical utility of regular dental floating in apparently healthy horses.     

Effect of premolar and molar occlusal angle on feed digestibility, water balance, and fecal particle size in horses

OBJECTIVE: To determine whether occlusal angle of the premolar and molar teeth (ie, molar occlusal angle) was associated with feed digestibility, water balance, or fecal particle size in adult horses. DESIGN: Observational study. ANIMALS: 40 pregnant mares ranging from 3 to 19 years old. PROCEDURE: The horses were randomly allocated to 1 of 5 feeding groups with 8 horses/group. Horses were sedated, and molar occlusal angle was measured with 2 methods. An oral examination was performed, and total number of dental abnormalities was recorded. Feed digestibility, water balance, and fecal particle size were measured 7 and 16 weeks later. RESULTS: Molar occlusal angle ranged from 6.3 degrees to 19.3 degrees and was not significantly associated with feed digestibility, water balance, or fecal particle size. The number of dental abnormalities was not associated with feed digestibility. Molar occlusal angle did not vary significantly with horse age. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that molar occlusal angles between 6 degrees and 19 degrees do not adversely affect feed digestibility, water balance, or fecal particle size in adult horses. Additionally, there was no association between age and molar occlusal angle.     

Extraction techniques for equine incisor and canine teeth

Extraction of equine incisor and canine teeth is a vital part of equine dentistry. Although dental pathology involving the incisor and canine teeth is less common, the practitioner should be prepared to diagnose conditions and develop a treatment plan. Depending on the pathology revealed via oral examination and intraoral radiographs, the treatment plan may include either simple (nonsurgical) or surgical extraction of an incisor or canine tooth. Technique and instrumentation refinement over the last 20 years has led to more precise extraction procedures with reduced secondary trauma to healthy tissues. As a result, incisor and canine extraction procedures are more predictable in execution and quality, with minimal complications.     

Radiation safety practices among Canadian equine veterinary workers during diagnostic procedures with portable X-ray equipment

The objective of this study was to report observed radiation safety practices among equine workers using portable X-ray units at 3 veterinary practices in Canada. Practice 1 was comprised of equine field service workers from an academic institution, whereas Practices 2 and 3 were comprised of workers from private equine referral practices. Out of 2969 exposure-worker observations, protective aprons were worn for > 99% (2968/2969), thyroid shields for 87% (2584/2969), and eyeglasses for 10% (310/2969). The cassette was held by hand for 97% (1078/1114) of observations, and the X-ray unit was held by hand for 100% (1293/1293) of observations. Gloves were used for 54% (606/1114) and < 1% (5/1293) of observations involving cassette holders and X-ray tube operators, respectively. Use of gloves was more frequent among technologists than DVMs (P = 0.004), and among workers in Practices 1 and 3 than in Practice 2 (P < 0.001). In conclusion, given that workers commonly hold cassettes and X-ray tubes by hand, improvement in shielding use is needed. Consideration should be given to specific behavior recommendations in radiation regulations.