Oxidative Stress Associated With Spasmodic,Flatulent, and Impaction Colic in Draft Horses

The aim of the present study was to evaluate the oxidative stress level and antioxidant trace elements status associated with spasmodic, flatulent, and impaction colic in draft horses. For this purpose, venous blood samples were obtained from 20 randomly selected clinically healthy draft horses (control group) and 60 draft horses with different types of colic (spasmodic colic, n = 20; flatulent colic, n = 20; and impaction colic, n = 20). In horses with flatulent and impaction colic, there was a significant (P < .05) decrease in the total antioxidant capacity and activity of reduced glutathione (GSH) and catalase (CAT) as well as level of selenium, copper, zinc, and iron. However, there was a significant (P < .05) increase in the activity of superoxide dismutase (SOD) and in the level of malondialdehyde (MDA), interleukin-6 (IL-6), and manganese. Meanwhile, glutathione reductase (GR) was significantly (P < .05) increased in flatulent colic and significantly (P < .05) decreased in impaction colic. The oxidative stress index (OSI) was significantly (P < .05) increased in horses with flatulent and impaction colic. In horses with flatulent colic, there was a negative correlation between CAT and SOD (r = −0.446), MDA and zinc (r = −0.450), and IL-6 and zinc (r = −0.470). However, those with impaction colic, a negative correlation was recorded between CAT and MDA (r = −0.602), copper and GSH (r = −0.474), iron and GR (r = −0.511), and OSI and GR (r = −0.662). The results of the present study indicate that oxidative stress, with alteration of antioxidant trace element levels, is a feature of flatulent and impaction colic in draft horses.     

Effect of soil characteristics, seeding depth, operating speed, and opener design on draft force during direct seeding

Direct seeding practices that promote soil and water conservation and reduce input costs have become an increasingly accepted alternative to conventional tillage systems in western Canada. The objective of the present study was to determine the relative importance of soil characteristics, seeding depth, operating speed, and opener design on draft forces during direct seeding in central Saskatchewan. Draft was measured for nine different openers operated at 1–5 cm seeding depths and three ground speeds in four untilled Chernozemic soils that differed in soil moisture and/or texture. The average increase in opener draft for all fields was 4% for each km h⁻¹ increase in speed. Although the range in soil consistency was small, there was a 24% increase in draft in heavy clay compared to sandy loam soil. Draft force of the average opener increased by nearly 20% for each centimeter increase in seeding depth. However, highly significant interactions among most of the variables investigated indicated that the relative performance of openers was not consistent for the range of conditions evaluated. Large differences among the draft forces of different openers operated at different depths in soils with different consistencies were particulary noteworthy. For example, a 4.5-fold increase in the draft of a low versus a high draft opener operated at 1.25 versus 5.0 cm seeding depth at 7.5 km h⁻¹ in moist, heavy clay soil emphasized the large influence that opener design and seeding depth have on tractor power requirements and direct seeding input costs.     

Prognostic Significance of Oxidative Stress Markers in Colitis Associated with Phenylbutazone Administration in Draft Horses

The present study was carried out to assess the prognostic significance of oxidative stress markers in draft horses with colitis associated with phenylbutazone administration under field condition. For this purpose, a total of 40 native breed draft horses were studied. Based on case history, physical examination, and postmortem findings, diagnosis was made. According to the clinical outcome, horses were categorized into survivors and nonsurvivors. Clinically, there was significant association between nonsurvivors and anorexia (P < .01), stasis of intestinal motility (P < .01), melena (P < .01), and diarrhea (P < .001). Biochemically, malondialdehyde and nitric oxide showed a significant increase (P < .05) in nonsurvivors compared with survivors, whereas activities of superoxide dismutase showed a significant decrease (P < .05). Analysis of receiver operating characteristic curve indicated a high sensitivity and specificity of malondialdehyde, nitric oxide, and superoxide dismutase levels (P < .001) to predict the clinical outcome of colitis. Additionally, total protein and albumin showed a significant decrease in nonsurvivors compared with survivors; however, aspartate aminotransferase, sorbitol dehydrogenase, urea, and creatinine showed an increase (P < .05). The present results suggest that estimation of oxidative stress markers and antioxidant parameters may be useful predictors of the clinical outcomes of colitis associated with phenylbutazone administration in draft horses.