Effect of Pregnancy on Oxidative Status of Sheep

The ob oxidative status of sheep Specific goal of the study was to determine the impact of pregnancy the level of lipid peroxidation pregnant and non pregnant ewes were used for the study. ewes were at third trimester of pregnancy which was confirmed abdominal palpation and serum progesterone level above 2.2ng/ml. Serum levels of catalase, superoxide dismutase, glutathione peroxidase enzymes and m (p>0.05) mean values of serum concentratio dismutase and glutathione peroxidase. was significantly higher in pregnant ewes compared to non pregnant animals. It can be concluded that third trimester of pregnancy is associated with higher s


INTRODUCTION
Reactive oxygen species play a critical role in many physiological processes but are detrimental to bod at high concentration (Hohn et al., 2013).associated with proinflamatory state due to increased activity of monocytes and macrophages resulting in high concentration of oxidative stress biomarkers ( 2004).Adverse effect of oxidative stress on reproductive performance of sows have been documented, decrease litter size and birth weight were associated with oxidative stress (Zhao et al., 2013).Oxidation of proteins can modify their structure thereby causing adverse effec functions of the protein.Oxidized proteins can also generate antigens that stimulate immune response (Halliwell and Whiteman, 2004).Increase oxidative stress has been associated with prolonged concentrate feeding in dairy cows, this is attributed to increase rumen endotoxins associated with high concentrate and low neutral detergent fibre content which may stimulate Para Reactive oxygen species play a critical role in many processes but are detrimental to body cells 2013).Pregnancy is with proinflamatory state due to increased activity of monocytes and macrophages resulting in high concentration of oxidative stress biomarkers (Ness, Adverse effect of oxidative stress on reproductive performance of sows have been documented, decrease litter size and birth weight were associated with oxidative Oxidation of proteins can eby causing adverse effects on Oxidized proteins can also generate antigens that stimulate immune response Increase oxidative stress has been associated with prolonged concentrate feeding , this is attributed to increase rumen endotoxins associated with high concentrate and low neutral detergent fibre content which may stimulate Para inflammatory reactions and (Golder, 2013).Lipid mobilization associated with energy balance have also been associated with increase reactive oxygen species Pedemera et al. ( Reactive oxygen species play a critical role reproductive processes such as ovulation, fertilization and early embryo development.However, stress is associated with embryo losses and it is involve in the pathogenesis of follicular cyst and repeat breeder syndrome in dairy cows (Talkdor et al., 2014).antioxidant activity can lead to poor pregnancy outcome including fetal growth restrictions.associated with pregnancy may result in impaired oxidative status leading to adverse effects on pregnancy establishment and maintenance.study, therefore, was to determine pregnancy on serum concentration of super oxide dismutase, catalase and  2010).Reactive oxygen species play a critical role in reproductive processes such as ovulation, fertilization and early embryo development.However, oxidative stress is associated with embryo losses and it is involve in the pathogenesis of follicular cyst and repeat breeder syndrome in dairy cows (Talkdor et al., 2014).Insufficient antioxidant activity can lead to poor pregnancy outcome l growth restrictions.The metabolic changes associated with pregnancy may result in impaired oxidative status leading to adverse effects on pregnancy establishment and maintenance.The objective of this study, therefore, was to determine the effects of serum concentration of superand glutathione peroxidase

MATERIALS AND METHODS
The objective of the study was to determine the effect of pregnancy on oxidative status of sheep.Two groups of sheep (n=10) consisting of pregnant and non pregnant ewes were used for the study.The pregnant ewes were at third trimester of pregnancy which was confirmed by abdominal palpation and serum progesterone level above 1.2 ng/ml.Blood samples were collected trough the jugular vein for determination antioxidant enzymes concentration.

Determination of serum antioxidant enzymes
Serum level of superoxide dismutase was determined by calorimetric method based on the ability of the enzyme to inhibit phenazine methosulphate mediated reduction of nitro blue as described by Weydert, 2003.Catalase activity was measured using combination of optimized enzymatic conditions and spectrophotometric assay of hydrogen peroxide as described by Laszo et al., 1991.Glutathione peroxidase activity was measured using hydrogen peroxide as a substrate as described by Liu, 2004.Serum malondialdehyde was determined in terms of thiobarbituric acid reactive substances using spectrophotometer as reportedby Surapon, 2009.

Statistical Analysis
Data obtained was subjected to student t test using statistical tool for agricultural research (STAR).Means separation was done using least significant difference where significant differences exist.

RESULTS AND DISCUSSION
The effects of pregnancy on oxidative status of sheep is shown on Table 1.The results indicated similar mean values of catalase, superoxide dismutase and glutathione peroxidase enzymes in both groups.The serum level of malondialdehyde is however, higher (p>0.05) in pregnant ewes compared to non-pregnant ewes.The concentration of malondialdehyde is an established indicator of cellular injury as well as a biomarker of oxidative stress in cells and tissues (Simek et al., 2006).Pregnancy is associated with increase generation of reactive oxygen species which is linked to oocyte maturation, luteolysis and embryo implantation.Oxidative stress adversely affect placental functions which may lead to poor pregnancy outcome (Hussain et al., 2021).This may be attributed to changing metabolic demands associated with pregnancy.Oxidative stress result from disruption of balance between antioxidant system and reactive oxygen species.Decrease plasma antioxidant have been observed in early phase of pregnancy, while total antioxidant capacity improves in the second and third stage of pregnancy (Toescu et al., 2002).
The findings of this study showed that pregnancy is associated with potential impairment of oxidative status.Increased serum malondialdehyde indicating higher level of lipid peroxidation was recorded in this study.Supplementation with antioxidants is recommended in pregnant ewes.
xxx, January, 2023 Effect of Pregnancy on Oxidative Status of Sheep and Yusuf Ibrahim Hussaini 3 rmined the effects of pregnancy on oxidative status of sheep Specific goal of the study was to determine the on serum concentration of antioxidant enzymes and Two groups of sheep (10) consisting of pregnant and non pregnant ewes were used for the study.The pregnant ewes were at third trimester of pregnancy which was confirmed by abdominal palpation and serum progesterone level above 2.2ng/ml.Serum levels of catalase, superoxide dismutase, glutathione peroxidase enzymes The results indicated similar n of catalase, superoxide The serum level of malondealdehyde was significantly higher in pregnant ewes compared to non pregnant animals.It can be concluded that third trimester of pregnancy is associated Antioxidant enzymes, Antioxidant status, Ewes, Oxidative stress, reactive oxygen species Golder, 2013).Lipid mobilization associated with low energy balance have also been associated with increase oxygen species Pedemera et al. ( row bearing different superscript are significantly different (P<0.05),Ns = Not significant, * = Significant (P<0.05),Los = Level of Significance enzymes.The impact of pregnancy on lipid peroxidation was also evaluated as indicated by serum level of malondealdehyde.

Table 1 .
Effects of pregnancy on serum level of antioxidant enzymes (mean)