University of Maiduguri Annals of Borno Volume XXVI, June 2016 Effects of Pregnancy on Some Serum Electrolytes and Liver Enzymes in Yankasa Ewes D. Yahi 1 *, N.A. Ojo 1 and G.D. Mshelia 2 1 Department of Veterinary Physiology, Pharmacology and Biochemistry, Faculty of Veterinary Medicine, University of Maiduguri, Nigeria; 2 Department of Veterinary Surgery and Theriogenology, Faculty of Veterinary Medicine, University of Maiduguri, Nigeria *yahidauda@gmail.com; +23408037811882 ABSTRACT Changes in some serum electrolytes concentrations and liver enzymes in pregnant Yankasa ewes were studied. Thirteen Yankasa sheep comprising 12 ewes (6 pregnant, 6 non-pregnant) and one ram were used. Pregnancy was achieved following natural mating after estrus synchronization by intramuscular administration of cloprostenol (250 µg) to each ewe at 11-day interval. Nonpregnant ewes with normal estrous cycle were served as control. Blood samples were collected from day 0 of observation in both groups and thereafter on bi-weekly basis for analysis of biochemical parameters (aspartate amino-transferase (AST), alanine amino-transferase (ALT), alkaline phosphatase (ALP) and electrolytes (calcium (Ca 2+ ), sodium (Na + ) and potassium (K + ) using standard methods. Serum AST and ALT levels decreased significantly (p < 0.05) from 2 nd to 5 th month of gestation compared to control. However, ALP significant (p < 0.05) increased during the gestation compared to control. Mean Ca 2+, Na + and K + did not vary significantly (p > 0.05) during pregnancy. It was concluded that decreased serum AST and ALT and increased ALP were features of pregnancy in Yankasa ewes. Serum electrolyte levels were not negatively affected during pregnancy in Yankasa ewes. Key words: Yankasa ewes, pregnancy, enzymes, electrolytes INTRODUCTION According to the classification by Adu and Ngere (1979) the predominant type of sheep breed in Nigeria is the Yankasa sheep followed by Uda, Balami and West African Dwarf sheep in that order. Yankasa sheep are mostly found in the north and north central regions of Nigeria (Adu and Ngere 1979) with highest populations in the North-Eastern part of the country (Olufunmilayo et al., 2000). As sheep contribute greatly to the economic earnings of both urban and rural dwellers alike (Hassan et al., 2004; Gall, 1996), thorough understanding and practical scientific manipulation of reproductive functions need to be employed to achieve higher reproductive efficiency. Pregnancy causes physiological and biochemical changes needed to support fetal growth and development. Annals of Borno, Volume XXVI, 2016 Page 193
D. YAHI 1 *, N.A. OJO 1 ANDG.D. MSHELIA 2 The physiological changes of pregnancy can make the interpretation of serum test results related to disease difficult. Liver function tests and analysis of blood electrolytes are usually used for the diagnosis of several pregnancy-related diseases (Bani et al., 2008). Serum biochemical parameters in different breeds of ewes were previously reported (Marai et al., 2006; Reid, 1968; Bath, 1983; Ford et al., 1990; Sigurdsson, 1988a; Sigurdsson, 1988b). However, little information is available regarding serum changes in electrolyte concentrations and liver enzymes in yankasa ewes during different stages of pregnancy. Therefore, the aim of this study was to determine the variations in electrolytes and liver enzymes in pregnant yankasa ewes in Maiduguri, Nigeria. MATERIALS AND METHODS Experimental Animals Thirteen apparently healthy adult Yankasa sheep comprising 12 multiparous ewes and one ram were used for this study. The ewes were 3-3½ years of age while the ram was 3 years old, based on dentition (Dyce, et al., 1987). The ewes weighed 30-35 kg and the ram was 39 kg. They were managed intensively in the University of Maiduguri livestock research farm. Their feed rations consisted of wheat offals, beans husks, groundnut haulms and maize bran. Mineral salt licks and water were given ad libitum. During the stabilization period, the animals were prophylactically treated with oxytetracycline LA (Introxin-200, Interchiemie, Venray, Holland) at 20mg/kg body weight and ivermectin (paramectin, pharma Swede, Egypt) at 200µg/kg body weight. Estrus Synchronization and Animal grouping The ewes were synchronized using a synthetic analogue of prostaglandin F2α, cloprostenol (Estrumate, Schering-Plough Animal Health, Germany), at 250µg administered twice to each doe intramuscularly at 11-day interval, as previously reported (Akusu and Egbunike, 1984; Akusuet al., 1989). The animals were teased with apronned male daily. The ewes that came into estrus after the second treatment were randomly separated into two groups of six each. Ewes in pregnant (PGN) group were allowed to be served naturally by the male. The day of service was considered as day 0 of the gestation. Non returns to service were taken as indications of successful conceptions, which were later confirmed by ultrasonograhy using Draminski Ultrasound Pregnancy Detector (UPD-PD032013EX-1.2, Draminski Agricultural Engineering Co. Inc., Owocowa- Olsztyn, Poland). The animals in the non-pregnant (NPN) group were not served by the males. Blood Sample Collection and Analysis Blood samples were collected on day 0 in all groups and thereafter on biweekly basis throughout the period of the observation. Blood sample (5 mls) was collected from each Annals of Borno, Volume XXVI, 2016 Page 194
Effects of Pregnancy on Some Serum Electrolytes and Liver Enzymes in Yankasa Ewes animal through jugular vein puncture on the same day prior to feeding with minimal excitement. The blood sample from each animal was placed in sample tubes without anticoagulant and the blood was allowed to clot. The serum was harvested and stored at - 20 0 C before the estimation of the biochemical parameters namely: aspartate aminotransferase (AST) alanine-amino transferase (ALT), alkaline phosphatase (ALP) and Ca 2+ by Colorimetric method as described by Lorentz (1982) using reagents kits (Randox Laboratory Limited, Ardmore, UK). Serum Na + and K + concentrations were determined by flame photometry (Treitz, 1994). All analyses were done at University of Maiduguri Teaching Hospital, Chemical Pathology Department. Statistical Analysis Data were summarized as Means ± S.D and analyzed using one-way analysis of variance (ANOVA) for significant variations among the different reproductive stages. The differences between pregnant (PGN) and non-pregnant (NPN) groups were evaluated using Student s t test with computer software package (GraphPadInStat (2003). Significant differences were considered at (p < 0.05). RESULTS AND DISCUSSION Serum liver enzymes levels of AST, ALT and ALP, and serum concentrations of Ca 2+, K + and Na + are presented in Table 1. The mean values of AST and ALT concentrations decreased significantly (p < 0.05) in pregnant ewes compared to control during the period of observation. However, there was significant (p < 0.05) increase in serum ALP in pregnant group compared to control. Serum Ca 2+, Na + and K + did not vary (p > 0.05) in both pregnant and non-pregnant ewes. Annals of Borno, Volume XXVI, 2016 Page 195
D. YAHI 1 *, N.A. OJO 1 ANDG.D. MSHELIA 2 Table 1: Effects of pregnancy on some electrolytes and liver enzymes in Yankasa ewes Periods of observation (Months) Parameters Groups* 0 1 2 AST(IU/L) PGN 57.50+0.5 57.30+0.20 56.10+0.25 bd NPN 57.20+0.37 57.40+0.30 57.80+0.26 ALT(IU/L) PGN 38.74+0.18 37.30+0.29 bd 35.61+0.30 bd NPN 38.70+0.40 38.60+0.25 38.40+0.23 ALP(IU/L) PGN 48.60+0.33 48.90+0.35 a 54.40+0.18 ac NPN 48.70+0.38 48.50+0.19 48.45+0.33 Ca 2+ (mmol/l) PGN 8.50+0.17 8.54+0.27 8.50+0.32 NPN 8.52+0.21 8.50+0.35 8.51+0.25 K + (mmol/l) PGN 4.56+0.31 4.51+0.19 4.50+0.35 NPN 4.51+0.27 4.52+0.25 4.54+0.31 Na + (mmol/l) PGN 138.10+1.03 139.0+1.05 138.0+1.08 NPN 137.60+1.05 138.40+1.03 137.70+1.13 Annals of Borno, Volume XXVI, 2016 Page 196
Effects of Pregnancy on Some Serum Electrolytes and Liver Enzymes in Yankasa Ewes Table 1 cont d Periods of observation (Months) Parameters Groups* 3 4 5 AST(IU/L) PGN 55.0+0.44 bd 50.70+0.5 bd 50.0+0.24 bd NPN 57.20+0.23 57.62+0.25 57.48+0.33 ALT(IU/L) PGN 35.30+0.31 b 35.10+0.32 b 35.40+0.18 b NPN 38.50+0.35 38.30+0.20 38.90+0.34 ALP(IU/L) PGN 55.30+0.18 ac 55.50+0.36 a 55.80+0.24 a NPN 48.50+0.28 48.40+0.34 48.52+0.23 Ca 2+ (mmol/l) PGN 8.50+0.28 8.55+0.17 8.50+0.20 NPN 8.52+0.30 8.50+0.21 8.50+0.30 K + (mmol/l) PGN 4.54+0.37 4.55+0.27 4.56+0.29 NPN 4.55+0.37 4.57+0.41 4.54+0.25 Na + (mmol/l) PGN 137.6+1.12 137.80+1.11 138.50+1.05 NPN 138.10+1.14 138.0+1.09 137.20+1.16 Keys: PGN = Pregnant; NPN = Non pregnant (Control); AST=Aspartate amino transferase; ALT=Alkaline amino transferase; ALP=Alkaline phosphatase; * N=6 for both groups; a =Significant (p<0.05) increase compared to respective control group b =Significant (p<0.05) decrease compared to respective control group c = Significant (p<0.05) increase compared to preceding gestational stage d =Significant (p<0.05) decrease compared to preceding gestational stage The decrease in the mean values of AST and ALT in the pregnant ewes implied that the liver functions were not impaired during pregnancy in Yankasa ewes and there was. The decrease in AST and ALT concentrations in this study may be due to the expansion of extracellular fluid or reduction in the activities of apoenzyme of the aminotransferase. It may also be due to depletion of pyridoxine or increase demand for pyridoxine. This observation is parallel with that of Soliman (2014), who reported significant (P<0.05) increase in mean AST and ALT Concentrations in pregnant Ossimi ewes during late pregnancy compared to control. The difference could be due to breed variations. The increase in ALP concentration was probably due to placental secretions. ALP is a produced in the liver, placenta, lactating mammary gland, intestines and bones and to a lesser extent, kidneys (Tietz, 1999; Nduka, 1997). Intrahepatic and extrahepatic cholestasis could have elevated serum ALP, but it might not have occurred because there were normal serum AST and ALT concentrations. The rarefaction of bones during increased demand for Ca 2+ could also elicit increased serum ALP. Based on the data Annals of Borno, Volume XXVI, 2016 Page 197
D. YAHI 1 *, N.A. OJO 1 ANDG.D. MSHELIA 2 obtained in this study, the significant rise in serum ALP level is most probably due to increased synthesis of placental isoenzymes. The lack of significant changes in the mean levels of Na +, K + and Ca 2+ obtained in the present are similar to previous reports in other species (Waziri et al., 2010; Kadzereet al., 1996). Azab and Abdel-Maksoud (1999) reported increase in serum Na + concentrations and decrease in serum K + concentration during late pregnancy in Baladi goats. Despite high demands for minerals, particularly Ca 2+ for milk synthesis in preparation for lactation the Yankasa ewes were able to maintain normal levels of these electrolytes. This is one of the several physiological adaptations during pregnancy that make yankasa ewes capable of preventing hypocalcaemic disorders or other pregnancy related disease. CONCLUSION Serum electrolytes levels and hepatobiliary functions were not affected during pregnancy in Yankasa ewes. Increase in serum ALP and decrease AST and ALT concentrations were features of pregnancy in Yankasa ewes. Acknowledgements The technical assistance during laboratory works rendered by Mrs. Rhoda Genesis and her team in the Chemical Pathology Department, University of Maiduguri Teaching Hospital (UMTH) is hereby acknowledged. Also, the contribution of Mr. Bello Usman and his team is gratefully acknowledged REFERENCES Adu, I.F. and Ngere, L.O. (1979). The indigenous sheep of Nigeria; World Rev. Anim. Prod., 15: 5 1-62 Akusu, M.O. and Egbunike, G. N. (1984). Fertility of West Africa Dwarf goats in native environment followingpgf2α induced estrus; Veterinary Quarterly, 6:173-176. Akusu, M. O., Nduka, E and Egbunike, G. N. (1989). Peripheral plasma levels of progesterone and oestradiol-17βduring the reproductive cycle of West African Dwarf goats, Proc.Conf. African small ruminant Res. Dev., Bamenda, Cameroon.18-25 January, 1989 (Wilson, R.T. and Melaku, A. (eds). ILCA (International Livestock Centre for Africa), Addis Ababa, Ethiopia. pp. 316-328. Azab, M. E. and Abdel-Maksoud, H. A. (1999). Changes in some hematological and biochemical parameters during prepartum and postpartum periods in female Baladi goats. Small Rum. Res. (34): 77-85. Bani, I.Z. A., Al-Majali, A.M., Amireh, F. and Al-Rawashreh, O.F. (2008). Metabolic profile in goat- does in late pregnancy with and without subclinical pregnancy toxemia. Vet ClinPathol. 2008; 37:434 437. Bath, G.K. (1983). Differentiation between hypocalcaemia and pregnancy ketosis of Annals of Borno, Volume XXVI, 2016 Page 198
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D. YAHI 1 *, N.A. OJO 1 ANDG.D. MSHELIA 2 hematological and some serum biochemical profiles in the gestation period in the Sahel goats. Vet. Arhiv., 80(2): 215-224. Annals of Borno, Volume XXVI, 2016 Page 200