BLOOD SERUM CONCENTRATIONS OF THYROID HORMONES, TOTAL PROTEIN AND AMINOTRASFERASE DURING PREGNANCY, PARTURITION AND POSTPARTUM IN EGYPTIAN BALADI GOATS

Assiut Vet. Med. J. Vol. 52 No. 110 July 2006

Dept. of Animal Prod., Fac. of Agric., Al-Azhar University, Nasr City, Cairo, Egypt.

BLOOD SERUM CONCENTRATIONS OF THYROID HORMONES, TOTAL PROTEIN AND AMINOTRASFERASE DURING PREGNANCY,

PARTURITION AND POSTPARTUM IN EGYPTIAN BALADI GOATS

(With 2 Tables and 2 Figures)

By A.M. ASHOUR (Received at 4/6/2006)

ترکيز هرمونات الغدة الدرقية والبروتين الکلي والإنزيمات الناقلة لمجموعة الأمين في سيرم الدم أثناء فترات الحمل والولادة وبعد الولادة

في الماعز البلدي المصري

عبد الله محمد عاشور

استخدم في هذه الدراسة عينات دم من۱۳ماعز بلدي لتقدير مستويات هرمونات الغدة الدرقية والبروتين الکلي والإنزيمات الناقلة لمجموعة الأمين لهذه الحيوانات طبقا لنوع الحمل فردي وتوأم خلال فترة الحمل وحتى الأسبوع الثالث بعد الولادة. أوضحت النتائج المتحصل عليها انخفاض معنوي في مستويات الهرمون ثلاثي اليود من يوم التلقيح وحتى الأسبوع الرابع من الحمل- ثم اتبع ذلک زيادة غير معنوية حتى الأسبوع العاشر من الحمل. ثم أظهرت النتائج بعد ذلک انخفاض معنوي عند يوم الولادة.. وبالنسبة للهرمون رباعي اليود. أوضحت النتائج أن الهرمون يزيد زيادة غير معنوية من يوم التلقيح حتى الأسبوع۱۸من الحمل. وانخفض بعد ذلک انخفاضا معنويا عند الولادة. کما أوضحت النتائج أنه لا يوجد اختلاف في مستوى ترکيز هرموني الدرقية بين الماعز الحوامل في مفرد أو توأم. بعد الولادة لوحظ زيادة طفيفة غير معنوية في هرموني الدرقية. وبالنسبة للبروتين الکلي فقد أوضحت النتائج انخفاض في البروتين عند الولادة، وأنه لا يوجد اختلاف معنوي في ترکز البروتين الکلي بين الحيوانات الحوامل في فرد أو توأم. بعد الولادة حدث زيادة في البروتين الکلي لکنها غير معنوية أما بالنسبة للإنزيمات الناقلة لمجموعة الأمين. أوضحت النتائج زيادة في ترکز هذه الإنزيمات بتقدم الحيوانات في الحمل، کما حدث انخفاض في يوم الولادة. بعد الولادة حدث تذبذب في مستوى الإنزيمات حتى الأسبوع الثالث. وأوضحت الدراسة أنه لا يوجد اختلاف معنوي بين الإنزيمات الناقلة لمجموعة الأمين للماعز الحوامل في مفرد أو توأم.

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SUMMARY

Seurm triiodothyronine (T3), thyroxine (T4), total proteins and aminotrasnferase were measured during pregnancy, parturition and postpartum periods in the serum of 13 Baladi goats carrying single and twin. Serum T3 levels significantly decreased (P<0.05) from day of mating to 4 weeks of gestation, thereafter, T3 slightly increased at the 10th week, then significant decreased (P<0.05) at day of Kidding. Serum T4 level was no significantly different between day of mating and 18th week. Thearafter, serum T4 levels decreased significantly (P<0.01) at the day of kidding. No significant differences were observed both in T3 and T4 values during post partum period. No significant changes were recorded between goats bearing singles and twins. Serum total proteins decreased (P<0.01) with advancing pregnancy. No significant difference in total protein concentration was noticed between goats delivering singles and twins. After parturition, serum proteins significantly (P<0.05) increased at one week post peartum, followed by a gradual significant (P<0.05) decrease till the 3rd week after parturition. Serum AST and ALT increased (P<0.05) with advancing pregnancy and reached the maximum level during the 20th week of gestation, then they decreased towards parturition. After parturition, the AST and ALT concentration fluctuated. Differences in AST and ALT were not significant between goats bearing single and twin foetuses throughout the pregnancy period.

Key words: Pregnancy parturition, postpartum, triiodothyronine, thyroxine,

proteins, aminotransferase, goats.

INTRODUCTION

During pregnancy, a female will undergo stress of sustaining the fetus in its well - controlled and protected intrauterine environmental, while the fetus derives most of its nutritional and other requirements from maternal blood. These fetal demands are met by remarkable changes in the edocrinological and biochemical milieu of the dam (Agrawal et al., 1992). After parturition for the formation of colostrums; at the beginning of lactation there is heavy load upon the blood constituents (Hafez, 1980). To meet these needs, the dam attempts to re set up its endocrine function, including that of thyroid gland (Riis and Madsen, 1985).

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Triiodo thyroxine (T3) and thyroxine (T4) are hormones which affect the metabolic pools of nitrogen and available energy necessary for the reproduction system and the developing embryo. Therefore abnormal decrease in thyroid hormones may interfere with normal pregnancy (Hafez, 1980). Thyroid hormones have been observed to decrease in several species during late pregnancy in goats (Riis and Madesn, 1985, Khan and ludri, 2002 and Leela et al. 2003), sheep (Sutherland and Irvine, 1974, Okab et al., 1993 and Sen and Irmak, 2003), cattle (Boots et al., 1969) and camel (Agarwal et al., 1992).

Pregnancy and parturition, as well as lactation bring in farm animals due to the reproductive function (Herz and Hod, 1969). Plasma total proteins have an important role as a constituent of plasma (Harper, et al., 1977) and serve as indication of amino acids pool for protein synthesis in the liver. Serum aminotransferase activity is considered as index for the diagnosis of tissue necrosis, hepatic injury and muscular degeneration (Kuttler and Marble, 1958 and Cornelius, 1960). Stress predisposes gluconeogenesis with associated rise in circulatory transminases (Kaushik and Bugalia, 1999). The present study was undertaken to deterimine the changes is surm triiodothyronine (T3) and thyroxine (T4), proteins and Aminotransferase at various stages of pregnancy, parturition, postpartum and their variations between single and twins pregnancy in Egyptian baladi goats.

MATERIALS and METHODS

Experimental animals: The present study was carried out on 13 pregnant Egyptian baladi goats aged 2-3 years with weight range of 20 32kg, located at the sheep and goats, experimental station belonging to the Department of Animal production, Faculty of Agriculture, Al-Azhar university. Animals were fed ad-Libitum on pelleted concentrate mixture containing 61% TDN and 13% digestible protein plus Egyptian clover (Trifolium alexandrinum) in winter and clover hay in summer. Animals were allowed to drink fresh water twice daily. All animals were kept in semi-open pens exposed to the external environmental conditions. After kidding, the goats were classified into two groups depending on litter size (single or twins).

Blood sampling: Blood samples were taken via jugular venipuncture early in the morning and were allowed to clot, then centrifuged and the serum was obtained and stored at 20°C. Samples

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were obtained after mating, at 2 weeks intervals throughout pregnancy and weekly after kidding till the third week postpartum.

Assay: Blood serum Triiodothyronine (T3) and thyroxine (T4) concentrations were estimated using the solid-phase radioimmunoassy technique with no-extraction as adopted by Larson (1972) and Chopra (1972) for the two hormones, respectively. RIA kits Diagnostic Products Corporation, Los Angeles, CA, USA) were used. Serum total proteins and aminotransferase were colorometrically determined by kits according to Weichselbaum (1946) and Ritman and Frankel (1957).

Data analysis: Analysis of variance was followed to test the significant differences between serum hormone levels and serum constituents in pregnant and postpartum does using GLM Procedure of SAS (1988). Student T test was used to test the effect of type of birth (single and twins). Least square method was used to compare weekly means of different serum constituents.

RESULTS

Triiodothyronine (T3) and Throxyine (T4): The changes in concentration of serum T3 and T4 during pregnancy, parturition and postpartum periods are shown in table (1) and figure (1). Gestation had a significant effect on T3 and T4 concentration. In pregnant goats serum T3 level significantly decreased (P<0.05) from day of matin to 4 weeks of gestation. After, 4 weeks of gestation, peripheral serum T3 steadily increased (P< 0.05) and reached the maximum level during the 10th week of gestation. This was followed by a gradual but significant (P<0.05) decrease on the day of kidding.

As shown in Table (1) and Figure (1), no significant changes were noticed in blood serum T4 concentration in pregnant goats between conceptiond and 18th week of pregnancy (Figure 1). Serum T4 slightly increased and attained a peak at 12 week of gestation. Thereafter, serum T4 steadily decreased with the advancement of gestation and the reduction was significant (P<0.01) at the day of delivery. As shown in Table (1), the mean T3 an T4 concentration did not differ significantly between goats delivering single and twin kids.

The changes in the serum total proteins during pregnancy, at parturition and postpartum period are presented in Table (2) and Figure (2). A gradual decrease in the serum proteins concentration was noticed between day of mating and the 16' week, although the changes were slight and not significant in most cases. After the 16th week, serum

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proteins decreased continued (P<0.01) till the day of kidding. Serum total protein during the first week after parturition increased significantly (P<0.05). This was followed by a gradual but insignificant decrease till the 3ta week after parturition (Table 2). As shown in (Table 2), there were no significant difference between goats carrying single or twin fetuses.

Aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Serum AST and ALT during gestation, at parturition and post partum periods are illustrated in Table (2) and Figure (2). Gestation had a significant effect on the AST and ALT concentrations. As shown in Table (2), no significant changes were obtained in blood serum AST and ALT concentration in pregnant goat between day of mating and 10 week of gestation.

After, the 10" week, serum AST and ALT increased (P< 0.01) with advance in gestation and reached the maximum levels during the 20" week of gestation, then they decreased towards parturition (Table 2).

After parturition, the AST and ALT concentration fluctuated with differences being non significant.

Table 1: Blood serum concentrations of triiodothyronine (T3) and

thyroxine (T4) during pregnancy, at parturition and postpartum period in Egyptian Baladi goats.

Triiodothyronine (T) (ng/dL)

Thyroxine (T4) (ug/dL) Weeks

Single (8) Twin (5) Overall mean (13) Single (8) Twin (5) Overall mean (13)

(0)

66.60–3.90a

67.58:36.52a

1

66.97+3.30h

6.28=0.49a

6.18+0.86a

6,24+0.45a,b,c

mating

2

78.73+5.71a

72.84+4.32a

6.18+0.74a

75.21+3.67a

76,53£3.54d,efs

75.66+2.67e,fg| 83.403.91b,c,d,e

96.7643.14a

6.17:0.42a,b,c 6.30£0.43a,b,c 6.49+0.41a,b

6.740.41a

84.84£6,58a

99.87:4.82a1

6,20+0.56a 6.36+0.56a 6.53+0.49a 6.81+0.550

6.95+0.54a 7.30+0.57a

75.18=4.98a

82.30=3.24a 91.60:34.29a 92.7423.59a 87.3642.64a 90.77#2.85a

98.613.14a

6.80+0.4a

7.08-0.48a

89.84+3.36a,b,c,d

90.78+2.85a,b,

86.45+2.90b,c,d

1

6.22+0.75a 6.420.77a 6.6240.682 5.56+0.69a 6.72+0.69a 6.98-0.92a 6.18+0,86a

5.60+0.61a 5.10+0.38a

4.9340.42a

7.0140.59a

6,99+0.48a

16

80.86+5.28a

6.28+0.40a

102.26+4.22a 91.385,30a

93.84+3.23a 89.95+2.99a

68.143.34a

64.68+3.81 63.26:13.72a 66,03+3.85a 66.71+4.01a 67.80+2.42a

5.9740.54a

6.24+0.39a,b,c

5.83+0.39a,b,c

5.24£0.35b,c

5.010.29c

68.96+2.91fgh 64.8042.85h

64.14+2.975

20 delivery

+ 1

5.32+0.41a

70.28+5.872 63.98-4.800 6 5.54:5.41a 6 6.85+5.84a

64.1834.98a 6 5.36:+4.34

4.96+0.46

5.11:0.29c

5.11+0.39a 5.210.40

5.30+0.39 5.32:0.41

66.4343 24h 65.18+3.22h 66,143.37h

+ 2

5.06+0.39 5.01+0.38

5.21:0.28b.c 5.24:0.286,0

+ 3

|

Figures with similar superscripts do not differ significantly from each other.

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Table 2: Blood serum concentrations of total protein, aspartate

aminotransferase (AST) and Alanine aminotransferase (ALT) during pregnancy, at parturition and after parturition in Egyptian Baladi goat.

Wecks

Total proteins (gm / 100ml)

Overall mean Twins (5)

(13)

Single (8)

9.6240.412

9.600.42a

9.6130.28a

Aspartate aminotransferase (AST "U/L)

Overall mean Single (8) Twins (5)

(13) 24.95+1.580 25.82+1.95a 25.2841.04e

24.841.362 26.0&+1.44a

25.29+0.98e 24.88=1.30a 25.88+1.99a 25.36+1.07e 25.111.373 26.281.13a

25 5610.93e

9.50 +0.53a

9.430.14a 9.1210.52a

9.410.3la 9.4740.28a 9.43+0.32a 9.3240.25a 9.16+0.312 9.9120.48a 9.04+0.248

9.4540.26a, 9.45:0. 14a,b 9.3130.272,b,c 9.240.18a,b.c 9.090 26a,b,c.

28.234:1.982

28.14+1.50a

28,2041.30d.e

9.10+0.31a

8.98+0.43a

10

29.9642.48a

30.04#2.13a 31.60+2.153

29.98+1.64c,d,e

31.73€1.6Ib.c,d

Alanine aminotransferase (ALT "U/L)

Overall mean Single (8) Twins (5)

(13) 21.8220.89a 22.48+1 G6a 22.07+0.800 21.64+0.82a 22.4841.450 21.9640.72d 22.0120.87a 21.74+1.200 21.910.680 22.51+0.80a 22.02+1 341 22.32+0.68d 23.52+0.65a 22.74+1.Sla 23.27+0,672

23.78+1.14a 23.561.70a 23.70+0.910 27.05+0.78a 25.62+1.37a 26.50:0. 70C 28.9020.69a 26.0642.06a 27.8120.936.c 28.07+1.16a 26.782.20a 27.5720.93b.c 30.09=1.77a 28.64£1.99a 29.53#1.29b 32.77*1.54a 32.4242.39a 32.63#1.25a 29.04=2.14a 30.16+1.32a 29.52+1.75a 30.50+1.42a 29.822.332 30.2131.22a 31.85*0.91a 31.08+2.39 31.80+1.03a

31.90=102a 30.85:2.29a 30.78=1.03a

12

9.70+0.44a

9.7730.28a

14

8.780.44a

8.9130.21a,b,c

31.8042.53a

34.94+2.692

36.2442,21a

33.81:02.74a 35.99$1.95a

34.1941.36b.c

16

8.84.0.33a

8.6450.17a

8.760.21a,b,c

36.09£1.41b

18

7.62*0.18a

40.6742.11a

41.24+2.567

40.891.560

44.94#1.51a

20

6.860.61a

7.87+0.300.C 7.27+0.41e 7.210.32€

44.80H:1.92a

45.182.71a

8,0320.33a 7.53+0.55a 7.48%0.49a 8.92+0.51a 8.770.56a

Delivery

6.83+0.53a

40.6642.60a

41.62:+2.11a

40.17+1.73a

8.42+0.43a

43.522.26a

+ 2

8.73+0.35a.b.c

8.53+0.395.c.d 8.3940.36c.d

41.7151.63a

42.7551.67a

S.1430.52a

40.02+2.54a 43.162.11a 41.112.18a

42.50#-2.65a | 41.11+1.95a

8.65 0.49a

7.98+0.Sla

41.53+2.19a

Figures with similar superscripts do not differ significantly from each other.

Parturition

Trodothyronine (13) ing/dl)

Single Twins Mean

0

2

4

12

14

16

18

20

b

6 8 10 Weeks of pregnancy

) 2 3 Weeks of post partum

Thyroxine (T4) (ugal)

+ Single ---

+Mesa

Wecks of pregnancy

Weeks oppos: partu.

Fig. 1: Blood serum concentration of triiodothyronine (T3) and thyroxine (T4)

during pregnancy, at parturition and post partum in goats.

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Parturition

Total Protein (m/100ML)

Single + Twins

Mean

2

4

12

14

16

18

20

2

3

6 8 10 Weeks of pregnancy

Weeks of post partum

AST (1/1)

- Single - Twins

-Vean

12

14

16

18

20

8 10 Weeks of pregnancy

i Weeks of post partum

-

Single

ALT (U/I.)

Twins + Mean

0

2

4

2

14

16

18

20

0

6 8 10 Weeks of pregnancy

2 3 Weeks of post partum

Fig. 2: Serum concentrations of total protein, aspartate aminotransferase

(AST) and alanine aminotransferase (ALT) in goats during pregnancy, at parturition and post partum.

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DISCUSSION

The changes in concentration of serum Tz and T4 in pregnant goats in the present study are similar to those reported by (Riis and Madsen, 1985, Khan and Ludri, 2002 and Leel et al., 2003), sheep (Sutherland and Irvine, 1974, Jacob and Vadoria 2002 and Sen and Irmak, 2003) and camel (Agarwal et al. 1992). Increased T3 and T4 concentration during early and mid pregnancy was observed. Similarly, Okab et al., (1993) and Sen Irmak (2003) found that the levels of Tz and T4 in ewes were significantly lower late pregnancy than in early and mid pregnancy.

The increase in serum Tz and T4 activity at early and mid pregnancy may be attributed to the increase in metabolic process during these stages. Avruskin et al., (1976) indicated that the rise in thyroidal activity at early and mid pregnancy may be due to the influence of newly synthesized placental estrogenes.

The decline in serum T3 and T4 concentrations during late pregnancy could be attributed to the inhibitory effect of glucorticoids, which rise before parturition on pituitary thyroid axis (klein et al., 1978).

The decrease in T3 and T4 levels during late pregnancy can also be attributed to a placental transfer of these hormones to the fetus (Khurana and Madan, 1986 and Sen and Irmak 2003). Additionally the rise in blood volume particularly during late pregnancy would cause the dilution of thyroidal hormones and thus contribute to the decline in serum T3 and T4 (Okab et al., 1991 and Sen and Irmak, 2003).

The reduction in thyroidal activity at late pregnancy could be defense mechanism of the organism to reduce metabolic demands in situations where catabolic functions are high (Blum and Kunz, 1981 and Gerloff et al., 1986). Chen and Walfish (1978) suggested that the high levels of estrogen may modulate the secretion rate and dynamic action of thyroid hormones. Riis and Madsen (1985) found that the level of thyroxine concentrations in the goat decreased 1-2 days before parturition, perhaps as a result of nutrient redistribution to the mammary gland in preparation for lactation.

In the present study, serum T3 and T4 did not differ significantly between goats delivering single and twin. This was similar to those previously obtained by Khan and Ludri (2003). It can be concluded that the number of fetuses did not significantly influences the hormone profile during pregnancy and postpartum.

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The gradual decrease in the level of serum proteins with progress of pregnancy has been observed in goats (Olssen et al., 1982, Hassanin et al. 1996, Ashour 1998 and Kaushik and Bugalia, 1999), in sheep (Abdel - Bary, 1990 Mahmoud, 1993), in cattle (Larson and Kendall, 1957) and in Friesian cows (Fahmy et al., 2004).

The increased serum proteins at 12th week of gestation, could be attributed the increase in protein retention at this stage. This was similar to the results previously reported (Mahmoud, 1993). Bayoumi et al. (1986) referred the increase in protein requirement for the growing embryo. The decrease in serum total proteins as the animals approach parturition may be due to the storage of proteins in the liver or other organs or being utilized under the stress of pregnancy (Larson and Kendall, 1957). The same authors reported that the drop in serum protein at parturition was caused by a loss of immune B2 and 81 globulins and some globulins from the blood. This coincided with the time the colostrums began formation in the mammary gland. Also, the utilization of maternal amino acids by the foetus to synthesize its own tissue may reduce maternal serum protein (Jainudeen and Hafez, 1980). The fell in plasma protein at late pregnancy appears to be due to utilization of immunoglobulins for cholesterol synthesis (Kaushik and Bugalia, 1999). El-Naggar and Abdel-Raouf (1971) reported that reduction in serum proteins in late gestation coincide with the rapid increase in the uterine weight and contents, namely the foetal fluids and the foetal membranes. Khalil et al. (1986) observed that the reduction in serum proteins in late gestation was attributed to the decrease in both albumin and globulin.

In the present study, serum total protein did not differ significantly between goats delivering single and twins. These results are in agreement with those reported by Abd El-All et al. (1990) and Kaushik and Bugalia (1999) who found no significant differences in plasma total protein in goats carrying single and twin foetuses.

Serum total protein increased at the first week after kidding. Similar observations was recorded in goats (Hassnin, 1993) in buffaloes (Badr et al. 2002) and in Freisian cows (Fahmy et al. 2004). Rowland et al. (1975) and (Hassan et al., 1986) reported that, high milk yield was associated with low total proteins in the blood. Fahmy et al. (2004) found that the total protein increased at the first week after birth, which they referred to the increase in both albumin and globulin.

The trend of change in AST and ALT concentration in the present study are in accordance with those reported on goats (Sarma and Ray, 1985 and Kaushik and Bugalia, 1999) in cattle (Boots et al. 1969)

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and in buffaloes (Badr et al., 2002). Kaushik and Bugalia (1999) observed that the plasma AST and ALT activities in pregnant goats registered significant (P<0.05) increase with of advancement of pregnancy. However, pervious study on sheep (Okab et al., 1993) Showed that the highest overall mean values for AST and ALT were noted after mid pregnancy, but values dropped shortly before parturition and in the postpartum period.

In the present study, serum AST and ALT did not differ significantly between goats delivering single and twin. Similarly, Kaushik and Bugalia (1999) found no significant differences between goats giving singles and twins.

Increased AST and ALT concentration during late pregnancy was observed. Hafez, et al. (1983) showed that AST and ALT activity increased in late pregnancy, reaching the maximum one week pre partum. This increase in the enzyme activity was attributed to the increasing requirements of the foetus for syntehesis of new tissues where both enzymes are necessary for accelerating the rate of metabolism and protein biosynthesis needs for foetal growth. The present results indicated that AST and ALT activities were highly affected by advanced pregnancy and physiological status at parturition and postpartum period.

Bugalia et al. (1986) observed elevated AST level during prepartum compared to postpartum period. They suggested that extended uterus, due to pregnancy and increased cellular permeability due to stress induced transfer of aminotransferase from uterine and placental tissues blood circulation evidencing prepartum rise in plasma AST and ALT. In addition, elevated catecholaminess during stress due to pregnancy induced gluconeogosis and raised AST level (Kaushik and Bugalia, 1999).

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