Early Pregnancy Diagnosis by Means of Ultrasonography as a Method of Improving Reproductive Efficiency in Goats

The use of ultrasonographic measurement of the heart size and fetal heart rate variation for gestational age determination in local Bulgarian goats

Background

Determination of gestational age in goats was performed using ultrasound measurements of different fetal biometric parameters. There are no data showing quadratic and exponential dependence between fetal heart parameters and gestational age.

Objectives

The objective of the present study was to test the significance of the defined indicators (fetal heart rate, longitudinal and transverse fetal heart axes) for determining gestational age in local Bulgarian goats.

Methods

A total of 24 pregnant local Bulgarian goats, aged between 2 and 5 years, body weight 42–50 kg were included in the study. Ultrasonographic examinations were performed weekly on gestational days 21, 28, 35, 42 and 49. After gestational day 49 until parturition, scans were performed biweekly. The data from the measurements were subjected to linear (y = a + bx), quadratic (y = aх² + bх + c) and exponential (y = axⁿ) correlation. Results: Average fetal heart rate values decreased with pregnancy progression. The coefficient of determination (R²) and standard error of estimate (SEE) of the heart rate indicator were 0.72, 0.75, 0.58 and 15.1, 14.4, 19.2 days, respectively, for the three correlations. Longitudinal diameter (long axis) had the following values for R² = 0.94, 0.96, 0.96 and for SEE = 7.0, 5.5, 5.5 days, for the linear, quadratic and exponential correlations, respectively, while the values of the fetal heart transverse diameter (short axis) were higher than those of the external one (R² = 0.95, 0.97, 0.97). Simultaneously, SEE is lower (SEE = 6.1, 4.9, 5.0 days) compared to that found for the long heart fetal axis.

Conclusions

For precise estimation of gestational age, use of longitudinal (long) and transverse (short) axes is recommended. Fetal heart rate is not an exact indicator but can be used as a reference for gestational age along with changes in the heart size and echogenicity.

Follicle stimulating hormone receptor gene polymorphism and its association with fecundity in goats

Pluriparous goats (73) in between second to fifth parity with history of breeding 30 days before were selected for present study. A real time B-mode ultrasonography machine equipped with a linear array 7.5 MHz transrectal scanner was used for diagnosis of early pregnancy and twinning in goats. Out of 73 goats, 40 were detected pregnant with 22 goats with single embryo and 18 goats with twin embryos. Genomic DNA was extracted from the blood of all pregnant goats and polymerase chain reaction (PCR) with FSHR gene specific primers was carried out. The PCR product for FSHR gene was digested by restriction enzyme MSCI. Two genotypes AA and AB having amplification size (214 bp, 90 bp) and (214 bp, 90 bp and 304 bp) were detected, respectively. In AA genotype, 21 single and 9 twins were observed while 1 single and 9 twin embryos were observed in AB genotype. The percentage of single and twins was 70% and 30% in AA genotype, and 10% and 90% in AB genotype. In AA genotype, the average litter size was 1.3 while in AB genotype it was 1.9 and the difference was statistially significant. The AB genotype for the FSHR gene is responsible for more twining percentage.

Use Of Hormonal and Ultrasonographic Examinations to Determine the Fetal Number in Bulgarian Local Goats

The purpose of the present study was to determine the fetal number in goats by using hormonal and ultrasonographic examinations. The experiments were conducted with 106 clinically healthy Bulgarian local goats, 1.5 to 7 years of age, weighing 35-52 kg. Hormonal examinations were performed on 24 goats. Serum progesterone concentrations were measured during a 7 days interval, between 21-63 day of pregnancy, and during a 14 days interval until the 133rd day of pregnancy. Ultrasound examinations were performed on 82 goats with a multi-frequency linear transducer (5.0-12.0 MHz). All animals were studied once during an interval of 7 days transrectally (21-28 day, 29-35 day, 36-42 day) and transabdominally (43-49 day, 50-56 day, 57-63 day), respectively. The accuracy of determining the number of singleton and multiple pregnancies by hormonal analysis were 51%, 58%, 69% and 47%, 52%, 62%, respectively. The accuracy of ultrasonography to determine the number of fetuses is highest in singletons 76.18%, followed by twins 72.56% and the lowest in triplets and more fetuses 21.43%. Highest accuracy, sensitivity and positive predictive diagnosis were established in the period 43-49 day of pregnancy (P<0.05). The obtained results show that the most appropriate period is between 42 and 49 day of pregnancy for determination of the fetal number in Bulgarian local goats using ultrasonography.

Determination of gestational age by measuring defined embryonic and foetal indices with ultrasonography in Abaza and Gurcu goats

The aim of this study was to determine gestational age in Abaza and Gurcu goats by measuring certain embryonic and foetal indices with ultrasonography. A 5–7.5 MHz linear probe was used to obtain ultrasound measurements from 30 pregnant goats (10 Abaza and 20 Gurcu). Heart diameter (HD), biparietal diameter (BPD), crown-rump length (CRL), trunk diameter (TD) and placentome diameter (PD) were measured to determine gestational age. The mean of embryonic and foetal indices were calculated and linear regression was performed. Heart diameter measurements for Abaza and Gurcu goats were significantly different on days 45 (P= 0.048) and 60 (P= 0.019). Biparietal diameter values were significantly different on day 45 (P= 0.035). Crown-rump length measurements were significantly different at days 30 (P= 0.003) and 60 (P= 0.002). We determined that HD and TD were the best predictors of gestational age for Abaza goats (R2= 0.952, R2= 0.949, respectively), whereas HD and CRL were the best predictors of gestational age for Gurcu goats (R2= 0.933, R2= 0.942, respectively). Based upon our study results, these specific indices could be applied during ultrasonographic examinations of Abaza and Gurcu goats to confirm gestational age when the day of mating is unknown.

Two-dimensional and three-dimensional ultrasonography for pregnancy diagnosis and antenatal fetal development in Beetal goats

Aim:

The objective of this study was to compare two-dimensional (2D) and three-dimensional (3D) study of the pregnant uterus and antenatal development of the fetus.

Materials and Methods:

2D and 3D ultrasound were performed from day 20 to 120 of gestation, twice in week from day 20 to 60 and once in week from day 60 to 120 of gestation on six goats. The ultrasonographic images were obtained using Toshiba, Nemio-XG (Japan) 3D ultrasound machine.

Results:

On the 20^th day of gestation, earliest diagnosis of pregnancy was done. First 3D ultrasonographic image of the conceptus, through transabdominal approach, was obtained on day 24. On 39^th day, clear pictures of conceptus, amniotic membrane, and umbilicus were seen. On 76^th day of gestation, internal organs of fetus viz heart, kidney, liver, urinary bladder, and stomach were seen both in 2D and 3D images. 3D imaging showed better details of uterine structures and internal organs of the fetus.

Conclusions:

Comparing 3D images with 2D images, it is concluded that 2D was better in visualizing fluid while 3D images were better to view details of attachment of fetus with endometrium.

Accuracy of B-mode ultrasonography for diagnosing pregnancy and determination of fetal numbers in different breeds of goats

A total of 150 does of different breeds were used to evaluate the accuracy of transrectal (TRU) and transabdominal ultrasonography (TAU) for pregnancy diagnosis and fetal number estimation and to study the effect of breed and age of goats on the accuracy of ultrasonography. All does were scanned by TRU at days 17-22, 24-29 and 31-36 and by TAU at days 39-44 and 46-51 after breeding. The sensitivity (Se) of TRU for detecting pregnant does increased significantly (81.6% vs. 97.7%; P<0.0005) from days 17-22 to 24-29. There was a significant (P<0.05) effect of breed of goats on the specificity (Sp) of TAU for diagnosing non-pregnancy between days 39 and 51. In addition, there was a significant (P<0.01) effect of breed of goats on the Se and Sp of TRU for determination of does carrying multiples and singles, respectively, between days 24 and 36. The sensitivity of TAU for diagnosing pregnant does tended to be significantly (P=0.06) higher in young does (1.5-2 yr) than in older does (>2-9 yr) at days 39-44. The accuracy of TRU for determination of does carrying singles was significantly (P<0.05) higher in young does than that in older ones at days 24-29. In conclusions, TRU could be accurately used for early pregnancy diagnosis and fetal number estimation at days 24-29 and days 31-36, respectively, with accuracy similar to that of TAU at days 39-51. Furthermore, breed and age of does might influence the accuracy of ultrasonography for pregnancy diagnosis and fetal numbers estimation.

Correlation between serum and fecal concentrations of reproductive steroids throughout gestation in goats

Non-invasive techniques such as the measurement of fecal steroids are now widely used to monitor reproductive hormones in captive and free-ranging wild-life. These methods offer great advantages and deserve to be used in domestic animals. The aim of the present study was to determine the endocrine profile of dairy goats throughout pregnancy by the quantification of fecal progestins and estrogens and assess its correlation with serum concentrations. Blood and fecal samples were collected weekly from 11 adult, multiparous goats, from mating through pregnancy and 2 weeks post-partum. The extraction of estradiol and progesterone fecal metabolites was performed by dilution in ethanol. The radioimmunoassay (RIA) in solid phase was used to quantify serum 17beta-estradiol (estradiol) and progesterone, as well as their fecal metabolites. The mean concentrations of both fecal and serum estradiol started to increase between weeks 7 and 11, reached peak values near parturition and then decreased sharply (range: 19.8+/-5.8 ng/g of feces to 608.6+/-472.4 ng/g of feces and 0.007+/-0.005 ng/ml to 0.066+/-0.024 ng/ml). An increase in both fecal and blood progestagens occurred in the second week, mean concentrations remained greater until week 20, and then decreased in the last week of gestation and 2 weeks post-partum (range: 108.8+/-43.6 ng/g of feces to 3119.5+/-2076.9 ng/g of feces and 0.12+/-0.04 ng/ml to 13.10+/-4.29 ng/ml). The changes in blood and fecal hormone concentrations were analyzed and compared throughout gestation for each single goat, for each breed and for the whole group. Results indicated that matched values of serum and fecal hormone concentrations were correlated (r=0.79; p<0.001 for progesterone and r=0.84; p<0.001 for estradiol mean concentrations in the whole group). Regression analysis showed that logarithmic model allows significant prediction of serum from fecal concentrations with an R(2)=0.729 (y=0.013ln x-0.021) for estradiol and R(2)=0.788 (y=3.835ln x-18.543) for progesterone. Neither fecal nor serum concentrations were affected by the breed but a significant effect of the number of fetuses on progestin concentrations was found. Therefore, the profiles of progesterone and estradiol fecal metabolites reflect the serum concentrations of the same hormones in pregnant goats.

Follicular and Hormonal Dynamics during the Estrous Cycle in Goats

Transrectal ultrasonography of ovaries was performed daily in 6 goats for 3 consecutive estrous cycles. Blood samples collected daily were measured for concentrations of FSH, inhibin A, and estradiol-17beta. Follicular and hormonal data were analyzed for associations between the follicular waves and hormonal concentrations. During the interovulatory intervals, follicular growth and regression occurred in a wave like pattern (2-5 waves), and the predominant patterns were three and four follicular waves. In addition, there was no significant difference among the diameters of dominant follicles during the growth phase of the follicular waves. The number of 3 mm follicles peaked on days 0, 7, and 11 in interovulatory intervals that had three follicular waves and on days -1, 5, 11, and 15 in those that had four follicular waves. Plasma concentrations of FSH increased around the day of follicular wave emergence and declined with the growth of follicles. Circulating FSH increased again concomitant with regression of dominant follicles in the anovulatory wave, whereas FSH levels remained low in the ovulatory wave. Inhibin A was negatively correlated with FSH, while it was positively correlated with estradiol-17beta, suggesting that inhibin A is a product of healthy growing follicles and that it contributes to the suppression of FSH secretion. In conclusion, the growth of ovarian follicles in goats exhibits a wave-like pattern, and follicular dominance is less apparent in goats. Moreover, inhibin A may be a key hormone for regulation of the follicular wave through suppression of FSH secretion in goats.