Comparison of various examination methods used in ovarian diagnostics in cattle

In this study diagnostic certainty of ultrasonography and rectal palpation concerning the detection of follicles and C.I. was compared by evaluation of the findings obtained with ultrasonography in waterbath and dissection of the ovaries after slaughter. Clinical examinations were performed on a total of 30 cows (transrectally and ultrasonographically, 5.0 mhz, linear) in slaughterhouse. In the laboratory ovaries were evaluated after slaughter both macroscopically and by ultrasonography in waterbath. Diagnostic reliabilities of these methods were compared. No difference between the methods was determined concerning the longitudinal measurements of corpora lutea (19.96 +/- 4.83 mm, 20.41 +/- 5.41 mm, 21.45 +/- 5.26 mm by ultrasonography, waterbath and macroscopy respectively). By means of determining the correct identification of corpora lutea, the error rate was 24.1% and 17.2% for rectal palpation and ultrasonography respectively. The comparison of rectal palpation and macroscopy showed that three small corpora lutea and two corpora lutea with small cavity were determined wrongly as small follicles and two corpora lutea were determined whereas they were not present actually. With ultrasonography four small C.I. could not be detected and one C.I. with cavity was wrongly determined as follicle. It was noticed that follicles bigger than 10 mm (F2 = 10-15 mm, F3 = 16-20 mm) could be determined more accurately by means of ultrasonography than by rectal palpation (with ultrasonography: F2 = 90.48%, F3 = 100.0%; with rectal palpation, F2 = 61.9%, F3 = 200.0%). The correlation of the findings of rectal palpation or ultrasonography and blood progesterone levels was 86.2% and 89.7% respectively. This accordance was 96.6% for progesterone levels and waterbath and macroscopic findings.     

Relationship of ovarian contents to plasma progesterone concentration in the swamp buffalo (Bubalus bubalis)

Using rectal palpation and laparoscopy, the relationship of ovarian contents to plasma progesterone concentration during the oestrous cycle, early pregnancy and post partum periods in the swamp buffalo (Bubalus bubalis) was studied. During the oestrous cycle, four stages in the lifespan of the corpus luteum were seen laparoscopically. The mean (+/- sd) concentrations of progesterone in plasma in cows with and without a corpus luteum on their ovaries were 1.49 +/- 0.78 ng/ml (n = 31) and 0.14 +/- 0.09 ng/ml (n = 14), respectively. Plasma progesterone levels reflected age-dependent changes occurring in the cyclic corpus luteum. The accuracy of diagnosing ovarian contents was 82 and 91 per cent for rectal palpation and plasma progesterone levels respectively. Approximately 29 per cent follicles (larger than 10 mm) were incorrectly diagnosed as corpora lutea by rectal palpation.     

A Study of the Equivalence Between Rectal Palpation, Laparoscopy, Laparotomy and Ovarian Dissection for Evaluation of the Ovarian Response of PMSG-Superovulated Cows

The PMSG-superovulatory response was determined by ovarian dissection in 20 cows and compared with estimates made by laparoscopy laparotomy and rectal palpation at day 7 of the induced estrus. The corpora lutea count made transrectally seriously underestimated real corpora lutea numbers when more than nine corpora lutea were present. Rectal palpation failed to correctly identify the number of follicles ≥ 10 mm when more than four follicles were present. After ovarian dissection, laparotomy was the most constant and accurate method to obtain the number of ovulations, followed by laparoscopy. The excessive weight and the large size of the ovaries associated with the presence of large unovulated luteinized follicles were often responsible for the erroneous estimates of the ovulation rate by rectal palpation.     

Estimation of superovulation response in donor cows

Estimates were made of the superovulation response in donor cows using ovarian size, the number of corpora lutea (palpated per rectum) and blood progesterone levels. Neither the estimated number of corpora lutea nor ovarian size gave a satisfactory prediction of superovulation response. There was a large discrepancy between the number of corpora lutea present on the ovaries of nine superovulated cows (166) and the estimated number (106). All the corpora lutea on superovulated ovaries were smaller than normal (1.95 g). Blood progesterone levels at the time of embryo recovery were correlated with both the number of corpora lutea on the superovulated ovaries (r = 0.9, P less than 0.001) and the weight of the corpora lutea (r = 0.95, P less than 0.001). There were 67 embryos and ova recovered from the nine donors, representing 40 per cent of the actual and 63 per cent of the palpated corpora lutea. However, neither ovarian size, the number of corpora lutea nor blood progesterone levels were correlated with embryo production.     

Effect of large palpable ovarian follicles on response to prostaglandin administration in dairy cows with corpora lutea

We examined the response to exogenous prostaglandin F2α in cattle with or without palpable structures believed to be ovarian follicles. All animals had ovarian structures diagnosed by palpation as corpora lutea. The cows were placed into two groups: those with follicles which were estimated by the palpators to be ≤13 mm diameter (n=60); and cows with no palpable follicles or with follicles <13 mm diameter (n=133). Comparisons of proportion in estrus within five days, days to estrus, and milk progesterone levels failed to show significant differences between the groups.     

Comparison of palpable corpora lutea with serum progesterone concentrations in cows

Serum progesterone concentrations were used to evaluate rectal palpation of corpora lutea as a method for assignment of postpartum beef cows to prostaglandin treatment and nontreatment groups. On the basis of 124 evaluations, 18% of the cows were assigned incorrectly to the treatment group and 37% of the cows were assigned incorrectly to the nontreatment group. The inability of palpators to accurately select cows with a mature corpus luteum may diminish the success of estrus synchronization regimens that use rectal palpation of corpora lutea for selection of cows for prostaglandin therapy.     

A study of the central cavity in the bovine corpus luteum

Seven hundred and six bovine corpora lutea in various luteal stages were examined morphologically and endocrinologically to discover whether there is a relationship between the presence of a central cavity in the corpus luteum and infertility in cows. A central cavity was found in 42.1 per cent (80/190) of developing corpora lutea, 33.7 per cent (126/374) of fully developed corpora lutea, 11.1 per cent (7/63) of corpora lutea in regression and in 5.1 per cent (4/79) of corpora lutea in pregnancy. There was no significant difference between the rates of appearance of midcycle follicles in corpora lutea either with or without a central cavity. The proportion of luteal cell type 1 was higher in fully developed corpora lutea with a central cavity than without, but the reverse was found with luteal cell type 2. In fully developed corpora lutea the concentration of progesterone in the luteal tissue was significantly higher in corpora lutea with a central cavity. These results suggest that there are some differences in luteal function between corpora lutea with and without a central cavity, but that the presence of a central cavity in a corpus luteum cannot be described as a pathological condition.     

Progesterone assays and rectal palpation in pre-service management of a dairy herd.

Fifty-one dairy cows were examined three times at weekly intervals during weeks 5 to 7 after calving. Rectal palpation of the ovaries and plasma progesterone assay were used to determine cyclic ovarian function. Eight of 51 cows exhibited true anoestrus by day 49 after calving. Only 23 of 43 cycling cows were served by day 77, the end of the target period for first service. In 77 per cent of 142 examinations, rectal palpation and progesterone assay gave compatible results. Most incompatibility occurred early or late inthe cycle, or in association with cystic structures in the ovaries. Eleven of the 51 cows had cysts in the ovaries but cyclicity and fertility were not adversely affected.     

Relative accuracy of the identification of ovarian structures in the cow by ultrasonography and palpation per rectum

Manual palpation or ultrasonographic examination of the cow's genital tract are currently used by veterinarians involved in reproductive management, but knowledge of the potential and the limitations of both methods is important to obtain an optimal accuracy in the diagnosis of physiological and pathological ovarian structures. This review presents the main features of manual and ultrasonographic characteristics of follicles, corpora lutea (with or without a cavity), follicular and lutenized cysts and the reliability of the two methods is compared. Manual diagnosis of follicles <10 mm is rather inaccurate, but ultrasound offers the possibility to diagnose follicles <5 mm and to measure their inner diameter. The predictive values of the presence or absence of a corpus luteum as determined by palpation are similar (78 vs. 75%). Manual or ultrasonographic diagnosis of the growing or regressing corpus luteum is rather difficult. The positive predictive value of a mature corpus luteum diagnosed by ultrasonography is lower (87%) than the negative predictive value (92%). Compared to manual palpation, ultrasonography permits a better estimation of the number and to determine more precisely the size of the mature corpus luteum. The positive values for follicular cysts diagnosed by palpation or by ultrasonography are 66 and 74% respectively, and for luteal cysts, the values are 66 and 85%, respectively.Manual palpation or ultrasonography are useful tools to diagnose ovarian structures in the cow. The accuracy of such methods can be enhanced by securing information on the reproductive history of the animal, palpation of uterine horns, vaginal examination or progesterone determinations.     

Pathological changes in the reproductive organs of cows and heifers culled because of infertility

The reproductive organs of 20 Estonian Holstein Breed (EHF) cows and three heifers, culled because of infertility, were studied by palpation per rectum and ultrasonography. In addition, pathoanatomical and pathohistological studies were carried out after slaughtering. The pathohistological study revealed that small cysts often (12 animals) existed in culled cows, whose diameter was less than 2.5 cm. These cysts were frequently accompanied by changes in secondary and Graafi follicles, rete ovarii, ovarian stroma, and the endometrium. Three cows had follicular cysts in the ovaries, which were 25-35 mm in diameter. Two cows revealed luteal cysts in the ovaries; one of them had vaginal prolapse. Four animals (one heifer and three cows) manifested tumours or tumour-like malformations: ovarian endosalpingiosis, germ and stromal cell tumour, oviductal myolipoma, and haemangiosarcoma in the uterine blood vessels. One heifer had been culled because of two abscesses in the vaginal wall close to the cervix and another had chronic endometritis. The research findings indicate that the most common cause of infertility in the culled cows was cystic degeneration in ovaries (85%), accompanied by pathological changes elsewhere in the reproductive organs. We claim that these changes are responsible for the low pregnancy rate after the treatment of ovarian cysts. The second most common reason was genital tumours (15%). In heifers, infertility is rare and its causes are heterogeneous.     

Effect of ovarian follicles on luteal regression in heifers

Our objectives were to determine whether or not ovarian follicles contribute to spontaneous luteal regression in heifers and, if so, when during diestrus do follicles exert their effect. Thirty-one Holstein heifers having displayed at least one estrous cycle (19 to 21 d) were assigned, as available, to randomized blocks for a factorial experiment. Reproductive organs were exposed through a midventral incision on d 9, 12 or 15 postestrus (estrus = d 0). Visible follicles were electrocauterized and both ovaries were x-irradiated (1,500 rads) in treated heifers, whereas ovaries of controls were exteriorized but follicles were not destroyed and ovaries were not x-irradiated. In two additional heifers, the ovary containing the corpus luteum was exteriorized and x-irradiated on d 15 postestrus, but follicles were not electrocauterized. Jugular blood was collected before and every 8 h after surgery until d 24 postestrus. All heifers were ovariectomized on d 24 postestrus to inventory follicles and to weigh corpora lutea. No follicles (greater than or equal to 1 mm diameter) were observed in ovaries from treated animals and concentrations of estradiol-17 beta did not change over time, whereas different numbers of follicles were observed in ovaries from controls and concentrations of estradiol-17 beta increased (P less than .05) during proestrus. Hence, treatment destroyed follicles and prevented follicular development. On d 24 postestrus, corpora lutea from treated heifers (5.5 +/- .5 g) were heavier (P less than .001) than corpora lutea from controls (1.1 +/- .1 g), independent of day when follicles were destroyed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diagnosis of luteal and follicular ovarian cysts by palpation per rectum and linear-array ultrasonography in dairy cows.

The purpose of this study was to determine and compare the accuracy of palpation per rectum and linear-array ultrasonography for diagnosing follicular vs luteal ovarian cysts in cows. Forty-seven examinations of ovarian cysts from 28 cows were diagnosed by palpation per rectum as either a firm, thick-walled structure (luteal cyst) or a soft, thin-walled structure (follicular cyst) during weekly herd examinations. The ovaries of each cow were then examined by ultrasonography. Ultrasonograms of cysts greater than 25 mm in diameter were diagnosed as luteal or follicular cysts and were recorded on videotape for evaluation by a second clinician. Serum progesterone concentrations at the time of examination were determined by radioimmunoassay and used to classify luteal (greater than 0.5 ng/ml) or follicular (less than or equal to 0.5 ng/ml) cysts. Selection of this discriminatory level was based on response of a proportion of cows with luteal cysts that were given 25 mg of prostaglandin F2 alpha at the time of diagnosis by ultrasonography. Sensitivity and specificity of palpation per rectum for diagnosis of type of ovarian cyst were low (43.3 and 64.7%, respectively). In contrast, sensitivity and specificity of ultrasonography were considerably higher (86.7 and 82.3%, respectively). Agreement between the 2 methods of diagnosis was 57.4%. Overall agreement between the 2 clinicians' diagnoses by ultrasonography was 85.1%. On the basis of our findings, we confirm that luteal and follicular cysts cannot be accurately differentiated by palpation per rectum alone. These data suggest that linear-array ultrasonography is more effective than palpation per rectum for diagnosing type of ovarian cyst in cows.     

Evaluation of numbers of microscopic and macroscopic follicles in cattle selected for twinning

We hypothesized that the number of microscopic follicles present in the ovaries of cattle selected for twin births (Twinner) would be greater than in the ovaries of contemporary Controls. Ovaries were collected from seven Control and seven Twinner cows at slaughter. The number of Small (1 to 3.9 mm), Medium (4 to 7.9), and Large (> 8 mm) surface follicles was counted and one ovary was fixed for histological evaluation. Fifty to sixty consecutive 6-microm slices were taken from a piece of cortical tissue, approximately 1 cm x 1 cm in area, located between the surface follicles. Microscopic follicles were classified as primordial (oocyte surrounded by a single layer of squamous pregranulosa cells), primary (oocyte surrounded by a single layer of one or more cuboidal granulosa cells), secondary (oocyte surrounded by two or more layers of granulosa cells), or tertiary (oocyte surrounded by multiple layers of granulosa cells with initiation of antrum formation to < or = 1 mm in diameter). The total number of follicles was counted in 200 fields (2 mm x 2 mm) per ovary. A field containing no follicles was classified as empty. There were significantly more secondary follicles in Twinner compared with Control ovaries (12.9 vs 6.3; P < .05). Twinners also tended to have more small surface follicles (35.4 vs 49.0; P < 0.1). We conclude that ovaries of Control and Twinner cows do not differ in the number of primordial follicles or in the number of follicles activated into the growing pool; however, Twinner cows are able to maintain more growing follicles at the secondary and subsequent stages of development.     

Ovariectomy by colpotomy in cows.

For the purpose of collecting active ovarian structures for cell culture, unilateral ovariectomy (n = 34 ovaries) was performed per vagina on 17 dairy cows having normal estrous cycles, bilateral ovariectomy was performed on 9 (n = 18 ovaries) dairy cows, and corpora lutea (n = 13) were removed from 11 beef cows having normal estrous cycles. None of the cows was clinically ill after the operation. Nine of 37 cows developed adhesions of both uterine horns and the body of the uterus. Three instruments were used to perform colpotomy. The described surgical technique for removal of the ovaries or corpora lutea is practical and inexpensive, and has low morbidity associated with it.     

Within and between observer agreement on ultrasonic evaluation of bovine ovarian structures

A diagnostic ultrasound unit with a 5 MHz probe was used to examine ovarian structures in vitro from 32 reproductive tracts obtained at slaughter from young cows. Agreement between and within observers, and between observers and dissection results was evaluated using the kappa statistic. Agreement was high (kappa from 0.531 to 0.969) for all evaluations of corpora lutea. The sensitivity, specificity and predictive value of both positive and negative findings for presence of a corpus luteum was > 0.9. Agreement between and within observers was little better than chance for follicles measuring 4 to < 6 mm and for follicles measuring 6 to < 10 mm. However, agreement between observers and dissection results indicated that observers could detect follicles 4 to < 6 mm and 6 to < 10 mm (kappa 0.301 to 0.731 and 0.414 to 0.612, respectively). Kappa values within and between observers and between observers and dissection results for observations of follicles measuring > or = 10 mm were almost all > 0.4 indicating that large follicles can be readily detected using ultrasound. It is suggested that further validation of ultrasound methods is needed to determine whether follicles measuring < 4 mm can be accurately identified, and whether follicles can be accurately identified and monitored over a number of days. The ultrasound unit was useful for detecting the presence of corpora lutea and follicles. However, agreement between and within observers on the presence of follicles measuring < 10 mm was poor.     

Incidence of ovarian dysfunction in post partum dairy cows and the effectiveness of its clinical diagnosis and treatment

Ovarian function was assessed from milk progesterone profiles in 236 cows that were presented for clinical examination after parturition and in 227 unexamined herdmates. By 30 days after calving, 81 per cent of the cows had ovulated and by 42 days 92 per cent had resumed cycling. On average milk samples were taken for 155 days, and during this period 67 luteal cysts or cystic corpora lutea and 24 follicular cysts were recorded, and 88 cows were anoestrus for more than 30 days. Luteal cysts, follicular cysts and prolonged anoestrus all occurred twice as frequently in the cows which were clinically examined as in those which were not examined. Progesterone profiles indicated that at the time of clinical examination 72.4 per cent of the cows examined were cycling normally, 11.3 per cent were anoestrus, 6.7 per cent had follicular cysts, 8.0 per cent had luteal cysts and 1.6 per cent were pregnant. Rectal palpation correctly identified ovarian function in only 63.5 per cent of examinations, with 29.8 per cent of cows that were cycling normally, 58.1 per cent that were anoestrus, 70.3 per cent with follicular cysts and 25 per cent with luteal cysts being incorrectly diagnosed. Progesterone profiles confirmed normal oestrous cyclicity in 81.9 per cent of these cows diagnosed as cycling normally by the clinician. The clinical treatments administered included prostaglandin, gonadotrophin-releasing hormone (GnRH), progesterone (PRID) and the physical expression of ovarian structures. Cows diagnosed as cycling normally were left untreated. At the time of treatment, 28.8 per cent of prostaglandin-treated cows had low progesterone concentrations indicating that no luteal tissue was present.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of surface diameters and dissected diameters of bovine ovarian follicles

Comparisons were made between diameters of 54 bovine follicles greater than 5.9 mm from 32 pairs of ovaries measured on the ovarian surface and diameters of the same follicles subsequently dissected from the ovaries. Seventy-eight percent of follicles measured on the ovarian surface were within 1.9 mm of the size measured after dissection. The remaining 22% of follicles measured on the surface had diameters recorded that were 2.0 to 3.9 mm different than their diameter after dissection. Surface diameter tended to underestimate dissected diameter for small follicles (less than 8.0 mm) and to overestimate dissected diameter for large (greater than or equal to 12.0 mm) follicles. The correlation coefficient between surface and dissected follicular diameters was .83. We conclude that measuring the diameter of the largest follicles on the ovarian surface and after dissection yield approximately equivalent results.     

Steroids and cAMP in follicles of postpartum beef cows treated with norgestomet.

To determine time of occurrence of follicular changes that may be associated with the length of the subsequent luteal phase, follicles were collected at different times before ovulation from cows expected to have corpora lutea of short (control) or normal (norgestomet-treated) life span. Beginning on d 20 to 23 postpartum (d 0 of study), 34 crossbred beef cows received either a 6-mg implant of norgestomet for 9 d or served as untreated controls. Ovaries were removed from norgestomet-treated cows on d 6 (N6; n = 9), d 8 (N8; n = 8), or the day after implant removal (N10; n = 8). Control cows were ovariectomized on d 6 (C6; n = 4) or d 10 (C10; n = 5). The largest and second largest follicles greater than 8 mm (F1 and F2, respectively) were dissected from the ovaries. Granulosal and thecal layers and follicular fluid were separated and assayed for estradiol-17 beta, progesterone, androstenedione, and testosterone. Cyclic 3'5'adenosine monophosphate (cAMP) was determined in thecal and granulosal tissue. Diameters of the F1 (14.6 +/- .4 mm) and F2 (10.6 +/- .4 mm) did not differ due to treatment. A greater proportion (P less than .05) of the F1 (20/33) than of the F2 (4/27) had estradiol:progesterone ratios of greater than 1 in follicular fluid. Contents of estradiol, androstenedione, and testosterone in theca and granulosa and follicular fluid, androstenedione in theca, and testosterone in theca and follicular fluid (all P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of Maternal Undernutrition on the Hypothalamic–Pituitary–Gonadal Axis Function in Female Sheep Offspring

A study was conducted to evaluate the effects of maternal undernutrition on the hypothalamic–pituitary–gonadal axis in female sheep offspring. Pregnant ewes were fed to 100% throughout pregnancy (Control) or to 50% from 0 to 30 (R1) or from 31 to 100 days of gestation (R2). Female lambs were selected and fed to appetite throughout the study. At 2, 5.5 and 10 months of age a GnRH challenge was conducted. At the age of 10 months lambs were synchronized and blood samples were collected at 3 h intervals for 72 h following sponge removal. At slaughter (10 months) ovaries were removed and examined macroscopically. Maternal undernutrition did not affect the time of the onset of puberty, defined as the first increase in plasma progesterone concentrations ≥1 ng/ml. The magnitude of the pre-ovulatory gonadotrophin surge and the time to surge were unaffected by treatment. The LH and FSH response to GnRH challenge did not differ between groups at 2 and 5.5 months but at 10 months of age a higher (p < 0.05) FSH response was found in R1 group. Although the total number of visible follicles and corpora lutea did not differ between groups, a significant higher (p < 0.05) number of small (2–3 mm diameter) follicles in R1 group and a significant lower number (p < 0.05) of corpora lutea with diameter 8–11 mm and not even one with diameter >12 mm were detected in the ovaries of R2 lambs. In conclusion, maternal undernutrition during the first month of pregnancy resulted in increased pituitary sensitivity to GnRH and increased number of small follicles in the ovary, while during mid to late gestation resulted in a reduction of large corpora lutea in female offspring.     

Detection of a corpus luteum in apparently anoestrous cows by manual palpation, transrectal ultrasonography and plasma progesterone concentration

AIMS: To determine the level of agreement between transrectal ultrasonography, manual palpation and measurement of progesterone in the detection of corpora lutea in post-partum cows. To evaluate the reproductive performance of cows not detected in oestrus prior to mating, but detected with a corpus luteum at the start of mating. METHODS: Cows from seven herds which were not detected in oestrus were examined between 5 and 7 days before the herd's planned start of mating. Ovaries were examined by palpation and ultrasonography in 160 cows and plasma progesterone concentrations were also measured in 103 cows. Insemination dates and pregnancy data were recorded in 159 cows not detected in oestrus but having a corpus luteum and 1405 cycling herd mates. RESULTS: The level of agreement between ultrasonography and measurement of progesterone (kappa = 0.74) was higher than with manual palpation (kappa = 0.67) although it was significant for both techniques (p <0.001). Cows which were not detected in oestrus, but detected with a corpus luteum had a longer interval to first service (12 v. 10 days, p <0.05) and conception (19 v. 15 days, p = 0.01) than cycling herd mates and had a higher empty rate (9.7% v. 3.8%, p <0.001). CONCLUSIONS: These data indicate that ultrasonography may provide a better diagnostic tool for examining cows not detected in oestrus than manual palpation or measurement of progesterone concentration. Cows not detected in oestrus but having a corpus luteum were shown to have significantly poorer reproductive performance than cycling herd mates.