Use of ultrasound scanning in swine for detection of pregnancy and some pathological conditions

The adaptation of ultrasound scanning to the diagnosis of pregnancy and other physiological conditions in swine was examined. The scanner was equipped with a 3.5-MHz transducer. The probe was placed against the skin in the area of the abdominal flank of a standing sow and moved between the first and third posterior teats. The 2,257 sows were all presumed to be pregnant and underwent a single echography examination between 18 and 90 d post-insemination. For pregnant sows, the accuracy rate of diagnosis averaged 98.7 %. The majority of errors were made between 18 and 21 d of pregnancy in sows which subsequently gave birth to fewer than five piglets. This technique allowed us to detect only 54 % of non-pregnant sows. Nevertheless, a high accuracy rate was obtained when examination was performed within 7 d before the return of estrus (80 %). Conditions at the time of the examination were also an important factor. Ultrasound scanning opened up possibilities for observing other conditions such as cystic ovaries and metritis.     

Early pregnancy diagnosis in swine by direct radioimmunoassay for progesterone in blood spotted on filter paper.

A direct radioimmunoassay method for the measurement of progesterone in blood dried on filter paper has been developed for the early pregnancy diagnosis in sows, as well as for monitoring progesterone levels during the oestrous cycle.Pregnancy diagnosis was performed with 95 sows on Days 17-22 after artificial insemination (AI). The cut-off value for pregnancy diagnosis of 7.5 ng/ml was calculated (mean+/-2S.D.) from the progesterone concentrations measured on the same days from non-inseminated animals. There were 85 cases considered pregnant on the basis of progesterone concentration, leaving 10 animals non-pregnant. The accuracy for the positive cases was 98.8%. Two of the 10 sows considered as negative subsequently farrowed, giving an accuracy of 80%. The overall accuracy of the method was 96.8%.The blood-spot assay may be a useful tool for early pregnancy diagnosis in swine, with respect to sampling, simplicity, speed and accuracy.     

Pregnancy diagnosis in swine by palpation and by amplitude-depth ultrasound scanning

The relative accuracy of two pregnancy testing methods for swine were compared in a field study. The procedures used were manual palpation and amplitude-depth ultrasonic scanning. A total of 369 sows were examined by both methods. Seven additional gilts were examined by ultrasound only and 46 sows by palpation per rectum only. The number of correct positive and negative diagnoses made by both methods were calculated, and determination of accuracy as well as comparison between the tests were made on this basis. The relative accuracy was 97.6% for the manual method and 96.8% for the ultrasound method. Both tests had a high sensitivity, 99.2 and 98.9%, respectively. The ability of the tests to detect the non-pregnant animals was not as high, which is reflected by a lower specificity. No significant differences were noted between the two methods. A lower specificity and a lower negative predictive value were provided by ultrasound scanning as compared with those acquired by manual palpation. Both procedures were considered to be quick and convenient to perform. It was concluded that in spite of the new pregnancy testing methods introduced in the swine industry, manual palpation remains the most practical in terms of its accuracy, ease, and the minimal requirement for equipment. In gilts, palpation is unsuitable and ultrasonography currently remains the best choice for the diagnosis of pregnancy.     

Direct ELISA for estrone measurement in the feces of sows: prospects for rapid, sow-side pregnancy diagnosis

Both free and conjugated fecal estrogens were surveyed in sows by means of RIA's after extraction and column chromatography. Six different RIA's were performed using the same fecal suspension. Based on differences in concentration in feces from 6 pregnant and 4 nonpregnant sows, estrone (E1) was selected for the development of a homologous, competitive ELISA for pregnancy diagnosis purposes. Polyclonal antibodies were raised against 6-keto-E1-carboxymethyloxime coupled to BSA. Biotinylated E1 was used as the competitive agent and was detected with a streptavidin-peroxidase conjugate. Tetramethylbenzidine was used as chromogen. Validation of this direct, easy to perform ELISA showed satisfactory specificity, accuracy, precision and sensitivity. Comparison of the assay with a validated RIA (including extraction and column chromatography) resulted in a linear regression equation of ELISA = 0.88 RIA - 0.72 (r = 0.95; n = 24 fecal samples). The E1 values in feces from 11 pregnant sows during the first 40 d of gestation compared with values from 10 nonpregnant sows showed significant differences between Days 23 and 35 of pregnancy (P < 0.05). The highly significant difference in E1 concentrations (P < 0.0012) between Days 27 and 30 in particular offers promise for pregnancy diagnosis.     

Pregnancy diagnosis in swine: A comparison of the technique of rectal palpation and ultrasound

The accuracy of pregnancy diagnosis in swine by rectal palpation and by ultrasound was compared using sows and gilts thirty days or more after breeding. A total of eighty-four pigs were included in this experiment and they were examined an average of thirty-nine days following breeding. Forty-nine animals were slaughtered within a few days of pregnancy examination and thirtyfive were allowed to farrow. Pregnancy status was correctly diagnosed by palpation per rectum in eighty-three of the eighty-four pigs (98.8%) and by ultrasound in eighty-one of the eighty-four pigs (96.6%) examined. The accuracy of the two methods was not significantly different.     

Pregnancy diagnosis in sows: direct ELISA for estrone in feces and its prospects for an on-farm test, in comparison to ultrasonography

The usefulness of fecal estrone (E1) measurement as a tool for pregnancy diagnosis was investigated. Concentrations of E1 were measured in feces from pregnant and nonpregnant sows by a direct ELISA without extraction. Highly significant differences in E1 concentrations were found in feces from nonpregnant and pregnant sows (P = 0.016 to < 0.001). Pregnancy diagnosis on Days 26 to 32 after insemination, based both on fecal E1 concentrations as measured by ELISA and ultrasonography using a 5.0 MHz linear-array transducer, was performed in a group of 496 gilts and sows. The fecal E1 test had a sensitivity (correct diagnosis of pregnancy) of 96.5% and a specificity (correct diagnosis of nonpregnancy) of 93.6%, using 3.65 ng E1/g feces as a cut-off value. For ultrasonographic pregnancy diagnosis the test sensitivity and specificity were 99.3 and 92.5%, respectively. Although an increase of fecal E1 concentrations was noticed for increasing litter sizes, the results indicated that these concentrations could not be used to predict litter size. It is concluded that the distribution of fecal E1 concentrations in both nonpregnant and pregnant sows offers a suitable basis for the development of a simple, sow-side pregnancy test.     

Direct estimation of urine estrone conjugate for a rapid pregnancy diagnosis in sows

A rapid and direct radioimmunoassay of urine estrone conjugate (E₁C) was developed. Urine samples were taken from Large White sows by inserting sponges in the vagina which were expelled during micturition. Analysis of samples collected daily from 13 sows between 2 and 40 days after service showed that high urine E₁C levels occurred between day 20 and 30 after insemination in pregnant sows; maximum concentrations were observed on day 25 (79.4 ± 11.7 ng/ml, $\text{X}\text{± s.e.m.}$). In this period E₁C levels never exceeded 1 ng/ml in nonpregnant sows. A single urine sample was then taken from 84 sows, 25 days after insemination, to check the accuracy of E₁C estimation as a test for early pregnancy diagnosis. Seventy-six of the examined animals were correctly diagnosed, giving an overall accuracy of 90.4%. No relationship was found between litter size and urine E₁C levels.     

Ultrasonic observation of postpartum uterine involution in the cow

To learn about the progress of postpartum uterine involution in the dairy cow, the authors wanted to know whether the ultrasonic linear scanner is applicable for this purpose. The uterus was observed by the transducer, which was inserted into the rectum. Clear cross-sectional images of the endometrium were obtained in this way; however, those of the myometrium and the perimetrium were not very clear. Observation on the progress of uterine involution was started on Day 8 postpartum and continued to Day 43 postpartum. The diameter and area of the uterine horn and the endometrium in cross-sectional ultrasonograph images of the endometrium were estimated using a Magiscan 2 image analyzer. The relationship between the estimated dimensions of the uterine horn and postpartum days were satisfactorily fitted into polynomial regressions. Using the ultrasonic linear scanner, it was confirmed that uterine involution was completed at approximately 40 d postpartum. The applicability of the ultrasonic linear scanner for diagnosis of uterine involution in the postpartum cow is demonstrated by the results of the present study.     

Some Factors Influencing Pregnancy Rate and Subsequent Litter Size in Primiparous Sows

The pregnancy rate and the subsequent litter size were studied in 332 Swedish Yorkshire primiparous sows, fed according to a commercial Swedish feeding regime during lactation. The sows were weighed and backfat depth was recorded at the first farrowing, at weaning, and at mating. Oestrous detection was performed once daily after weaning, and the interval from weaning to first oestrus (IWO) was recorded. Blood samples for determination of plasma progesterone were drawn regularly after the first weaning. Statistical analyses were only performed on sows with an IWO of 3-8 days. Of these 206 sows were mated on their first (OE1 sows) and 87 sows on their second (87 OE2 sows) oestrus after weaning. The pregnancy rate was 85.4% for OE1 sows and 75.9% for OE2 sows (p=0.048). There was no significant difference in pregnancy rate between OE1 sows with an IWO of 3-5 days and OE1 sows with an interval of 6-8 days. OE2 sows with an IWO of 6-8 days, on the other hand, had a significantly lower pregnancy rate compared with OE2 sows with an interval of 3-5 days. The pregnancy rate in sows that lost more than 30 kg during the first lactation period did not differ from that of sows losing less than 30 kg. In sows with a first litter size of more than 9 piglets alive at birth, the pregnancy rate decreases significantly if mating is delayed until the second oestrus after weaning. OE2 sows had a significantly larger second litter size at birth than OE1 sows (+ 2.0). The litter size at six weeks did not, on the other hand, differ significantly (+ 0.4). There was a positive correlation between the IWO and 2nd litter size, although significant only for OE1 sows between the IWO and litter size alive at birth. In the OE1 group, sows losing 20 kg or less during lactation had significantly larger second litters at birth than the sows losing 21-30 kg, but not significantly larger than the sows losing more than 30 kg. One piglet more, at birth, in the first litter resulted in 0.25 piglet more in the second litter. For sows with a large first litter there was a low probability of also having a large second litter.     

Evaluation of false ultrasonographic pregnancy diagnoses in sows by measuring the concentration of unconjugated estrogens in feces

On Days 26, 28, and 30 after AI, ultrasonographic pregnancy diagnoses were performed on 207 gilts and sows by using a 3.5 MHz linear-array transducer. Fecal samples were taken from the rectum after each ultrasonographic examination, and the concentrations of unconjugated estrogens in selected samples (n = 73) were measured by RIA. Fecal unconjugated estrogen concentration of 11.7 ng/g feces or higher was indicative of pregnancy. The overall sensitivity and specificity of the ultrasonographic test was 99% for farrowing sows and 73.1% for nonfarrowing sows. With one exception, sows with a false negative diagnosis by ultrasonography on Day 26 were correctly diagnosed pregnant by elevated fecal unconjugated estrogens or repeated ultrasonographic examinations on Days 28 or 30. Return to estrus around the sampling period may cause false positive results in the unconjugated estrogen assay, while early embryonic mortality can result in false positive diagnoses in both the ultrasonographic test and estrogen assay. Although there was a positive correlation between the concentrations of unconjugated estrogens in the feces and litter size at farrowing in the selected sows, it seems very unlikely that fecal estrogens can provide an accurate tool for predicting litter size.     

Visualization of male and female characteristics of bovine fetuses by real-time ultrasonics

Sexing of bovine embryos can enhance breeding programs at a rather early stage of pregnancy. The accurate predictability of the sex of the fetus can, for example, speed up breeding programs and allows an early selection of pregnant heifers for certain purposes according to the sex of their fetuses. Ultrasonic images were produced by a real image-producing sector scanner that was inserted per rectum into pregnant cows and heifers. Scrotal swellings and mammary teats were recognizable, allowing sexing of the fetuses between gestational day 73 and 120. The tests carried out showed an accuracy of 94%. Forty-nine of 52 ultrasonic diagnoses were confirmed as correct by subsequent calvings.     

Nephrosonography in Infants and Children: A New Technique

A technique has been developed for the ultrasonic investigation of renal disease in infants using a specially designed water-bath with a conventional ultrasonic scanner. This permits ultrasonic studies of the renal tract from the neonatal period onwards; the procedure does not distress the child and the water acts as an excellent coupling medium.     

Development and evaluation of a direct enzyme immunoassay for oestrone sulphate in urine as a tool for diagnosis of early pregnancy in swine

A competitive inhibition-type enzymeimmunoassay (EIA) has been developed using 3-hemisuccinate-oestrone-peroxidase as conjugate for direct measurement of the hormone in swine urine. The method has a minimum detection level at 0.3 ng ml(-1) and satisfactory specificity, recovery and reproducibility. In a field trial with a group of 387 sows (7 in oestrus, 16 non-pregnant and 364 pregnant sows at several stages post service), it was shown that the assay is potentially an accurate pregnancy test in assessing the viability of the fetoplacental unit from day 23 up to day 30 post service. The assay is well suited for routine testing, particularly as a swine early pregnancy diagnosis test since urine sampling is easier and does not disturb the animal, while in the present assay there is no restriction in the time of sampling and the sample storage conditions.     

Effect of feeding level on progesterone concentration in early pregnant multiparous sows

The effect of three feeding regimens on progesterone level was tested during early pregnancy in multiparous sows. A total of eighteen sows in their eighth parity (8.1 +/- 2.8, mean +/- S.D.) were used. During lactation the sows were fed to appetite and after weaning they received 4 kg (52 MJ) a commercial feed per day. Following ovulation, sows were allocated to one of three treatment groups and fed 2 kg/day (low feeding, LLL) or 4 kg/day (high feeding, HHH) throughout the trial or 2 kg/day for 11 days, 4 kg/day for 10 days, and 2 kg/day for the remaining days of the study (modified feeding, LHL). Blood for progesterone and cortisol analyses was collected daily throughout the study, and for luteinizing hormone (LH) assay for 12 h at 15 min intervals on days 14 and 21 of pregnancy. An adrenocorticotropic hormone (ACTH) challenge test was performed on all sows day 28 of pregnancy. Dietary treatment did not significantly affect hormonal parameters. However, progesterone concentration tended to be lower (P = 0.08) in the HHH group than in the LLL group. In the LHL group venous progesterone concentration seemed to fluctuate. No effects of feeding were observed on progesterone concentration in allantoic fluid on day 35 of pregnancy. Venous cortisol level was significantly higher (P < 0.05) during proestrus and oestrus in all groups and there was no significant difference between groups in response to ACTH challenge. The mean amplitude of LH pulses decreased significantly (P < 0.01) from days 14 to 21 of pregnancy in all groups. In addition, an interaction was found between feeding level and baseline LH concentration and also between feeding level and mean LH concentration. Embryonic recovery was highest in the LLL (69%), lowest in the HHH (45%) and moderate in the LHL (55%) group. Neither high feeding nor modified feeding provided any benefits for reproductive performance in multiparous sows. A low feeding regimen thus appears optimal for multiparous sows in early pregnancy at least with the management regime described.     

A comparison between plasma oestrone sulphate concentration and doppler ultrasound as methods for pregnancy diagnosis in sows

Plasma oestrone sulphate (E(1)S) concentration and doppler ultrasound as methods of pregnancy diagnosis in sows were compared. Using either method, pregnancy was accurately detected (test sensitivity > 94% for pregnant sows). E(1)S was a better predictor of nonpregnant animals (test specificity 78 vs 66%, respectively; P < 0.01) and could be used at least 1 wk earlier than doppler ultrasound (24 to 30 d vs 35 d postservice, respectively). E(1)S concentration was not an accurate predictor of litter size.     

Semen controlled-release capsules allow a single artificial insemination in sows

Controlled-release capsules containing boar spermatozoa were developed to extend the preservation time of spermatozoa and maximize the efficiency of a single artificial insemination. A large trial (4245 sows) was performed with these capsules using double/triple conventional artificial insemination as a control. The effect of treatment on pregnancy diagnosis, delivery, and born piglets was investigated, with allowance being made for considering season, spermatozoa amount, and the weaning-to-estrus interval as confounding variables. The same pregnancy rate and prolificacy were obtained by two insemination techniques, and a higher parturition frequency was reached with capsules. The reproductive performance in pigs has therefore been optimized by a single instrumental insemination with controlled-release capsules.     

功能与分子影像在头颈部肿瘤放射治疗计划和疗效评价中的应用

目前临床普遍采用功能与分子影像检测手段能来评价头颈部肿瘤的放射治疗计划和疗效,可指导个体化治疗从而提高疗效。文章概述了功能与分子影像技术CT,MRI,PET-CT,超声检测技术在头颈部肿瘤放射治疗计划制定和疗效评价中的应用进展。结果显示,不同分子影像检测方法如在检查时机的选择、诊断和鉴别诊断的价值、观察放射治疗后肿瘤的残存和复发、预测放射治疗效果、指导后续治疗等方面均可起到重要作用。采用图像融合技术进行联合应用,如PET-CT和MRI-CT等,可提高检测的准确率。临床医生需在常规影像学手段的基础上,根据头颈部肿瘤患者病情和治疗方法的不同选用正确的功能和分子影像检测手段,更好地指导制定放射治疗计划及综合评价放射治疗后的疗效。     

Comparative Transcriptome Analysis Reveals Early Pregnancy-Specific Genes Expressed in Peripheral Blood of Pregnant Sows

Early and accurate diagnosis of pregnancy is important for effective management of an economical pig farm. Besides the currently available methods used in early diagnosis of sows, circulating nucleic acids in peripheral blood may contain some early pregnancy-specific molecular markers. For the first time, microarray analysis of peripheral blood from pregnant sows versus non-pregnant sows identified 127 up-regulated and 56 down-regulated genes at day 14 post-insemination. Gene Ontology annotation grouped the total differently expressed genes into 3 significantly enriched terms, cell surface receptor linked signal transduction, G-protein coupled receptor protein signaling pathway and regulation of vesicle-mediated transport. Signaling pathway analysis revealed the only one significantly changed pathway was arachidonic acid metabolism. Of the differently expressed genes, nine (including LPAR3, RXFP4, GALP, CBR1, CBR2, GPX6, USP18, LHB and NR5A1) were found to exert function related to early pregnancy processes. This study provides a clue that differentially abundant RNAs in maternal peripheral blood can help to identify the molecular markers of early pregnancy in pigs.     

Evaluation of different techniques for pregnancy diagnosis in sheep

Fifty Corriedale ewes were used in this study to evaluate pregnancy diagnosis in sheep. Ewes were bred under a pen mating system and pregnancy diagnosis was initiated from day 15 post-mating, applying the diagnostic techniques of trans-abdominal real-time B-mode ultrasonography, Preg-alert (A-mode ultrasonography), the Doppler ultrasonic fetal pulse detector or the plasma progesterone concentration assay (EIA). These tests were repeated fortnightly on all the ewes until the onset of lambing. The accuracy of trans-abdominal real-time B-mode ultrasonography (68%) at days 15–30 of pregnancy increased to 100% by days 61–75 and remained constant until lambing. The accuracy of the Preg-alert (56%) diagnosis at days 31–45 increased to 94% by days 91–105 of gestation and then decreased to 82% from days 136 of gestation to lambing. The accuracy of both the Doppler ultrasound (56%) at days 31–45 and plasma progesterone assay (98%) at days 15–30 of gestation increased to 100% at days 76–90 and 46–60 of gestation, respectively and remained constant until parturition. The mean plasma progesterone concentration at days 0–6 (1.41 ± 0.21 ng/ml) increased to 4.0 ± 0.87 ng/ml at days 16–30 (days 18.23 ± 0.78) post-mating. Animals returning to estrus recorded less than 1 ng/ml at days 18.23 ± 0.78 post-mating. The accuracy of both the B-mode ultrasonic technique (78%) and plasma progesterone assay (98%) was significantly higher (P < 0.05) than the accuracy obtained with the A-mode and Doppler ultrasound (both 56%) at days 31–45 of gestation. The study concluded that real-time B-mode ultrasonography is the earliest, most accurate, safest, fastest and most economical method of pregnancy diagnosis in sheep at farm level. The A-mode and Doppler methods can also be used under field conditions, where sophisticated laboratory facilities are not available. Plasma progesterone assays (EIA) can be used as a means of early pregnancy diagnosis in organized sheep farms with fair accuracy.     

Effects of L-carnitine on reproductive performance,milk composition,placental development and IGF concentrations in blood plasma and placental chorions in sows

Recent studies have shown that L-carnitine supplementation of sows during pregnancy and lactation enhances their reproductive performance, but the underlying mechanisms are still needed to be further confirmed. This study was conducted to investigate the function of L-carnitine on placental development, milk nutrient content and release of hormones in sows. In this experiment, 40 multiparous crossbred sows (Yorkshire × Landrace) were allotted to two groups fed diets with or without a supplemental 50 mg/kg L-carnitine. The experimental diets were fed from d 1 post-coitus until d 21 post-partum. L-carnitine-treated sow had fewer weak piglets (p < 0.05) and a greater percentage of oestrus by 5 after 5-d post-partum (p < 0.05) than control sows. The percentage fat from colostrum was greater in L-carnitine-treated sow than control sows (p < 0.05). L-carnitine-treated sows had greater plasma concentrations of triglyceride and insulin-like growth factor (IGF)-1 and lesser plasma concentrations of glucose and IGF-binding protein (IGFBP-3) on day 60 of pregnancy (p < 0.05). A clearer structure of chorions, better-developed capillaries and absence of necrosis were observed in L-carnitine-treated sows compared with control sows. The protein abundance of IGF-1 and IGF-2 in placental chorions was greater in L-carnitine-treated sows compared with control sows (p < 0.05). This study suggests that sows fed an L-carnitine supplemented diet during pregnancy improved reproductive performance through enhancement of placental development and by increasing IGF concentrations in blood plasma and placental chorions.