Urinary excretion of collagen degradation markers by sows during postpartum uterine involution

Metabolomics analysis of the effect of GnRH on the pregnancy rate of ewes with estrus synchronization scheme based on progesterone

Introduction

Gonadotropin-releasing hormone (GnRH) is widely used in the timed artificial insemination protocol for sheep. However, there remains a debate regarding its impact on pregnancy rates during artificial insemination. This study aims to evaluate the effect of GnRH on the pregnancy rates in Huyang ewes, analyze the pre-implantation metabolite changes caused by GnRH using metabolomics, and elucidate the mechanism effect on pregnancy rates.

Methods

All ewes were administered a vaginal progesterone sponge containing 45 mg of flurogestone acetate for 12 days and received 330 units of equine chorionic gonadotropin (eCG) intramuscularly after sponge removal. The experimental group (n = 69) received an intramuscular treatment of 17 μg GnRH agonist triptorelin 48 h after sponge removal on Day 0, while the control group (n = 41) received 1 mL of sterile saline solution. All ewes underwent a single vaginal insemination 58 h after the withdrawal of the progesterone sponge. The difference in pregnancy rates between the two groups was calculated. Metabolomic analysis was performed on plasma samples collected on Day 7 after the treatment of GnRH agonist.

Results

Gonadotropin-releasing hormone (GnRH) treatment significantly reduced the pregnancy rate in the experimental group compared with the control group (72.2 vs. 82.9%, p < 0.05). Metabolomic analysis indicated that GnRH treatment affected metabolites involved in collagen synthesis and prostaglandin synthesis in the endometrial tissue, which includes a marked decrease in hydroxyproline amino acid content and a significant increase in corticosterone and prostaglandin D2 lipids and unsaturated fatty acids.

Conclusion

In summary, the injection of GnRH agonist Triptorelin 48 h after progesterone sponges removal reduces the pregnancy rate of Huyang ewe following artificial insemination. It also affects the metabolite levels related to endometrial collagen and prostaglandin synthesis, harming embryo implantation.

Reproductive health of the sow during puerperium

The modern hyperprolific sow is susceptible to metabolic disease and chronic inflammation. The most sensitive phase is parturition, when the sow experiences systemic inflammation and stress, and major changes in metabolism and endocrinology. Resolution of inflammation and stress needs to happen quickly to ensure good reproductive health during puerperium. If the sow fails to adapt to these changes, puerperal disease may occur. The economically most important puerperal disease complex is the postpartum dysgalactia syndrome (PPDS). Other puerperal diseases include infections of the urogenital tract. Diagnosis of PPDS and urogenital disease on-farm is challenging but several diagnostic methods, including clinical examination, behavioral observations, ultrasonography and biomarkers are available. Ultrasonography is an excellent tool for monitoring the health of the urogenital tract, the mammary gland, and uterine involution and guide further diagnostic interventions. Biomarkers such as Chromogranin A, tumor necrosis factor-α, and interleukin-6 represent promising tools to monitor general health and the systemic state of inflammation and oxidative stress of the sow. Nonsteroidal anti-inflammatory drugs, dopamine antagonists, and oxytocin are promising to address the symptoms of PPDS. Reducing of stress, improving nutrition and intestinal health, and supporting animal welfare-friendly husbandry help in the prevention of PPDS.

[Continuous, subjective sonographic grayscale analysis of uterine involution in sows during the postpartum period]

OBJECTIVE

The aim of this study was to analyse the continuous and subjective evaluation of echogenicity, echotexture of the puerperal uterus as well as the presence of intrauterine fluid in sows of differing parity stages. The goal was to determine associations between grayscale values and simultaneously assessed uterine diameter, body condition, and additional performance parameters such as farrowing duration, placenta expulsion duration, placenta weight and litter weight.

MATERIAL AND METHODS

The study population included 95 sows housed either in free farrowing (n = 46) or crated (n = 49) stables. Transabdominal ultrasound was performed daily between postpartum days 2-14 (p. p.) and the day before weaning. Echogenicity (ranging between anechoic (1)-hyperechoic (6)), echotexture (homogenous/heterogeneous), and the presence of intrauterine fluid (yes/no) was evaluated on three cross-sections of the uterine horn/sow/day.

RESULTS

In the first week p.p, most sows showed a medium (median = 4.0) echogenicity, whereas from day 7 p. p., echogenicity decreased (median = 3.5 to 3.0). Echotexture between days 2-7 p.p was mainly heterogeneous, whereas between days 8-14 p.p, it proved to be mostly homogeneous. Intrauterine fluid was detected until day 9. Echogenicity exhibited significant association with farrowing duration (FD) on days 8-14 p. p. (p = 0.048). Sows with FD > 300 min showed slightly lower echogenicity (median = 3.0) than sows with FD ≤ 300 min (median = 3.5). There was a positive correlation between uterine diameter and echogenicity on day 2-7 p. p. (r = 0,359, p < 0.001) and days 8-14 p. p. (r = 0,381, p < 0.001).

CONCLUSIONS

Subjective grayscale analysis by ultrasonography is suitable in characterizing uterine echogenicity and echotexture as well as intrauterine fluid in post-partum sows. The presented findings suggest that this may aide in assessing patterns of the sow's puerperium.

CLINICAL RELEVANCE

The subjective grayscale analysis is suitable in clinically assessing echogenicity and echotexture during the postpartum phase. The subjective grayscale analysis provides initial indications concerning status of uterine health and involution in sows. Based on the ultrasonographic findings, treatment may be initiated and subsequently evaluated. Furthermore, the results of the subjective grey analysis in combination with further performance characteristics can be implemented to cull breeding sows. Furthermore, the results of the subjective grey analysis in combination with additional performance characteristics may be used in order to cull/reject sows exhibiting pathophysiologic findings from further breeding.

Malnutrition with hypoaminoacidemia in a 22-year-old pregnant patient masking a likely ornithine transcarbamylase deficiency

BACKGROUND

Symptoms and clinical presentations of OTC deficiency vary widely according to the remaining activity of the enzyme. Three factors determine the residual enzyme activity. First, as the OTC gene is carried on the X chromosome, a complete inactivation of this enzyme in a newborn boy results an acute ammonia intoxication. Second, the female mosaicism due to lyonization (differential randomized X-inactivation) leads to differential OTC expression in hepatocytes. Third, the degree of severity depends on the mutation and the level of remaining activity it leaves to the protein. Published cases of OTC deficiency during pregnancy are scant. Most often, diagnosis of the metabolic disease is made before pregnancy or during the post-partum period.

METHODS

We report the case of a 22-year-old woman's successful pregnancy with a moderate form of ornithine transcarbamylase (OTC) deficiency, unsuspected before pregnancy, biochemically consistent with plasma aminoacidogram and orotic acid analysis, and initially masked by malnutrition.

RESULTS - CONCLUSION

Although maternal ammonia was subnormal and the neonate was safe, an OTC deficiency was revealed by stress factors such as the pregnancy itself and infection, and associated with uncontrollable maternal vomiting and psychiatric syndrome. However, this metabolic disease, revealed by aminoacidogram and urine orotic acid analysis, fortunately did not prevent a successful pregnancy. Even if infrequent, this situation deserves to be highlighted.

Elevated urinary excretion of free pyridinoline in Friesian horses suggests a breed-specific increase in collagen degradation

Background

Friesian horses are known for their high inbreeding rate resulting in several genetic diseases such as hydrocephaly and dwarfism. This last decade, several studies focused on two other presumed hereditary traits in Friesian horses: megaoesophagus and aortic rupture. The pathogenesis of these diseases remains obscure but an important role of collagen has been hypothesized. The purpose of this study was to examine possible breed-related differences in collagen catabolism. Urinary specimens from Friesian (n = 17, median age 10 years old) and Warmblood horses (n = 17, median age 10 years old) were assessed for mature collagen cross-links, i.e. pyridinoline (PYD) (=hydroxylysylpyridinoline/HP) and deoxypyridinoline (DPD) (lysylpyridinoline /LP).

Solid-phase extraction was performed, followed by reversed-phase ion-paired liquid chromatography prior to tandem mass spectrometry (MS/MS) detection.

Results

Mean urinary concentrations of free PYD, expressed as fPYD/creatinine ratio, were significantly higher in Friesian horses compared to Warmblood horses (28.5 ± 5.2 versus 22.2 ± 9.6 nmol/mmol, p = 0.02) while mean fDPD/creatinine ratios were similar in both horse breeds (3.0 ± 0.7 versus 4.6 ± 3.7 nmol/mmol, p = 0.09).

Conclusions

Since DPD is considered a specific bone degradation marker and PYD is more widely distributed in connective tissues, the significant elevation in the mean PYD/DPD ratio in Friesian versus Warmblood horses (9.6 ± 1.6 versus 5.7 ± 1.8, p < 0.0001) suggests a soft tissue origin for the increased fPYD levels. Considering that a previous study found no differences in total collagen content between Friesian and Warmblood horses for tendon and aortic tissue, this indicates a higher rate of collagen degradation. The latter might, at least in part, explain the predisposition of Friesians to connective tissue disorders.

Parturition effects on reproductive health in the gilt and sow

In this review, we address significant characteristics of parturition in the pig and their connection to post-partum reproductive health and fertility. We discuss the normal physiology and behaviour around parturition and the effect of the second phase (expulsion of foetuses) on the third phase of parturition (expulsion of foetal membranes). In addition, we intend to cover retained placenta, and the connection to post-partum uterine health and fertility in the contemporary prolific sow. We also explore factors that support successful parturition or can cause potential problems. Successful parturition in the pig includes the possibility to express adequate maternal behaviour, rapid expulsion of the piglets, complete expulsion of the placenta, neonatal activity and colostrum intake. Abnormal incidents during any phase of parturition can cause subsequent problems. Duration of the expulsion phase of foetuses can be used as a simple measure of whether parturition is considered successful. Prolonged parturition can impair health of the sow and piglet and fertility after weaning. New insights, such as adding more fibre to sow diets during pregnancy, and especially during the period prior to farrowing, may prevent constipation, increase water intake of the sow around parturition and increase milk intake and performance of piglets. Maternal characteristics, including maternal behaviour, ease of parturition, colostrum production and piglet quality parameters, may be utilized to improve success rate of reproductive management during farrowing and early lactation. Additionally, we share some of the recent developments in methods, including ultrasonography in evaluation of post-partum uterine health. In conclusion, successful farrowing is of the greatest importance for reproductive health of the sow and survival of the piglets. We suggest connections exist among prolonged farrowing and yield of colostrum, retained placenta, development of PDS, and impaired involution of the uterus and reduced subsequent fertility.

Prolonged duration of farrowing is associated with subsequent decreased fertility in sows

In modern swine production failure of sows to become pregnant within the expected time after weaning results in major economic loss and culling of sows. The objective of this study was to determine the effects of duration of farrowing on subsequent repeat breeding rate. The study was performed in a commercial sow-pool piggery system in Finland comprising 148 sows (Yorkshire × Landrace). A multivariate analysis was undertaken on data for parity, weaning to estrus interval, boar, number of inseminations, season, sow back-fat thickness, gestation length, duration of farrowing, number of live-born piglets, number of stillborn piglets, lactation length, and number of piglets weaned. Furthermore, two farrowing systems (crate vs. pen) were investigated. A binary logistic regression was used to analyze the effect of these factors on the repeat breeding rate (pregnant vs. not pregnant at first insemination after weaning). The total duration of previous farrowing was longer in rebred sows (357 ± 207 minutes, average ± SD) than in pregnant sows (255 ± 126 minutes; P < 0.01). The other parameters were not statistically significant to the outcome of first insemination after weaning. In conclusion, we established that sows with long duration of farrowing have higher repeat breeding rate at the first insemination after weaning and could be used as an indicator for subsequent fertility.

The influence of late pregnancy and lactation on bone metabolism in mares

Pregnancy and lactation are periods of significant influence on bone metabolism that has not been investigated in equines. To examine the influence of late pregnancy and lactation on bone metabolism in mares, the changes in the blood serum/plasma total calcium (Ca), inorganic phosphates (Pi), pyridinoline (Pyd) and 17beta-estradiol (E2) concentration and the bone alkaline phosphatase (BAP) activity were investigated. The samples were taken from 11 mares on 60+/-10 and 20+/-10 days before foaling, and 20+/-10 and 60+/-10 days after foaling. The concentration/activity of Ca, Pi, Pyd and BAP increased significantly in early lactation, but the Pyd than decreased in the 4th period. A significant correlation was observed between the E2 and bone metabolism parameters. The results indicate low maintenance of normocalcaemia with reduced bone synthesis in late pregnancy and prove the role of estradiol in bone metabolism in mares during pregnancy and lactation.