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Among other bioactive molecules, milk contains high amounts of sialylated milk oligosaccharides (MOs) that influence numerous processes in the offspring. For instance, sialylated MOs inhibit the invasion of pathogens and positively influence the gut microbiome to support the optimal development of the offspring. For these reasons, sialylated MOs are also used in infant formula as well as food supplements and are potential therapeutic substances for humans and animals. Because of the high interest in sialylated bovine MOs (bMOs), we used several analytical approaches, such as gas and liquid chromatography in combination with mass spectrometry, to investigate in detail the profile of sialylated bMOs in the milk of Holstein Friesian cows during early lactation. Most of the 40 MOs identified in this study were sialylated, and a rapid decrease in all detected sialylated bMOs took place during the first day of lactation. Remarkably, we observed a high variance within the sialylation level during the first two days after calving. Therefore, our results suggest that the content of sialylated MOs might be an additional quality marker for the bioactivity of colostrum and transitional milk to ensure its optimized application for the production of milk replacer and food supplements.

The losses of piglets in commercial pig farming remain at concerning levels and need to be addressed through the implementation of new sustainable breeding and management strategies. In fact, piglets are especially at risk in the first days of life. Both genetics and the farrowing process have been shown to impact piglet vitality. In addition, knowledge of the animal-intrinsic responses in adapting to extra-uterine life is particularly important but is scarcely described in the scientific literature. In this review, the three phases that constitute neonatal adaptation in the pig are systematically presented. The first phase of early adaptation involves primarily the development of cardiorespiratory function (within the first 10 min of life) as well as thermoregulatory processes and acid–base balance (up to 24 h of life). In the second phase, homeostasis is established, and organ maturation takes place (up to 14 d post natum). The final third phase aims at the development of neurological, immunological and muscular features (up to 28 d of life). The involvement of aggravating and ameliorating factors such as dystocia, low colostrum yield and heat supply is key to the development of strategies to reduce piglet losses and increase vitality. The insights are of particular value in addressing current concerns in pig farming and to further improve animal welfare in pig production across different management types.

Ovulation is an inflammation-like process, and cyclooxygenase-2 (COX-2)-dependent production of prostaglandin E2 (PGE2) is its key mediator. Balanced regulation of inflammatory processes in high-yielding dairy cows may be essential for physiological ovulation and fertility. This study aimed to elucidate the mechanisms underlying ovulation failure and cyst development after disturbing intrafollicular inflammatory cascades. Therefore, nonselective (indomethacin and flunixin-meglumine), COX-2 selective (meloxicam), and highly COX-2 selective (NS-398) inhibitors were injected into preovulatory follicles 16 h after administration of GnRH, and ovulation was monitored via ultrasound examination. Additionally, follicular fluid was collected after injection of indomethacin, meloxicam, and NS-398. Moreover, primary granulosa cell cultures from preovulatory follicles were prepared and treated with indomethacin, meloxicam, and NS-398. The concentrations of 17β-estradiol, progesterone, and prostaglandin E2 (PGE2) in the follicular fluid and cell supernatant were estimated. Indomethacin and flunixin-meglumine blocked ovulation, even at low doses, and led to ovarian cyst development. The selective and highly selective COX-2 inhibitors meloxicam and NS-398 were not effective in blocking ovulation. However, indomethacin, meloxicam, and NS-398 significantly and comparably reduced PGE2 concentration in vivo and in vitro (P < 0.05) but had no effect on estradiol or progesterone production. This may contradict the generally accepted hypothesis that PGE2 is a key mediator of ovulation and progesterone production. Our results suggest a connection between ovarian disorders and inflammatory actions in early postpartum cows.

Among other bioactive molecules, milk contains high amounts of sialylated milk oligosaccharides (MOs) that influence numerous processes in the offspring. For instance, sialylated MOs inhibit the invasion of pathogens and positively influence the gut microbiome to support the optimal development of the offspring. For these reasons, sialylated MOs are also used in infant formula as well as food supplements and are potential therapeutic substances for humans and animals. Because of the high interest in sialylated bovine MOs (bMOs), we used several analytical approaches, such as gas and liquid chromatography in combination with mass spectrometry, to investigate in detail the profile of sialylated bMOs in the milk of Holstein Friesian cows during early lactation. Most of the 40 MOs identified in this study were sialylated, and a rapid decrease in all detected sialylated bMOs took place during the first day of lactation. Remarkably, we observed a high variance within the sialylation level during the first two days after calving. Therefore, our results suggest that the content of sialylated MOs might be an additional quality marker for the bioactivity of colostrum and transitional milk to ensure its optimized application for the production of milk replacer and food supplements. [ABSTRACT FROM AUTHOR]

The aim of this study was to establish a model to induce cystic ovarian follicles (COFs) in cattle using the cyclooxygenase inhibitor, indomethacin. Eighteen Holstein-Frisian cattle were synchronized with prostaglandin F2alpha (PGF2α) and gonadotropin-releasing hormone (GnRH). Ultrasound-guided transvaginal intrafollicular injections were performed in 23 preovulatory follicles with different concentrations of indomethacin 16 h after GnRH administration. An injection of 0.2 ml 35 µM indomethacin solution (resulting in a final concentration of 8 µg/ml in the follicular fluid) was the minimal dosage leading to COF formation. The induced COFs reached a maximum mean diameter of 36.9 ± 4.5 mm eleven days after injection. The estrous cycle was extended to 25–39 days. Luteinization was first observed 4 days after injection, accompanied by a slight increase in plasma progesterone concentration. The bioactivity of indomethacin was demonstrated by the decrease of prostaglandin E2 in the follicular fluid of three animals. The method presented here is minimally invasive and allows for the generation of defined COFs for further investigations.

Ultrasound examinations offer the possibility to monitor fetal growth and estimate fetal weight, but reference data for such techniques in pigs are rare. The aim of this study was therefore to identify suitable anatomical fetal structures for monitoring physiological growth dynamics by ultrasound examinations and to estimate fetal weight using appropriate mathematical models. For this purpose, 198 fetuses of 15 primiparous Landrace sows were examined by ultrasound on days 36, 50, 64, 79 and 92 of gestation in live sows and in utero after slaughter. Biparietal distance (BPD), rostro-occipital distance (ROD), corpus vitreum diameter, heart length, abdominal circumference (AC) and transverse and sagittal abdominal diameter were determined by ultrasound in utero, and the fetuses were subsequently ex uteri determined and weighed. Reference curves for the continuous increase in fetal parameters over the pregnancy were established. Weight estimation could be performed with linear models at a known stage of pregnancy using one or a combination of parameters. Cubic equations were developed to describe the relationships between body measurements and weight over the course of gestation. BPD, ROD and AC have been shown to be the most suitable parameters for fetal weight estimation, but in live sows, only the fetal head parameters could be easily and reliably determined. These techniques could initially be of interest for research into fetal growth, but future application in veterinary practice is also conceivable.

Sialylated milk oligosaccharides and glycoconjugates have several positive effects on the mucosal barrier, the gut microbiome, and an effective immune system. For this reason, they are important biomolecules for mammary gland health and optimal development of offspring. In milk, the major sialic acid, N-acetylneuraminic acid (Neu5Ac), can be attached as monosialyl-residues or as polymers. To investigate the sialylation processes during lactation of German Holstein cows, we analyzed udder tissue in addition to milk at different time points of lactation. The analysis of the milk samples revealed that both the levels of Neu5Ac and its polymer, polysialic acid (polySia), rapidly decreased during the first three days of lactation, and a high interindividual variance was observed. In mature milk, however, the sialylation status remains relatively constant. The results indicate that mammary gland epithelial cells are one source for milk polySia, since immunohistochemistry of udder tissue exhibited strong polySia staining in these cells. Furthermore, both polysialyltransferases, ST8SiaII and ST8SiaIV, are expressed. Based on known functions of monosialyl residues and polySia, we discuss the potential impact of these biomolecules and the consequences of the heterogeneous sialylation status of milk in relation to udder health and offspring health.

Here we assessed the effects of dietary essential fatty acids on the developmental competence of oocytes in cows and on the functionality of follicular granulosa cells (GC). Lactating German Holstein cows were supplemented from week 9 ante partum (ap) until week 8 post-partum (pp) in four dietary groups designed as (i) control (CTRL: coconut oil), (ii) essential fatty acid (EFA: linseed and safflower oil), (iii) conjugated linoleic acid (CLA: Lutalin®), and (iv) EFA+CLA (mixture of linseed oil, safflower oil and Lutalin®). EFA, CLA or EFA+CLA supplementation did not improve in vitro embryo production. However, higher proportions of α-linolenic acid (ALA) and cis-9, trans-11 CLA were observed in the follicular fluid suggesting the exposure of GC to relatively high levels of ALA and cis-9, trans-11 CLA. Consequently, we tested different concentrations of ALA and cis-9, trans-11 CLA in a bovine GC culture model for their effects on steroid production, marker gene expression and viability. Both fatty acids upregulated CD36 and downregulated the expression of FOXL2, while ALA significantly increased SOX 9 transcript levels. Both ALA and cis-9, trans-11 CLA reduced the CCND2 expression and cis-9, trans-11 CLA induced apoptosis. ALA and cis-9, trans-11 CLA significantly down-regulated the expression of STAR, CYP19A1, FSHR, LHCGR and decreased the 17β-Estradiol (E2) and progesterone (P4) production. In conclusion, dietary lipids did not improve in vitro embryo production, while ALA and cis-9, trans-11 CLA affected the morphology and functionality of GC. This could suggestively lead to compromised follicle development and ovarian cyclicity in dairy cows.

The placenta is the central foetal organ that ensures a sufficient exchange of nutrients and metabolites for adequate foetal growth. Specific data profiles for placental characteristics from modern pig lines with high fertility and today's genetics are not currently available. This study focuses on describing the placental weight and size of German Landrace pigs and any subsequent relationship to litter number and important fertility parameters for these sows. As a basis for data collection, 55 litters from primi- and multiparous German Landrace sows with a total of 832 piglets were used. From these births, 766 placentas were recovered and weighed, with their lengths measured and the placental efficiency per litter also calculated. Mean placental weights ranged from 179 ± 60 to 422 ± 96 g between litters, and the mean length was between 61 ± 12 and 145 ± 19 cm. The placental efficiency was at a level of 5.1 ± 0.7. The investigated parameters were only slightly affected by the litter number (r = 0.3), and the means did not significantly differ between different litter numbers. With increasing litter size, the piglet weights and placental lengths were significantly decreased (r = -0.4 and r = -0.3), possibly due to limited uterine space. However, litter size had a strong positive correlation with the total litter placental weight (r = 0.7); therefore, in this study, the placental efficiency was not affected by a higher number of piglets per sow. Higher means for placental weights (r = 0.7) and lengths (r = 0.7) in a particular litter significantly improved the piglet birth weights. The reported variability in placental characteristics between litters suggests that there is an opportunity to selectively breed for improved piglet weight and homogeneity and thus improved piglet health and survival.

Transcriptome profiling of FACS purified small luteal cells (SLC) and large luteal cells (LLC), isolated from mid-cycle corpora lutea (day 10–11), was performed using Affymetrix GeneChip Bovine Gene 1.0 ST Arrays. Gene expression was recorded using an Affymetrix gene chip scanner 3000. The corresponding expression array intensity (.CEL) files were deposited in the Gene Expression Omnibus (GSE106641). The subsequent expression analyses of CEL files were carried out for identifying important transcripts and their functions associated with SLC and LLC. These data have been comprehensively evaluated and interpreted in the companion article, “Global gene expression analysis indicates that small luteal cells are involved in extracellular matrix modulation and immune cell recruitment in the bovine corpus luteum” [1].

The bioactivity of the IGF system is not a function of isolated hormone concentrations in a given biological matrix. Instead, the biological activities of IGFs are regulated by IGFBPs, IGFBP proteases, and inhibitors of IGFBP proteases. Therefore, assays based on IGF-related bioactivity may describe functions of the complete IGF system in a given biological matrix. Of particular interest are the IGF system effects on the AKT/mTOR pathway, as a dominant system for controlling growth, metabolism, and aging. In order to improve the sensitivity of IGF-dependent bioactivity, we made use of the known short-term and enhancing effects of IGFBP2 on the intracellular PI3K pathway. As a specific readout of this pathway, and further as a marker of the mTOR pathway, we assessed the phosphorylation of AKT-Ser473. Preincubation using IGFBP2 enhanced IGF1-dependent AKT-Ser473 phosphorylation in our experimental system. The assay’s specificity was demonstrated by inhibition of IGF1 receptors outside or inside the cell, using antiserum or small molecule inhibitors, which reduced AKT phosphorylation in response to exogenous IGF1 (p < 0.05). The maximal response of AKT phosphorylation was recorded 15 to 60 min after the addition of IGF1 to cell monolayers (p < 0.001). In our cellular system, insulin induced AKT phosphorylation only at supra-physiological concentrations (µM). Using this novel assay, we identified the differential biological activity of the IGF system in AKT-Ser473 phosphorylation in serum (mouse, naked mole rat, and human), in cerebrospinal fluid (human), and in colostrum or mature milk samples (dairy cow). We have developed a sensitive and robust bioassay to assess the IGF-related activation of the AKT/mTOR pathway. The assay works efficiently and does not require expensive cell culture systems. By using capillary immuno-electrophoresis, the readout of IGF-related bioactivity is substantially accelerated, requiring a minimum of hands-on time. Importantly, the assay system is useful for studying IGF-related activity in the AKT/mTOR pathway in a broad range of biological matrices.

The provision of NaCl, according to current recommendations, to horses in moderate work has been shown to induce immediate postprandial acidosis. The present study aimed to clarify whether this NaCl induced acidosis i) persists beyond the immediate postprandial period, and ii) is still present after a 2 week adaptation period. Six adult warmblood mares in moderate work received daily 1.00 kg hay per 100 kg body weight (bwt) only together with 0.64 kg unprocessed cereal grains/100 kg bwt.d as fed basis. Using a 3x3 Latin Square, either 0 (NaCl-0), 50 (NaCl-50) or 100 (NaCl-100) g NaCl/d were fed together with the concentrates in two equal doses for 3 weeks. During the final week, a mineral digestibility trial was undertaken. The middle sodium and chloride intake (NaCl-50) at least met the most common recommendations for moderate work. Morning (7:00 AM) urine and venous blood samples were collected on days 0, 1-4, 8, and 15, and analysed for pH, acid-base status, creatinine and electrolyte concentrations. Fractional electrolyte clearances (FC) were determined. Mean apparent sodium digestibility ranged between 60-62% whereas chloride digestibility was consistently above 94%. Supplementing 100 g but not 50 g of NaCl resulted in significant reduction of blood pH and base excess as well as urinary pH and urine acid excretion. Both 50 g and 100 g NaCl supplementation caused a significant reduction in base and net acid-base excretion, urine density and potassium concentration, but increased urine sodium concentration and the FC of sodium and chloride (P < 0.05). This suggests that a high proportion of the recommended salt doses is excreted renally. The above effects of NaCl supplementation persisted over the 2 week measurement period. Results suggest that feeding 100 g NaCl to moderately exercising horses results in mild metabolic acidosis, whereas feeding 50 g according to current recommendations resulted in compensated acidosis.

Double fixed-time insemination after ovulation induction is commonly used in pigs to obtain in vivo produced embryos at defined stages of development for downstream biotechnological applications. However, variations in the time of ovulation and fertilisation of the ovulated oocytes by spermatozoa, mainly in one of the inseminations, can cause diversities in embryo development. The aim of the present study was to reduce embryo diversity and to achieve a 'uniform outcome' of porcine embryo stages using single laparoscopic fixed-time insemination (LIUI). Altogether, 48 puberal German Landrace gilts were included in the study. Estrus of gilts was synchronized by 15-day long altrenogest (Regumate®) feeding and follicle development was stimulated with 850 IU eCG 24 h after the final altrenogest application. Ovulation was induced with 500 IU hCG 80 h after eCG. LIUI was performed 31 h after hCG treatment. Gilts under general anaesthesia were fixed in a dorsal position, a pneumoperitoneum was produced and three trocar cannulas were inserted into the abdomen for optics and instruments. Each uterine horn was carefully punctured 10-15 cm caudal from the utero-tubal junction with a 2.5 mm trocar. A 2.2 mm catheter was inserted about 3 cm into the uterine lumen and 20 ml of extended fresh boar semen (32.2 × 106 sperm cells/ml) were injected. Embryos were surgically flushed from the genital tract two (Day 2) and three (Day 3) days after insemination. Altogether, 778 oocytes/embryos were recovered (recovery rate 68 ± 17%); 45 of 48 gilts (93.8%) revealed fertilisation and 76.1% of the recovered embryos (n = 592) were at the 2- and 4-cell stage. On Day 2 (n = 22 gilts), a higher percentage of gilts (72.7%, P < 0.05) displayed only 2-cell embryos compared with gilts which had 2- and 4-cell (22.7%), or only 4-cell embryos (4.6%). On Day 3 (n = 23 gilts), the proportion of gilts with 2-cell, 2- and 4-cell, and only 4-cell embryos shifted to 4.3%, 0% and 95.7%, respectively (P < 0.05). The results of the present study demonstrate high rates of fertilisation and homogenously developed embryos after single fixed-time laparoscopic intrauterine insemination in gilts. Additionally, these results were achieved by inseminating a 60% lower number of sperm cells per insemination dose compared to usual doses used for transcervical insemination. In conclusion, LIUI can be recommended for the in vivo production of embryos in a homogeneous developmental stage, and also as an alternative method for low-dose insemination.

Secretion of adequate levels of progesterone from a proper corpus luteum (CL), which develops out of the cells of a healthy preovulatory follicle, is a key-factor for establishment of a pregnancy. The aim of this study was to investigate the relationship between morphological and secretory characteristics of preovulatory follicles and their corresponding corpus luteum with regard to the post-partum period in high-yielding dairy cows. Therefore, ultrasound-guided aspirations of preovulatory follicles were performed repeatedly, using 20 first lactating cows between 26 and 121 days after parturition. Heat was induced with a PGF analogon followed by administration of a GnRH analogon. The dominant follicle was aspirated 21 h after administration of the GnRH analogon. The diameters of the follicles were estimated at aspiration and the morphology of the resulting luteal tissue was examined on day 14 after follicle aspiration using ultrasonographic examinations. Concentrations of progesterone (P4) and 17-beta-oestradiol (E2) were determined in the follicular fluids (FF) and P4 concentration was estimated at the time of CL examination in plasma. A CL development occurred in 82% after dominant follicle aspiration. The interval of time between parturition and follicle aspiration did not affect the investigated variables. The diameter of the aspirated preovulatory follicle was positively correlated to the cross-section area of the developed luteal tissue (R = 0.60; P < 0.01) as well as to the plasma P4 concentration on day 14 after follicle aspiration (R = 0.47; P < 0.05). Also, E2 concentrations in FF were positively correlated to cross-section area of the luteal tissue (R = 0.54; P < 0.05). Comparing the FF of the follicles that gave rise to a CL after aspiration to follicles that did not, both types had comparable P4, but the former type harboured higher E2 concentrations. In conclusion, preovulatory follicle diameter as well as steroid concentrations in the follicular fluid could be used prospectively to identify cows which will have well-developed CLs and high plasma P4 levels later. On the other hand, CL development after follicle aspiration can be used as a retrospective quality parameter of dominant follicles. These results will help to identify suitable animals for breeding or recipients for embryo transfer.

[This corrects the article DOI: 10.1371/journal.pone.0152689.].

The peptide hormone INSL3 is uniquely produced by the fetal testis to promote the transabdominal phase of testicular descent. Because it is fetal sex specific, and is present in only very low amounts in the maternal circulation, INSL3 acts as an ideal biomarker with which to monitor the movement of fetal hormones within the pregnant uterus of a polytocous species, the pig. INSL3 production by the fetal testis begins at around GD30. At GD45 of the ca. 114 day gestation, a time at which testicular descent is promoted, INSL3 evidently moves from male to female allantoic compartments, presumably impacting also on the female fetal circulation. At later time-points (GD63, GD92) there is less inter-fetal transfer, although there still appears to be significant INSL3, presumably of male origin, in the plasma of female fetuses. This study thus provides evidence for substantial transfer of a peptide hormone between fetuses, and probably also across the placenta, emphasizing the vulnerability of the fetus to extrinsic hormonal influences within the uterus.

High environmental temperatures induce detrimental effects on various reproductive processes in cattle. According to the predicted global warming the number of days with unfavorable ambient temperatures will further increase. The objective of this study was to investigate effects of acute heat stress during the late pre-ovulatory phase on morphological, physiological and molecular parameters of dominant follicles in cycling cows during lactation. Eight German Holstein cows in established lactation were exposed to heat stress (28°C) or thermoneutral conditions (15°C) with pair-feeding for four days. After hormonal heat induction growth of the respective dominant follicles was monitored by ultrasonography for two days, then an ovulatory GnRH dose was given and follicular steroid hormones and granulosa cell-specific gene expression profiles were determined 23 hrs thereafter. The data showed that the pre-ovulatory growth of dominant follicles and the estradiol, but not the progesterone concentrations tended to be slightly affected. mRNA microarray and hierarchical cluster analysis revealed distinct expression profiles in granulosa cells derived from heat stressed compared to pair-fed animals. Among the 255 affected genes heatstress-, stress- or apoptosis associated genes were not present. But instead, we found up-regulation of genes essentially involved in G-protein coupled signaling pathways, extracellular matrix composition, and several members of the solute carrier family as well as up-regulation of FST encoding follistatin. In summary, the data of the present study show that acute pre-ovulatory heat stress can specifically alter gene expression profiles in granulosa cells, however without inducing stress related genes and pathways and suggestively can impair follicular growth due to affecting the activin-inhibin-follistatin system.

The innate immune system has numerous mechanisms to fight against pathogens, including the formation of neutrophil extracellular traps (NETs). By spreading out chromatin, antimicrobial peptides and enzymes, neutrophils efficiently trap pathogens like bacteria and facilitate their elimination. During this process, high concentrations of extracellular histones can be reached. Several researchers have demonstrated that the cytotoxic characteristics of these histones can trigger diseases like sepsis. Interestingly, the carbohydrate polysialic acid (polySia) can bind histones and reduce histone-mediated cytotoxicity in a chain length-dependent manner. In the present study, we examined the chain length of polySia in plasma and tested its ability to decrease the cytotoxic characteristics of extracellular histones. Remarkably, we detected polySia not only in the soluble fraction of plasma, but also on enriched extracellular vesicles (EVs). Chain length analysis revealed that polySia chains originating from human plasma can consists of more than 40 sialic acid residues and show a cytoprotective effect against extracellular histones. Intriguingly, polySia is not only present in human plasma but also in fish and other branches of vertebrates. Thus, polySia is a physiological element in plasma and may represent a natural buffer for extracellular histones.

Simple Summary: In addition to their function as energy sources, monosaccharides are used to build complex structured oligo- and polysaccharides, which play numerous essential roles as functional biomolecules. Such bioactive sugars are also key components of milk, since they have positive impacts on intestinal development, the gut microbiome, and an effective immune system, along with the learning and memory ability of offspring. Moreover, milk oligo- and polysaccharides have anti-adhesive properties against pathogenic microorganisms and viruses and are, therefore, important for the health of the mammary gland and the offspring. One key monosaccharide of such oligo- and polysaccharides is the sialic acid N-acetylneuraminic acid (Neu5Ac). Since bovine milk is not only important for calf health but also, in the case of colostrum, as a functional food for humans, it is of particular interest, at which time of lactation the highest amounts of these bioactive molecules are found in bovine milk. Our results demonstrate that on the day of calving, the highest amounts of Neu5Ac and its polymers are present in bovine milk and, thus, the sialic acid-dependent benefits of bovine milk are also highest at this time. Sialylated milk oligosaccharides and glycoconjugates have several positive effects on the mucosal barrier, the gut microbiome, and an effective immune system. For this reason, they are important biomolecules for mammary gland health and optimal development of offspring. In milk, the major sialic acid, N-acetylneuraminic acid (Neu5Ac), can be attached as monosialyl-residues or as polymers. To investigate the sialylation processes during lactation of German Holstein cows, we analyzed udder tissue in addition to milk at different time points of lactation. The analysis of the milk samples revealed that both the levels of Neu5Ac and its polymer, polysialic acid (polySia), rapidly decreased during the first three days of lactation, and a high interindividual variance was observed. In mature milk, however, the sialylation status remains relatively constant. The results indicate that mammary gland epithelial cells are one source for milk polySia, since immunohistochemistry of udder tissue exhibited strong polySia staining in these cells. Furthermore, both polysialyltransferases, ST8SiaII and ST8SiaIV, are expressed. Based on known functions of monosialyl residues and polySia, we discuss the potential impact of these biomolecules and the consequences of the heterogeneous sialylation status of milk in relation to udder health and offspring health. [ABSTRACT FROM AUTHOR]

Ultrasound examinations offer the possibility to monitor fetal growth and estimate fetal weight, but reference data for such techniques in pigs are rare. The aim of this study was therefore to identify suitable anatomical fetal structures for monitoring physiological growth dynamics by ultrasound examinations and to estimate fetal weight using appropriate mathematical models. For this purpose, 198 fetuses of 15 primiparous Landrace sows were examined by ultrasound on days 36, 50, 64, 79 and 92 of gestation in live sows and in utero after slaughter. Biparietal distance (BPD), rostro-occipital distance (ROD), corpus vitreum diameter, heart length, abdominal circumference (AC) and transverse and sagittal abdominal diameter were determined by ultrasound in utero, and the fetuses were subsequently ex uteri determined and weighed. Reference curves for the continuous increase in fetal parameters over the pregnancy were established. Weight estimation could be performed with linear models at a known stage of pregnancy using one or a combination of parameters. Cubic equations were developed to describe the relationships between body measurements and weight over the course of gestation. BPD, ROD and AC have been shown to be the most suitable parameters for fetal weight estimation, but in live sows, only the fetal head parameters could be easily and reliably determined. These techniques could initially be of interest for research into fetal growth, but future application in veterinary practice is also conceivable. [ABSTRACT FROM AUTHOR]

Ovulation is an inflammation-like process, and cyclooxygenase-2 (COX-2)-dependent production of prostaglandin E2 (PGE2) is its key mediator. Balanced regulation of inflammatory processes in high-yielding dairy cows may be essential for physiological ovulation and fertility. This study aimed to elucidate the mechanisms underlying ovulation failure and cyst development after disturbing intrafollicular inflammatory cascades. Therefore, nonselective (indomethacin and flunixin-meglumine), COX-2 selective (meloxicam), and highly COX-2 selective (NS-398) inhibitors were injected into preovulatory follicles 16 h after administration of GnRH, and ovulation was monitored via ultrasound examination. Additionally, follicular fluid was collected after injection of indomethacin, meloxicam, and NS-398. Moreover, primary granulosa cell cultures from preovulatory follicles were prepared and treated with indomethacin, meloxicam, and NS-398. The concentrations of 17ß-estradiol, progesterone, and prostaglandin E2 (PGE2) in the follicular fluid and cell supernatant were estimated. Indomethacin and flunixinmeglumine blocked ovulation, even at low doses, and led to ovarian cyst development. The selective and highly selective COX-2 inhibitors meloxicam and NS-398 were not effective in blocking ovulation. However, indomethacin, meloxicam, and NS-398 significantly and comparably reduced PGE2 concentration in vivo and in vitro (P < 0.05) but had no effect on estradiol or progesterone production. This may contradict the generally accepted hypothesis that PGE2 is a key mediator of ovulation and progesterone production. Our results suggest a connection between ovarian disorders and inflammatory actions in early postpartum cows. [ABSTRACT FROM AUTHOR]