Role of eicosanoids in abortion and its prevention by treatment with flunixin meglumine in cows during the first trimester of pregnancy

The Association of the Potential Risk Factors and Nutrition Elements with Abortion and Calving Rates of Egyptian Buffaloes (Bubalus bubalis)

Simple Summary

The association of the risk factors, serum constituents related to abortion and calving rates were investigated. Multiparous buffaloes were less likely to abort and more likely to calving than primiparous. Dry buffaloes had lesser odds of abortion and were six times more likely to give birth than those lactating. Conversely, the sex of the fetus had no impact. In aborted animals, serum glucose and copper were higher, whereas urea, uric acid, total proteins, total cholesterol, phosphorus, magnesium and iron were lower than in normal pregnancy. This emphasizes that risk factors and serum constituents associated with abortion aid to construct suitable preventive measures to raise reproductive performance.

Abstract

The aim of the present study was to investigate risk factors, serum minerals, and metabolites associated with non-infectious abortion and calving rates of Egyptian buffaloes. Data were obtained from 364 pregnant buffaloes of different ages and parities over 7 years from 2014 to 2020. Body condition score (BCS) was a risk factor regarding abortion and calving; the thinnest buffaloes were more likely to abort and less likely to calving than those with body energy reserves. In comparison with the spring season, aborting probability decreased 49.7% the odds ratio (OR = 0.503), while the chance of calving increased 72.1% (OR = 1.721) during winter. The parity was another significant factor related to abortion and calving rates; multiparous buffaloes were less likely to abort and more likely to calving than primiparous. Dry buffaloes had 88.2% (OR = 0.118) lesser odds of abortion and six times (OR = 6.012) more likely to give birth than those lactating. The sex of the fetus was not a risk factor regarding abortion or calving. Other variables significantly associated with abortion rate were glucose and copper in the sera of aborted buffaloes were significantly higher (p < 0.05), and those of urea, uric acid, total protein, total cholesterol, phosphorus, magnesium and iron were significantly (p < 0.05) lower than a normal pregnancy. In conclusion, the present results emphasize that the identification of the risk factors, serum minerals and metabolites associated with fetus abortion of Egyptian buffalo may provide useful information, which assists to construct suitable preventive measures to raise reproductive performance.

The genomic architecture of mastitis resistance in dairy sheep

Background

Mastitis is the most prevalent disease in dairy sheep with major economic, hygienic and welfare implications. The disease persists in all dairy sheep production systems despite the implementation of improved management practises. Selective breeding for enhanced mastitis resistance may provide the means to further control the disease. In the present study, we investigated the genetic architecture of four mastitis traits in dairy sheep. Individual animal records for clinical mastitis occurrence and three mastitis indicator traits (milk somatic cell count, total viable bacterial count in milk and the California mastitis test) were collected monthly throughout lactation for 609 ewes of the Greek Chios breed. All animals were genotyped with a custom-made 960-single nucleotide polymorphism (SNP) DNA array based on markers located in quantitative trait loci (QTL) regions for mastitis resistance previously detected in three other distinct dairy sheep populations.

Results

Heritable variation and strong positive genetic correlations were estimated for clinical mastitis occurrence and the three mastitis indicator traits. SNP markers significantly associated with these mastitis traits were confirmed on chromosomes 2, 3, 5, 16 and 19. We identified pathways, molecular interaction networks and functional gene clusters for mastitis resistance. Candidate genes within the detected regions were identified based upon analysis of an ovine transcriptional atlas and transcriptome data derived from milk somatic cells. Relevant candidate genes implicated in innate immunity included SOCS2, CTLA4, C6, C7, C9, PTGER4, DAB2, CARD6, OSMR, PLXNC1, IDH1, ICOS, FYB, and LYFR.

Conclusions

The results confirmed the presence of animal genetic variability in mastitis resistance and identified genomic regions associated with specific mastitis traits in the Chios sheep. The conserved genetic architecture of mastitis resistance between distinct dairy sheep breeds suggests that across-breed selection programmes would be feasible.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-017-3982-1) contains supplementary material, which is available to authorized users.

Lipopolysaccharide enhances apoptosis of corpus luteum in isolated perfused bovine ovaries in vitro

Lipopolysaccharide (LPS), the endotoxin of Gram-negative bacteria, has detrimental effects on the structure and function of bovine corpus luteum (CL)in vivo. The objective was to investigate whether these effects were mediated directly by LPS orviaLPS-induced release of PGF2α. Bovine ovaries with a mid-cycle CL were collected immediately after slaughter and isolated perfused for 240 min. After 60 min of equilibration, LPS (0.5 μg/ml) was added to the medium of five ovaries, whereas an additional six ovaries were not treated with LPS (control). After 210 min of perfusion, all ovaries were treated with 500 iu of hCG. In the effluent perfusate, concentrations of progesterone (P4) and PGF2αwere measured every 10 and 30 min, respectively. Punch biopsies of the CL were collected every 60 min and used for RT-qPCR to evaluate mRNA expression of receptors for LPS (TLR2,-4) and LH (LHCGR); the cytokineTNFA; steroidogenic (STAR,HSD3B), angiogenic (VEGFA121,FGF2), and vasoactive (EDN1) factors; and factors of prostaglandin synthesis (PGES,PGFS,PTGFR) and apoptosis (CASP3,-8,-9). Treatment with LPS abolished the hCG-induced increase in P4(P≤0.05); however, there was a tendency (P=0.10) for increased release of PGF2αat 70 min after LPS challenge. Furthermore, mRNA abundance ofTLR2,TNFA,CASP3,CASP8,PGES,PGFS, andVEGFA121increased (P≤0.05) after LPS treatment, whereas all other factors remained unchanged (P>0.05). In conclusion, reduced P4responsiveness to hCG in LPS-treated ovariesin vitrowas not due to reduced steroidogenesis, but was attributed to enhanced apoptosis. However, an impact of luteal PGF2αcould not be excluded.

Production of prostaglandins in placentae and corpus luteum in pregnant hinds of red deer (Cervus elaphus)

Prostaglandins (PGs) are synthesized from arachidonic acid by prostaglandin synthase 2 (PTGS2) and specific terminal PG synthases such as PGES and PGFS. The role of PGs in the reproductive processes of domestic ruminants is well recognized, whereas in cervidae, it is almost unknown, although it is noteworthy because some species of this family are valued in meat production and trophies. The aim of this study was to determine an effective marker of pregnancy and investigate the production and secretion of PGs in placenta and CL tissue in pregnancy. In the preliminary experiment, the levels of progesterone and 17-β estradiol (RIA; N = 14 divided into seven pregnant and seven nonpregnant hinds) were measured in the peripheral blood. In the main experiment, a comparison of messenger RNA (real-time polymerase chain reaction) and protein expression (Western blotting) of PTGS2, PGES, and PGFS, the level of prostaglandin E2 (PGE2) and PGF2α in the placentae and CL in pregnant hinds (aged 3-4 years, ca. 100 days of pregnancy, N = 6). In pregnant hinds, the level of progesterone in the blood was higher than that in nonpregnant hinds (P < 0.05), whereas the level of E2 was similar in all animals (P > 0.05). The highest messenger RNA expression of PTGS2, PGES, and PGFS was observed in the placentae than in the CL (P < 0.05). The protein expression of PTGS2 and PGES was elevated in the placentae compared with the CL (P < 0.05). The PGE2 output was the highest in cotyledonary tissue (P < 0.05). Pregnancy development in hinds around 100 days is regulated by arachidonic acid metabolites, especially PGE2 produced by the placentae, which production increases in pregnancy. Further studies are required to unravel the mechanisms involved in the regulation of PG and biosynthetic enzymes in uteroplacental and ovarian tissues during pregnancy in red deer females.

Effects of flunixin meglumine and transportation on establishment of pregnancy in beef cows1

Objectives of these studies were to determine the effects of flunixin meglumine (FM) administration on early embryonic mortality and circulating PG and cortisol concentrations in transported and non-transported cows. Cows (n = 483) from 3 locations were used to evaluate the effects of transportation and FM approximately 14 d after AI on the establishment of pregnancy and serum concentrations of progesterone, PGF metabolite (PGFM), and cortisol. Treatments were transport (n = 129), transport + FM (n = 128), no transport (n = 130), and no transport + FM (n = 96). Multiparous cows (n = 224) were used at 2 locations, and nulliparous cows (n = 259) were used at 1 location. The no transport + FM treatment was used at only 2 locations. Flunixin meglumine (approximately 1.1 mg/kg of BW; i.m.) was administered before the cows were separated into transportation groups. Transportation included 4 to 6 h of transportation, without calves, via semitractor trailer. Nontransported cows remained penned, with their calves in adjacent pens, during the same period as the transported cows. Blood samples were collected from all cows before and after treatment and, at 2 locations, approximately 3 h after the onset of treatment. Location affected AI pregnancy rate (P < 0.01). Treatment effects, although not significant (P = 0.16), were of a magnitude to be considered practically important. Cows that received transportation + FM tended (P = 0.07) to have greater AI pregnancy rates (74%) than those that did not receive FM (66%), irrespective of transportation. Cortisol concentration was greater (P < 0.05) for transported cows than for nontransported cows. Cows receiving FM had greater (P < 0.05) AI pregnancy rates than non-FM cows (71 vs. 61%, respectively). Cows receiving transportation had lower (P < 0.01) mean PGFM concentrations than nontransported cows (45.4 vs. 54.6 pg/mL, respectively), and cows receiving FM had lower (P < 0.01) mean PGFM concentrations than non-FM cows (39.4 vs. 60.6, respectively). We conclude that transportation of cows approximately 14 d after AI increased serum cortisol concentrations but did not affect AI pregnancy rates. However, treatment of cows with FM increased AI pregnancy rates, irrespective of whether they were transported.

F4 fimbriae expressed by porcine enterotoxigenic Escherichia coli, an example of an eccentric fimbrial system?

An overwhelming number of infectious diseases in both humans and animals are initiated by bacterial adhesion to carbohydrate structures on a mucosal surface. Most bacterial pathogens mediate this adhesion by fimbriae or pili which contain an adhesive lectin subunit. The importance of fimbriae as virulence factors led to research elucidating the regulation of fimbrial expression and their molecular assembly process. This review provides an overview of the current knowledge of induction, expression and assembly of F4 (K88) fimbriae and discusses its unique as well as its identical characteristics compared to other intensively studied fimbriae or pili expressed by Escherichia coli.

Do calcium-mediated cellular signalling pathways, prostaglandin E2 (PGE2), estrogen or progesterone receptor antagonists, or bacterial endotoxins affect bovine placental function in vitro?

The major objective of this experiment was to determine whether the bovine placenta could be stimulated to secrete progesterone, since the bovine placenta secretes little progesterone when the corpus luteum is functional. Secondly, we wanted to determine whether reported abortifacients or progesterone or estrogen receptor antagonists affected bovine placental prostaglandin secretion. The ovine placenta secretes half of the circulating progesterone at day 90 of pregnancy and PGE2 appears to regulate ovine placental progesterone secretion. Calcium has been reported to regulate placental progesterone secretion in cattle. Diced 186-245-day placental slice explants from six Brahman and six Angus cows were incubated in vitro at 39.5 degrees C under 95% air: 5% CO2 at pH 7.2 in 5 ml of M-199 for 1 h in the absence of treatments and for 4 and 8 h in the presence of treatments. Treatments were: vehicle; R24571; compound 48/80; IP3; PGE2; CaCl2; cyclosporin A; lipopolysaccharide (endotoxin) from Salmonella abortus equi., enteriditis, and typhimurium; monensin; ionomycin; arachidonic acid; mimosine; palmitic acid; progesterone, androstenedione; estradiol-17beta; A23187; RU-486; or MER-25. Jugular and uterine venous plasma and culture media were analyzed for progesterone, PGE2 and PGF2alpha by radioimmunoassay (RIA). Plasma hormone data were analyzed by a One-Way Analysis of Variance (ANOVA). Hormone data in culture media were analyzed for breed and treatment effects by a Factorial Design (2 breeds, 2-range of days, 21 treatments) for ANOVA (2 x 2 x 21). Since hormone data secreted by placental tissue in vitro did not differ (P > or = 0.05) by breed or range of days of pregnancy, data were pooled and analyzed by a One-Way ANOVA. Concentrations of PGE2 in uterine venous blood were two-fold greater (P < or = 0.05) in Angus than Brahman cows. PGE2 and PGF2alpha in vehicle controls increased from 4 to 8h (P < or = 0.05), but not progesterone (P > or = 0.05) Progesterone in culture media treated with RU-486 increased (P < or = 0.05) at 4 and 8 h compared to vehicle controls and was not affected by other treatments (P > or = 0.05). Concentrations of PGE2 in media at 4 and 8 h were lower (P < or = 0.05) when compared to controls except treatment with PGE2 at 4 and 8h and RU-486 at 8h (P > or = 0.05). PGF2alpha was increased (P < or = 0.05) by RU-486 at 8h and no other treatment affected PGF2alpha at 4 or 8 h (P < or = 0.05). In conclusion, modulators of cellular calcium signalling pathways given alone do not affect bovine placental progesterone secretion at the days studied and progesterone receptor-mediated events appear to suppress placental progesterone, PGF2alpha, and PGE2 secretion in cattle. In addition, PGE2 does not appear to regulate bovine placental progesterone secretion when the corpus luteum is functional and bacterial endotoxin does not appear to affect bovine placental secretion of PGF2alpha or PGE2.

Influence of subclinical mastitis during early lactation on reproductive parameters

Our objective was to determine the effects of mastitis during early lactation on the reproductive performance of Jersey cows. From 1986 to 1997, quarter foremilk samples were collected every 4 to 8 wk during lactation, at drying off, near calving, and when clinical mastitis was diagnosed and were evaluated microbiologically to identify causative bacteria. Services per conception, days open, and days to first service were obtained from DHIA records on 752 cows. Cows were separated by mastitis type (clinical, n = 186; subclinical, n = 240; control, uninfected or infected after confirmed pregnancy, n = 326). Cows were reclassified based on the time of clinical or subclinical mastitis as follows: period 1, before first service (n = 374); period 2, between first service and pregnancy (n = 52); and period 3, after confirmed pregnancy or uninfected (control; n = 326). Milk production did not differ for any group separations. Reproductive performance did not differ between gram-negative or gram-positive mastitis pathogens. Cows with clinical or subclinical mastitis before first service had increased days to first service (77.3+/-2.7 and 74.8+/-2.7 d), days open (110.0+/-6.9 and 107.7+/-6.9 d), and services per conception (2.1+/-0.2 and 2.1+/-0.2) compared with controls (67.8+/-2.2 d, 85.4+/-5.8 d, 1.6+/-0.2; P < 0.05). Days to first service were not increased in cows with clinical or subclinical mastitis during period 2 (70.6+/-3.3 and 61.2+/-7.8 d). However, days open (143.6+/-8.5 d) and services per conception (3.0+/-0.2) were increased (P < 0.05) in cows with clinical mastitis during period 2, but not in cows with subclinical mastitis (90.9+/-20.2 d and 2.1+/-0.5). Cows initially diagnosed subclinical that became clinical during period 2 exhibited increased days to first service (93.9+/-10.1 d), days open (196.0+/-26.2 d), and services per conception (4.3+/-0.7) compared with control animals (P < 0.05). In conclusion, subclinical mastitis reduced reproductive performance of lactating cows similar to clinical mastitis. Subclinical mastitis followed by clinical mastitis resulted in the most severe loss in reproductive performance.

Influence of clinical mastitis during early lactation on reproductive performance of Jersey cows

The purpose of this study was to determine the influence of clinical mastitis on reproductive performance of high producing Jersey cows. Cows (n = 102) with clinical mastitis during the first 150 d of lactation were evaluated. Groups were balanced according to lactation number and days of lactation and sub-divided as follows: group 1, clinical mastitis before first artificial insemination (AI) (n = 48); group 2, clinical mastitis between first AI and pregnancy (n = 14); group 3, clinical mastitis after confirmed pregnancy (n = 40); and group 4, control cows (n = 103) with no clinical mastitis. No differences in reproductive performance were detected because of milk production or mastitis caused by Gram-positive or Gram-negative pathogens. The number of days to first AI was significantly greater for cows with clinical mastitis before first AI (93.6 d) than for all other groups (71.0 d). Artificial inseminations per conception were significantly greater for cows with clinical mastitis after first AI (2.9) than for cows with clinical mastitis before first AI (1.6), cows with no clinical mastitis, or cows with clinical mastitis after confirmed pregnancy (1.7). The number of days to conception for cows with clinical mastitis after first AI (136.6 d) was significantly greater than that for control cows and that for cows that developed clinical mastitis after confirmed pregnancy (92.1 d). Clinical mastitis during early lactation markedly influenced reproductive performance of Jersey cows.

Pathogenesis of preterm labor and preterm premature rupture of membranes associated with intraamniotic infection

We have proposed a model in which the initiation of human parturition in the presence of infection is controlled by the host. Systemic maternal infections such as pyelonephritis or localized infections such as deciduitis can trigger parturition by the activation of the monocyte and macrophage system in peripheral blood and human decidua. Preterm labor and preterm PROM can, according to this, be considered events that occur when the intrauterine or maternal environment is hostile and threaten the survival of the fetal-maternal pair. From this point of view, the initiation of preterm labor may have survival value. Why does intrauterine infection result in preterm labor in some cases and PROM in others? It is possible that regulation of different components of the host response has an important role to play in determining clinical presentation. Thus, if preferential activation of the host response leads to the secretion of uterotonic agents (i.e., prostaglandins), preterm labor will result. On the other hand, if the activation of the host response results predominantly in the production of proteases (i.e., leukocyte elastase and MMPs), patients are more likely to experience PROM. Preterm labor and preterm PROM can be considered expressions of the same basic phenomenon: activation of the host-defense macrophage system. Although we have provided evidence that infection is an important factor in the pathogenesis of these conditions, preterm parturition should be considered as a syndrome with multiple causes.

Associations among prostaglandin F2alpha, plasma zinc, copper and iron concentrations and fetal loss in cows and mares

The objective of this study was to test the hypothesis that PGF2alpha is associated with abortion and changes in plasma Zn, Cu, and Fe concentrations in cows and mares in their first trimester of pregnancy. Eleven pregnant cows were infused with endotoxin (n = 5) or endotoxin plus an inhibitor of cycloxygenase, flunixin meglumine (n = 6). Blood was collected over a 5-d period. Additionally, 4 mares were treated every 24 h with cloprostenol sodium and blood was collected hourly until abortion. Plasma Zn, Cu, and Fe were determined. Three of five cows treated with endotoxin aborted, but none of the six cows treated with endotoxin and flunixin meglumine aborted. Aborting cows had lower plasma Zn (P = 0.048) over the 5-d study period compared with the nonaborting cows. The changes in Zn corresponded to release of PGF2alpha. All 4 mares aborted and plasma Zn concentrations were lower (P = 0.008) and Cu/Zn was higher (P = 0.02) 12 h after cloprostenol treatment. Plasma Zn may be a useful biomarker for risk of spontaneous abortion, and the decline in plasma Zn may be caused by PGF2alpha.

Bacterial endotoxemia and reproductive effects in ruminants

Gram-negative bacterial infections are fairly common in domestic ruminants. They can cause an endotoxemia with a variety of systemic signs, including fever, leukopenia, and ruminal stasis. Reproductive effects of endotoxemia include alterations in the estrous cycle and inability to maintain pregnancy. Diagnosis of endotoxemia is based largely on clinical evaluation. Confirming the diagnosis of endotoxin-induced reproductive alterations also is complicated by the lag period between clinical signs and abortion or infertility.

Cellular and chemical mediators of type 1 hypersensitivity in calves infected with Ostertagia ostertagi: histamine, prostaglandin D2, prostaglandin E2 and leukotriene C4

Plasma histamine, prostaglandin E2 (PG) D2, PGE2, and leukotriene (LT) C4 levels were determined in 26 Holstein steers before and after natural or experimental infection with Ostertagia ostertagi. Post-infection abomasal lymph was also assayed for PGD2, PGE2, and LTC4. Histamine determinations were performed on abomasal tissue from three locations. Results showed that: (1) tissue histamine levels increased in steers with type 2 ostertagiosis, (2) lymphatic PGD2 and PGE2 levels were increased, probably as a result of macrophage activity, (3) lymphatic LTC4 levels increased in steers with type 1 ostertagiosis, and were correlated with tissue eosinophilia, and (4) plasma levels of PGD2, PGE2, LTC4 and histamine were not useful for predicting worm burdens. These findings suggest a functional role for eosinophils and mast cells in the pathophysiology of ostertagiosis, through mediation of a type 1 hypersensitivity reaction.