The relationship between accessory corpus luteum maintenance and pregnancy-specific protein B in pregnant Japanese Black cows

Nerve Growth Factor-Beta, purified from bull seminal plasma, enhances corpus luteum formation and conceptus development in Bos taurus cows

Nerve growth factor-β (NGF) has been identified in the seminal plasma of livestock and is required for the induction of ovulation in camelids. Until recently, it was thought to play a negligible role in species with spontaneous ovulation. On the contrary, recent studies have shown that systemic administration of NGF, purified from llama seminal plasma, was associated with larger corpus luteum (CL) diameter and higher concentrations of progesterone (P) following ovulation. The objective of the current project was to determine if systemic administration of NGF, purified from bovine seminal plasma, would improve CL formation and enhance embryonic development. Our hypothesis was that systemic administration of NGF at the time of artificial insemination in cows would lead to increased CL volume, increased P secretion, and improved expression of markers of conceptus development and maternal recognition of pregnancy. Seminal plasma was harvested from semen collected by electroejaculation in Angus cross bulls. Purification of NGF was performed using a combination of anion- and cation-exchange chromatography and gradient elution. Beef cows were randomly assigned to CONT (n = 30) or NGF (n = 30) groups and synchronized using a 7-day Co-Synch + CIDR program. At time of insemination (day 0), NGF cows received 296 µg of purified NGF, reconstituted in 12 mL of PBS, and CONT cows received 12 mL of PBS intramuscularly. Blood samples were collected from the coccygeal vein of each cow at days 0, 3, 7, 10, 14, 19, 21, 28, 31, 38, 45, and 66. Ultrasound was performed at each time point for determination of ovarian structures (day 0), corpus luteum volume (all time points), and fetus detection (day 28). Statistical analysis was performed using analysis of variance with repeated-measures in R (R version 3.2.2; https://www.r-project.org/). At day 28, 17/30 (57%) CONT cows and 21/30 (70%) NGF cows were diagnosed as pregnant (P = 0.15). At day 0, cows that later became pregnant had a larger follicular diameter (1.46 cm) than those diagnosed as open (1.16 cm; P < 0.01). Follicular diameter at day 0 did not differ significantly between CONT and NGF groups for either open (P = 0.35) or pregnant (P = 0.90) cows. CL volume in open cows was affected by day (P < 0.001) with no treatment (P = 0.84) or treatment by day (P = 0.42) interaction. CL volume in pregnant cows was affected by both day (P < 0.001) and treatment (P < 0.001), with CONT cows having a higher CL volume than NGF cows. Though NGF appeared to have an inhibitory effect on CL volume in pregnant cows, results are still pending for quantification of P, insulin-like growth factor 1, pregnancy-specific protein B, and interferon-stimulated genes, which will more accurately assess the effects that NGF may have on conceptus development. The results of this study will help us to better understand the role of the seminal plasma protein, NGF, at ovulation and determine if it can be utilised to enhance insemination programs in cattle.

Proposal of a new model for CL regression or maintenance during pregnancy on the basis of timing of regression of contralateral, accessory CL in pregnant cows

Methods for pregnancy determination and the effects of body condition on pregnancy status in Rocky mountain elk ([formula omitted

Characteristics and retention of luteal structures, extended postinsemination cycle, progesterone, and pregnancy-specific protein B in serum after human chorionic gonadotropin treatment of dairy cows

Effect of Luteinizing Hormone (LH), PGE 2, 8-EPI-PGE 1, 8-EPI-PGE 2, Trichosanthin, and Pregnancy Specific Protein B (PSPB) on Secretion of Progesterone In Vitro by Corpora Lutea (CL) from Nonpregnant and Pregnant Cows

Effects of Luteinizing Hormone (LH), PGE 2, 8-Epi-PGE 1, 8-Epi-PGF 2α, Trichosanthin and Pregnancy Specific Protein B (PSPB) on Secretion of Prostaglandin (PG) E (PGE) or F 2α (PGF 2α) In Vitro by Corpora Lutea (CL) From Nonpregnant and Pregnant Cows

What regulates placental steroidogenesis in 90-day pregnant ewes?

Temporarily decreasing progesterone after timed artificial insemination decreased expression of interferon-tau stimulated gene 15 (ISG15) in blood leukocytes, serum pregnancy-specific protein B concentrations, and embryo size in lactating Holstein cows

Pregnancy-specific protein B (PSPB) and progesterone concentrations were determined by RIAs in venous plasma during early pregnancy after 177 artificial inseminations (AI) performed in 76 cows and 71 heifers. The females were bled at 24, 26, 30-35 days and approximately 70 days (for non-returns to oestrus) after AI. In non-pregnant females without extended CL maintenance (progesterone less than 1.5 ng/ml on Day 24) and or showing a normal time of return to oestrus (Group 1, N = 63), PSPB concentrations were undetectable whatever the stage after AI except in 2 cows. In pregnant animals (N = 83; Group 2) progesterone concentrations were greater than 10 ng/ml from Day 24 to the time of rectal palpation and PSPB concentrations rose continuously from 0.42 +/- 0.07 (s.e.m.) ng/ml (Day 24) to 4.06 +/- 0.3 ng/ml (time of rectal palpation). No coefficient of correlation between PSPB and progesterone concentrations was significant whatever the day of gestation studied. In cows with extended luteal function and subsequently found to be non-pregnant (late embryonic mortality) PSPB was undetectable (N = 21; Group 3) or detectable (N = 10; Group 4) at Days 24, 26 and/or 30-35 of pregnancy. At 24 and 26 days after AI progesterone concentrations were intermediate between those of Groups 1 and 2. At Day 24 females of Group 4 had higher progesterone concentrations than those of Group 3 (P less than 0.05), but no differences between these two groups existed at subsequent stages after AI.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in serum pregnancy-associated glycoprotein, pregnancy-specific protein B, and progesterone concentrations before and after induction of pregnancy loss in lactating dairy cows

Circulating microRNAs (miRNAs) have been used as biomarkers for various diseases and physiological conditions in humans and mice; studies in domestic animals, particularly cattle, are limited. The importance of early pregnancy diagnosis (especially within the 21-d cow estrous cycle) in the livestock industry is extremely high. This study compared the circulating miRNAs in bred non-pregnant and pregnant Japanese Black cows, explored miRNAs as biomarkers for early pregnancy diagnosis, and established a measurement system that included selecting an appropriate reference miRNA and determining the effect of hemolysis on miRNA quantification in plasma. miRNA was extracted from the plasma of Japanese Black cows on day 21 after artificial insemination and subjected to a customized bovine oligonucleotide microarray for expression analysis. Differentially expressed miRNAs and reference miRNA candidates were selected and validated using reverse transcription-quantitative PCR (RT-qPCR). An appropriate endogenous reference miRNA for normalization was selected using NormFinder software. To evaluate the effect of hemolysis on miRNA quantification, hemolyzed samples were prepared using plasma from four cows in the estrous cycle and subjected to RT-qPCR. A total of 124 miRNAs were detected in bovine plasma by microarray analysis in bred non-pregnant and pregnant cows. The levels of five circulating miRNAs were significantly higher in pregnant cows than in bred non-pregnant cows, and 24 miRNAs were detected only in the pregnant group. NormFinder analysis and RT-qPCR validation showed that miR-2455 was an appropriate reference miRNA in the plasma of bred non-pregnant and pregnant Japanese Black cows, and miR-19b, miR-25, miR-29a, and miR-148a were significantly higher in the pregnant group. These four circulating miRNAs did not change during the estrous cycle and were less affected by hemolysis. In the current study, we found four miRNAs, miR-19b, miR-25, miR-29a, and miR-148a, which were present at high levels in the plasma of pregnant Japanese Black cows. Since these miRNAs are less affected by hemolysis, they may potentially be used as biomarkers for early pregnancy diagnosis in cattle.

Pregnancy-specific protein B and progesterone in monitoring viability of the embryo in early pregnancy in the cow after experimental infection with [formula omitted

Dynamics of ovarian follicular development in cattle following hysterectomy and during early pregnancy

Volume of luteal tissue and concentration of serum progesterone in cows bearing homogeneous corpus luteum or corpus luteum with cavity.