Blood tests for early detection of pregnancy in cattle based on pregnancy-associated glycoproteins (PAGs) are commercially available. The objective of these studies were to compare the accuracy of ...blood tests to transrectal ultrasonography in detecting AI pregnancies, and to compare the accuracy of blood tests in predicting pregnancy loss. Beef cattle from 6 herds were synchronized using a recommended CIDR based protocol (Study 1: n = 460; Study 2: n = 472). Pregnancy status was determined by transrectal ultrasonography between days 28-40 following AI, blood samples were collected at this time. In study 2 a final pregnancy determination was performed at the end of the breeding season to determine pregnancy loss. Each serum sample was examined for PAG concentrations using a microtiter plate reader and/or scored by two technicians blind to pregnancy status and pregnancy loss. For study 1 Cohen's kappa statistics were calculated to assess the agreement between each test and transrectal ultrasonography. For study 2 data was analyzed using the GLIMMIX procedure of SAS with herd as a random effect, and loss, age, and their interaction included in the model. Agreement was good to very good for each test. There was no difference (P = 0.79) in sensitivity, but a difference (P<0.01) in specificity of the assays (88%, 64%, 87%, 90%) and in the overall percent correct (93%, 84%, 93%, 93%). There was an effect of pregnancy loss (P = 0.04), age (P = 0.0002), and their interaction (P = 0.06) on PAG concentrations. In conclusion both pregnancy tests were accurate at detecting AI pregnancies, and were in very good agreement with transrectal ultrasonography. Both tests detected differences in PAGs among females that maintained and lost pregnancy; however, prediction proved to be difficult as most females were above the threshold and would have been considered pregnant on the day of testing.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Embryo survival and pregnancy success is increased among animals that exhibit estrus prior to fixed time-artificial insemination, but there are no differences in conceptus survival to d16. The ...objective of this study was to determine effects of preovulatory estradiol on uterine transcriptomes, select trophectoderm (TE) transcripts, and uterine luminal fluid proteins. Beef cows/heifers were synchronized, artificially inseminated (d0), and grouped into either high (highE2) or low (lowE2) preovulatory estradiol. Uteri were flushed (d16); conceptuses and endometrial biopsies (n = 29) were collected. RNA sequencing was performed on endometrium. Real-time polymerase chain reaction (RT-PCR) was performed on TE (n = 21) RNA to measure relative abundance of IFNT, PTGS2, TM4SF1, C3, FGFR2, and GAPDH. Uterine fluid was analyzed using 2D Liquid Chromatography with tandem mass spectrometry-based Isobaric tags for relative and absolute quantitation (iTRAQ) method. RT-PCR data were analyzed using the MIXED procedure in SAS. There were no differences in messenger RNA (mRNA) abundances in TE, but there were 432 differentially expressed genes (253 downregulated, 179 upregulated) in highE2/conceptus versus lowE2/conceptus groups. There were also 48 differentially expressed proteins (19 upregulated, 29 downregulated); 6 of these were differentially expressed (FDR < 0.10) at the mRNA level. Similar pathways for mRNA and proteins included: calcium signaling, protein kinase A signaling, and corticotropin-releasing hormone signaling. These differences in uterine function may be preparing the conceptus for improved likelihood of survival after d16 among highE2 animals. Summary sentence Preovulatory estradiol did not impact conceptus survival to d16; however, it did influence uterine gene/protein expressions related to adhesion, endometrial remodeling, metabolism, and immune regulation, which may explain improved pregnancy success.
Transrectal ultrasonography is known as the gold standard for pregnancy detection, but requires costly equipment and technical skills; therefore, access to an inexpensive and more user-friendly ...method with similar accuracy could benefit cattle producers. Detection of pregnancy-associated glycoproteins can accurately determine pregnancy in ruminants; however, usually requires specialized equipment for the assay. Thus, the objectives of these studies were to 1) validate the IDEXX Alertys OnFarm Pregnancy Test (lateral flow) and compare the accuracy of all three commercial PAG assays to transrectal ultrasonography and 2) to determine the postpartum interval necessary for clearance of pregnancy-associated glycoproteins from the previous pregnancy to avoid false positives. In study 1, blood samples from previously identified pregnant Bos taurus females from six different herds (nulliparous n = 1,205 and multiparous n = 1,539; samples collected between d 27 to 285 of gestation over a three-year period) were utilized. In study 2, postpartum females (primiparous n = 48 and multiparous n = 66) from one herd were utilized: (n = 1,066; samples collected weekly for up to 12 weeks postpartum). In study 1, level of agreement between different methods of pregnancy detection was determined by Pearson's correlation and Kappa scores. In study 2, data were analyzed as a repeated measure using the MIXED procedure of SAS with main effects of parity, days postpartum (dpp), and parity by days postpartum, then data were analyzed further using the REG procedure of SAS. In study 1, transrectal ultrasonography and lateral flow were positively correlated (r = 0.77; P <0.01), with 92.4% agreement. In study 2, the abundance of absorbance of PAGs rapidly decreased from 0 to 50 days postpartum, then continued to gradually decrease (P <0.01; r = 0.90). Prior to 42 days postpartum, PAG concentrations were sufficiently elevated resulting in false positive readings in all assays. In conclusion, there is very good agreement between transrectal ultrasonography and PAG assays, but likelihood of false positive results are highif assays are performed fewer than 42 days postpartum.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Preovulatory estradiol is known to impact embryo quality and survival. The objective of this study was to determine the effects of preovulatory estradiol on the uterine environment and conceptus ...survival through maternal recognition of pregnancy. Beef cows/heifers were AIed following induced ovulation. Cows were grouped into high and low preovulatory estradiol. Conceptuses were collected on day 16 nonsurgically (Rep 1; n = 20), or following slaughter (Rep 2; n = 29). Blood was collected to determine plasma glucose concentrations, and uterine luminal fluid (ULF) was analyzed for protein, glucose, and interferon tau (IFNT) concentrations. Total cellular RNA was extracted from caruncular (CAR) and intercaruncular (INCAR) endometrial tissue. There was no effect of preovulatory estradiol on conceptus recovery rate (P = 0.38) or on apoptosis rate in the trophectoderm (P = 0.64). Cows in which a conceptus was recovered had greater concentrations of protein in the ULF (P = 0.04). Animals with elevated preovulatory estradiol had greater endometrial abundance of SLC2A1 (P = 0.05) and SLC5A1 (P = 0.04) in both INCAR and CAR tissue. Presence of a conceptus also tended to increase (P = 0.10) abundance of SLC5A1 in INCAR. In CAR tissue, cows with a conceptus had decreased SLC2A4 abundance (P = 0.05). In summary, conceptus recovery rates, apoptosis in the trophectoderm, IFNT, glucose, and protein concentration in ULF did not differ between cows that did or did not have an increase in preovulatory estradiol concentrations. Thus, there is no indication of increased conceptus survival to day 16 of pregnancy based on estradiol concentrations. Summary Sentence Conceptus survival to d 16 was similar among cows with and without elevated preovulatory estradiol; however, glucose transporter expression, and glucose and protein concentration in uterine fluids were influenced by estradiol and conceptus presence.
The uterine environment must provide sufficient endocrine conditions and nutrients for pregnancy maintenance and conceptus survival. The objective of this study was to determine the effects of ...preovulatory estradiol and conceptus presence on uterine transcripts and uterine luminal fluid (ULF) proteins. Beef cows/heifers were synchronized and artificially inseminated (d 0). Uteri were flushed (d 16); conceptuses and endometrial biopsies were collected. Total cellular RNA was extracted from endometrium for RNA sequencing and RT-PCR validation. There were two independent ULF pools made for each of the following groups: highE2/conceptus, highE2/noconceptus, lowE2/conceptus, and lowE2/noconceptus that were analyzed using the 2D LC-MS/MS based iTRAQ method. There were 64 differentially expressed genes (DEGs) and 77 differentially expressed proteins (DEPs) in common among the highE2/conceptus vs highE2/noconceptus and lowE2/conceptus vs lowE2/noconceptus groups. In summary, the interaction between preovulatory estradiol and the conceptus induces the expression of genes, proteins, and pathways necessary for pregnancy.
•There were 64 DEGs in common among the highE2/conceptus vs highE2/noconceptus groups and lowE2/conceptus vs lowE2/noconceptus groups.•There were 77 DEPs in common among highE2/conceptus vs highE2/noconceptus and lowE2/conceptus vs lowE2/noconceptus.•The interaction between preovulatory estradiol and conceptus presence influences uterine gene and protein expression.
Previous research has indicated that gender-sorted semen has decreased conception rates compared to conventional semen. A new method to skew the gender ratio of semen has been developed that does not ...use traditional sorting technology. Thus, the objective of this study was to evaluate the use of gender-ablated semen in a fixed-time AI protocol. Beef heifers and cows (n = 878) from six herds were synchronized with the 7-d CO-Synch plus CIDR protocol, and artificially inseminated (AI) after CIDR removal (cows 60–66 h; heifers 52–56 h). Estrus detection aids were applied at CIDR removal and estrus activity was determined at time of AI. Animals remained separated from bulls for at least 10 d after AI. Pregnancy success and fetal age were determined between d 28 and 70 after AI. Semen from five sires was utilized in this study, with two sires used in each herd. Sire 1 was used in all herds and the use of the second sire varied by herd (both conventional and gender-ablated semen from each sire was used in each herd). Data were analyzed using the GLIMMIX procedure in SAS and included the influence of semen type, estrus expression, semen type by estrus expression, dam age, and sire in the model. Herd was included as a random variable. Overall, conventional semen had greater conception rates compared to gender-ablated semen (P < 0.01; 67% vs 52%), and cows that had fully activated patches and partially activated patches had greater conception rates compared to animals that had not exhibited estrus (P < 0.01; 69%, 65%, and 45%). There was no semen type by estrus expression interaction (P = 0.24). Conception rates tended to be greater for conventional semen among animals that had activated patches (P = 0.06; 73% vs 65%) and partially activated patches (P = 0.06; 72% vs 59%). Conception rates were greater for conventional semen (P < 0.01; 56% vs 33%) among animals that did not exhibit estrus. There was no effect of dam age (P = 0.40) or sire (P = 0.92) on conception rates. In conclusion, Sexcel™ gender-ablated semen can successfully be used in fixed-time AI protocols among animals that exhibit estrus, but caution should be used among animals that do not exhibit estrus.
•Conventional semen had greater conception rates compared to gender-ablated semen.•Estrus increased conception rates with both gender-ablated and conventional semen.•Gender-ablated semen conception rates only tended to be decreased among animals in estrus.•Conventional semen had greater conception rates when animals did not exhibit estrus.
The objective was to determine the effects of pregnancy status on oxylipin profiles and eicosanoid metabolizing enzymes and in corpora lutea (CL) or endometrial (caruncle; CAR and intercaruncle; IC) ...tissues. Angus crossed cattle were synchronized with the CO-Synch protocol and artificially inseminated (AI). Sixteen days after AI, cattle were euthanized, and reproductive tracts collected from 6 non-pregnant and 6 pregnant cows. Oxylipin profiles and concentrations of progesterone (P4) were obtained from CL tissues. The activity of cytochrome P450 1A (CYP1A) and UDP-glucuronosyltransferase (UGT) enzymes were determined using specific luminogenic substrates. Data were analyzed using the MIXED procedure of SAS, and the model included pregnancy status. Corpora lutea of pregnant cattle contained greater (P < 0.05) concentrations of 9,10-DiHODE, 15,16-DiHODE, and 9,10-DiHOME. These oxylipins have been observed to increase cellular proliferation and vasodilation. Activity of CYP1A in the CL and UGT in CAR and IC was not different (P > 0.05) between pregnant and non-pregnant cattle. In the CL, activity of UGT was decreased (P < 0.05) in pregnant vs. non-pregnant cattle. The decrease in CL UGT activity during pregnancy indicates alterations in local hormone metabolism, while no differences in CL weight nor amount of P4 in CL were different between pregnant and non-pregnant cattle. Moreover, the increase in specific concentrations of oxylipins in the CL may indicate a novel pathway of steroid and eicosanoid metabolism during maternal recognition of pregnancy.
•UDP-glucuronosyltransferase activity is decreased in the CL during pregnancy.•Oxylipin concentrations vary in the CL of pregnant versus non-pregnant cattle.•These metabolic alterations may indicate novel pathways in pregnancy establishment.
Presynchronization was evaluated as a method to improve estrus response before fixed-time AI (FTAI). The objective was to compare FTAI results in beef cows from two different presynchronization ...approaches. Blood samples were collected on Day −14 (Day 0 = CIDR removal) to determine progesterone concentration (≥1 ng/mL = high, <1 ng/mL = low). In a subset (n = 1289), an additional blood sample was collected between Day −21 and −29 to determine cyclicity (if both the Day −14 and Day −21 to −29 samples were classified as low progesterone cows were classified as noncycling). Cows (n = 1388) from 30 herds were grouped by days postpartum (DPP) and age, and randomly assigned to either of two protocols. Cows assigned to the PG 6-day CIDR & FTAI protocol (PG6d) received prostaglandin F2α (PG) on Day −9, CIDR insertion and GnRH on Day −6, and CIDR removal and PG on Day 0. Cows assigned to the 7&7 Synch protocol (7&7) were administered PG and CIDR insertion on Day −14, GnRH on Day −7, and CIDR removal and PG on Day 0. For both protocols, FTAI occurred concurrently with GnRH 66 h after second PG. Pregnancy was determined by transrectal ultrasonography 30–40 d after FTAI. The GLIMMIX procedure of SAS was used to detect differences in estrus response and pregnancy success with herd as a random variable. Estrus response (0–66 h) was analyzed with two models, one included cyclicity and another replaced cyclicity with progesterone concentration at Day −14. In both models, cows assigned to the 7&7 protocol had greater (P < 0.01) estrus response than cows assigned to the PG6d protocol. The model including cyclicity, estrus response was impacted by the cyclicity by DPP interaction (P = 0.03), cyclicity by protocol interaction (P = 0.04), and the tendency of BCS by protocol interaction (P = 0.08). In the estrus response model that included progesterone concentration at Day −14, significant variables included the protocol by progesterone concentration at Day −14 (P = 0.01), and BCS (P < 0.01), while DPP (P = 0.08) and progesterone concentration at Day −14 (P = 0.07) were tendencies. Pregnancy success was influenced by estrual status (P < 0.01), body condition score (P = 0.04), and cycling status (P = 0.02), but was not influenced by protocol (P = 0.75; PG6d = 38 ± 5% and 7&7 = 37 ± 5%). In conclusion, effectiveness of presynchronization method depended on a cows’ physiological status, and the 7&7 protocol increased estrus response compared with PG6d, but there was no difference in pregnancy success.
•Estrus response was greater after the 7&7 protocol (76 ± 3% vs 56 ± 4%).•Estrus response was influenced by condition score, cycling status, and progesterone.•Pregnancy success was influenced by estrus, body condition, and cycling status.•Pregnancy success was not influenced by protocol (PG6d = 38 ± 5% and 7&7 = 37 ± 5%).•Effectiveness of presynchronization method depended on physiological status.
Abstract
Trace minerals are known to play important roles in early embryo development. The study objective was to determine effects of trace mineral source on heifer reproductive performance. Beef ...heifers (n = 129) were randomly assigned to one of two treatments. From weaning through breeding, all heifers were individually fed a basal diet supplemented with cobalt (Co), copper (Cu), manganese (Mn), and zinc (Zn) either from organic sources (COMP; Cu, Mn, and Zn amino acid complexes and Co glucoheptonate; Availa-4, Zinpro Corporation, Eden Prairie, MN) or inorganic sources (INORG; Cu, Mn, and Zn hydroxychlorides; Intellibond C, M, and Z, Micronutrients, Indianapolis, IN) and Co as CoSO4. Blood samples and a reproductive tract score (RTS) were collected to determine pubertal status. All animals were synchronized and artificially inseminated. Pregnancy status was determined by lymphocyte gene expression, circulating concentrations of pregnancy-associated glycoproteins (PAGs), and by transrectal ultrasonography after artificial insemination. Embryonic loss was defined as when a previously pregnant animal was subsequently diagnosed not pregnant. Data were analyzed using the MIXED procedure in SAS. Puberty (P = 0.44), pelvic area (P = 0.74), RTS (P = 0.49), and estrus expression (P = 0.82) were not influenced by treatment. There was no effect of treatment (P = 0.37) or treatment by time (P = 0.19) on pregnancy, but there was a tendency (P = 0.13) for decreased embryonic loss among COMP heifers (27 ± 6%) compared to INORG heifers (38 ± 6%). There was a treatment by pregnancy status by time interaction (P < 0.01) on circulating PAG concentrations with PAG concentrations tending (P = 0.08) to be greater on day 25 among heifers in the COMP treatment compared to heifers in the INORG group. In summary, source of trace mineral did not affect puberty, RTS, pelvic area, or overall pregnancy success, but feeding complexed trace minerals tended to increase circulating PAG concentrations and embryo survival.
Increased antral follicles are associated with greater fertility and a uterine environment that is more supportive of early embryonic development in beef heifers. Glucose is a primary energy source ...for embryos, and glucose concentrations are elevated in uterine luminal fluid (ULF) of pregnant heifers. We hypothesized that ULF glucose concentrations and endometrial transcript abundance for glucose transporters on d16 after insemination would be greater in heifers with increased numbers of antral follicles. Heifers classified with either increased or diminished antral follicle counts were artificially inseminated following the CO-Synch protocol (d0). On d16 after insemination, reproductive tracts of heifers were collected at an abattoir to retrieve conceptuses to determine pregnancy. Uterine luminal fluid was collected, endometrium was biopsied, total RNA was extracted and glucose transporter transcript abundances were determined. Data were analyzed using the MIXED procedure of SAS with antral follicle group, pregnancy status, and the interaction as fixed effects. Glucose concentrations in ULF were greater in heifers with increased antral follicle numbers. Glucose ULF concentrations increased in pregnant heifers. Facilitated glucose transporter member 1 (SLC2A1) transcript abundance was increased in the endometrium of pregnant heifers but was not different due to antral follicle number or the interaction. Differences in uterine concentrations of glucose associated with antral follicle number could be due to another mechanism, since glucose transporters were not different between antral follicle numbers. Therefore, heifers with increased number of antral follicles have increased energy availability in the uterus to support trophoblast proliferation and function.
•Increased antral follicles associated with greater uterine glucose concentrations.•Pregnancy status influences uterine glucose abundance at day 16 of gestation.•Antral follicle number does not impact abundance of glucose transporters.
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