scholarly journals Effects of administering exogenous bovine somatotropin to beef heifers during the first trimester on conceptus development as well as steroid and eicosanoid metabolizing enzymes

2021 ◽  
Author(s):  
Carla D Sanford ◽  
Megan P T Owen ◽  
Nicola Oosthuizen ◽  
Pedro L P Fontes ◽  
Kimberly A Vonnahme ◽  
...  
Keyword(s):  
Fetal Liver ◽  
Average Daily Gain ◽  
Plasma Concentrations ◽  
First Trimester ◽  
Bovine Somatotropin ◽  
Fetal Membrane ◽  
Beef Heifers ◽  
Placental Development ◽  
Tissue Samples ◽  
Fetal Fluid

ABSTRACT The aim of this study was to evaluate the effect of bovine somatotropin (bST) on fetal and placental development during the first third of gestation in beef heifers. Angus heifers (n = 97) were randomly assigned to either receive a 500 mg injection of bST (BST) biweekly on d 0, 15, 29, 43, and 57 of gestation, or not receive bST (CTL) throughout the experiment. Body weight (BW) was assessed on d -9, -3, 0, 15, 22, 29, 43, 50, 57, 64, and 77, while blood samples were collected on d 0, 22, 50, and 64. Pregnancy status was determined via transrectal ultrasonography on d 29 and 64. A subset of pregnant heifers (BST, n = 7; CTL, n = 5) were harvested on d 84 and complete gravid reproductive tracts and liver tissue were collected for analysis. Cytochrome P450 1A (CYP1A), 2C (CYP2C), 3A (CYP3A), and uridine 5’-diphospho-glucuronosyltransferase (UGT) activities were determined. Mean change in BW and average daily gain of heifers between fixed-time artificial insemination (d 0) and d 77 did not differ between treatments (P ≥ 0.05). Mean concentrations of insulin-like growth factor 1 (IGF-1) were greater (P < 0.001) in BST (347 ± 27.7 ng/mL) compared to CTL (135 ± 32.8 ng/mL) heifers. Mean placental weight, fetal membrane weight, uterine weight, ovarian and corpus luteum (CL) weights, as well as fetal morphometric data did not differ (P ≥ 0.05) between treatments. However, BST heifers had greater (P = 0.03) quantities of combined fetal fluid compared to CTL (521.6 ± 22.9 g vs. 429.6 ± 27.14 g, respectively). Tendencies were observed for BST heifers to have reproductive tracts with fewer placentomes (P = 0.08) and fetuses with greater umbilical diameters (P = 0.09) compared to CTL. Activity of CYP1A did not differ (P ≥ 0.05) within maternal and fetal liver, caruncle, cotyledon, or CL tissue samples between treatments. Furthermore, CYP3A activity was only observed in maternal liver samples and was not different between treatments (P ≥ 0.05). Interestingly, CYP2C activity was greater (P = 0.01) in the liver of BST vs. CTL heifers, and UGT activity was greater (P = 0.02) in the CL from BST heifers compared to CTL. In conclusion, administration of bST during the first third of gestation increased plasma concentrations of IGF-1, which resulted in an increase in fetal fluid, decrease in placentome number, and greater umbilical diameter, but failed to alter fetal development.

scholarly journals The Nasopharyngeal, Ruminal, and Vaginal Microbiota and the Core Taxa Shared across These Microbiomes in Virgin Yearling Heifers Exposed to Divergent In Utero Nutrition during Their First Trimester of Gestation and in Pregnant Beef Heifers in Response to Mineral Supplementation

2021 ◽  
Vol 9 (10) ◽  
pp. 2011
Author(s):  
Samat Amat ◽  
Devin B. Holman ◽  
Kaycie Schmidt ◽  
Ana Clara B. Menezes ◽  
Friederike Baumgaertner ◽  
...  
Keyword(s):  
Reproductive Tract ◽  
Average Daily Gain ◽  
Methanogenic Archaea ◽  
16S Rrna Gene Sequencing ◽  
First Trimester ◽  
Vaginal Microbiota ◽  
Rrna Gene ◽  
Beef Heifers ◽  
Β Diversity ◽  
Significant Difference

In the present study, we evaluated whether the nasopharyngeal, ruminal, and vaginal microbiota would diverge (1) in virgin yearling beef heifers (9 months old) due to the maternal restricted gain during the first trimester of gestation; and (2) in pregnant beef heifers in response to the vitamin and mineral (VTM) supplementation during the first 6 months of pregnancy. As a secondary objective, using the microbiota data obtained from these two cohorts of beef heifers managed at the same location and sampled at the same time, we performed a holistic assessment of the microbial ecology residing within the respiratory, gastrointestinal, and reproductive tract of cattle. Our 16S rRNA gene sequencing results revealed that both α and β-diversity of the nasopharyngeal, ruminal and vaginal microbiota did not differ between virgin heifers raised from dams exposed to either a low gain (targeted average daily gain of 0.28 kg/d, n = 22) or a moderate gain treatment (0.79 kg/d, n = 23) during the first 84 days of gestation. Only in the vaginal microbiota were there relatively abundant genera that were affected by maternal rate of gain during early gestation. Whilst there was no significant difference in community structure and diversity in any of the three microbiota between pregnant heifers received no VTM (n = 15) and VTM supplemented (n = 17) diets, the VTM supplementation resulted in subtle compositional alterations in the nasopharyngeal and ruminal microbiota. Although the nasopharyngeal, ruminal, and vaginal microbiota were clearly distinct, a total of 41 OTUs, including methanogenic archaea, were identified as core taxa shared across the respiratory, gastrointestinal, and reproductive tracts of both virgin and pregnant heifers.

320 The effects of biweekly administration of recombinant bovine somatotropin during the first trimester on fetal development in gestating beef heifers

2017 ◽  
Vol 95 (suppl_4) ◽  
pp. 158-159
Author(s):  
C. D. Sanford ◽  
N. Oosthuizen ◽  
P. L. P. Fontes ◽  
L. B. Canal ◽  
K. A. Vonnahme ◽  
...  
Keyword(s):  
Fetal Development ◽  
First Trimester ◽  
Bovine Somatotropin ◽  
Beef Heifers ◽  
Recombinant Bovine Somatotropin

scholarly journals 273 Impacts of commingling on health and productive responses of beef heifers during feedlot receiving

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 193-194
Author(s):  
Jacob Wiegand ◽  
Reinaldo F Cooke ◽  
Alice Brandão ◽  
Kelsey Schubach ◽  
Eduardo Colombo ◽  
...  
Keyword(s):  
Feed Intake ◽  
Average Daily Gain ◽  
Plasma Concentrations ◽  
Stress Reactions ◽  
Beef Heifers ◽  
Mineral Supplement ◽  
Feed Withdrawal ◽  
Access To Water ◽  
And Performance ◽  
Daily Gain

Abstract This experiment compared physiological, health, and performance responses of beef heifers assigned to different commingling schemes (1, 2, or 4 sources/pen) during a 56-d feedlot receiving period. Ninety-six recently weaned Angus-influenced heifers were purchased from a commercial auction facility. Heifers originated from 4 cow-calf ranches, and were reared in the same herd within each ranch since birth. Heifers were loaded by source into commercial livestock trailers at the auction yard, and transported for 8 h to stimulate the stress of a long haul. Heifers were not mixed with cohorts from other sources prior to and at the auction yard. Upon arrival at the receiving yard (d -2), shrunk body weight (BW) was recorded, and heifers were maintained in 4 paddocks by source with ad libitum access to hay, water, and a mineral supplement for 36 h. On d 0, heifers were ranked by source and shrunk BW and allocated to 1 of 24 drylot pens (4 heifers/pen) containing: 1) heifers from a single source (NOCOM, n = 8 pens), 2) heifers from 2 sources (COM2, n = 8 pens), or 3) heifers from 4 sources (COM4, n = 8 pens). From d 0 to 55, heifers had free-choice access to water and a total-mixed ration. Heifers were assessed for bovine respiratory disease (BRD) signs and feed intake was recorded from each pen daily. Blood samples were collected from all heifers on d 0, 6, 13, 27, 41, and 55, and shrunk BW (after 16 h of water and feed withdrawal) was collected on d 56 for average daily gain (ADG) calculation. Final shrunk BW and ADG did not differ (P ≥ 0.83) between NOCOM, COM2, and COM4 heifers (0.85, 0.88, and 0.82 kg/d of ADG, respectively, SEM = 0.08). No treatment effects were detected (P ≥ 0.77) for feed intake and feed efficiency, as well as plasma concentrations of haptoglobin and cortisol. No treatment differences were noted (P ≥ 0.49) for morbidity (53.1, 68.7, and 56.2% of NOCOM, COM2, and COM4 heifers diagnosed with BRD, respectively; SEM = 9.7) or mortality during the experiment. A similar (P ≥ 0.97) proportion of NOCOM, COM2, and COM4 heifers diagnosed with BRD required at least two treatments to recover from sickness. In turn, a third treatment was not required for NOCOM heifers, which was less compared with COM4 (P = 0.05) and similar (P = 0.23) compared with COM2 heifers. Perhaps the number of heifers assigned to commingled pens, and resultant pre-existing social groups, was not sufficient to stimulate the stress reactions caused by social destabilization.

scholarly journals Temporal Changes of the Endothelin System in Human Cytotrophoblasts During the First Trimester of Pregnancy

2018 ◽  
pp. S247-S255 ◽  
Author(s):  
A. MAJALI-MARTINEZ ◽  
S. BARTH ◽  
U. LANG ◽  
G. DESOYE ◽  
M. CERVAR-ZIVKOVIC
Keyword(s):  
First Trimester ◽  
Temporal Changes ◽  
Trophoblast Invasion ◽  
Receptor Subtypes ◽  
Placental Development ◽  
Receptor System ◽  
Tissue Samples ◽  
Endothelin System ◽  
First Trimester Of Pregnancy ◽  
Proliferation And Invasion

The first trimester of pregnancy is characterized by continuous proliferation, invasion and differentiation of cytotrophoblasts. These processes are precisely controlled both, in space and time by molecules such as endothelin-1 (ET-1). ET-1 is expressed in human first trimester trophoblast and is known to stimulate cytotrophoblast proliferation through endothelin A and B receptor subtypes (ETA and ETB), and cytotrophoblast invasion through ETB. However, temporal changes of the ET system during the first trimester of pregnancy have not been previously studied. This study tested the hypothesis that ET-1 release, ETA and ETB expression are increased towards the end of the first trimester of pregnancy (weeks 10-12 vs. weeks 6-9), resulting in increased cytotrophoblast proliferation and invasion. Tissue samples were obtained from 17 surgical pregnancy interruptions (week 6-9: n=9; week 10-12: n=8). After cytotrophoblast isolation, the invasive and proliferative phenotypes were immune-separated by an α6-integrin antibody. Both proliferative and invasive cytotrophoblasts were cultured separately on plastic or Matrigel for 24 h. ET-1 release into the culture medium of both cytotrophoblast subtypes was measured by radioimmunoassay. ETA and ETB mRNA expression was measured by RT-PCR, and the ET-1 effect on cytotrophoblast proliferation and invasion was determined using proliferation and invasion assays, respectively. ET-1 release increased from early to late first trimester of pregnancy in both proliferative (1.8-4.5 fold) and invasive cytotrophoblasts (9.3-28 fold), especially when cultured on Matrigel. This was paralleled by less ETB mRNA on invasive cytotrophoblasts independent of the time period in first trimester, whereas ETA expression was similar on proliferative an invasive cytotrophoblasts. Proliferation and invasion of cytotrophoblasts under control conditions decreased from early to late first trimester. ET-1 stimulated both processes at both periods with the most pronounced effect (7-fold) on invasion in late first trimester. The ET-1/ET-receptor system changes between weeks 6-9 and 10-12 in pregnancy. Our data suggest an autocrine and endocrine ET-1 effect, which is stronger in late than in early first trimester of pregnancy paralleled by different stimulatory effects on trophoblast invasion and proliferation. In general, this suggests time as an additional effector of the critical processes governing placental development in the first trimester of human pregnancy.

scholarly journals Supplementation frequency and amount modulate postweaning growth and reproductive performance of Bos indicus-influenced beef heifers

2020 ◽  
Vol 98 (8) ◽  
Author(s):  
Philipe Moriel ◽  
Elizabeth Palmer ◽  
Marcelo Vedovatto ◽  
Matheus B Piccolo ◽  
Juliana Ranches ◽  
...  
Keyword(s):  
Nutritive Value ◽  
Average Daily Gain ◽  
Plasma Concentrations ◽  
Bos Indicus ◽  
Prostaglandin F2α ◽  
Beef Heifers ◽  
Negative Effects ◽  
Concentrate Supplementation ◽  
Supplementation Frequency ◽  
Calving Season

Abstract This 2-yr study evaluated the growth and puberty attainment of Bos indicus-influenced beef heifers offered 2 different postweaning concentrate supplementation amounts and delivery frequencies. On day 0 of each year, 64 Brangus crossbred heifers were stratified by initial body weight (BW) and age (mean = 244 ± 22 kg; 314 ± 17 d) and assigned into 1 of 16 bahiagrass pastures (4 heifers/pasture/yr). Treatments were randomly assigned to pastures in a 2 × 2 factorial design (4 pastures/treatment/yr) and consisted of concentrate dry matter (DM) supplementation at 1.25% or 1.75% of BW which were offered either daily (7×) or 3 times weekly (3×) for 168 d. On day 56 of each year, heifers were assigned to an estrus synchronization protocol consisting of intravaginal controlled internal drug release (CIDR) insertion on day 56, CIDR removal on day 70, i.m. injection of 25 mg of prostaglandin F2α (PGF2α) on day 86, and i.m. injection of 100 µg of gonadotropin-releasing hormone and timed-AI at 66 h after PGF2α injection (day 89). Heifers were exposed to Angus bulls from day 89 to 168 (1 bull/pasture). Pregnancy diagnosis was assessed on day 213 of each year. Supplementation amount × frequency effects were not detected (P ≥ 0.12) for any variable, except for plasma concentrations of glucose (P = 0.10) and urea nitrogen (PUN; P = 0.01). Herbage mass, herbage allowance, and nutritive value did not differ (P ≥ 0.12) among treatments. Increasing supplementation DM amount from 1.25% to 1.75% of BW increased (P ≤ 0.05) plasma concentrations of insulin-like growth factor 1 (IGF-1), overall average daily gain (ADG), final BW, percentage of pubertal heifers on day 89, pregnancy and calving percentages, and percentage of heifers calving within the first 21 d of the calving season. However, reducing the supplementation frequency from daily to 3× weekly, regardless of supplementation amount, did not impact overall pregnancy and calving percentages (P ≥ 0.42), but caused (P ≤ 0.05) fluctuations in plasma concentrations of insulin and IGF-1 and decreased (P ≤ 0.03) overall ADG, final BW, puberty attainment on days 56, 89, and 168, and percentage of heifers calving during the first 21 d of the calving season. Hence, increasing the supplement DM amount did not prevent the negative effects of reducing the frequency of supplementation (3× vs. 7× weekly) on growth and reproduction of replacement Bos indicus-influenced beef heifers.

scholarly journals Supplementing Yucca schidigera extract to mitigate frothy bloat in beef cattle receiving a high-concentrate diet

2020 ◽  
Vol 98 (11) ◽  
Author(s):  
Bruna Rett ◽  
Reinaldo F Cooke ◽  
Alice P Brandão ◽  
Vitor S M Ferreira ◽  
Eduardo A Colombo ◽  
...  
Keyword(s):  
Feed Efficiency ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Average Daily Gain ◽  
Plasma Concentrations ◽  
Latin Square ◽  
Fluid Viscosity ◽  
Beef Heifers ◽  
Yucca Schidigera ◽  
And Performance

Abstract This experiment compared incidence of frothy bloat, as well as ruminal, physiological, and performance responses of beef heifers receiving a bloat-provoking diet and supplemented with Yucca schidigera extract. Sixteen ruminally cannulated Angus-influenced heifers were ranked by body weight (BW) and assigned to 4 groups of 4 heifers each. Groups were enrolled in a replicated 4 × 4 Latin square design containing 4 periods of 28 d, and a 21-d washout interval between periods. Groups were assigned to receive no Y. schidigera extract (CON), or Y. schidigera extract at (as-fed basis) 1 g/heifer daily (YS1), 2 g/heifer daily (YS2), or 4 g/heifer daily (YS4). During each period, heifers (n = 16/treatment) were housed in individual pens, and fed a sorghum (Sorghum bicolor L.)-based bloat-provocative diet at 2% of their BW. Diet and treatments were individually fed to heifers, twice daily in equal proportions (0700 and 1600 hours). Heifers were assessed for bloat score (0 to 5 scale, increasing according to bloat severity) 3 hr after the morning feeding. Blood samples were collected on days 0, 7, 14, 21, and 28 prior to (0 hr) and at 3, 6, and 9 hr relative to the morning feeding. Rumen fluid samples were collected at the same time points on days 0 and 28. Orthogonal contrasts were tested to determine whether inclusion of Y. schidigera extract (0, 1, 2, or 4 g/heifer daily) yielded linear or quadratic effects, and explore an overall effect of Y. schidigera extract supplementation (CON vs. YS1 + YS2 + YS4). Rumen fluid viscosity was impacted quadratically by Y. schidigera extract inclusion (P = 0.02), being greatest in YS1, followed by YS2, and equivalent between CON and YS4 heifers. Heifers receiving Y. schidigera extract had greater (P ≤ 0.05) rumen propionate, iso-valerate, and valerate concentrations, as well as less (P < 0.01) acetate : propionate ratio compared with CON heifers. Inclusion of Y. schidigera extract linearly increased (P ≤ 0.04) average daily gain and feed efficiency. No other treatment effects were noted (P ≥ 0.19) including bloat score (1.07 ± 0.03 across treatments), ruminal protozoa count, plasma concentrations of cortisol, haptoglobin, urea N, total protein, and rumen concentration of total volatile fatty acids. Supplementing Y. schidigera extract up to 4 g/d favored rumen propionate concentrations and linearly increased growth and feed efficiency but failed to mitigate incidence of frothy bloat in beef heifers consuming a grain-based bloat-provocative diet.

scholarly journals 267 Supplementing Ca salts of soybean oil to late-gestating beef cows: Impacts on performance and physiological responses of the offspring

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 192-192
Author(s):  
Alice Brandão ◽  
Reinaldo F Cooke ◽  
Kelsey Schubach ◽  
Bruna Rett ◽  
Osvaldo Souza ◽  
...  
Keyword(s):  
Soybean Oil ◽  
Dry Matter ◽  
Body Condition Score ◽  
Physiological Responses ◽  
Average Daily Gain ◽  
Plasma Concentrations ◽  
Beef Cows ◽  
Late Gestation ◽  
Muscle Area ◽  
Matter Basis

Abstract This experiment compared performance and physiological responses of the offspring from cows supplemented with Ca salts of soybean oil (CSSO) or prilled saturated fat (CON) during late gestation. Non-lactating, pregnant Angus × Hereford cows (n = 104) that conceived during the same fixed-time artificial insemination protocol, using semen from 2 sires, were used in this experiment. Cows were ranked by pregnancy sire, body weight (BW), and body condition score (BCS). On d 180 of gestation (d -15), cows were randomly assigned to receive (dry matter basis) 415 g of soybean meal per cow daily in addition to 1) 195 g/cow daily of CSSO (n = 52) or 2) 170 g/cow daily of CON (n = 52). Cows were maintained in 2 pastures (26 cows/treatment per pasture), and received daily 12.7 kg/cow (dry matter basis) of grass-alfalfa hay. From d 0 until calving, cows were segregated into 1 of 24 feeding pens thrice weekly and received treatments individually. Cow BW and BCS were recorded, and blood samples were collected on d -15 of the experiment and within 12 h after calving. Calf BW was also recorded and blood sample collected within 12 h of calving. Calves were weaned on d 290 of the experiment, preconditioned for 35 d (d 291 to 325), and transferred to a feedyard where they remained until slaughter. Upon calving, CSSO cows and calves had greater (P < 0.01) plasma concentrations of linoleic acid and total ω - 6 FA compared with CON cohorts. No differences in calf birth BW, weaning BW, and final preconditioning BW were noted (P ≥ 0.36) between treatments. Average daily gain and final BW in the feedlot were greater (P ≤ 0.05) in steers from CSSO cows compared with CON. The incidence of calves diagnosed with BRD that required a second antimicrobial treatment was less (P = 0.03) in calves from CSSO cows, resulting in reduced (P = 0.05) need of treatments to regain health compared with CON (Table 5). Upon slaughter, longissimus muscle area was greater (P = 0.03) in calves from CSSO cows compared with CON. Collectively, these results suggest that supplementing CSSO to late-gestating beef cows stimulated programming effects on postnatal offspring growth and Page 2 of 15 For Peer Review health. Therefore, supplementing late-gestating beef cows with CSSO appears to optimize offspring welfare and productivity in beef production systems.

Expression of interleukin-6 (IL-6), signal transducer and activator of transcription-3 (STAT-3) and telomerase in choriocarcinomas

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Luciana Pietro ◽  
Fátima Bottcher-Luiz ◽  
Lício Augusto Velloso ◽  
Joseane Morari ◽  
Marcelo Nomura ◽  
...  
Keyword(s):  
Cell Transformation ◽  
First Trimester ◽  
Bewo Cell ◽  
Placental Development ◽  
Trimester Abortion ◽  
Bewo Cells ◽  
Culture Cells ◽  
Bewo Cell Line ◽  
Blastocyst Implantation ◽  
First Trimester Of Pregnancy

Abstract Blastocyst implantation and neoplastic invasion have some common properties related to tissue invasion, mediated by various cytokines. Aim To compare the expression of IL-6, STAT-3 and telomerase in material of abortions in the first trimester of pregnancy, at term placentas and in choriocarcinomas. Methods Immunohistochemical reactions were performed on formalin fixed and included in paraffin samples from 3 groups: abortions, normal at term placentas and choriocarcinomas. Western Blot and Real-Time PCR assays were performed on fresh material from BeWo cell line and in primary culture cells of normal placenta. Results Immunohistochemical reactions: IL-6 expression was moderate in the first trimester abortion samples and high in at term placentas and choriocarcinomas. STAT-3 was strongly positive in all groups. Telomerase expression was absent in normal at term placentas but was increased in BeWo cells. Conclusion IL-6 and STAT-3 are present in the invasion process of the normal placental development and they are maintained during the malignant transformation to choriocarcinoma. The intense telomerase expression observed in BeWo cells was strongly associated with the malignant phenotype, confirming it as a good marker for cell transformation and tumor progression.

scholarly journals Effects of providing artificial shade to pregnant grazing beef heifers on vaginal temperature, growth, activity, and behavior

2021 ◽  
Author(s):  
Gleise M Silva ◽  
Lautaro R Cangiano ◽  
Thiago F. Fabris ◽  
Victoria R Merenda ◽  
Ricardo C Chebel ◽  
...  
Keyword(s):  
Growth Performance ◽  
Average Daily Gain ◽  
Experimental Period ◽  
Paspalum Notatum ◽  
Beef Heifers ◽  
Shade Treatment ◽  
Growth Activity ◽  
Gps Devices ◽  
And Behavior ◽  
Vaginal Temperature

Abstract This experiment evaluated the effects of providing artificial shade during summer on activity, behavior, and growth performance of pregnant grazing beef heifers. Thirty-six black-hided Angus and Angus crossbred pregnant heifers [418 ± 9 kg body weight (BW); approximately 90 d of gestation] were stratified by breed, blocked by BW, and allocated to 12 ‘Pensacola’ bahiagrass pastures (Paspalum notatum Flüggé; 1.3 ha, n = 3 heifers/pasture) with or without access to artificial shade (SHADE vs. NO SHADE; 6 pastures each) for 7 wk during summer. The shade structures were composed of shade cloth (11 × 7.3 m length, 2.4 m height: 26.8 m 2 of shade per heifer). Shrunk BW was recorded on enrollment (d 0) and wk 7 (d 47), whereas full BW was obtained on wk 2 (d 14), 4 (d 28), and 6 (d 42) to assess average daily gain (ADG). Vaginal temperature was recorded for five consecutive days during wk 1, 3, 5, and 7 using an intravaginal digital thermo-logger, and individual GPS devices were used to quantify the use of shade for an 8-h period. Activity was monitored using automated monitoring devices (HR-LDn tags SCR Engineers Ltd., Netanya, Israel) through the experimental period. Vaginal temperature was lower (P < 0.01) for heifers in the SHADE compared with heifers in the NO SHADE treatment from 1200 to 1600 h and 1100 to 1900 h for wk 1 and 3, respectively. Heifers in the SHADE treatment spent 70% of the 8-h period evaluated under the shaded structure. Provision of shade increased (P < 0.01) daily lying time (11.4 ± 0.2 vs. 10.3 ± 0.2 h/d) and standing bouts per day (P < 0.01; 12.6 ± 0.4 vs. 10.8 ± 0.4 bouts/d), whereas it reduced (P < 0.01) standing bout duration (61.6 ± 3.0 vs. 82.9 ± 3.0 min/bout) relative to heifers without access to shade. The interaction between treatment and hour affected (P < 0.01) daily rumination time because heifers with access to SHADE had greater rumination between 1000 and 1200 h. Although ADG tended (P = 0.08) to be greater for the heifers in the SHADE treatment (0.20 vs. -0.02 kg, respectively), the access to shade did not (P = 0.79) affect the final BW. In conclusion, providing artificial shade during summer to pregnant grazing beef heifers was effective in reducing vaginal temperatures and exerted changes in heifer behaviors that translated into slight improvements in growth performance.

scholarly journals Radioimmunoassay of plasma ouabain in healthy and pregnant individuals

2000 ◽  
Vol 165 (3) ◽  
pp. 669-677 ◽  
Author(s):  
O Vakkuri ◽  
SS Arnason ◽  
A Pouta ◽  
O Vuolteenaho ◽  
J Leppaluoto
Keyword(s):  
Pregnant Women ◽  
Human Plasma ◽  
High Performance ◽  
Chemical Nature ◽  
Solid Phase ◽  
Plasma Concentrations ◽  
First Trimester ◽  
Plasma Samples ◽  
Third Trimester ◽  
Endogenous Substances

Ouabain was recently isolated from human plasma, bovine hypothalamus and bovine adrenal in attempts to identify endogenous substances inhibiting the cell membrane sodium pump. A number of radioimmunoassays have been developed in order to study the clinical significance of ouabain. The results have been controversial with regard to the presence and chemical nature of plasma ouabain-like immunoreactivity. We have now measured ouabain in healthy and pregnant individuals using solid-phase extraction of plasma samples followed by a new radioimmunoassay with the extraordinary sensitivity of at least 2 fmol/tube (5 pmol/l). Plasma extracts, a previously isolated human plasma ouabain-like compound and bovine hypothalamic inhibitory factor displaced the tracer in parallel and eluted identically with ouabain in high-performance liquid chromatography. Plasma ouabain immunoreactivity was found to be much lower than reported previously: 12.6+/-1.3 pmol/l in healthy men (mean+/-s.e., n=20) and 9.4+/-0.7 pmol/l in women (n=14). In pregnant women (n=28) plasma ouabain concentration was 16.3+/-4.0 pmol/l during the first trimester, 18.8+/-4.3 pmol/l during the second trimester and 24.3+/-4.0 pmol/l during the third trimester (all P<0.01 compared with non-pregnant women). Plasma ouabain 3-5 days after the delivery was 13.6+/-1.1 pmol/l (n=10, P<0.05-0.01 compared with second and third trimesters). The pregnancy-related changes in the plasma concentrations of ouabain resembled those of cortisol. Therefore cortisol was measured from the same plasma samples and a significant positive correlation was found (r=0.512, P=0.006). The similar profiles of plasma ouabain and cortisol during pregnancy and their rapid decreases postpartum are consistent with the adrenal cortical origin of ouabain and also show that the secretions of these hormones are possibly under the control of same factors.

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