Interferometric control of magnon-induced nearly perfect absorption in cavity magnonics.

The perfect absorption of electromagnetic waves has promoted many applications, including photovoltaics, radar cloaking, and molecular detection. Unlike conventional methods of critical coupling that require asymmetric boundaries or coherent perfect absorption that require multiple coherent incident beams, here we demonstrate single-beam perfect absorption in an on-chip cavity magnonic device without breaking its boundary symmetry. By exploiting magnon-mediated interference between two internal channels, both reflection and transmission of our device can be suppressed to zero, resulting in magnon-induced nearly perfect absorption (MIPA). Such interference can be tuned by the strength and direction of an external magnetic field, thus showing versatile controllability. Furthermore, the same multi-channel interference responsible for MIPA also produces level attraction (LA)-like hybridization between a cavity magnon polariton mode and a cavity photon mode, demonstrating that LA-like hybridization can be surprisingly realized in a coherently coupled system.

Differential Transcript Profiles in Cumulus-Oocyte Complexes Originating from Pre-Ovulatory Follicles of Varied Physiological Maturity in Beef Cows.

Small dominant follicle diameter at induced ovulation, but not at spontaneous ovulation, decreased pregnancy rate, fertilization rate, and day seven embryo quality in beef cows. We hypothesized that the physiological status of the follicle at GnRH-induced ovulation has a direct effect on the transcriptome of the Cumulus-Oocyte complex, thereby affecting oocyte competence and subsequent embryo development. The objective of this study was to determine if the transcriptome of oocytes and associated cumulus cells (CC) differed among small (≤11.7 mm) and large follicles (≥12.7 mm) exposed to a GnRH-induced gonadotropin surge and follicles (11.7-14.0 mm) exposed to an endogenous gonadotropin surge (spontaneous follicles). RNA sequencing data, from pools of four oocytes or their corresponding CC, revealed 69, 94, and 83 differentially expressed gene transcripts (DEG) among oocyte pools from small versus large, small versus spontaneous, and large versus spontaneous follicle classifications, respectively. An additional 128, 98, and 80 DEG were identified among small versus large, small versus spontaneous, and large versus spontaneous follicle CC pools, respectively. The biological pathway "oxidative phosphorylation" was significantly enriched with DEG from small versus spontaneous follicle oocyte pools (FDR < 0.01); whereas the glycolytic pathway was significantly enriched with DEG from CC pools obtained from large versus small follicles (FDR < 0.01). These findings collectively suggest that altered carbohydrate metabolism within the Cumulus-Oocyte complex likely contributes to the decreased competency of oocytes from small pre-ovulatory follicles exposed to an exogenous GnRH-induced gonadotropin surge.

Interleukin 15 skews monocyte differentiation into dendritic cells with features of Langerhans cells.

Langerhans cells (LCs) represent a subset of immature dendritic cells (DCs) specifically localized in the epidermis and other mucosal epithelia. As surrounding keratinocytes can produce interleukin (IL)-15, a cytokine that utilizes IL-2Rgamma chain, we analyzed whether IL-15 could skew monocyte differentiation into LCs. Monocytes cultured for 6 d with granulocyte/macrophage colony-stimulating factor (GM-CSF) and IL-15 differentiate into CD1a(+)HLA-DR(+)CD14(-)DCs (IL15-DCs). Agents such as lipopolysaccharide (LPS), tumor necrosis factor (TNF)alpha, and CD40L induce maturation of IL15-DCs to CD83(+), DC-LAMP(+) cells. IL15-DCs are potent antigen-presenting cells able to induce the primary (mixed lymphocyte reaction [MLR]) and secondary (recall responses to flu-matrix peptide) immune responses. As opposed to cultures made with GM-CSF/IL-4 (IL4-DCs), a proportion of IL15-DCs expresses LC markers: E-Cadherin, Langerin, and CC chemokine receptor (CCR)6. Accordingly, IL15-DCs, but not IL4-DCs, migrate in response to macrophage inflammatory protein (MIP)-3alpha/CCL20. However, IL15-DCs cannot be qualified as "genuine" Langerhans cells because, despite the presence of the 43-kD Langerin, they do not express bona fide Birbeck granules. Thus, our results demonstrate a novel pathway in monocyte differentiation into dendritic cells.

Direct phase probing and mapping via spintronic Michelson interferometry.

A spintronic approach is introduced to transform classic Michelson interferometry that probes the electromagnetic phase only. This method utilizes a nonlinear four-wave coherent mixing effect. A previously unknown striking relation between spin dynamics and the relative phase of electromagnetic waves is revealed. Spintronic Michelson interferometry allows direct probing of both the spin-resonance phase and the relative phase of electromagnetic waves via microspintronics. Thereby, it breaks new ground for cross-disciplinary applications with unprecedented capabilities, which we demonstrate via a powerful phase-resolved spin-resonance spectroscopy on magnetic materials and an on-chip technique for phase-resolved near-field microwave imaging.

Effect of bovine genotype on innate immune response of heifers to repeated lipopolysaccharide (LPS) administration.

This pilot study provides a preliminary assessment of the impact of genotype on acute innate immune pro-inflammatory, metabolic and endocrine responses to repeated lipopolysaccharide (LPS) administered to growing heifers. Heifers (n = 4/genotype) were from unselected (stable milk yield since 1964, UH) or contemporary (CH) Holstein cows that differed in milk yield (6200 vs 11,100 kg milk/305 d) or from contemporary Black Angus (CA) cows bred to contemporary Red Angus bulls. Heifers were challenged with iv administration of 0.5 µg LPS/kg body weight on day 1 (Challenge 1) and d 5 (Challenge 2) of study to assess endotoxin tolerance. Plasma was collected at -1, -0.5, 0, 1, 2, 3, 4, 6, 8, and 24 h relative to each LPS administration. Rectal body temperature (BT) was measured before each blood sampling and at 5 and 7 h. Data were analyzed by repeated measures with sampling time as the repeated effect. Each genotype had at least one pro-inflammatory response that indicated it might have a more robust response than the other genotypes. The CH heifers had a greater TNF-α response, UH heifers had greater IL-6 and XO responses and CA heifers had greater BT and SAA response to LPS than the other genotypes. There was a genotype by time by interaction as cortisol peaked earlier in CH and UH than in CA heifers. Glucose response was less in CA and insulin response was greater in CH heifers. Endotoxin tolerance to LPS was evident as pro-inflammatory, cortisol, glucose and insulin responses were less during Challenge 2 than during Challenge 1. Differences among genotypes during Challenge 1 were eliminated during Challenge 2 except for the greater SAA response in CA heifers and indicate the potential for differential impacts of genotype on the development of endotoxin tolerance. Specific reasons for these effects of genotype are not clear from these data but the results support the hypothesis for differential innate immune signaling among these bovine genotypes.

Response to GnRH on day 6 of the estrous cycle is diminished as the percentage of Bos indicus breeding increases in Angus, Brangus, and Brahman x Angus heifers.

Angus (n=6), Brangus (5/8 Angus x 3/8 Brahman, n=6), and Brahman x Angus (3/8 Angus x 5/8 Brahman, n=6) heifers exhibiting estrous cycles at regular intervals were used to determine if the percentage of Bos indicus breeding influenced the secretory patterns of LH in response to a GnRH treatment on Day 6 of the estrous cycle. Heifers were pre-synchronized with a two-injection PGF(2 alpha) protocol (25 mg i.m. Day -14 and 12.5 mg i.m. Day -3 and -2 of experiment). Heifers received 100 microg GnRH i.m. on Day 6 of the subsequent estrous cycle. Blood samples were collected at -60, -30, and -1 min before GnRH and 15, 30, 60, 90, 120, 150, 180, 240, 300, 360, 420, and 480 min after GnRH to determine concentrations of serum LH. Estradiol concentrations were determined at -60, -30, and -1 min before GnRH. On Day 6 and 8, ovaries were examined by ultrasonography to determine if ovulation occurred. On Day 13, heifers received 25 mg PGF(2 alpha) i.m. and blood samples were collected daily until either the expression of estrus or Day 20 for heifers not exhibiting estrus to determine progesterone concentrations. There was no effect (P>0.10) of breed on ovulation rate to GnRH as well as size of the largest follicle, mean estradiol, and mean corpus luteum volume at GnRH. Mean LH was greater (P<0.05) for Angus (7.0+/-0.8 ng/mL) compared to Brangus (4.6+/-0.8 ng/mL) and Brahman x Angus (2.9+/-0.8 ng/mL), which were similar (P>0.10). Mean LH peak-height was similar (P>0.10) for Brangus (13.9+/-3.4 ng/mL) compared to Angus (21.9+/-3.4 ng/mL) and Brahman x Angus (8.0+/-3.4 ng/mL), but was greater (P<0.05) for Angus compared to Brahman x Angus. Interval from GnRH to LH peak was similar (P>0.10) between breeds. As the percentage of Bos indicus breeding increased the amount of LH released in response to GnRH on Day 6 of the estrous cycle decreased.

Decreasing the interval between GnRH and PGF2alpha from 7 to 5 days and lengthening proestrus increases timed-AI pregnancy rates in beef cows.

Four experiments were conducted in postpartum beef cows to evaluate the influence of reducing the interval from GnRH to PGF(2alpha) from 7 to 5d in a Select-Synch + CIDR or CO-Synch + CIDR estrous synchronization program. In Expt 1, cows (n=156) were treated with either a 7 or 5d Select-Synch + CIDR program. A second PGF(2alpha) treatment was given to all cows in all experiments at 12h after the initial PGF(2alpha) (to ensure that luteolysis occurred with the 5d program). Estrous response, interval to estrus, conception rate, and first service AI pregnancy rates were similar between treatments. In Expt 2, cows (n=223) were treated with either a 7 or 5d CO-Synch + CIDR program, with timed-AI concomitant with GnRH at 60 h after PGF(2alpha). Timed-AI pregnancy rates were similar between treatments. In Expt 3 (n=223) and 4 (n=400) cows were treated with either a 7 or 5d CO-Synch + CIDR program with timed-AI concurrent with GnRH at either 60 h (7d) or 72 h (5d) after CIDR withdrawal. Timed-AI pregnancy rates were 13.3% (P<0.05; Expt 3) and 9.1% (P<0.05; Expt 4) greater for the 5 than 7d program. In conclusion, timed-AI pregnancy rates were improved with a 5d CO-Synch + CIDR program with timed-AI at 72 h after CIDR withdrawal, compared to a 7d CO-Synch + CIDR program with timed-AI at 60 h after CIDR withdrawal.

Role of progesterone concentrations during early follicular development in beef cattle: I. Characteristics of LH secretion and oocyte quality.

Objective was to investigate the effect of different progesterone (P4) concentrations during early follicular development on luteinizing hormone (LH) secretion and oocyte characteristics in beef cows. Primiparous cows (n = 24) were estrous pre-synchronized and follicular ablation was performed (d 0) 6 days following the time of ovulation. At the time of follicular ablation, cows were assigned to either: 1) high P4 treatment - HiP4; a new CIDR was inserted on d 0 to supplement P4 from the existing corpus luteum [CL], or 2) low P4 treatment - LoP4; a previously-used CIDR and two doses of PGF 8 to 12 h apart were given on d 0. Concentrations of P4 were greater (P < 0.01) in the cows of the HiP4 than LoP4 group on d 1.5, 2.5, and 3.5. Peripheral concentrations of E2 were greater (P < 0.05) in the cows of the LoP4 than HiP4 group on d 2.5 and 3.5. Frequency of LH pulses was greater (P <  0.05) in the LoP4 than HiP4 group on d 2.5, but mean LH concentration and pulse amplitude did not differ between treatments. Number of follicles aspirated per cow, total oocytes recovered, recovery rate, percentage of oocytes graded 1 to 3, oocyte diameter, percentage BCB+ oocytes, and relative abundance of oocyte mRNA for FST did not differ (P >  0.10) between treatments. In conclusion, lower P4 concentrations during early follicular development resulted in increased LH pulse frequency and E2 concentrations, but did not affect characteristics of oocyte developmental competence.

Role of progesterone concentrations during early follicular development in beef cattle: II. Ovulatory follicle growth and pregnancy rates.

Two experiments were conducted to investigate the role of relatively lesser and greater progesterone (P4) concentrations during early follicular development on ovulatory follicle growth and pregnancy rate in beef cattle. In Experiment 1, time of ovulation was synchronized with the 5 d CO-Synch + CIDR (Controlled Internal Drug Release) program in multiparous cows (n = 241). Six days after the 2nd GnRH injection of the pre-synchronization program (d 0), ablation of follicles ≥ 5 mm in the ovaries was performed and cows were assigned to receive either a previously used CIDR and 2x-25 mg PGF2α doses 8 h apart (LoP4), or a new CIDR (HiP4). On d 5, CIDR were removed from all cows, 2x-25 mg PGF2α were administered, and estrous detection tail paint was applied. Timed artificial insemination (TAI) was performed on d 8. On d 5, P4 concentrations were greater (P <  0.01) in the HiP4 (4.9 ± 0.13 ng/mL) than LoP4 (1.0 ± 0.06 ng/mL) treatment group. Conversely, d 5 estradiol (E2) concentrations and follicular diameter were greater (P <  0.01) in the LoP4 (5.0 ± 0.23 pg/mL and 8.9 ± 0.20 mm) than HiP4 (1.5 ± 0.12 pg/mL and 7.4 ± 0.15 mm) treatment group. Follicular diameter at TAI (12.0 ± 0.12 mm, Table 1) and TAI pregnancy rate did not differ (P >  0.10) between treatment groups. In Experiment 2, a new follicular wave was induced with estradiol benzoate on d -7, and cows (n = 275) were assigned on d 0 to receive 25 mg PGF2α and either have the CIDR replaced with a new CIDR (HiP4) or the used CIDR was left in place (LoP4).Furthermore, all cows received GnRH on d 0. The CIDRs were removed from all cows on d 5 and two doses of -25 mg PGF2α were administered. Estrous detection combined with AI 12 h later (Estrus-AI) was performed for 60 h after CIDR removal with TAI coupled with GnRH administration at 72 h if estrus was not detected. The concentrations of P4 on d 5 were greater (P <  0.01) in the HiP4 (2.8 ± 0.10 ng/ml) than LoP4 (1.7 ± 0.05 ng/mL) treatment group. For cows that were detected in estrus after PGF2α administration, estrous response (83.5%) and interval to estrus (55.0 ± 0.5 h) did not differ between treatment groups. Pregnancy rate (combined Estrus-AI and TAI) that resulted from breeding at the time of the synchronized time of estrus was similar between treatment groups (HiP4: 77.1%; LoP4: 82.3%). In conclusion, differences in P4 concentrations during early follicular development do not effect pregnancy rate in beef cows when the cows are inseminated at the time of a synchronized estrus if the cows have similar intervals of proestrus.

Dielectrophoresis study of temporal change in internal conductivity of single CHO cells after electroporation by pulsed electric fields.

Applying sufficiently strong pulsed electric fields to a cell can permeabilize the membrane and subsequently affect its dielectric properties. In this study, we employ a microfluidic dielectrophoresis cytometry technique to simultaneously electroporate and measure the time-dependent dielectric response of single Chinese hamster ovary cells. Using experimental measurements along with numerical simulations, we present quantitative results for the changes in the cytoplasm conductivity of single cells within seconds after exposure to 100 µs duration pulsed electric fields with various intensities. It is shown that, for electroporation in a medium with conductivity lower than that of the cell's cytoplasm, the internal conductivity of the cell decreases after the electroporation on a time scale of seconds and stronger pulses cause a larger and more rapid decrease. We also observe that, after the electroporation, the cell's internal conductivity is constrained to a threshold. This implies that the cell prevents some of the ions in its cytoplasm from diffusing through the created pores to the external medium. The temporal change in the dielectric response of each individual cell is continuously monitored over minutes after exposure to pulsed electric fields. A time constant associated with the cell's internal conductivity change is observed, which ranges from seconds to tens of seconds depending on the applied pulse intensity. This experimental observation supports the results of numerical models reported in the literature.

Influence of post-insemination nutrition on embryonic development in beef heifers.

Previous studies have demonstrated that a decrease in nutrition immediately following AI reduces pregnancy success in beef heifers. The objective of this experiment was to determine if nutrient restriction following AI impacted early embryonic development among non-super ovulated heifers. Beef heifers in eight replications (Rep; Rep 1; n = 14, Rep 2; n = 15, Rep 3; n = 15, Rep 4; n = 14, Rep 5; n = 15, Rep 6; n = 15, Rep 7; n = 25, Rep 8; n = 25) across two locations (UMN, SDSU) were developed in a dry-lot and fed 125% NRC requirements from weaning to timed-AI (d 0). Heifers were timed-AI to a single sire in all replications. Immediately following AI, heifers were assigned, based on age, weight, and estrous response to one of two post-AI nutritional treatments. Half the heifers in each replication continued on the pre-insemination diet, serving as the control treatment (CON) and the remaining heifers were restricted to a sub-maintenance diet (RES). At UMN, heifers in the RES treatment were fed the same diet, but intake was limited to 80% NEm, while at SDSU, DMI remained the same, but diet composition was altered with the addition of straw to reduce NEm to 50% of requirements. On d 6, single embryos were collected nonsurgically and recovered embryos (CON; n = 46, RES; n = 42) were evaluated to determine quality (grade 1-9) and stage (1-4). Embryos were then stained and evaluated to determine the number of dead cells and total blastomeres. In Reps 1 through 6, concentrations of IGF-1 were assessed on d 0 and 6 and progesterone concentrations on d 4 and 6. Data were analyzed using the Mixed procedures of SAS. There were no treatment by Rep or treatment by location interactions for any embryo parameter evaluated, thus all data were pooled. Embryo stage and quality were improved (P < 0.01) in the CON (4.4 ± 0.16, 2.2 ± 0.19, respectively) compared to RES treatment (3.7 ± 0.16, 2.9 ± 0.19, respectively). Embryos in the CON treatment had greater total blastomeres (66.9 ± 5.05; P < 0.01) and tended to have a greater percentage of live cells (P < 0.10; 80.9 ± 4.19%) compared to RES (47.9 ± 5.41; 69.7 ± 4.39%, respectively). Progesterone and IGF-1 concentrations did not differ between treatments. In summary, nutrient restriction for 6 days immediately following AI resulted in poorer quality embryos that were delayed in stage of development, suggesting that immediate changes in nutritional status after insemination can alter early embryonic development.

Dielectric model for Chinese hamster ovary cells obtained by dielectrophoresis cytometry.

We present a dielectric model and its parameters for Chinese hamster ovary (CHO) cells based on a double-shell structure which includes the cell membrane, cytoplasm, nuclear envelope, and nucleoplasm. Employing a dielectrophoresis (DEP) based technique and a microfluidic system, the DEP response of many single CHO cells is measured and the spectrum of the Clausius-Mossotti factor is obtained. The dielectric parameters of the model are then extracted by curve-fitting to the measured spectral data. Using this approach over the 0.6-10 MHz frequency range, we report the values for CHO cells' membrane permittivity, membrane thickness, cytoplasm conductivity, nuclear envelope permittivity, and nucleoplasm conductivity. The size of the cell and its nuclei are obtained using optical techniques.

Changes in ovarian function associated with circulating concentrations of estradiol before a GnRH-induced ovulation in beef cows.

These studies were conducted to evaluate causes for differences in circulating concentrations of estradiol before a GnRH-induced ovulation. Beef cows were synchronized by an injection of GnRH on day -7 and an injection of prostaglandin F2α (PGF2α) on day 0. In experiment 1, blood samples were collected every 3 h from PGF2α on day 0 to hour 33 after PGF2α and at slaughter (hour 36 to 42; n = 10). Cows were assigned to treatment group based on circulating concentrations of estradiol (E2): HighE2 vs LowE2. At slaughter, follicular fluid (FF) and granulosa cells were collected from the dominant follicle. In experiment 2, blood samples (n = 30) were collected every 8 h from PGF2α until the dominant follicle was aspirated via ultrasound-guided follicular aspiration to collect FF and granulosa cells (hour 38 to 46). In experiment 1, HighE2 had increased abundance of 3ß-hydroxysteroid dehydrogenase, cytochrome P450 aromatase, and LHR (P ≤ 0.02), and greater concentrations of estradiol and androstenedione (P ≤ 0.02) in the FF. In experiment 2, HighE2 had increased abundance of CYP11A1, 3ß-hydroxysteroid dehydrogenase, cytochrome P450 aromatase, and LHR (P ≤ 0.03) vs either LowE2 or GnRHLowE2. There was a tendency (P = 0.07) for LH pulse frequency to be increased in both the GnRHLowE2 and HighE2 compared with LowE2. HighE2 cows experienced increas in circulating concentrations of estradiol compared with LowE2. In conclusion, animals with greater concentrations of circulating estradiol before fixed-time AI experienced an upregulation of the steroidogenic pathway during the preovulatory period.

Assessment of serum 25-hydroxyvitamin D concentrations of beef cows and calves across seasons and geographical locations.

Vitamin D is critical for the growth and development of calves and positively contributes to immune function of cattle. Serum 25-hydroxyvitamin D (25(OH)D) concentrations above 20 ng/mL have traditionally been considered adequate for growth and development of cattle, but recent evidence has indicated that concentrations below 30 ng/mL are insufficient for immunity. Because little information is available regarding vitamin D status of beef cattle, the objective of this study was to evaluate vitamin D status of beef cow-calf herds on pasture as affected by season and location. Serum samples were collected from 43 cow-calf pairs plus an additional 54 calves in herds located in Florida, Idaho, and Minnesota in the spring calving season. Samples were collected again over the summer months from animals in the Florida and Minnesota herds. Effects of subcutaneous injection of vitamins A, D, and E also were investigated in a subset of calves from the Idaho herd. All cows sampled had serum 25(OH)D concentrations above 30 ng/mL at the time of calving in the spring. The average serum 25(OH)D concentrations of cows rose from near 60 ng/mL in the spring to 75 ng/mL in the summer ( < 0.001). Most calves, on the other hand, had serum 25(OH)D concentrations below 20 ng/mL. The calves in the Florida and Minnesota herds similarly rose from averages of 10 to 15 ng/mL at birth to near 50 ng/mL by the end of summer. Serum 25(OH)D of severely deficient calves increased from 3 ng/mL in nonsupplemented calves to 11 ng/mL at 48 h after birth if given a bolus supplementation of 40,000 IU of vitamin D via subcutaneous injection of a vitamin A, D, and E supplement at birth ( < 0.001). Vitamin D supplementation of cows late in pregnancy has been shown to increase serum 25(OH)D of calves; however, beef cattle generally receive very little supplemental vitamin D, as was the case for the cows studied here. The lower serum 25(OH)D of cows in spring compared with summer and the prevalence of vitamin D deficiency of calves observed here indicate that increased vitamin D supplementation of cows over the winter months or vitamin D supplementation of newborn calves would be beneficial.

Using estrus detection patches to optimally time insemination improved pregnancy risk in suckled beef cows enrolled in a fixed-time artificial insemination program.

A multilocation study examined pregnancy risk (PR) after delaying AI in suckled beef cows from 60 to 75 h when estrus had not been detected by 60 h in response to a 7-d CO-Synch + progesterone insert (CIDR) timed AI (TAI) program (d -7: CIDR insert concurrent with an injection of GnRH; d 0: PGF injection and removal of CIDR insert; and GnRH injection at TAI [60 or 75 h after CIDR removal]). A total of 1,611 suckled beef cows at 15 locations in 9 states (CO, IL, KS, MN, MS, MT, ND, SD, and VA) were enrolled. Before applying the fixed-time AI program, BCS was assessed, and blood samples were collected. Estrus was defined to have occurred when an estrus detection patch was >50% colored (activated). Pregnancy was determined 35 d after AI via transrectal ultrasound. Cows ( = 746) detected in estrus by 60 h (46.3%) after CIDR removal were inseminated and treated with GnRH at AI (Control). Remaining nonestrous cows were allocated within location to 3 treatments on the basis of parity and days postpartum: 1) GnRH injection and AI at 60 h (early-early = EE; = 292), 2) GnRH injection at 60 h and AI at 75 h (early-delayed = ED; = 282), or 3) GnRH injection and AI at 75 h (delayed-delayed = DD; = 291). Control cows had a greater ( < 0.01) PR (64.2%) than other treatments (EE = 41.7%, ED = 52.8%, DD = 50.0%). Use of estrus detection patches to delay AI in cows not in estrus by 60 h after CIDR insert removal (ED and DD treatments) increased ( < 0.05) PR to TAI when compared with cows in the EE treatment. More ( < 0.001) cows that showed estrus by 60 h conceived to AI at 60 h than those not showing estrus (64.2% vs. 48.1%). Approximately half (49.2%) of the cows not in estrus by 60 h had activated patches by 75 h, resulting in a greater ( < 0.05) PR than their nonestrous herd mates in the EE (46.1% vs. 34.5%), ED (64.2% vs. 39.2%), and DD (64.8% vs. 31.5%) treatments, respectively. Overall, cows showing estrus by 75 h (72.7%) had greater ( < 0.001) PR to AI (61.3% vs. 37.9%) than cows not showing estrus. Use of estrus detection patches to allow for a delayed AI in cows not in estrus by 60 h after removal of the CIDR insert improved PR to TAI by optimizing the timing of the AI in those cows.

Progesterone status, parity, body condition, and days postpartum before estrus or ovulation synchronization in suckled beef cattle influence artificial insemination pregnancy outcomes.

Our objective was to assess the effects of progesterone before initiating an estrus- or ovulation-synchronization program in addition to the influence of parity, BCS, and days postpartum on resulting pregnancy rates per AI. Experimental data were combined from 73 herd-year studies consisting of more than 8,500 suckled beef cows exposed to variants of the CO-Synch program. Blood was harvested from samples collected at 10 and 0 d before the onset of CO-Synch, and progesterone concentrations of the samples were determined. The progesterone environment preceding synchronization was assessed in 3 ways on the basis of progesterone concentrations measured in the 2 defined blood samples. All binomial logistic regression models used procedure GLIMMIX in SAS and included the fixed effects of program duration, inclusion of progesterone via an intravaginal insert, parity, days postpartum at AI, BCS, and appropriate interactions. In addition, model 1 included 3 categories of progesterone concentrations (low [<1 ng/mL], medium [1.00 to 3.99 ng/mL], and high [≥4.00 ng/mL] concentrations) at 10 and 0 d before synchronization and their interaction. Model 2 included 4 categories defining the stage of the estrous cycle (late diestrus, early diestrus, and proestrus-estrus-metestrus) or anestrus, at which cows started the synchronization program. Model 3 defined cows as cycling or noncycling at the onset of the program. Significant effects of progesterone supplementation, which hormone was used to initiate the timed AI program, parity, BCS, days postpartum, and progesterone status assessed in 3 ways were consistent in nearly all models. Progesterone status at the onset of synchronization was not important to pregnancy outcomes in multiparous cows, whereas pregnancy rate per AI was suppressed in primiparous cows that began in a low-progesterone environment (proestrus, estrus, metestrus, or anestrus). A significant 3-way interaction of parity, BCS, and days postpartum in 2 models reinforced the importance of these factors to AI pregnancy outcomes. Ancillary analyses identified the significant effects of cycling status and BCS as well as days postpartum on luteolytic response to PGF(2α). Pregnancy loss of 2.7% to 4.2% was detected to occur between a positive pregnancy diagnosis at 35 d post-AI and later stages of pregnancy. We concluded that progesterone status at the onset of the synchronization program is critical to pregnancy outcomes in primiparous but not multiparous cows.

Feeding distiller's grains as an energy source to gestating and lactating beef heifers: Impact on female progeny growth, puberty attainment, and reproductive processes.

This study compared postweaning growth, puberty attainment, and reproductive processes of female progeny (n = 33) born to Angus-Simmental beef heifers treated with either a control diet or a diet in which dried distiller's grains with solubles (DDGS) were fed as an energy source during late gestation and early lactation. From 192 d of gestation through 118 ± 4 d in lactation, dams were fed either a corn silage­based control diet (CON) orcorn residue with DDGS, where DDGS were supplemented as an energy source (DG). Diets were formulated to provide similar daily NEg between diets, but CP requirements were drastically exceeded in the DG treatment. Heifer progeny (n = 33) were weaned, commingled at 191 ± 4 d of age, and similarly managed for the remainder of the project. Heifer BW and blood samples for progesterone assessment to determine onset of puberty were collected weekly beginning at weaning. At 255 ± 4 d of age, a single follicular wave was mapped via ultrasonography in 10 prepubertal heifers per treatment. Prepubertal antral follicle count and ovarian size were determined at 253 ± 4 d of age. Hip height was recorded at 213,297, and 437 ± 4 d of age. Estrous synchronization and AI was initiated at 447 ± 4 d of age. Binary data were analyzed with the GLIMMIX procedures of SAS and all other data were analyzed with the MIXED procedures of SAS. Progeny from DG-treated dams tended to be heavier (P = 0.08) than progeny from CON-treated dams from weaning until breeding. In addition, DG progeny had a greater (P < 0.01) frame score than CON throughout the developmental period. Ovarian size, antral follicle count, and follicular growth parameters did not differ between treatments. Age at puberty did not differ between CON (303 ± 10 d) and DG (320 ± 10 d) progeny; however, BW at puberty was greater (P = 0.01) for DG (326 ± 7 kg) than CON (298 ± 8 kg) progeny. Pregnancy rates to AI were greater (P = 0.05) in DG progeny (70.6%) than CON (33.3%), but overall breeding season pregnancy rate did not differ (P = 0.97). Moreover, rate of dystocia in female progeny at first parturition and grand-offspring birth BW did not differ due to treatment (P ≥ 0.74). In summary, feeding DDGS as an energy source during late gestation and early lactation to first-parity heifers resulted in female progeny with greater skeletal growth that were heavier at onset of puberty and had increased AI pregnancy rates.

Influence of estrus at fixed-time artificial insemination on early embryonic development in beef cattle.

It has been repeatedly demonstrated that estrous expression before fixed-time AI (TAI) results in increased pregnancy success. Therefore, the objective of this experiment was to determine if preblastocyst embryonic developmental characteristics differed from heifers that did or did not exhibit estrus before TAI. Beef heifers (n = 113) were synchronized using the 5-d CO-Synch + controlled internal drug release device with TAI on d 0. Before TAI, estrous expression was assessed twice daily. On d 6, single embryos were collected and visually evaluated to determine quality (International Embryo Transfer Society standards; 1-4, in which 1 = excellent/good and 4 = degenerate) and stage (1-9, in which 1 = unfertilized and 9 = expanded hatched blastocyst). Embryos were stained and evaluated to determine number of dead blastomeres, number of total blastomeres, and number of accessory sperm. Estrous expression before TAI did not affect the percent of embryos recovered (P = 0.59), number of dead cells (P = 0.99), or number of total cells (P = 0.25). However, heifers that exhibited estrus had increased mean (P = 0.03) and median accessory sperm numbers and (P = 0.01) percent live cells when compared with nonestrus heifers. Heifers that exhibited estrus also produced embryos that had a more advanced stage (P = 0.03) and improved quality (P = 0.04) when compared with those heifers not exhibiting estrus. When all heifers were evaluated, there was no correlation between circulating concentration of estradiol at TAI and embryo quality or embryo stage. There was a significant correlation between accessory sperm numbers and embryo quality (P = 0.01) and embryo stage (P < 0.01), such that as accessory sperm numbers increased, embryo quality and stage increased. In conclusion, exhibiting estrus before TAI resulted in improved embryo quality and advanced embryo stage on d 6 and increased the number of accessory sperm associated with the embryo.

Torque-mixing magnetic resonance spectroscopy.

A universal, torque-mixing method for magnetic resonance spectroscopy is presented. In analogy to resonance detection by magnetic induction, the transverse component of a precessing dipole moment can be measured in sensitive broadband spectroscopy, here using a resonant mechanical torque sensor. Unlike induction, the torque amplitude allows equilibrium magnetic properties to be monitored simultaneously with the spin dynamics. Comprehensive electron spin resonance spectra of a single-crystal, mesoscopic yttrium iron garnet disk at room temperature reveal assisted switching between magnetization states and mode-dependent spin resonance interactions with nanoscale surface imperfections. The rich detail allows analysis of even complex three-dimensional spin textures. The flexibility of microelectromechanical and optomechanical devices combined with broad generality and capabilities of torque-mixing magnetic resonance spectroscopy offers great opportunities for development of integrated devices.

Noncollagenous proteins of a rat dentin matrix possessing bone morphogenetic activity.

An insoluble preparation of rat dentin matrix was shown to possess bone morphogenetic protein (BMP) activity, i.e. the capacity to induce the formation of catilage and bone when implanted intramuscularly. Since BMP activity was previously attributed to noncollagenous proteins (NCP) of bone and dentin, the nature of NCP of the rat dentin was examined. After treatment of the matrix with purified bacterial collagenase, three NCP were solubilized concomitantly with digestion of the dentin collagen to smaller peptides. The three proteins were separated by anion-exchange chromatography on DEAE-cellulose. Two of the NCP were rich in asparate, glutamate, glycine, serine, and alanine, and thus displayed compositions similar to acidic proteins of other connective tissues. The third NCP was shown by amino acid composition to be the aspartate, serine-rich phosphoprotein, which occurs mostly in a soluble form in rat dentin. This observation supports the view that a portion of dentin phosphotprotein is firmly bound.