Differential cross sections for Compton scattering from the proton have been measured at scattering angles of 55°, 90°, and 125° in the laboratory frame using quasimonoenergetic linearly (circularly) ...polarized photon beams with a weighted mean energy value of 83.4 MeV (81.3 MeV). These measurements were performed at the High Intensity Gamma-Ray Source facility at the Triangle Universities Nuclear Laboratory. The results are compared to previous measurements and are interpreted in the chiral effective field theory framework to extract the electromagnetic dipole polarizabilities of the proton, which gives α_{E1}^{p}=13.8±1.2_{stat}±0.1_{BSR}±0.3_{theo},β_{M1}^{p}=0.2∓1.2_{stat}±0.1_{BSR}∓0.3_{theo} in units of 10^{-4} fm^{3}.
Thirty-six Angus and Angus×Simmental heifers, averaging 291kg, were used to determine the effects of dietary Cr, in the form of Cr propionate (Cr Prop), on glucose metabolism and serum insulin ...concentrations following glucose administration. Heifers were stratified by body weight (BW) within a breed and randomly assigned to treatments. Treatments consisted of 0, 3, 6, or 9mg of supplemental Cr/d from Cr Prop. Based on dry matter (DM) intakes, the daily doses of Cr were equivalent to 0.47, 0.94, and 1.42mg of supplemental Cr/kg of DM. Heifers were individually fed a corn silage-based diet at a level of 2% of BW. Each heifer was also fed 0.45kg of a ground corn supplement daily that served as a carrier for supplemental Cr. Glucose tolerance tests were performed on d 44 of the study. Glucose was infused via jugular catheters at a level of 0.45g/kg of BW0.75 over a course of 1 to 2min. Blood samples were collected at −10, 0, 5, 10, 15, 30, 45, 60, 90, 120, 150, and 180min relative to glucose dosing for glucose and insulin determination. Area under the glucose response curve was lower (1,603 vs. 1,964mg/dL per minute) in heifers supplemented with Cr from 0 to 45min following glucose challenge. Serum insulin concentrations were lower in Cr-supplemented heifers than in controls following glucose infusion. The molar ratio of insulin to glucose was also lower in Cr-supplemented heifers relative to controls. Serum insulin and serum insulin to glucose ratios did not differ among heifers supplemented with 3, 6, or 9mg of Cr/d. Results indicate that Cr Prop supplementation increased tissue sensitivity to insulin in growing heifers. Based on insulin sensitivity, Cr requirements (as Cr Prop) of growing heifers can be met by supplementing with 3mg of Cr/d or 0.47mg of Cr/kg of DM.
This study was designed to investigate the effects of weaning age on specific components of the adaptive immune system in pigs. Twenty-three crossbred pigs were randomly assigned to 1 of 3 ...treatments: weaning at 14 (14D, n = 8), 21 (21D, n = 7), or 28 (28D, n = 8) d of age. Peripheral blood samples, obtained when pigs were 13, 15, 20, 22, 27, 29, and 35 d of age, were analyzed for peripheral blood cell percentages and concentrations of neutrophils, lymphocytes, T cell subsets, mature B cells, and plasma cortisol concentrations. For each of the 3 groups, weaning increased plasma cortisol concentrations (P < 0.001) and reduced BW percentage change (P < 0.017). Lymphocyte concentrations displayed a treatment effect for the 14D (P = 0.074) and 28D (P = 0.014) groups. Albeit inconsistent, lymphocyte concentrations were less in weaned pigs on the day after weaning than in pigs remaining on the sow or weaned at a younger age. Specifically, mature B cells (CD21+) and CD4+CD8+ cells decreased (P < 0.05) after weaning at 28 d of age. Other differences occurred among treatments; however, the differences apparently were not associated with weaning. Based upon the immunological measures used in the present study, there was not an explicit benefit to the adaptive immune system for any weaning age. Early weaning did not negatively affect the adaptive immunological competence of pigs as determined by changes in populations of immune cells.
A study was conducted to examine the effects of low dietary Mn on growth performance of pregnant heifers and fetal development of their offspring. Twenty pregnant Angus (n=9) and Simmental (n=11) ...heifers averaging 17 mo of age and 447.6kg of initial body weight were used in the 267-d study. Heifers were selected from a previous study examining the effects of supplemental Mn on growth and reproductive performance of heifers. Ten pregnant heifers per treatment from the control (analyzed at 15.8mg of Mn/kg of DM) and supplemental Mn (50 mg/kg of DM) treatments were randomly selected at the conclusion of the previous study to continue on their respective dietary treatments through gestation and early lactation. Serum cholesterol for the 267-d period was not affected by treatment. Whole-blood Mn concentration of heifers on d 267 was not affected by treatment. Whole-blood Mn concentration at birth was lower in calves born to control heifers than in those born to supplemented heifers. Calves born to control heifers weighed less at birth than those born to heifers receiving supplemental Mn. Calves born to control heifers suffered from varying signs of Mn deficiency, including superior brachygnathism, unsteadiness, disproportionate dwarfism, and swollen joints. Results suggest that feeding gestating heifers a diet containing 16.6mg of Mn/kg of DM is not adequate for proper fetal development. Supplementation of 50mg of Mn/kg of DM to the control diet was sufficient to overcome any signs of Mn deficiency in calves.
An experiment was conducted to examine the effects of dietary Mn on growth, reproductive performance, and Mn status of beef heifers. Eighty Angus (n = 40) and Simmental (n = 40) heifers, averaging ...249 kg, were stratified by BW within a breed and randomly assigned to 1 of 4 treatments providing 0 (control), 10, 30, or 50 mg of supplemental Mn/kg of DM from MnSO₄. Heifers were individually fed a diet containing cottonseed hulls, corn gluten feed, citrus pulp, and ground corn, and the control diet contained 15.8 mg of Mn/kg of DM by analysis. Average daily gain, DMI, and G:F for the 196-d period were not affected by Mn supplementation. Control heifers had reduced (P = 0.04) liver Mn when contrasted with the 3 levels of supplemental Mn. Serum cholesterol was greater (P = 0.001) in Angus compared with Simmental heifers over the course of the 196-d experiment but was not affected by treatment. Dietary Mn did not significantly affect measures of reproductive performance. Results of this study indicate that 15.8 mg of Mn/kg of diet DM should be adequate for growth, onset of estrus, and conception of beef heifers.
The efficacy of several protocols for ovulation synchronization and timed artificial insemination (TAI) in goats was examined. In addition, the relationship between levels of pregnancy specific ...protein B (PSPB) during gestation assessed with a commercially available ELISA and the number of offspring at birth was determined. In Experiment 1, 70 does were randomized into four treatments: (1) breed by estrus BBE, (2) 6-d treatment with a new C6N, (3) once-used C61, or (4) twice-used Controled Internal Drug Release (CIDR) device C62). BBE does received two 15 mg doses of prostaglandin-F2α (PGF) at a 10-d interval and were bred 12 h after estrus onset. CIDR groups received a CIDR for 6 d with 15 mg PGF given at CIDR removal. TAI was performed 48 h after CIDR removal and does were given 50 μg GnRH. All does were inseminated with a single dose of frozen semen using a non-surgical, transcervical technique. Pregnancy rates for the BBE, C6N, C61 and C62 treatment groups were 39% ± 12%, 64% ± 12%, 77% ± 12% and 57% ± 12%, respectively, and did not differ. Reuse of CIDRs, even with reuse extending for a total of 21 d, was as effective as new CIDRs for synchronization of ovulation. In Experiment 2, 68 does were randomized into four treatments: (1) BBE, (2) C6N, (3) NC.Synch NCS, (4) modified NCS NCSM. The BBE and C6N groups were as described for Experiment 1. The NCS and NCSM groups received 15 mg PGF on Day 1, 50 μg GnRH on Day 8 and 15 mg PGF on Day 15 (NCS) or Day 15.5 (NCSM). Does were bred by TAI at 72 h (NCS) or 60 h (NCSM) after the second PGF injection. All does in the NCS and NCSM groups received 50 μg GnRH at TAI. Pregnancy rates were 53% ± 12%, 30% ± 11%, 50% ± 11% and 41% ± 12% for does in the BBE, C6N, NCS and NCSM group, respectively, and did not differ. In Experiment 3, 62 does pregnant to TAI were bled at Days 48 and 85 post-insemination for PSPB. Data on kid numbers and birth weights were subsequently recorded. At Day 48 of gestation, PSPB levels for does birthing singletons were lower than for does birthing twins or triplets (25.0 ± 0.1a, 28.8 ± 0.1b and 30.7 ± 0b ng/mL, respectively, abP<0.05). At Day 85 of gestation, PSPB levels were progressively greater for does birthing singletons versus twins versus triplets (27.0 ± 0.1a, 28.5 ± 0.1b and 31.6 ± 0c ng/mL, abcP<0.05). In conclusion, PSPB concentrations detected using a commercially available ELISA at Day 48 or 85 of gestation could distinguish does carrying single versus multiple fetuses.
•Pregnancy Specific Protein B detected with ELISA identified does carrying single versus multiple fetuses.•Reuse of CIDRs, even extending to 21 d, was as effective as new CIDRs for ovulation synchronization.•Pregnancy rates following TAI were highest with insemination at 18 to 24 h after the LH surge.
The use of fixed-time artificial insemination (FTAI) provides producers with numerous benefits including the use of superior genetics, shorter breeding and calving seasons, and a more uniform calf ...crop. However, the cost of implementing FTAI protocols is one of the several drawbacks hindering their use in the beef industry. Potential injection-site lesions from intramuscular injections of the hormones necessary for estrus synchronization are also a cause of concern for carcass quality. The objectives of this experiment were to (1) determine whether or not a twice-used controlled internal drug release (CIDR) device would be effective in an FTAI protocol without adversely affecting pregnancy rate and (2) whether or not the subcutaneous administration of PGF2α affects pregnancy rate. Nulliparous females (n = 99) between 13 and 27 months of age and multiparous cows (n = 43) between 48 and 74 months of age were synchronized for estrus using the 7-day CO-Synch + CIDR protocol. The females were randomly assigned to one of the two treatments: (1) a once-used CIDR (control) or (2) a twice-used CIDR device (treatment) incorporated into their synchronization protocol. The females were also randomly assigned to have their injection of PGF2α administered either intramuscularly or subcutaneously. Blood was taken in a random subset of nulliparous females (n = 52) just before device removal and assayed for concentration of progesterone. The concentration of progesterone was higher (P = 0.01) in the animals that received once-used CIDR devices than that in those received twice-used CIDR devices (3.4 ± 0.5 and 1.4 ± 0.5 ng/mL, respectively). There was no significant effect of parity (P = 0.82), artificial insemination technician (P = 0.60), PGF2α administration (P = 0.83), or treatment (P = 0.67) on pregnancy rates to artificial insemination which were 75.4 ± 6.0% and 71.7 ± 6.4%, for animals that received once- and twice-used CIDR devices, respectively. This study provides evidence that although concentration of progesterone is decreased in animals treated with a twice-used CIDR device, there is still a sufficient release of progesterone from the device to effectively synchronize estrus without adversely affecting the fertility of a herd.
Maximum diurnal accumulation of soluble carbohydrates in warm-season grasses is an economic way of increasing hay quality; however, in the humid East, haymaking is difficult. This study evaluated ...gamagrass (Tripsacum dactyloides L.), topdressed with either 56 (LO) or 168 (HI) kg N ha–1, direct baled after mowing in the afternoon (PM/LO and PM/HI) or morning (AM/LO and AM/HI), wrapped with plastic film, and conserved as baleage. The four baleage treatments were evaluated by steers for dry matter intake (DMI), digestibility, and N retention. Neither harvest time nor N rate altered DMI (mean = 1.87 kg 100–1 kg body weight). Digestion was similar between PM and AM baleage but greater (P = 0.05) for HI vs. LO N rate (536 vs. 506 g kg–1) as was cellulose digestion (P = 0.02; 656 vs. 617 g kg–1). The digestion of crude protein was greater (P = 0.01) in the AM vs. PM baleage (519 vs. 443 g kg–1) and greater (P = 0.02) in HI vs. LO N rate (520 vs. 441 g kg–1). Fermentations differed (P < 0.01) between PM and AM baleage, as pH averaged 5.4 and 4.5, respectively. Greatest (P < 0.01) amounts of alcohols and least fatty acids occurred in PM baleage and N rate reduced (P < 0.01) alcohols but increased fatty acids. Total nonstructural carbohydrates (TNC) prebaling was 120 g kg–1 in the PM and 97 g kg–1 in the AM, but baleage averaged <38 g kg–1 and explains the lack of steer response to the PM harvest. Gamagrass preserved well as baleage and was readily consumed, but the TNC fraction was not preserved.
Weanling pigs (n = 132) were used to investigate the effects of three common stressors (and a control) and differing social status on behavior, immunity, plasma cortisol, blood chemical, and ...performance measures. Eleven blocks of 12 pigs each were evaluated. Each pen contained three pigs of dominant (DOM), intermediate (INT), or submissive (SUB) social status. Two weeks later, random pens of pigs experienced either a control treatment (CON) or they were stressed for 4 h by shipping (SHIP), heat-stressed (HEAT) with overhead heat lamps in their home pens, or cold-stressed (COLD) by direct application of water and an air current. Treatments did not influence body weights; however, percentage weight loss during SHIP was greater than for other treatments. Body weights were heavier for DOM pigs than for INT and SUB pigs. Social status had large effects on plasma cortisol, globulin, acute-phase proteins, body weight, and weight changes. Only acute shipping stress resulted in weight loss. Many immune and blood measures were not changed among acutely stressed pigs; however, the relationship between social status and mitogen-induced lymphocyte proliferation and natural killer cell cytotoxicity was disrupted during acute stress. Pig behavior was significantly changed by each stress treatment in a unique manner. During acute stress, behavioral changes seem to be the most consistent and reliable indicators
The objective of this study was to characterize correlated responses in testicular morphology and daily sperm production to divergent selection for testosterone production. Duroc boars from high and ...low lines (HTL and LTL, respectively) divergently selected over 10 generations for testosterone production in response to a GnRH challenge followed by random selection were used. Testicular tissues were sampled from all available males of generation 20 (HTL, n = 46; and LTL, n = 13). Volume densities for Leydig cells, seminiferous tubules, and Sertoli cells were estimated along with sperm production. The HTL boars had greater volume densities of Leydig cells than did LTL (P < 0.01). Volume density of seminiferous tubules tended to differ between lines (P < 0.07), but Sertoli cell volume densities did not differ (P < 0.27). Sperm production traits, adjusted for age, did not differ significantly between lines. Body, testicular, and epididymal weights were recorded for boars from HTL (n = 82) and LTL (n = 44) from generations 20 and 21. After adjustment for BW, average paired testicular weights for HTL and LTL were 417 and 457 g (P < 0.01), respectively. Epididymal weights, adjusted for BW, were heavier for HTL (P < 0.01) than for LTL. To demonstrate that the selection lines still differed for testosterone production, lines were evaluated in generation 21. Endogenous testosterone production of the HTL (n = 54) and LTL (n = 44) testosterone production line averaged 49.0 ng/mL and 27.8 ng/mL (P < 0.01), respectively. Plasma FSH concentrations did not differ between lines (P < 0.30). Selection for testosterone production in response to a GnRH challenge was an effective method of changing testosterone concentrations, testicular size, epididymal weight, and volume density of Leydig cells. However, daily sperm production per gram of testes was unchanged. Based on the results of this study, selection for testosterone production is not recommended as a method of increasing sperm production in pigs.
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