While feed efficiency (FE) is a trait of great economic importance to the pig industry, the influence of the intestinal microbiome in determining FE is not well understood. The objective of this ...experiment was to determine the relative influence of FE and farm of birth on the pig colonic microbiome. Animals divergent in residual feed intake (RFI) were sourced from two geographically distinct locations (farms A + B) in Ireland. The 8 most efficient (low RFI (LRFI)) and 8 least efficient (high RFI, (HRFI)) pigs from farm A and 12 LRFI and 12 HRFI pigs from farm B were sacrificed. Colonic digesta was collected for microbial analysis using 16S ribosomal RNA gene sequencing and also for volatile fatty acid analysis. The α-diversity differed between the farms in this study, with pigs from farm A having greater diversity based on Shannon and InvSimpson measures compared to pigs from farm B (P < 0.05), with no difference identified in either Chao1 or observed measures of diversity (P > 0.05). In the analysis of β-diversity, pigs clustered based on farm of birth rather than RFI. Variation in the management of piglets, weight of the piglets, season of the year, sanitary status and dam dietary influence could potentially be causative factors in this large variation between farms. However, despite significant variation in the microbial profile between farms, consistent taxonomic differences were identified between RFI groups. Within the phylum Bacteroidetes, the LRFI pigs had increased abundance of BS11 (P < 0.05) and a tendency toward increased Bacteroidaceae (P < 0.10) relative to the HRFI group. At genus level, the LRFI pigs had increased abundance of Colinsella (P < 0.05), a tendency toward increased Bacteroides and CF231 (P < 0.10). At species level, Ruminococcus flavefaciens had increased abundance in the LRFI compared to the HRFI animals. In conclusion, while farm of birth has a substantial influence on microbial diversity in the pig colon, a microbial signature indicative of FE status was apparent.
Genetic selection for increased sow prolificacy has resulted in decreased mean piglet birth weight. This study aimed to investigate the effect of l-carnitine (CAR) supplementation to sows during ...gestation and/or lactation on sow productivity, semitendinosus muscle (STM) maturity and lifetime growth in progeny. Sixty-four sows were randomly assigned to one of the four dietary treatments at breeding until weaning: CONTROL (0 mg CAR/d), GEST (125 mg CAR/d during gestation), LACT (250 mg CAR/d during lactation) and BOTH (125 mg CAR/d during gestation and 250 mg CAR/d during lactation). The total number of piglets born per litter was greater for sows supplemented with CAR during gestation (17·3 v. 15·8 (sem 0·52); P < 0·05). Piglet birth weight (total and live) was unaffected by sow treatment (P > 0·05). Total myofibre number (P = 0·08) and the expression level of selected myosin heavy chain genes in the STM (P < 0·05) were greater in piglets of sows supplemented with CAR during gestation. Pigs from sows supplemented with CAR during gestation had lighter carcasses at slaughter than pigs from non-supplemented sows during gestation (83·8 v. 86·7 (sem 0·86) kg; P < 0·05). In conclusion, CAR supplementation during gestation increased litter size at birth without compromising piglet birth weight. Results also showed that the STM of piglets born to sows supplemented with CAR during gestation was more developed at birth. However, carcass weight at slaughter was reduced in progeny of sows supplemented with CAR during gestation. The CAR supplementation strategy applied during gestation in this study could be utilised by commercial pork producers to increase sow litter size and improve offspring muscle development.
A 3×2 factorial experiment was conducted to investigate the effect of dietary supplementation of purified laminarin (LAM) and fucoidan (FUC), independently or in combination on growth performance, ...coefficient of total tract apparent digestibility (CTTAD), selected faecal microbial populations and volatile fatty acid concentrations (VFA) in weaned pigs. At weaning, 168 pigs (24 days of age, 6.8±0.6kg live weight) were assigned to one of six dietary treatments (n=14): (1) basal diet; (2) basal diet+240mg/kg FUC; (3) basal diet+150mg/kg LAM; (4) basal diet+150mg/kg LAM and 240mg/kg FUC; (5) basal+300mg/kg LAM; (6) basal diet+300mg/kg LAM and 240mg/kg FUC. The pigs were offered the diets ad libitum for 35 days post-weaning. Pigs offered 300mg/kg LAM supplemented diets had a higher average daily gain (ADG) throughout the entire experimental period (d 0–35) compared with pigs offered diets with 0mg/kg and 150mg/kg LAM supplementation (0.374kg/d vs. 0.346kg/d vs. 0.340kg/d, SEM±0.0094; P<0.05). There was an interaction between LAM and FUC supplementation on gain to feed (G:F) ratio (P<0.05) during the entire experimental period. Pigs offered the 300mg/kg LAM diet had a higher G:F ratio than pigs offered the basal diet. However, there was no effect of the 300mg/kg LAM on overall G:F ratio when combined with FUC. There was an interaction between LAM and FUC supplementation on the CTTAD of gross energy (GE) (P<0.05). Pigs offered the 150mg/kg or 300mg/kg LAM diets had an increased CTTAD of GE compared with pigs offered the basal diet. However, there was no further effect of LAM on the CTTAD of GE when combined with FUC. Pigs offered diets supplemented with FUC had an increased faecal Lactobacillus population compared with pigs offered diets without FUC supplementation (10.11 gene copy number/g vs. 9.62 gene copy number/g, SEM±0.173; P<0.05). Pigs offered the 150mg/kg and 300mg/kg LAM supplemented diets had an improved faecal consistency from d 7–14 compared with pigs offered diets without LAM supplementation (3.14 vs. 3.00 vs. 3.49, SEM±0.348; P<0.05). In summary, the inclusion of 300mg/kg LAM showed the greatest benefit in growth performance with improvements in ADG and G:F ratio partially due to an increased CTTAD of diet components and lower faecal score.
Rapeseed meal (RSM) and wheat dried distillers grains with solubles (DDGS) are byproducts which may be incorporated into pig diets. However, in comparison with wheat and soyabean meal, higher ...non-starch polysaccharide (NSP) content in RSM and DDGS may impose dietary limitations. Two 2×2 factorial experiments were conducted to investigate the interaction between xylanase (0 vs. 200mg/kg) and protease (0 vs. 200mg/kg) enzyme supplementation on (1) growth performance and carcass characteristics, and (2) apparent ileal (AID) and total tract nutrient digestibility (ATTD), manure gaseous emissions in grower–finisher pigs. In experiment 1, to assess growth performance, 128 pigs (body weight (BW), 34.2±2.1kg; n=32) were allocated to one of four treatments based on a basal diet containing DDGS (300g/kg) and RSM (210g/kg): (1) basal diet; (2) basal diet plus 200mg/kg protease enzyme; (3) basal diet plus 200mg/kg xylanase enzyme; (4) basal diet plus 200mg/kg protease and 200mg/kg xylanase enzymes. In experiment 1, pigs offered diets supplemented with protease had a lower ADG (P<0.001) during the combined grower and finisher period (d 0-slaughter) compared with pigs offered diets without protease. There was an interaction between growing phase, protease and xylanase supplementation on ADFI (P<0.01) and BW (P<0.01). During the finishing phase (d 28-slaughter), pigs offered diets containing both xylanase and protease had a reduced ADFI and a reduced BW compared with pigs offered the protease or xylanase only diets. However, this interaction was not evident during the growing period (d 0–28). In experiment 2, 24 entire male pigs (BW 78±2.3kg; n=6), were housed in metabolism crates and offered identical diets to those in experiment 1. There was an interaction between xylanase and protease (P<0.05) on the AID of GE. Diets containing protease only had increased AID of GE compared with basal fed pigs; however the AID of GE decreased when protease was combined with xylanase. Diets containing xylanase reduced manure odour emissions compared with diets without xylanase (598 vs. 1306OuE/m3; P<0.05). In conclusion, protease increased the AID of GE and xylanase reduced manure odour emissions, however neither enzymes improved growth performance of grower finisher pigs offered diets based on RSM and DDGS.
Two experiments were performed in weaner, grower and finisher pigs in order to monitor the changes in skeletal area bone mineral density (aBMD, g/cm2) and dietary phosphorus (P) concentrations using ...dual energy X-ray absorptiometry (DXA) scan data. In experiment 1, 24 female pigs were selected at 8kg (SD±1.04kg) and individually fed either high (3.7g/kg) or low (3.0g/kg) digestible P diets for 8weeks (with reductions of 0.5g/kg digestible P at 4weeks) until they reached ca. 30kg body weight. The pigs were anaesthetised and scanned at the start of the study (day 0) and after 28 and 56days. In experiment 2, 30 female pigs were selected at 34kg (SD±2.3kg) and individually fed high (2.8g/kg), medium (2.2g/kg) or low (1.6g/kg) digestible P until slaughter at 100kg (SD±4.3kg). These pigs were scanned at the start of the experiment (day 0) and after 35 and 70days. One foot from each pig in experiment 2 was collected at slaughter for analysis of metacarpal cross section area, moment of inertia, dry matter, apparent density, aBMD, and ash percentage. In both experiments, there were significant diet×time interactions (P<0.01—experiment 1; P<0.001—experiment 2) on whole body aBMD. Values of whole body aBMD (g/cm2) measured in pigs fed high and low P diets (experiment 1) were: 0.44, 0.50 and 0.62 vs. 0.45, 0.48 and 0.52 (SEM=0.020) for days 0, 28 and 56; respectively. In experiment 2, whole body aBMD values (g/cm2) for days 0, 35 and 70 were: 0.55, 0.75 and 0.97 vs. 0.56, 0.70 and 0.88 vs. 0.56, 0.64 and 0.73 (SEM=0.013) in pigs fed high, medium and low P diets; respectively. In experiment 2, metacarpal apparent density from pigs fed the high P diets was higher (P<0.001) than pigs fed medium and low P diets. The metacarpal aBMD was higher (P<0.001) in pigs fed the high and medium P diets than the low P diet. In conclusion, young pigs are highly sensitive to dietary P as their average weekly increases in aBMD for high and low digestible P diets were 0.023 and 0.009g/cm2; respectively. Finisher pigs accumulate aBMD at much higher rates (0.041, 0.032 and 0.017g/cm2/week for high, medium and low digestible P diets; respectively) than weaner pigs.
•Benzoic acid limited lactic acid bacteria growth in liquid feed for finisher pigs•The pH of liquid feed was stabilised with benzoic acid inclusion•Benzoic acid limited spontaneous fermentation in ...liquid feed for finisher pigs•Benzoic acid supplementation did not impact grow-finisher pig growth•Supplementation of benzoic acid to grow-finisher pigs did not impact carcass traits
Benzoic acid has long been used as a food preservative due to its antibacterial and antifungal effects. Supplementation to pig diets has also been shown to inhibit microbial free amino acid degradation and to control yeast growth in fermented liquid feed. However, the effect of dietary inclusion of benzoic acid (BA) in fresh liquid feed for grow-finisher pigs on feed quality and the resultant effects on pig growth remain unclear. The objective of the current study was to compare four inclusion levels of BA (VevoVitall®) on feed microbial quality and on the growth performance of grow-finisher pigs. Two-hundred and sixteen pigs with a starting weight of 30.0kg (± 7.43 SD) were used in the experiment. The four dietary treatments were as follows: (1) Basal diet + 0kg/t BA (0kg/t BA), (2) Basal diet + 2.5kg/t BA (2.5kg/t BA), (3) Basal diet + 5kg/t BA (5kg/t BA), (4) Basal diet + 10kg/t BA (10kg/t BA). Lactic acid bacteria (LAB) counts in the mixing tank were similar across treatments (P>0.05) but were lower in the troughs for the feed supplemented with 10kg/t BA than for all other treatments (P<0.01). The pH of the 10kg/t BA treatment was also lower than that of the other three treatments. However, this only occurred in the mixing tank (P<0.01), as in the trough, the basal diet had the lowest pH (lower than the other three treatments; P<0.01). Dietary BA inclusion did not affect average daily gain, average daily feed intake, feed conversion efficiency, final live-weight, carcass weight or carcass quality during the experimental period (P>0.05). In conclusion, while BA may limit the growth of LAB in liquid feed and stabilise feed pH, its inclusion in the diet did not improve the growth performance or carcass quality of grow-finisher pigs.
Intrauterine devices (IUDs), long‐acting and reversible contraceptives, induce a number of immunological and biochemical changes in the uterine environment that could affect endometrial cancer (EC) ...risk. We addressed this relationship through a pooled analysis of data collected in the Epidemiology of Endometrial Cancer Consortium. We combined individual‐level data from 4 cohort and 14 case‐control studies, in total 8,801 EC cases and 15,357 controls. Using multivariable logistic regression, we estimated pooled odds ratios (pooled‐ORs) and 95% confidence intervals (CIs) for EC risk associated with ever use, type of device, ages at first and last use, duration of use and time since last use, stratified by study and adjusted for confounders. Ever use of IUDs was inversely related to EC risk (pooled‐OR = 0.81, 95% CI = 0.74–0.90). Compared with never use, reduced risk of EC was observed for inert IUDs (pooled‐OR = 0.69, 95% CI = 0.58–0.82), older age at first use (≥35 years pooled‐OR = 0.53, 95% CI = 0.43–0.67), older age at last use (≥45 years pooled‐OR = 0.60, 95% CI = 0.50–0.72), longer duration of use (≥10 years pooled‐OR = 0.61, 95% CI = 0.52–0.71) and recent use (within 1 year of study entry pooled‐OR = 0.39, 95% CI = 0.30–0.49). Future studies are needed to assess the respective roles of detection biases and biologic effects related to foreign body responses in the endometrium, heavier bleeding (and increased clearance of carcinogenic cells) and localized hormonal changes.
What's new?
Are IUDs associated with endometrial cancer? Around the world, the intrauterine device is gaining popularity as a long‐term birth control strategy. Positioned as it is embedded in the uterine lining, an IUD could affect endometrial tissue. This study builds on previous work by considering the type of device used, in addition to factors such as duration of use. The authors found that women who had used an IUD, particularly an inert IUD, had less risk of endometrial cancer. The longer the device was used, they found, the more the cancer risk decreased.
The ATLAS group has evaluated the charge collection in silicon microstrip sensors irradiated up to a fluence of 1×1016neq/cm2, exceeding the maximum of 1.6×1015neq/cm2 expected for the strip tracker ...during the high luminosity LHC (HL-LHC) period including a safety factor of 2. The ATLAS12, n+-on-p type sensor, which is fabricated by Hamamatsu Photonics (HPK) on float zone (FZ) substrates, is the latest barrel sensor prototype. The charge collection from the irradiated 1×1cm2 barrel test sensors has been evaluated systematically using penetrating β-rays and an Alibava readout system. The data obtained at different measurement sites are compared with each other and with the results obtained from the previous ATLAS07 design. The results are very consistent, in particular, when the deposit charge is normalized by the sensor's active thickness derived from the edge transient current technique (edge-TCT) measurements. The measurements obtained using β-rays are verified to be consistent with the measurements using an electron beam. The edge-TCT is also effective for evaluating the field profiles across the depth. The differences between the irradiated ATLAS07 and ATLAS12 samples have been examined along with the differences among the samples irradiated with different radiation sources: neutrons, protons, and pions. The studies of the bulk properties of the devices show that the devices can yield a sufficiently large signal for the expected fluence range in the HL-LHC, thereby acting as precision tracking sensors.
Detailed studies of full-size ATLAS12 sensors Hommels, L.B.A.; Baca, M.; Broughton, J. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2016, Letnik:
831
Journal Article
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The “ATLAS ITk Strip Sensor Collaboration” R&D group has developed a second iteration of single-sided n+-in-p type micro-strip sensors for use in the tracker upgrade of the ATLAS experiment at the ...High-Luminosity (HL) LHC. The full size sensors measure approximately 97×97mm2 and are designed for tolerance against the 1.1×1015neq/cm2 fluence expected at the HL-LHC. Each sensor has 4 columns of 1280 individual 23.9mm long channels, arranged at 74.5μm pitch. Four batches comprising 120 sensors produced by Hamamatsu Photonics were evaluated for their mechanical, and electrical bulk and strip characteristics. Optical microscopy measurements were performed to obtain the sensor surface profile. Leakage current and bulk capacitance properties were measured for each individual sensor. For sample strips across the sensor batches, the inter-strip capacitance and resistance as well as properties of the punch-through protection structure were measured. A multi-channel probecard was used to measure leakage current, coupling capacitance and bias resistance for each individual channel of 100 sensors in three batches. The compiled results for 120 unirradiated sensors are presented in this paper, including summary results for almost 500,000 strips probed. Results on the reverse bias voltage dependence of various parameters and frequency dependence of tested capacitances are included for validation of the experimental methods used. Comparing results with specified values, almost all sensors fall well within specification.
A radiation hard n+-in-p micro-strip sensor for the use in the Upgrade of the strip tracker of the ATLAS experiment at the High Luminosity Large Hadron Collider (HL-LHC) has been developed by the ...“ATLAS ITk Strip Sensor collaboration” and produced by Hamamatsu Photonics.
Surface properties of different types of end-cap and barrel miniature sensors of the latest sensor design ATLAS12 have been studied before and after irradiation. The tested barrel sensors vary in “punch-through protection” (PTP) structure, and the end-cap sensors, whose stereo-strips differ in fan geometry, in strip pitch and in edge strip ganging options. Sensors have been irradiated with proton fluences of up to 1×1016 neq/cm2, by reactor neutron fluence of 1×1015 neq/cm2 and by gamma rays from 60Co up to dose of 1MGy. The main goal of the present study is to characterize the leakage current for micro-discharge breakdown voltage estimation, the inter-strip resistance and capacitance, the bias resistance and the effectiveness of PTP structures as a function of bias voltage and fluence. It has been verified that the ATLAS12 sensors have high breakdown voltage well above the operational voltage which implies that different geometries of sensors do not influence their stability. The inter-strip isolation is a strong function of irradiation fluence, however the sensor performance is acceptable in the expected range for HL-LHC. New gated PTP structure exhibits low PTP onset voltage and sharp cut-off of effective resistance even at the highest tested radiation fluence. The inter-strip capacitance complies with the technical specification required before irradiation and no radiation-induced degradation was observed. A summary of ATLAS12 sensors tests is presented including a comparison of results from different irradiation sites. The measured characteristics are compared with the previous prototype of the sensor design, ATLAS07.
•Surface study verified high radiation resistance of developed n-in-p strip sensors.•Sensors have high breakdown voltage before and after irradiation.•Inter-strip capacitance is sufficiently low and does not change with irradiation.•Primary factor of inter-strip resistance decrease is total ionizing dose.•New gated PTP doubles current flowing into bias rail without onset voltage increase.
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