1,403 research outputs found
The Globular Cluster Systems in the Coma Ellipticals. III: The Unique Case of IC 4051
Using archival \hst WFPC2 data, we derive the metallicity distribution,
luminosity function, and spatial structure of the globular cluster system
around IC 4051, a giant E galaxy on the outskirts of the Coma cluster core. The
metallicity distribution derived from the (V-I) colors has a mean [Fe/H] =
-0.3, a near-complete lack of metal-poor clusters, and only a small metallicity
gradient with radius; it may, however, have two roughly equal metallicity
subcomponents, centered at [Fe/H] ~ 0.0 and -1.0. The luminosity distribution
(GCLF) has the Gaussian-like form observed in all other giant E galaxies, with
a peak (turnover) at V = 27.8, consistent with a Coma distance of 100 Mpc. The
radial profiles of both the GCS and the halo light show an unusually steep
falloff which may indicate that the halo of this galaxy has been tidally
truncated. Lastly, the specific frequency of the GCS is remarkably large: we
find S_N = 11 +- 2, resembling the central cD-type galaxies even though IC 4051
is not a cD or brightest cluster elliptical. A formation model consistent with
most of the observations would be that this galaxy was subjected to removal of
a large fraction of its protogalactic gas shortly after its main phase of
globular cluster formation, probably by its first passage through the Coma
core. Since then, no significant additions due to accretions or mergers have
taken place.Comment: 24 pp. plus 13 Figures. Postscript file for the complete paper can
also be downloaded from http://www.physun.mcmaster.ca/~harris/WEHarris.html.
Astron.J., in pres
Unveiling Palomar 2: The Most Obscure Globular Cluster in the Outer Halo
We present the first color-magnitude study for Palomar 2, a distant and
heavily obscured globular cluster near the Galactic anticenter. Our (V,V-I)
color-magnitude diagram (CMD), obtained with the UH8K camera at the CFHT,
reaches V(lim) = 24 and clearly shows the principal sequences of the cluster,
though with substantial overall foreground absorption and differential
reddening. The CMD morphology shows a well populated red horizontal branch with
a sparser extension to the blue, similar to clusters such as NGC 1261, 1851, or
6229 with metallicities near [Fe/H] = -1.3, placing it about 34 kpc
from the Galactic center. We use starcounts of the bright stars to measure the
core radius, half-mass radius, and central concentration of the cluster. Its
integrated luminosity is M_V = -7.9, making it clearly brighter and more
massive than most other clusters in the outer halo.Comment: 25 pages, aastex, with 8 postscript figures; accepted for publication
in AJ, September 1997. Also available by e-mail from
[email protected]. Please consult Harris directly for (big)
postscript files of Figures 1a,b (the images of the cluster
Evaluation of Extreme Thermal Processing Methods to Improve Nutrient Utilization of Low-Energy Diets for Finishing Pigs
A total of 270 pigs (PIC 337 × 1050; initially 115.7 lb) were used in a 79-d experiment to determine the effects of long-term conditioning or extrusion on finishing pig nutrient digestibility, growth performance, and carcass characteristics. There were 7 or 8 pigs per pen and 9 pens per treatment. Treatments included the same basal diet processed as: 1) nonprocessed mash; 2) pelleted with 45-s conditioner retention time; 3) pelleted with 90-s conditioner retention time; or 4) extruded. Diets were fed in three phases with the same low-energy diet formulation fed across treatments, containing 30% corn dried distillers grains with solubles and 19% wheat middlings. Pigs fed thermally processed feed, regardless of method, had improved ADG, F/G, ether extract, and crude fiber apparent total tract digestibility (P \u3c 0.05) compared to those fed the mash diet, but thermal processing did not affect ADFI . Extruded diets tended to improve F/G compared to pelleted diets (P = 0.09). Pigs fed any thermally processed treatment had greater HCW compared to those fed mash (P \u3c 0.05). Improvements in fat and crude fiber digestibility (P \u3c 0.05) led to improved caloric efficiency in pigs fed thermally processed diets. Thermal processing did not influence percentage yield, backfat, or loin depth when HCW was used as a covariate. However, pigs fed thermally processed diets had greater jowl fat iodine value compared to those fed mash diets (P \u3c 0.05). Electrical energy usage during thermal processing was recorded. Pigs fed mash diets had greater (P \u3c 0.05) cost per lb of gain, as well as reduced gain value and income over feed costs, compared to those fed thermally processed diets. This experiment confirms the benefits of thermally processing feeds to improve ADG and F/G, but compromises carcass fat iodine value. Additionally, this research suggests that more extreme thermal processing conditions may be used without hindering nutrient utilization
New Insights from HST Studies of Globular Cluster Systems I: Colors, Distances and Specific Frequencies of 28 Elliptical Galaxies
We present an analysis of the globular cluster systems of 28 elliptical
galaxies using archival WFPC2 images in the V and I-bands. The V-I color
distributions of at least 50% of the galaxies appear to be bimodal {\it at the
present level of photometric accuracy}. We argue that this is indicative of
multiple epochs of cluster formation early in the history of these galaxies,
possibly due to mergers. We also present the first evidence of bimodality in
low luminosity galaxies and discuss its implication on formation scenarios. The
mean color of the 28 cluster systems studied by us is V-I = 1.040.04
(0.01) mag corresponding to a mean metallicity of Fe/H = -1.00.19 (0.04).
We find that the turnover magnitudes of the globular cluster luminosity
functions (GCLF) of our sample are in excellent agreement with the distance
measurements using other methods and conclude that the accuracy of the GCLF is
at least as good as the surface brightness fluctuation method. The absolute
magnitude of the turnover luminosity of the GCLF is M = -7.41 (0.03) in V
and M = -8.46 (0.03) in I. The mean local specific frequency of our
sample of elliptical galaxies within the WFPC2 field-of-view is 2.41.8
(0.4), considerably higher than the 1.00.6 (0.1) derived for a comparable
sample of S0s in a similar analysis. It shows no obvious correlation with
metallicity, host galaxy mass or membership in a galaxy cluster. The median
size of clusters in all galaxies appears to be remarkably constant at 2.4
pc. We suggest that in the future it might be possible to use the sizes of
clusters in the inner regions of galaxies as a simple geometrical distance
indicator.Comment: 45 pages including 13 figs (4 two-part figs) and 8 tables. Accepted
for publication in the Astronomical Journa
Evaluation of different oil sources for nursery pigs
A total of 210 pigs (PIC 327 × 1050, initially 28.9 lb BW) were used in a 21-d trial to evaluate the effects of increasing oil sources on nursery pig growth performance. The 2 oil sources included a commercial source of soybean oil and a proprietary source of corn oil originating from the ethanol industry (Corn Oil ONE, Feed Energy Co., Pleasant Hill, IA). The 5 experimental diets included: a control diet without added oil, diets with 2.5 or 5% added soybean oil, or diets with 2.5 and 5% added corn oil. Diets were formulated with an identical standardized ileal digestible lysine:calorie ratio and were fed in meal form. There were 6 pens per treatment with 7 pigs per pen. Overall, from d 0 to 21, no oil source × level interactions were observed. Increasing corn oil or soybean oil had no effect on ADG or final BW. Increasing corn oil or soybean oil decreased (linear, P \u3c 0.05) ADFI, which resulted in improved (linear, P \u3c 0.01) F/G. Caloric efficiency was not affected by oil source or level. Feed cost per pig tended to decrease (linear, P = 0.066) for pigs fed increasing levels of soy oil. Cost per pound of gain decreased for both Corn Oil ONE (linear, P = 0.032) and soybean oil (linear, P = 0.008) as oil level increased. Value of the weight gain and income over feed cost was similar for pigs fed diets with Corn Oil ONE and soybean oil (P = 0.833). This study shows the benefits of adding a dietary oil source in late-phase nursery diets to achieve improved feed efficiency. Corn Oil ONE is a suitable alternative for soybean oil, and cost and availability should dictate which source is used.; Swine Day, Manhattan, KS, November 20, 201
Finely Grinding Cereal Grains in Pelleted Diets Offers Little Improvement in Nursery Pig Growth Performance
Five experiments were conducted to determine the effects of corn particle size and diet form on nursery pig performance and feed preference. In Exp. 1, 192 nursery pigs (PIC 327 × 1050; initially 14.7 lb and 26 d of age) were used in a 35-d experiment. Pens of pigs were balanced by BW and allotted to 1 of 4 treatments with 6 pigs per pen and 8 pens per treatment. The same corn and soybean meal-based diet formulation was used for all treatments. The 2 × 2 factorial consisted of the main effects of corn particle size (400 vs. 700 μm) and diet form (mash vs. pelleted). Pigs fed mash diets had improved overall ADG and greater ADFI during all periods (P \u3c 0.05) and particle size did not impact (P \u3e 0.10) performance. In Exp. 2, a study utilized 96 pigs to evaluate feed preference of pigs consuming mash diets with either 400 or 700 μm corn. Pigs overwhelmingly (P \u3c 0.05) preferred to consume 700 μm corn compared to 400 μm corn (79.3 vs. 20.7%).
In Exp. 3, 224 nursery pigs (PIC 327 × 1050; initially 24.1 lb and 40 d of age) were used in a 10-d experiment to determine the effects of corn particle size in pelleted diets on nursery pig performance. Experimental treatments were formed by grinding corn to 1 of 4 different particle sizes (250, 400, 550, or 700 μm). Particle size tended to affect (P \u3c 0.10) ADG in a quadratic manner, but did not impact (P \u3e 0.10) ADFI or F/G. Pigs fed pelleted diets from either 250 or 700 μm corn had poorer ADG than the intermediate treatments. Exp. 4 utilized 91 pigs to evaluate the preference of pigs consuming pelleted diets with either 250 or 700 μm corn from Exp. 3. Even in pelleted form, pigs preferred (P \u3c 0.05) to consume diets manufactured with the coarser particle size corn (58.2 vs. 41.8%).
In Exp. 5, 180 nursery pigs (PIC 327 × 1050; initially 15.8 lb and 36 d of age) were used in a 35-d experiment to determine the effects of corn particle size and pelleting on nursery pig growth performance. The 2 × 2 factorial consisted of 2 corn particle sizes (500 μm vs. 750 μm) and two diet forms (mash vs. pelleted). Overall, reducing particle size from 750 to 500 μm did not affect growth performance (P \u3e 0.10). Pelleting reduced (P \u3c 0.05) feed intake, but did not affect ADG or F/G (P \u3e 0.10). These studies suggest that there is little value to be gained by grinding corn to less than 700 microns if fed in pelleted form. Furthermore, our data suggest that, regardless if fed as mash or pellets, pigs prefer to consume diets manufactured with coarser ground corn if given the choice
Effects of diet form and feeder adjustment on growth performance of nursery and finishing pigs
Citation: Nemechek, J. E., Tokach, M. D., Dritz, S. S., Fruge, E. D., Hansen, E. L., Goodband, R. D., . . . Woodworth, J. C. (2015). Effects of diet form and feeder adjustment on growth performance of nursery and finishing pigs. Journal of Animal Science, 93(8), 4172-4180. doi:10.2527/jas2015-9028Three experiments were conducted to determine the effects of feeder adjustment and diet form on growth performance of nursery (Exp. 1 and 2) and finishing (Exp. 3) pigs. Treatments were arranged as a 2 x 3 factorial with the main effects of feeder adjustment and diet form. The 2 feeder adjustments were a narrow and wide feeder adjustment (minimum gap opening of 1.27 and 2.54 cm, respectively). The 3 diet forms were meal, poor-quality pellets (70% pellets and 30% fines for Exp. 1 and 2 and 50% pellets and 50% fines for Exp. 3), and screened pellets with minimal fines (3 to 10%). In Exp. 1, 210 pigs (initially 11.9 kg BW) were used in a 21-d trial with 7 pigs per pen and 5 pens per treatment. No feeder adjustment x diet form interactions were observed. There were no differences in ADG, ADFI, or G:F due to feeder adjustment. Pigs fed the meal diet had increased (P < 0.05) ADG and ADFI compared with pigs fed the poor-quality or screened pellets. Pigs fed meal or poor-quality pellets had decreased (P < 0.05) G: F compared with pigs fed screened pellets. In Exp. 2, 1,005 nursery pigs (initially 14.1 kg BW) were used in a 28-d trial with 26 to 28 pigs per pen and 6 pens per treatment. Pigs fed from the narrow feeder adjustment had decreased (P < 0.05) ADG and ADFI compared with pigs fed from the wide adjustment with no differences in G: F. Pigs fed the meal diet had decreased (P < 0.05) ADG compared with pigs fed poor-quality or screened pellets. Pigs fed meal or poor-quality pellets had decreased (P < 0.05) G: F compared with pigs fed screened pellets. In Exp. 3, 246 pigs (initially 56.8 kg BW) were used in a 69-d trial with 5 pens per treatment and 6 or 7 pigs per pen. Overall, ADFI decreased (P < 0.05) and G: F increased (P < 0.05) for pigs fed from the narrow adjusted feeders compared with the wide adjustment with no differences in ADG. Overall, pigs fed meal diets tended to have decreased (P < 0.10) ADG and had decreased (P < 0.05) G: F compared with pigs fed screened pellets; ADG and G: F in those fed poor-quality pellets were intermediate. Feeding meal or poor-quality pellets increased (P < 0.05) ADFI compared with pigs fed screened pellets. In conclusion, feeding nursery pigs from a wide feeder gap may increase ADG and ADFI with no negative effects on G: F. For finishing pigs, reducing feeder gap reduced feed disappearance and improved G: F. In all experiments, the greatest G: F improvements from pelleting were observed when the percentage of fines was minimized
Evaluating the Accuracy of the 3-Sieve Particle Size Analysis Method Compared to the 12-Sieve Method
The 3-sieve particle size analysis method was developed to estimate the particle size of ground grain within feed mills without the time and expense required for a 12-sieve analysis. The 3-sieve method is more simplistic because it is hand-shaken and uses fewer sieves but has drawbacks because it is not as precise as the 12-sieve method. Because shaking is not automated, technician variation may impact results. Furthermore, the accuracy of the original 3-sieve method has been questioned because the method was developed for corn between 400 to 1,200 μm, and the industry now grinds various grains more finely. Some variations, such as changing the top sieve to a smaller diameter hole or using flow agent, may help improve its accuracy. In this instance, 420 grain samples were used to determine the impact of top sieve size, grain type, technician, and flow agent on the ability of a 3-sieve analytical method to accurately predict the mean particle size determined by a standardized 12-sieve method. The experiment was a 3 × 2 × 2 × 3 factorial with three technicians, two sieve sizes (U.S. No. 12 vs. 16 sieve as the top sieve), flow agent (0 vs. 0.5 g), and three grain types (corn, sorghum, or wheat). Prior to the experiment, all samples were analyzed according to the standard ASAE S319.4 method using a 12-sieve stack with a 15-min tap time and 1 g of flow agent. Linear regression was used to develop individual equations to predict the mean particle size for each of the 3-sieve methods compared to the standard 12-sieve method, and the GLIMMIX procedure of SAS was used to evaluate the impact main effects and interactions on prediction accuracy. All interactions were removed from the model due to insignificance (P \u3e 0.10). Technician, screen size, and flow agent did not affect the accuracy of the prediction equations. Grain was the only main effect of significance (P \u3c 0.05), where the prediction equation overestimated the particle size of wheat by approximately 15 μm and underestimated the particle size of corn by approximately 12 μm. While statistically significant, these variations were deemed to be sufficiently accurate for the 3-sieve method, and separate equations for each grain type were not warranted to retain the simplicity of the method. In summary, technician, sieve size, grain type, and the use of flow agent did not greatly affect the accuracy of the 3-sieve particle size analytical method, so the original method was concluded to be accurate and the preferred method
Effects of diet form and type on growth performance, carcass yield, and iodine value of finishing pigs
Citation: Nemechek, J. E., Tokach, M. D., Dritz, S. S., Goodband, R. D., DeRouchey, J. M., & Woodworth, J. C. (2015). Effects of diet form and type on growth performance, carcass yield, and iodine value of finishing pigs. Journal of Animal Science, 93(9), 4486-4499. doi:10.2527/jas2015-9149Two experiments were conducted to determine the effects of pelleting, diet type (fat and fiber level), and withdrawal of dietary fiber and fat before marketing on growth performance, carcass yield, and carcass fat iodine value (IV) of finishing pigs. Each experiment used 288 pigs (initially 49.6 and 48.5 kg BW, respectively) with 6 dietary treatments arranged as 2 x 3 factorials. In Exp. 1, main effects were diet form (meal vs. pellet) and diet regimen. Diet regimens were 1) a low-fiber, low-fat (corn-soybean meal) diet from d 0 to 81, 2) a high-fiber, high-fat (30% dried distillers grains with solubles [DDGS] and 19% wheat middlings [midds]) diet from d 0 to 64 followed by the low-fiber, low-fat diet from d 64 to 81 (fiber and fat withdrawal), and 3) the high-fiber, high-fat diet fed from d 0 to 81. Pigs fed pelleted diets had increased (P < 0.05) ADG and G:F compared with those fed meal diets. Pigs fed pelleted diets had increased belly fat IV (2.9 mg/g) compared with those fed meal diets, with a greater increase when fed high-fiber, high-fat diets throughout the entire study (interaction, P < 0.05). Pigs fed the low-fiber, low-fat diet throughout had increased (P < 0.001) G:F compared with pigs fed the other 2 treatments. Pigs fed low-fiber, low-fat diets throughout the study or pigs withdrawn from high-fiber, high-fat diets had increased (P < 0.001) carcass yield compared with pigs fed high-fiber, high-fat diets throughout. In Exp. 2, treatment main effects were diet form (meal vs. pellet) and diet type (corn-soybean meal-based control, the control with 30% DDGS and 19% midds, or the control diet with 3% corn oil). The diet containing corn oil was calculated to produce carcass fat IV similar to diets containing DDGS and midds. Overall, pigs fed pelleted diets had increased (P < 0.05) ADG, G:F, and belly fat IV (1.3 mg/g) compared with those fed meal diets. Pigs fed the diets containing DDGS and midds had decreased (P < 0.05) ADG, carcass yield, and HCW compared with pigs fed the control or corn oil diets and decreased (P < 0.001) G:F compared with pigs fed added corn oil. Belly IV was greatest (P < 0.001) for pigs fed diets with DDGS and midds and lowest for pigs fed the control diet, with pigs fed the corn oil diets intermediate. In conclusion, pelleting diets improves pig ADG (approximately 3%) and G:F (approximately 6%); however, a novel finding of this study is that pelleting diets fed to finishing pigs also increases belly fat IV
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