Is The Old House Standing Yet?

https://digitalcommons.library.umaine.edu/mmb-vp/5116/thumbnail.jp

Comparison of models including cytoplasmic effects for traits of Rambouillet sheep

The objective was to determine appropriate analytical models considering cytoplasmic inheritance for birth weight (BWT, n = 35,604), weaning weight (WWT, n = 34,114), fleece weight (FWT, n = 38,113) and number born (NB, n = 39,029) for Rambouillet sheep. For BWT, models that included dam by year, dam by number born, and sire by dam effects, in addition to direct and maternal effects, were significantly better than the basic maternal effects model. For WWT, variances due to direct, maternal, and maternal permanent environmental effects (0.05 of variance) were not zero. For FWT, heritability was 0.55 for all models, but models with dam by year (0.02), sire by dam (0.05), and sire by cytoplasmic line (0.02) were jointly significantly better than models with permanent environmental effects. For NB, only direct heritability (0.08) and relative permanent environmental variance (0.04) were not zero. No trait showed evidence of variation due to cytoplasmic effects. Adding seldom considered effects to the model did not change estimates of variance due to direct and maternal genetic effects. Variance due to dominance effects may be important for BWT and FWT. The basic direct–maternal effects model seems sufficient for genetic evaluations for WWT and FWT but models for BWT and NB may need to include other effects

Estimates of genetic parameters and genetic change for reproduction, weight, and wool characteristics of Columbia sheep

Genetic parameters from both single-trait and bivariate analyses for prolificacy, weight and wool traits were estimated using REML with animal models for Columbia sheep from data collected from 1950 to 1998 at the U.S. Sheep Experiment Station (USSES), Dubois, ID. Breeding values from both single-trait and seven-trait analyses calculated using the parameters estimated from the single-trait and bivariate analyses were compared with respect to genetic trends. Number of observations were 31,401 for litter size at birth and litter size at weaning, 24,741 for birth weight, 23,903 for weaning weight, 29,572 for fleece weight and fleece grade, and 2,449 for staple length. Direct heritability estimates from single-trait analyses were 0.09 for litter size at birth, 0.06 for litter size at weaning, 0.27 for birth weight, 0.16 for weaning weight, 0.53 for fleece weight, 0.41 for fleece grade, and 0.55 for staple length. Estimate of direct genetic correlation between litter size at birth and weaning was 0.84 and between birth and weaning weights was 0.56. Estimate of genetic correlation between fleece weight and staple length was positive (0.55) but negative between fleece weight and fleece grade (−0.47) and between staple length and fleece grade (−0.70). Estimates of genetic correlations were positive but small between birth weight and litter size traits and moderate and positive between weaning weight and litter size traits. Fleece weight was lowly and negatively correlated with both litter size traits. Fleece grade was lowly and positively correlated with both litter size traits, while staple length was lowly and negatively correlated with the litter size traits. Estimates of correlations between weight traits and fleece weight were positive and low to moderate. Estimates of correlations between weight traits and fleece grade were negative and small. Estimates of correlations between staple length and birth weight (0.05) and weaning weight were small (−0.04). Estimated breeding values averaged by year of birth from both the single-trait and multiple-trait analyses for the prolificacy and weight traits increased over time, but were unchanged for the wool traits. Estimated changes in breeding values over time did not differ substantially for single-trait and multiple-trait analyses, except for traits highly correlated with another trait that was responding to selection

Amyloglucosidase enzymatic reactivity inside lipid vesicles

Efficient functioning of enzymes inside liposomes would open new avenues for applications in biocatalysis and bioanalytical tools. In this study, the entrapment of amyloglucosidase (AMG) (EC 3.2.1.3) from Aspergillus niger into dipalmitoylphosphatidylcholine (DPPC) multilamellar vesicles (MLVs) and large unilamellar vesicles (LUVs) was investigated. Negative-stain, freeze-fracture, and cryo-transmission electron microscopy images verified vesicle formation in the presence of AMG. Vesicles with entrapped AMG were isolated from the solution by centrifugation, and vesicle lamellarity was identified using fluorescence laser confocal microscopy. The kinetics of starch hydrolysis by AMG was modeled for two different systems, free enzyme in aqueous solution and entrapped enzyme within vesicles in aqueous suspension. For the free enzyme system, intrinsic kinetics were described by a Michaelis-Menten kinetic model with product inhibition. The kinetic constants, Vmax and Km, were determined by initial velocity measurements, and Ki was obtained by fitting the model to experimental data of glucose concentration-time curves. Predicted concentration-time curves using these kinetic constants were in good agreement with experimental measurements. In the case of the vesicles, the time-dependence of product (glucose) formation was experimentally determined and simulated by considering the kinetic behavior of the enzyme and the permeation of substrate into the vesicle. Experimental results demonstrated that entrapped enzymes were much more stable than free enyzme. The entrapped enzyme could be recycled with retention of 60% activity after 3 cycles. These methodologies can be useful in evaluating other liposomal catalysis operations

Use of modified cages attached to growing calves to measure the effect of stable flies on dry matter intake and digestibility, and defensive movements

The effects of stable flies on growing calves were examined using fly cages attached to the animals. Dry matter intake, DM digestibility (DMD), and behavioral responses of calves were monitored. Nine Holstein calves were exposed to 3 levels of stable flies (0, 10, 100 flies/animal) 3 times daily for 30 min. The study consisted of a 4-period crossover design; each period included 5-d adaptation, 7-d exposure, and 5-d postexposure. Calves were weighed at the beginning and end of each period. Feed consumption was continuously recorded. Fecal samples taken during and after exposure were used to determine DMD. Three calves were monitored for activity and defensive behavior during exposure. Caged stable flies successfully fed on the calves and invoked defensive behaviors similar to those observed in field studies. Defensive behaviors were proportionate to exposure level, and calves became more proficient at interfering with fly feeding over time. Stable fly exposure increased DMI relative to calf weight and decreased ADG/DMI. Calves initially exposed to 100 flies exhibited more defensive behaviors and lower relative DMI and ADG across all exposure levels relative to calves initially exposed to 10 flies. Stable fly exposure did not affect DMD, number of meals, time eating, or amount eaten per meal. Host defensive behavior, not reduced DMI or DMD, appears to be reducing ADG of calves exposed to stable flies. Results indicate that cages placed on calves may be used to study the effects of stable flies, but host exposure history and behavioral variables must be considered

Combined Analysis on the Effects of Late Gestation Supplementation in a Spring Calving Beef Herd

Data were compiled from 4 independent studies conducted over 13 years in the Nebraska Sandhills. Th is combined analysis evaluated the effects of late gestation supplementation on cow and calf productivity in a spring calving herd. Cows wintered on dormant range, sub- irrigated meadow or corn residue. Late gestation supplementation improved pregnancy rates regardless of supplement amount or over winter treatment. Supplement did not affect cow body weight and condition score. Calves born to cows fed supplement had greater weaning weights regardless of when they were weaned

Morphological and genetic analyses in the Melanoplus packardii group (Orthoptera: Acrididae)

Melanoplus packardii Scudder was described in 1897. Three additional closely-related species were later described and their status as species has been questioned on numerous occasions. We examined morphology from specimens collected in Nebraska which fit descriptions of three of the four forms and specimens that appeared to be hybrids. We found distinct morphological characters suggesting species status for M. foedus and M. packardii, but not for M. foedus fluviatilis. Examination of aedeagi of these three forms suggests that M. foedus and M. packardii are each distinct, but that the aedeagi of M. f. fluviatilis and M. f. foedus cannot be distinguished. Molecular analyses of the three groups did not produce clear separations and suggest gene exchange between these three forms may be ongoing. Together, these data suggest that M. foedus and M. packardii should be recognized as sibling species, but M. foedus fluviatilis is best considered a form of M. foedus, typically found in low lying areas

Rotorcraft Transmission Noise Path Model, Including Distributed Fluid Film Bearing Impedance Modeling

A computational approach for simulating the effects of rolling element and journal bearings on the vibration and sound transmission through gearboxes has been demonstrated. The approach, using ARL/Penn State s CHAMP methodology, uses Component Mode Synthesis of housing and shafting modes computed using Finite Element (FE) models to allow for rapid adjustment of bearing impedances in gearbox models. The approach has been demonstrated on NASA GRC s test gearbox with three different bearing configurations: in the first condition, traditional rolling element (ball and roller) bearings were installed, and in the second and third conditions, the traditional bearings were replaced with journal and wave bearings (wave bearings are journal bearings with a multi-lobed wave pattern on the bearing surface). A methodology for computing the stiffnesses and damping in journal and wave bearings has been presented, and demonstrated for the journal and wave bearings used in the NASA GRC test gearbox. The FE model of the gearbox, along with the rolling element bearing coupling impedances, was analyzed to compute dynamic transfer functions between forces applied to the meshing gears and accelerations on the gearbox housing, including several locations near the bearings. A Boundary Element (BE) acoustic model was used to compute the sound radiated by the gearbox. Measurements of the Gear Mesh Frequency (GMF) tones were made by NASA GRC at several operational speeds for the rolling element and journal bearing gearbox configurations. Both the measurements and the CHAMP numerical model indicate that the journal bearings reduce vibration and noise for the second harmonic of the gear meshing tones, but show no clear benefit to using journal bearings to reduce the amplitudes of the fundamental gear meshing tones. Also, the numerical model shows that the gearbox vibrations and radiated sound are similar for journal and wave bearing configurations

Morphological and genetic analyses in the Melanoplus packardii group (Orthoptera: Acrididae)

Melanoplus packardii Scudder was described in 1897. Three additional closely-related species were later described and their status as species has been questioned on numerous occasions. We examined morphology from specimens collected in Nebraska which fit descriptions of three of the four forms and specimens that appeared to be hybrids. We found distinct morphological characters suggesting species status for M. foedus and M. packardii, but not for M. foedus fluviatilis. Examination of aedeagi of these three forms suggests that M. foedus and M. packardii are each distinct, but that the aedeagi of M. f. fluviatilis and M. f. foedus cannot be distinguished. Molecular analyses of the three groups did not produce clear separations and suggest gene exchange between these three forms may be ongoing. Together, these data suggest that M. foedus and M. packardii should be recognized as sibling species, but M. foedus fluviatilis is best considered a form of M. foedus, typically found in low lying areas

The impact of cow size on cow-calf and postweaning progeny performance in the Nebraska Sandhills

Optimizing beef production system efficiency requires an understanding of genetic potential suitable for a given production environment. Therefore, the objective of this retrospective analysis was to determine the influence of cow body weight (BW) adjusted to a common body condition score (BCS) of 5 at weaning-influenced cow-calf performance and postweaning steer and heifer progeny performance. Data were collected at the Gudmundsen Sandhills Laboratory, Whitman, NE, on crossbred, mature cows (n = 1,607) from 2005 to 2017. Cow BCS at calving, prebreeding, and weaning were positively associated (P \u3c 0.01) with greater cow BW. Increasing cow BW was positively associated (P \u3c 0.01) with the percentage of cows that conceived during a 45-d breeding season. For every additional 100-kg increase in cow BW, calf BW increased (P \u3c 0.01) at birth by 2.70 kg and adjusted 205-d weaning BW by 14.76 kg. Calf preweaning average daily gain (ADG) increased (P \u3c 0.01) 0.06 kg/d for every additional 100-kg increase in cow BW. Heifer progeny BW increased (P \u3c 0.01) postweaning with every additional 100-kg increase in dam BW. Dam BW did not influence (P ≥ 0.11) heifer puberty status prior to breeding, overall pregnancy rates, or the percentage of heifers calving in the first 21 d of the calving season. Steer initial feedlot BW increased by 7.20 kg, reimplant BW increased by 10.47 kg, and final BW increased by 10.29 kg (P ≤ 0.01) for every additional 100-kg increase in dam BW. However, steer feedlot ADG was not influenced (P \u3e 0.67) by dam BW. Hot carcass weights of steers were increased (P = 0.01) by 6.48 kg with every additional 100-kg increase in cow BW. In a hypothetical model using the regression coefficients from this study, regardless of pricing method, cow-calf producers maximize the highest amount of profit by selecting smaller cows. Overall, larger-sized cows within this herd and production system of the current study had increased reproductive performance and offspring BW; however, total production output and economic returns would be potentially greater when utilizing smaller-sized cows