Technical note: Whole-pen assessments of nutrient excretion and digestibility from dairy replacement heifers housed in sand-bedded freestalls

Our objectives were to describe and test refined procedures for quantifying excreta produced from whole pens of dairy heifers. Previous research efforts attempting to make whole-pen measurements of excreta output have been complicated by the use of organic bedding, which requires cumbersome analytical techniques to quantify excreta apart from the bedding. Research pens equipped with sand-bedded freestalls offer a unique opportunity for refinement of whole-pen fecal collection methods, primarily because sand-bedded freestall systems contain no organic bedding; therefore, concentrations of ash within the manure, sand, and feces can be used to correct for contamination of manure by sand bedding. This study was conducted on a subset of heifers from a larger production-scale feeding trial evaluating ensiled eastern gamagrass [Tripsacum dactyloides (L.) L.] haylage (EGG) that was incorporated into a corn silage/alfalfa haylage-based blended diet at rates of 0, 9.1, 18.3, or 27.4% of total DM. The diet without EGG also was offered on a limited basis. Eighty Holstein dairy heifers were blocked (heavy weight, 424 ± 15.9 kg; light weight, 324 ± 22.4 kg) and then assigned to 10 individual pens containing 8 heifers/pen. One pen per block was assigned to each of the 5 research diets, and whole-pen fecal collections were conducted twice for each pen. Grab fecal samples also were gathered from individual heifers within each pen, and subsequent analysis of these whole-pen composites allowed reasonable estimates of OM and NDF excreta output. Under the conditions of our experimental design, pooled SEM for the excreta DM, OM, NDF, and NDF (ash corrected) output were 0.113, 0.085, 0.093, and 0.075 kg· heifer –1·d–1, respectively. For DM excretion, this represented about one-third of the SEM reported for previous whole-pen collections from bedded- pack housing systems. Subsequent calculations of apparent DM and OM digestibilities indicated that the technique was sensitive, and linear trends (P ≤ 0.027) associated with the inclusion rates of EGG within the diet were detected. This technique allows estimation of apparent diet digestibilities on multiple animals simultaneously, thereby mitigating the need for isolating individual animals to obtain digestibility coefficients. The approach appears viable but requires hand labor for collections of multiple pens and thorough mixing of large volumes of manure as well as analytical corrections for sand ingested by lounging heifers

Mantle-driven dynamic uplift of the Rocky Mountains and Colorado Plateau and its surface response: Toward a unified hypothesis

The correspondence between seismic velocity anomalies in the crust and mantle and the differential incision of the continental-scale Colorado River system suggests that significant mantle-to-surface interactions can take place deep within continental interiors. The Colorado Rocky Mountain region exhibits low-seismic-velocity crust and mantle associated with atypically high (and rough) topography, steep normalized river segments, and areas of greatest differential river incision. Thermochronologic and geologic data show that regional exhumation accelerated starting ca. 6-10 Ma, especially in regions underlain by low-velocity mantle. Integration and synthesis of diverse geologic and geophysical data sets support the provocative hypothesis that Neogene mantle convection has driven long-wavelength surface deformation and tilting over the past 10 Ma. Attendant surface uplift on the order of 500-1000 m may account for ~25%-50% of the current elevation of the region, with the rest achieved during Laramide and mid-Tertiary uplift episodes. This hypothesis highlights the importance of continued multidisciplinary tests of the nature and magnitude of surface responses to mantle dynamics in intraplate settings

Persistent left superior vena cava: Review of the literature, clinical implications, and relevance of alterations in thoracic central venous anatomy as pertaining to the general principles of central venous access device placement and venography in cancer patients

Persistent left superior vena cava (PLSVC) represents the most common congenital venous anomaly of the thoracic systemic venous return, occurring in 0.3% to 0.5% of individuals in the general population, and in up to 12% of individuals with other documented congential heart abnormalities. In this regard, there is very little in the literature that specifically addresses the potential importance of the incidental finding of PLSVC to surgeons, interventional radiologists, and other physicians actively involved in central venous access device placement in cancer patients. In the current review, we have attempted to comprehensively evaluate the available literature regarding PLSVC. Additionally, we have discussed the clinical implications and relevance of such congenital aberrancies, as well as of treatment-induced or disease-induced alterations in the anatomy of the thoracic central venous system, as they pertain to the general principles of successful placement of central venous access devices in cancer patients. Specifically regarding PLSVC, it is critical to recognize its presence during attempted central venous access device placement and to fully characterize the pattern of cardiac venous return (i.e., to the right atrium or to the left atrium) in any patient suspected of PLSVC prior to initiation of use of their central venous access device

Special Libraries, April 1933

Volume 24, Issue 3https://scholarworks.sjsu.edu/sla_sl_1933/1002/thumbnail.jp

Moult cycle specific differential gene expression profiling of the crab Portunus pelagicus

Background: Crustacean moulting is a complex process involving many regulatory pathways. A holistic approach to examine differential gene expression profiles of transcripts relevant to the moulting process, across all moult cycle stages, was used in this study. Custom cDNA microarrays were constructed for Portunus pelagicus. The printed arrays contained 5000 transcripts derived from both the whole organism, and from individual organs such as the brain, eyestalk, mandibular organ and Y-organ from all moult cycle stages.Results: A total of 556 clones were sequenced from the cDNA libraries used to construct the arrays. These cDNAs represented 175 singletons and 62 contigs, resulting in 237 unique putative genes. The gene sequences were classified into the following biological functions: cuticular proteins associated with arthropod exoskeletons, farnesoic acid O-methyltransferase (FaMeT), proteins belonging to the hemocyanin gene family, lectins, proteins relevant to lipid metabolism, mitochondrial proteins, muscle related proteins, phenoloxidase activators and ribosomal proteins. Moult cycle-related differential expression patterns were observed for many transcripts. Of particular interest were those relating to the formation and hardening of the exoskeleton, and genes associated with cell respiration and energy metabolism.Conclusions: The expression data presented here provide a chronological depiction of the molecular events associated with the biological changes that occur during the crustacean moult cycle. Tracing the temporal expression patterns of a large variety of transcripts involved in the moult cycle of P. pelagicus can provide a greater understanding of gene function, interaction, and regulation of both known and new genes with respect to the moulting process

Effects of spontaneous heating on fiber composition, fiber digestibility, and in situ disappearance kinetics of neutral detergent fiber for alfalfa-orchardgrass hays

During 2006 and 2007, forages from 3 individual hay harvests were utilized to assess the effects of spontaneous heating on concentrations of fiber components, 48-h neutral detergent fiber (NDF) digestibility (NDFD), and in situ disappearance kinetics of NDF for large-round bales of mixed alfalfa (Medicago sativa L.) and orchardgrass (Dactylis glomerata L.). Over the 3 harvests, 96 large-round bales were made at preset bale diameters of 0.9, 1.2, or 1.5 m, and at moisture concentrations ranging from 9.3 to 46.6%. Internal bale temperatures were monitored daily during an outdoor storage period, reaching maxima (MAX) of 77.2°C and 1,997 heating degree days \u3e30°C (HDD) for one specific combination of bale moisture, bale diameter, and harvest. Concentrations of all fiber components (NDF, acid detergent fiber, hemicellulose, cellulose, and lignin) increased in response to spontaneous heating during storage. Changes in concentrations of NDF during storage (poststorage – prestorage; ΔNDF) were regressed on HDD using a nonlinear regression model (R2 = 0.848) that became asymptotic after ΔNDF increased by 8.6 percentage units. Although the specific regression model varied, changes (poststorage – prestorage) in concentrations of acid detergent fiber, cellulose, and lignin also increased in nonlinear relationships with HDD that exhibited relatively high coefficients of determination (R2 = 0.710 to 0.885). Fiber digestibility, as determined by NDFD, was largely unaffected by heating characteristics except within bales incurring the most extreme levels of HDD or MAX. In situ assessment of ruminal NDF disappearance kinetics indicated that disappearance rate (Kd) declined by about 40% within the range of heating incurred over these hay harvests. The change in Kd during storage (ΔKd) was related closely to both HDD and MAX by nonlinear models exhibiting high R2 statistics (0.907 and 0.883, respectively). However, there was no regression relationship between changes (poststorage – prestorage) in effective ruminal disappearance of NDF and spontaneous heating, regardless of which heating measure was used as the independent variable. The close regression relationship between ΔKd and measures of spontaneous heating indicates clearly that ruminal NDF disappearance was altered negatively by some direct or indirect aspect of spontaneous heating. However, it was equally apparent that these effects were offset by an expanding pool of dry matter recovered as potentially degradable NDF

Storage characteristics, nutritive value, energy content, and in vivo digestibility of moist, large rectangular bales of alfalfa-orchardgrass hay treated with a propionic acid-based preservative

Unstable weather, poor drying conditions, and unpredictable rainfall events often place valuable hay crops at risk. Recent research with large round bales composed of alfalfa (Medicago sativa L.) and orchard grass (Dactylis glomerata L.) has shown that these large-bale packages are particularly sensitive to spontaneous heating and dry matter (DM) losses, as well as other undesirable changes with respect to forage fiber, protein, and energy density. Various formulations of organic acids have been marketed as preservatives, normally for use on hays that are not desiccated adequately in the field to facilitate safe bale storage. Our objectives for this study were to (1) evaluate the efficacy of applying a commercial (buffered) propionic acid-based preservative at 3 rates (0, 0.6, and 1.0% of wet-bale weight) to hays baled at 3 moisture concentrations (19.6, 23.8, and 27.4%) on the subsequent storage characteristics and post-storage nutritive value of alfalfa-orchard grass forages packaged in large rectangular (285-kg) bales, and then (2) evaluate the in vivo digestibility of these hays in growing lambs. Over a 73-d storage period, the preservative was effective at limiting spontaneous heating in these hays, and a clear effect of application rate was observed for the wettest (27.4%) bales. For drier hays, both acid-application rates (1.0 and 0.6%) yielded comparable reductions in heating degree days \u3e30°C relative to untreated controls. Reductions in spontaneous heating could not be associated with improved recovery of forage DM after storage. In this study, most changes in nutritive value during storage were related to measures of spontaneous heating in simple linear regression relationships; this suggests that the modest advantages in nutritive value resulting from acid treatment were largely associated with perturbations of normal heating patterns during bale storage. Although somewhat erratic, apparent digestibilities of both DM (Y = −0.0080x + 55.6; R2 = 0.45) and organic matter (Y = −0.0085x + 55.5; R2 = 0.53) evaluated in growing lambs were also directly related to heating degree days in simple linear relationships. Based on these data, applying propionic acid-based preservatives to large rectangular bales is likely to provide good insurance against spontaneous heating during storage, as well as modest benefits with respect to nutritive value and digestibility