5,622 research outputs found
Strategies to alleviate reproductive wastage in dairy cows
End of project reportgrass-based systems of production. A series of studies were carried out to (i) improve our understanding of the physiological basis of poor reproductive performance; (ii) examine management and nutritional strategies to improve fertility; and (iii) examine the potential role of extended lactation to mitigate the effects of poor reproductive performance.
A comprehensive characterization of the North American and New Zealand strains of Holstein-Friesian cow was carried out. North American cows produce a greater volume of milk, but yield a similar amount of fat and protein on a grass-based diet. Dry matter intake was greater for the larger NA strain, but energy balance did not differ during the first 20 weeks of lactation. Circulating concentrations of metabolic hormones and metabolites during the early lactation period were indicative of lesser bioenergetic status in the NZ strain compared to the NA strain. During established lactation, circulating concentrations of insulin-like growth factor-I (IGF-I) were greater in the NZ strain. Liver biopsies collected at day 35 and day 150 postpartum indicated that the greater circulating concentration of IGF-I was due to greater hepatic mRNA abundance of IGF-I and acid labile subunit (ALS). Embryos were collected from both strains after superovulation. A greater proportion of the embryos recovered were transferable in the NZ strain compared with the NA strain, indicating that the previously reported differences in reproductive performance were manifest as early as 7 days post-insemination. Collectively, the results of the study indicate that the NZ strain are genetically better equipped to survive on a pasture-based seasonal calving system.
A study was carried out to examine the effect of dry period duration and dietary energy density on milk production, bioenergetic status and postpartum ovarian function. Omitting the dry period and increasing dietary energy density both resulted in improved energy balance and metabolic status, but omitting the dry period reduced the postpartum interval to resumption of cyclicity whereas increasing dietary energy density had no effect. Omitting the dry period reduced the inherent drive to produce milk, and allowed the cow to fully meet nutritional requirements from voluntary dry matter intake. Increased dietary energy density also allowed the cow to more closely meet nutritional requirements from a higher energy density diet, albeit at a greater milk yield. The results suggest that the mechanism by which a cow arrives at a particular energy balance status may be as important as energy balance per se.
One of the main energy costs associated with lactation is milk fat. Trans 10, cis 12 conjugated linoleic acid (CLA) is a geometric and positional isomer of linoleic acid that reduces milk fat synthesis in a dose dependent manner. Supplementing cows with CLA resulted in improved energy balance status during the transition period and reduced postpartum body condition score loss. Some indices of reproductive performance were also improved.
In seasonal systems, cows that fail to become pregnant by the end of the breeding season are typically culled and replaced. When reproductive performance is poor, this represents a major cost on dairy farms. A study was carried out to examine the feasibility of extending the lactation to 22 months, resulting in a calving interval of 24 months instead of 12 months. High yielding cows produced the equivalent of 2 normal lactations in an extended lactation system. An economic analysis indicated that an efficient spring calving system with a compact calving pattern and a 12 month calving interval is still the most profitable, but with high yielding cows extending the lactation of non-pregnant cows is more profitable than culling and replacing
Previously unpublished Odonata records from Sarawak, Borneo : part 2, Kubah National Park
Records of Odonata from Kubah National Park, near Kuching in west Sarawak, are presented. Eighty-five species are known from the national park. Notable records include Drepanosticta drusilla, Rhinocypha species cf spinifer, Bornagriolestes species, Anaciaeschna species and Macromidia genialis erratica
Testing the chiral behavior of the hadron spectrum
We analyze the chiral behavior of the hadron spectrum obtained with quenched
Wilson fermions on 170 lattices at . We calculate
masses of hadrons composed of both degenerate and non-degenerate quarks. We
reduce the statistical errors in mass splittings by directly fitting to the
ratio of correlation functions. We find significant deviations from a linear
dependence on the quark mass, deviations that are consistent with the higher
order terms predicted by quenched chiral perturbation theory. Including these
corrections yields splittings in the baryon octet that agree with those
observed experimentally. Smaller higher order terms are also present in
and . By contrast, the decuplet baryons are well described by a
linear mass term. We find the decuplet splittings to be 30% smaller than
experiment. We extrapolate our data to by combining with the GF11
results, and the best fit suggests that the quenched approximation is only good
to .Comment: 4 pages. Poster presented at Lattice 95. Latex with modified "axis"
source for figures also include
Efficacy of Intravenous Ondansetron in Relieving Nausea/Vomiting and Pruritus Post Epidural Administered Opioids in the Obstetric Patient
One prominent side effect in the use of a neuraxial anesthesia is pruritus, with an incidence in the obstetric patient of 60-100% (Kumar & Singh, 2013). Another side effect of an epidural placement is nausea and vomiting. Nausea and vomiting occurs frequently during the progress of labor and is difficult to determine an incidence that is related to epidural opioid administration (Chestnut, Wong, Tsen, Ngan Kee, Beilin, & Mhyre, 2014). A review of literature was performed and established evidence that ondansetron is effective in reducing incidence of pruritus in intrathecal administered opioids for cesarean sections in the obstetric patient. No literature was found in ondansetron reducing either incidence of nausea/vomiting or pruritus in post epidural administered opioids for obstetric patient. A retrospective chart review was completed and statistical analysis concluded that in this sample ondansetron was not effective in reducing nausea/vomiting or pruritus in the obstetric population (Pruritus p = .195 and Nausea/Vomiting p = .844)
Problems and Limitations of Long-Term Timberland Leases For Non-Industrial Private Landowners
Over seven million acres of non-industrial private forest land are controlled by the forest industry under long-term lease agreements. While many landowners appear to be content with these arrangements, others are dissatisfied. Landowners should be aware of the potential benefits, problems, and costs of the long-term commitments
Quantitative determination of fluoride in pure water using luminescent europium complexes
Two luminescent probes [Eu.L1–2]+ are reported for the rapid detection of fluoride in water. Probes [Eu.L1–2]+ exhibit exceptional enhancements in Eu emission in the presence of fluoride, permitting its selective determination within the environmentally relevant concentration range (20–210 μM)
Quenched Chiral Perturbation Theory for Baryons
We develop quenched chiral perturbation theory for baryons using the
graded-symmetry formalism of Bernard and Golterman and calculate non-analytic
contributions to the baryon masses coming from quenched chiral loops. The usual
term proportional to is substantially altered due to the
cancellation of diagrams with internal quark loops. In addition, the
``hairpin'' vertex leads to a new correction, proportional to . We
compare our results to numerical lattice data and use them to estimate the size
of the quenching error in the octet baryon masses.Comment: 7 pages (An abridged version of this note will appear in the
proceedings of Lattice'93. Latex + 14 postscript files, bundled using
uufiles. Needs psfig.) UW/PT-93-0
Deriving Iodine-free spectra for high-resolution echelle spectrographs
We describe a new method to derive clean, iodine-free spectra directly from
observations acquired using high-resolution echelle spectrographs equipped with
iodine cells. The main motivation to obtain iodine-free spectra is to use
portions of the spectrum that are superimposed with the dense forest of iodine
absorption lines, in order to retrieve lines that can be used to monitor the
magnetic activity of the star, helping to validate candidate planets. In short,
we provide a straight-forward methodology to clean the spectra by using the
forward model used to derive radial velocities, the Line Spread Function
information plus the stellar spectrum without iodine to reconstruct and
subtract the iodine spectrum from the observations. We show our results using
observations of the star Ceti acquired with the PFS, HIRES and UCLES
spectrographs, reaching an iodine-free spectrum correction at the 1% RMS
level. We additionally discuss the limitations and further applications of the
method.Comment: 15 pages, 7 figures. Accepted for publication in A
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