41 research outputs found
Geographic origin of the Y Chromosomes in “old” inbred strains of mice
Six distinct Y Chromosomes (Chr) were identified among 39 standard inbred strains of mice with five probes that identified Y Chr-specific restriction fragments on Southern blots. Three Y Chr types, distributed among 31 strains, were of Asian Mus musculus origin. The remaining three Y Chr types, distributed among eight strains, were of M. domesticus origin. The Asian source of the M. musculus Y Chr was confirmed by determining the DNA sequence of 221 bp from an open reading frame within the Sry (sex determining region Y) gene (Gubbay et al., Nature 346 245–250, 1990) in three inbred strains (C57BL/6J, AKR/J, and SWR/J) and comparing the sequence to the homologous sequences derived from wild caught European and Asian M. musculus males. These data indicate that a minimum of six male mice contributed to the formation of the old inbred strains.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46993/1/335_2004_Article_BF00292153.pd
Respostas fisiológicas e de desempenho de leitões suplementados com B-glucanos e desafiados imunologicamente
Mouse Chromosome 11
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46996/1/335_2004_Article_BF00648429.pd
Leukocyte function in vitro after adding vitamins A, E, and Beta-Carotene
Blood neutrophils and pulmonary alveolar
macrophages isolated from calves at 3 and 6
wk of age were cultured in medium without
added vitamins or supplemented with vitamin
A, vitamin E, vitamin A and vitamin E, or Ăźcarotene
and vitamin E. Macrophage bactericidal
activity improved with A-E supplementation
compared to Ăź-carotene-E supplementation
at wk 3. Neutrophil bactericidal activity
decreased with all vitamin E treatments at wk 3
and with vitamins E and A-E at wk 6.
Neutrophil phagocytosis improved at wk 3 with
A, E, and A-E supplementations. The chemotactic
index improved at wk 3 with Ăź-carotene-
E compared to vitamin E alone and at wk 6
with vitamin E compared to vitamin A and
control treatments. The retinol content of
neutrophils at wk 3 was variable, but by wk 6,
cells supplemented with A, E, or A-E had
higher retinol concentrations than control cells.
Neutrophil a-tocopherol concentrations at 3 wk
increased over controls with vitamin E or Ăźcarotene-
E supplementation, but at wk 6,
vitamin E-supplemented cells were different
only from vitamin A-supplemented cells.
These data suggest that there are optimum
plasma concentrations of vitamins A and E for
leukocyte functions
Periparturient cortisol, acute phase cytokine, and acute phase protein profiles of gilts housed in groups or stalls during gestation
Use of gestation stalls in pork production remains a controversial topic in animal welfare. Immune status and measures are frequently used to assess stress levels and thus well-being of confined animals. The important welfare issue of close confinement among gestating gilts was tested by quantifying cortisol, acute phase cytokine, and acute phase protein pro-files before and after farrowing of gilts housed in 2 systems. Landrace × Yorkshire crossbred gilts housed in groups of 4 (group, n = 8) in pens (3.9 × 2.4 m with 4 individual feeding spaces, 9.36 m2 total or 2.34 m2/gilt) were compared with gilts housed in standard industry stalls (stall, n = 16; 2.2 × 0.6 m, 1.32 m2/gilt). Floors were fully slatted, and a substrate was not provided for either system. Cortisol was determined from saliva on d 105 of gestation, 1 h after moving the gilts into farrowing stalls (d 111), and 24 h and 7 d after farrowing. Cortisol was greater (P = 0.04) for group gilts compared with stall gilts 1 h after moving them into farrowing stalls and 24 h after farrowing. Cortisol concentrations decreased (P = 0.001) over time. Leukocyte mRNA expression of IL-1, IL-1 receptor antagonist, and tumor necrosis factor-α was determined by quantitative, reverse transcription PCR on d 35, 63, and 91 of gestation and 72 h after farrowing. Cytokine mRNA expression of peripheral blood mononuclear cells did not differ between housing systems for IL-1, its receptor antagonist, or for tumor necrosis factor-α. Acute phase proteins, including fibrinogen, haptoglobin, and α1-acid glycoprotein were determined for plasma samples taken at d 35, 63, and 91 of gestation and 72 h and 14 d after farrowing. In contrast to cortisol, plasma fibrinogen concentrations increased (P 0.10). Stall gilts tended to have greater (P = 0.07) plasma α1-acid glycoprotein concentrations than group animals at d 35 of gestation and d 14 after farrowing. These data showed a trend (P < 0.07) for α1-acid glycoprotein concentrations to return to baseline more quickly in group-housed gilts, which did not appear to be directly related to increased cortisol just before farrowing. In conclusion, few differences in the acute phase response were detected between housing systems, suggesting that the resting immunological responses are only mildly affected by gestation stalls
Stochastic simulation using @Risk for dairy business investment decisions
Purpose – The purpose of this paper is to develop a dynamic, stochastic, mechanistic simulation model of a dairy business to evaluate the cost and benefit streams coinciding with technology investments. The model was constructed to embody the biological and economical complexities of a dairy farm system within a partial budgeting framework. A primary objective was to establish a flexible, user-friendly, farm-specific, decision-making tool for dairy producers or their advisers and technology manufacturers. Design/methodology/approach – The basic deterministic model was created in Microsoft Excel (Microsoft, Seattle, Washington). The @Risk add-in (Palisade Corporation, Ithaca, New York) for Excel was employed to account for the stochastic nature of key variables within a Monte Carlo simulation. Net present value was the primary metric used to assess the economic profitability of investments. The model was composed of a series of modules, which synergistically provide the necessary inputs for profitability analysis. Estimates of biological relationships within the model were obtained from the literature in an attempt to represent an average or typical US dairy. Technology benefits were appraised from the resulting impact on disease incidence, disease impact, and reproductive performance. In this paper, the model structure and methodology were described in detail. Findings – Examples of the utility of examining the influence of stochastic input and output prices on the costs of culling, days open, and disease were examined. Each of these parameters was highly sensitive to stochastic prices and deterministic inputs. Originality/value – Decision support tools, such as this one, that are designed to investigate dairy business decisions may benefit dairy producers
Stochastic simulation using @Risk for dairy business investment decisions
Purpose – The purpose of this paper is to develop a dynamic, stochastic, mechanistic simulation model of a dairy business to evaluate the cost and benefit streams coinciding with technology investments. The model was constructed to embody the biological and economical complexities of a dairy farm system within a partial budgeting framework. A primary objective was to establish a flexible, user-friendly, farm-specific, decision-making tool for dairy producers or their advisers and technology manufacturers. Design/methodology/approach – The basic deterministic model was created in Microsoft Excel (Microsoft, Seattle, Washington). The @Risk add-in (Palisade Corporation, Ithaca, New York) for Excel was employed to account for the stochastic nature of key variables within a Monte Carlo simulation. Net present value was the primary metric used to assess the economic profitability of investments. The model was composed of a series of modules, which synergistically provide the necessary inputs for profitability analysis. Estimates of biological relationships within the model were obtained from the literature in an attempt to represent an average or typical US dairy. Technology benefits were appraised from the resulting impact on disease incidence, disease impact, and reproductive performance. In this paper, the model structure and methodology were described in detail. Findings – Examples of the utility of examining the influence of stochastic input and output prices on the costs of culling, days open, and disease were examined. Each of these parameters was highly sensitive to stochastic prices and deterministic inputs. Originality/value – Decision support tools, such as this one, that are designed to investigate dairy business decisions may benefit dairy producers
Assessing the potential value for an automated dairy cattle body condition scoring system through stochastic simulation
Assessing the potential value for an automated dairy cattle body condition scoring system through stochastic simulation
Purpose – The purpose of this paper is to develop a dynamic, stochastic, mechanistic simulation model of a dairy business to evaluate the cost and benefit streams coinciding with technology investments. The model was constructed to embody the biological and economical complexities of a dairy farm system within a partial budgeting framework. A primary objective was to establish a flexible, user-friendly, farm-specific, decision-making tool for dairy producers or their advisers and technology manufacturers. Design/methodology/approach – The basic deterministic model was created in Microsoft Excel (Microsoft, Seattle, Washington). The @Risk add-in (Palisade Corporation, Ithaca, New York) for Excel was employed to account for the stochastic nature of key variables within a Monte Carlo simulation. Net present value was the primary metric used to assess the economic profitability of investments. The model was composed of a series of modules, which synergistically provide the necessary inputs for profitability analysis. Estimates of biological relationships within the model were obtained from the literature in an attempt to represent an average or typical US dairy. Technology benefits were appraised from the resulting impact on disease incidence, disease impact, and reproductive performance. In this paper, the model structure and methodology were described in detail. Findings – Examples of the utility of examining the influence of stochastic input and output prices on the costs of culling, days open, and disease were examined. Each of these parameters was highly sensitive to stochastic prices and deterministic inputs. Originality/value – Decision support tools, such as this one, that are designed to investigate dairy business decisions may benefit dairy producers.Agriculture, Investment appraisal, Modelling, Net present value, Stochastic processes