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41.
GT Bleck MB Wheeler LB Hansen H Chester-Jones DJ Miller 《Reproduction in domestic animals》2009,44(2):241-247
It is believed that milk production is determined by the number and activity of mammary secretory cells. Secretory activity, as assessed by milk volume, depends on secretion of the major osmole in milk, lactose, which is produced by lactose synthase. The amount of either of the two proteins in lactose synthase may regulate milk production. The objective of this study was to determine whether the concentrations in milk of the two components of lactose synthase, α‐lactalbumin (α‐LA) and β1,4‐galactosyltransferase (B4GALT), were related to genetic background, stage of lactation, breed or parity of dairy cows. α‐Lactalbumin and B4GALT concentrations were measured by ELISA and by enzyme assays, respectively, from single milk samples. Two herds with a total of 279 cows were used in the analysis. One herd contained Ayrshire, Brown Swiss, Holstein and Jersey cows; the second herd contained two groups of cows; Holsteins selected for high milk production and Holsteins with 1960s genetics. The α‐LA concentration in milk was greater in Jerseys and Ayrshires than in Holsteins and Brown Swiss. However, no difference in α‐LA concentration was observed in milk from high and low genetic merit cows in the Minnesota herd or among different genetic backgrounds in the Illinois herd. β1,4‐Galactosyltransferase concentrations were similar for all groups that were analyzed. α‐Lactalbumin concentrations were positively correlated with milk protein concentration, milk fat concentration and lactose concentration. β1,4‐Galactosyltransferase concentration in milk exhibited a strong positive correlation with number of days in milk. Although the concentration of B4GALT increased as lactation progressed, the values did not show any correlation with persistency of lactation or late lactation milk production. In conclusion, this survey shows that the two components of lactose synthase are each correlated to protein concentration and individually correlated to the concentration of other milk components and stage of lactation. 相似文献
42.
43.
Emily Moser Michael McCulloch 《Journal of Veterinary Behavior: Clinical Applications and Research》2010,5(3):145-152
Early detection of cancers, although essential for treatment effectiveness, can be difficult to achieve, and some tests introduce additional health risks. New, non-invasive detection methods with greater sensitivity and specificity are needed. Several authors have published research suggesting that dogs may be able to detect lung, breast, prostate, ovarian, and melanoma cancers by smelling skin lesions, urine, exhaled breath, and surgically extracted tumors. We conducted a systematic search using the PubMed and EMBASE databases to identify all known published data on canine scent detection of cancers. Of 531 potentially relevant publications, 11 full text articles were examined, and 5 were selected for inclusion in the review. Two studies involved dogs detecting breast cancer (sensitivity 88% using exhaled breath and 22% using urine; specificity was 98% and 20%, respectively), 1 involved bladder cancer (41% of urine samples detected), 1 involved melanoma (75–85.7% of in situ tumors detected), 1 involved lung cancer (sensitivity 99% and specificity 99% using exhaled breath), 1 involved ovarian cancer (sensitivity 100% and specificity 97.5% using thawed frozen tumor samples), and 1 involved prostate cancer (18% of urine samples detected). One study on ovarian cancer is in progress. Early successes with canine scent detection suggest chemical analysis of exhaled breath may be a valid method for cancer detection. Tests using exhaled breath showed better sensitivity and specificity than with urine. Future research should target other tumor types, and seek to identify what exhaled compounds may signal a cancer diagnosis. 相似文献
44.
G. Moser C. Leuschner D. Hertel D. Hölscher M. Köhler D. Leitner B. Michalzik E. Prihastanti S. Tjitrosemito L. Schwendenmann 《Agroforestry Systems》2010,79(2):171-187
In South-east Asia, ENSO-related droughts represent irregularly occurring hazards for agroforestry systems containing cocoa
which are predicted to increase in severity with expected climate warming. To characterize the drought response of mature
cocoa trees, we conducted the Sulawesi Throughfall Displacement Experiment in a shaded (Gliricidia sepium) cocoa agroforestry system in Central Sulawesi, Indonesia. Three large sub-canopy roofs were installed to reduce throughfall
by about 80% over a 13-month period to test the hypotheses that (i) cocoa trees are sensitive to drought due to their shallow
fine root system, and (ii) bean yield is more sensitive to drought than leaf or stem growth. As 83% of fine root (diameter
<2 mm) and 86% of coarse root biomass (>2 mm) was located in the upper 40 cm of the soil, the cocoa trees examined had a very
shallow root system. Cocoa and Gliricidia differed in their vertical rooting patterns, thereby reducing competition for water. Despite being exposed for several months
to soil water contents close to the conventional wilting point, cocoa trees showed no significant decreases in leaf biomass,
stem and branch wood production or fine root biomass. Possible causes are active osmotic adjustment in roots, mitigation of
drought stress by shading from Gliricidia or other factors. By contrast, production of cocoa beans was significantly reduced in the roof plots, supporting reports
of substantial reductions in bean yields during ENSO-related drought events in the region. We conclude that cocoa possesses
traits related to drought tolerance which enable it to maintain biomass production during extended dry periods, whereas bean
yield appears to be particularly drought sensitive. 相似文献
45.
Information on the mating and dispersal behaviour of the rice stem borers Scirpophaga incertulas and Chilo suppressalis is necessary for the design of resistance management strategies for rice varieties genetically engineered with toxin genes from Bacillus thuringiensis (Bt). We investigated whether S. incertulas and C. suppressalis move from the site of adult eclosion before mating to determine the likelihood that random mating will occur between adults eclosing in fields of Bt rice and refuge fields of non-Bt rice. Observations were made under laboratory, screenhouse and field conditions. Almost all S. incertulas males and females flew out of sight after cuticle expansion and hardening, as did most C. suppressalis. Approximately 15% of C. suppressalis females called and mated within 3?m of the site of eclosion, and approximately 5% of C. suppressalis males mated within 5?m of the site of eclosion. These results suggest that random mating is likely to occur between S. incertulas eclosing in Bt rice fields and nearby refuge fields. Although a small proportion of C. suppressalis did not move far before mating, random mating of moths from Bt and nearby refuge fields is also likely to occur in this species if Bt-resistant moths are rare. 相似文献
46.
Bruce S. Dien Donald T. Wicklow Vijay Singh Robert A. Moreau Jill K. Winkler‐Moser Michael A. Cotta 《Cereal Chemistry》2012,89(1):15-23
Widespread epidemics of Stenocarpella ear rot (formerly Diplodia ear rot) have occurred throughout the central U.S. Corn Belt in recent years, but the influence of S. maydis infected grain on corn ethanol production is unknown. In this study, S. maydis infected ears of variety Heritage 4646 were hand‐harvested in 2010 from a production field in central Illinois and segregated into one of five levels of ear rot severity based upon visual symptoms. The concentration of ergosterol, a sterol produced by fungi but not plants, was observed to increase with the severity of ear rot (127–306.5 μg/g), and none was detected in the control corn. Corn test weight declined with progression of the disease and was 42.6% lower for the most severely rotted grain from ears infected early in their development. Accompanying changes in composition were also apparent. Crude fat and oil contents decreased (from 4.7 to 1.5%) and fiber increased (from 6.6 to 9.6%), but starch content remained largely invariant. Oil composition also varied among the infected samples. Control and infected corn samples were subjected to ethanol fermentation with a laboratory‐scale corn dry‐grind ethanol process. Ethanol yields for control and infected samples were similar on an equivalent weight basis (2.77–2.85 gal/bu). In comparison with the control, S. maydis infection altered the distillers dried grains with solubles (DDGS) properties, wherein the crude protein was significantly higher and oil significantly reduced, and ash, fiber, and yield per ton were not significantly different. Based upon these results, we conclude that Stenocarpella ear rot has the potential to affect DDGS composition but not ethanol yield on an equivalent weight basis. 相似文献
47.
Introduction and elimination of Bovine Viral Diarrhoea Virus in a commercial beef herd: a case study
MB Allworth R Long AK Smith EL Bergman M Hernandez-Jover 《Australian veterinary journal》2020,98(12):596-601
Routine Bovine Viral Diarrhoea Virus (BVDV) monitoring of a commercial beef herd in southern New South Wales over a 10-year period provided an opportunity to assess the impact of the introduction of BVDV on that herd. BVDV antibody testing provided strong evidence that the herd was initially free of BVDV (2009–2011). Testing from 2012 suggested BVDV had been introduced into the herd and this was confirmed in 2015 with the identification of persistently infected (PI) animals. Having become established in the herd, the owners then set out to eliminate BVDV from the herd. Antigen testing aimed at identifying PI animals revealed BVDV was already absent from the herd. Subsequent antibody testing confirmed that the herd was now free from BVDV. Despite the incursion of BVDV in this herd, there was little measurable impact on reproductive performance (pregnancy rates), although suspected increased calf losses from birth to calf marking were reported. This is the first time such self-clearance has been documented as part of a longitudinal study under Australian conditions. 相似文献
48.
The adoption of precision farming (PF) was studied on the basis of personal interviews conducted at several agricultural exhibitions
in Germany. Between 6.65% and 11% of the interviewed farmers used PF. The majority used data collection techniques such as
GPS-based area measurement and soil sampling rather than variable rate application techniques such as site-specific sowing
and fertilising. Roughly half the farmers interviewed knew about PF. About 7–10% of them intended to start using PF in the
future. The results indicated that a large number of farmers did not even know what PF meant. In order to get more insight
into this situation, several interviews were conducted with farmers already using PF techniques. A further study in 2005 of
PF education in Germany indicated that, especially at vocational and technical schools, the subject was only covered to a
small extent although the aim was to give a better coverage in future. At higher education levels, such as at universities
and technical colleges, the teaching of PF was clearly better established. In order to promote awareness of PF among farmers,
information and teaching materials adapted to the relevant educational levels were developed and tried out at training events.
The main topics addressed were parallel tracking systems, site-specific nitrogen fertilising, yield mapping in grain production
and the use of PDAs in crop farming. Finally, preliminary survey results are presented showing how knowledge about PF can
best lead to its adoption and transfer into daily practice. 相似文献
49.
E. Müller G. Moser H. Bartenschilager H. Geldermann 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2000,117(3):189-202
The genetic diversity between European Wild Boar, Pietrain and Meishan and their crossbred generations are described on the basis of performance traits for growth, carcass composition and meat quality. Using the results of 1333 pigs, the highest growth rates were found in crossbred generations, indicating positive heterosis effects. In carcass composition, high meat content is associated with Pietrain and high fat content with Meishan alleles. Weights of organs were greatest in Wild Boar, the weight of the head was greatest in Meishan. Meat quality and stress resistance parameters point to superior gene effects in Wild Boar and Meishan. Crossbred animals of these genetically diverse pig sources generate the maximum variability for all traits, help to demonstrate the range of values for the specified breeds of pig and allow an efficient analysis of the genes influencing performance traits. 相似文献
50.
Malm O Guimarães JRD Castro MB Bastos WR Viana JP Branches FJP Silveira EG Pfeiffer WC 《Water, air, and soil pollution》1997,97(1-2):45-51
Informal economy of gold mining has contaminated some important river basins in Amazon. Follow-up studies on critical compartments showed some areas with high Hg levels in fish as well as in human hair samples. Average Hg in piscivorous fish in the Madeira river itself was 846 ppb (N=284) with a maximum of 3921 ppb. Mercury in fish from non polluted areas in this basin shows high variability, even for single species. A seasonal variation in Hg content was observed, with higher values at the end of the dry season. In the upper Tapajós basin comparable values were found for fish but with a definite decreasing trend downstream. Average value for piscivorous fish in the whole Tapajós basin is 482 ppb (N=122) with a maximum value of 3770 ppb. Hair Hg was higher in fishing villages in the Tapajós (average: 17 ppm; with N=432 and maximum value of 176 ppm) than in the Madeira (average: 9 ppm; N=169; maximum 71 ppm), and data from some areas of the Tapajós suggest a decrease with time. Mercury was much higher in urine of goldshop workers in Santarém (low Tapajós) than in Alta Floresta (high Tapajbs) and show a decreasing trend in both cases, probably related to the significant decline in gold mining activities during the study period (1986–1994). 相似文献