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61.
In Pabna district, Bangladesh there are two cattle production systems: a draught-oriented system with local Deshi cattle and more milk-oriented production with Pabna Milking Cow (PMC) stock. Deshi animals are smaller than PMC animals. More PMC cows are milked than Deshi cows and the milk off-take of PMC cows is much higher. The calving interval in Deshi cows is one year longer than in PMC cows. The great majority of the bullocks and the bulls are used as draught animals. More than 80% of the Deshi cows also have to work compared with only about half of the PMC cows. The milk off-take of cows used for draught work is 30% less than that of other cows. One of the major differences between the two systems is that PMC cows have access to grazing along the rivers. These areas are increasingly taken up for cropping and the traditional Pabna milk production farming system is gradually being replaced.  相似文献   
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This study aimed to describe and compare village chicken production in two farming systems in Burkina Faso. The systems were those in which crops and livestock production were, respectively, the most important. A rapid rural appraisal preceded a monitoring study in which data were collected fortnightly for 2 months. The study revealed that village chickens are used as sacrifices, gifts and objects of exchange for traditional medicine, or are sold for a little money under both systems. Chicken production is a free-range procedure in both farming systems, but there are differences in management. On average, the flock size was 33.5±3 birds, of which 57% were chicks. During the period of 2 months in the rainy season, the overall mortality was relatively low (8.8%±1.5) but mortality in chicks was high (31.7%). The main cause of financial loss in the village chickens was mortality, which represented up to 84% of the total exits. The hatching rate and mortality in young chicks differed significantly (p<0.05) between the two farming systems.  相似文献   
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The aim of this study was to determine the optimal maturation culture period of ovum pick up (OPU)‐derived cumulus oocytes complexes (COCs) in relation to their developmental capacity. Embryo production, embryo cryotolerance, post‐transfer embryonic survival and calf characteristics such as gestation length, birthweight and sex ratio were investigated. This retrospective study covers the analyses of ovum pick up –in vitro production and calving results from a commercial programme that took place between March 1994 and September 2004. Donors were both heifers (of which approximately 90% pregnant) and cows (of which approximately 10% pregnant). Embryo production analyses were based on 7800 OPU sessions conducted from January 1995 until January 1999. Analyses of calving rate were based on 13 468 embryo transfers performed during January 1995 until May 2002. Analyses on calf characteristics were based on 2162 calves born between March 1994 and September 2004. The in vitro maturation culture period ranged from 16 to 28 h. The mean production rate of transferable embryos was 16.5% (1.2 embryos per OPU session). Length of maturation culture period did not affect the production of transferable embryos. Mean calving rate was 40.9% and 38.7% for fresh and frozen/thawed embryos, respectively. Calving rate was not affected by the maturation culture period. Mean birthweight, gestation length and proportion of male calves were 46 kg, 281.9 days and 52.8%, respectively. Maturation culture period did not affect these variables. In conclusion, this study shows that the in vitro maturation culture period within the range of 16–28 h does not affect in vitro embryo production, embryo cryotolerance, post‐transfer embryonic survival and calf characteristics, suggesting that all COC batches collected by OPU on the same day, can be fertilized in one IVF session without a significant loss in the production from oocyte to calf.  相似文献   
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The tetramic acid derivative spirotetramat (brand name Movento®), has shown an outstanding performance against sucking insect pests in laboratory and greenhouse assays as well as in semi-field and field trials. The product acts as an inhibitor of lipid biosynthesis and affects juvenile stages with additional effects on adult fecundity. There is no cross-resistance to any other insecticide. After foliar application spirotetramat penetrates through the leaf cuticle and is translocated as spirotetramat-enol via xylem and phloem, up to growing shoots and down to roots. This full ambimobility or two-way systemicity (phloem and xylem transport) ensures the control of hidden and soil living sucking pests after foliar application and protects new shoots. The worldwide field development of spirotetramat in Bayer CropScience AG resulted in numerous uses against many species of whiteflies, aphids, scales (soft and armoured scales), mealy bugs, psyllids and selected thrips species in vegetables, cotton, soybean, pome and stone fruit, grapes, hop, citrus, nut trees and banana. The new mode of action renders spirotetramat as an excellent rotation partner with existing products for the management of aphid, whitefly and psyllid populations, which are frequently resistant to conventional insecticides. Moreover, only low adverse effects have been found on beneficial arthropods, which make the product suitable for modern integrated pest management (IPM) systems. These unique properties contribute to safeguarding the crop yield potential both in quality and quantity. In this paper, the new chemistry is presented, compared with standard insecticides and novel applications in IPM systems are discussed.  相似文献   
66.
S Löffler  J Körber  U Nubbemeyer  K Fehsel 《Science (New York, N.Y.)》2012,337(6095):646; author reply 646
Ray et al. (Reports, 29 July 2011, p. 637) assume that clozapine-N4-oxide (CNO) represents a "biologically inert synthetic ligand" that selectively activates the M4 muscarinic receptor-based DREADD (designer receptor exclusively activated by a designer drug). In contrast, due to the redox cycling of CNO with clozapine and to their cell membrane permeability, CNO is biologically active and its conversion products are capable of undermining DREADD effects.  相似文献   
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The expression of human complement regulatory proteins (hCRP; hDAF, hCD59, and hMCP) in pig tissues has been suggested as one of strategies to overcome the hyperacute rejection (HAR) in pig‐to‐human transplantation. Expression of human tissue factor pathway inhibitor (hTFPI) in porcine endothelial cells has been suggested as a remedy to overcome microvascular thrombosis. To investigate the effects of these combined transgenes, we established transformed pig cells expressing human decay accelerating factor (hDAF) under the control of enhancer promoter (5′LTR‐PCMVIE), and the fusion protein (hTFPI/hCD4) consisting of the functional domains (K1 and K2) of hTFPI and membrane‐tethering domains (D3 and D4) of hCD4 under the control of PCMVIE. Transgenic pigs were generated with the transformed porcine cells through somatic cell nuclear transfer (SCNT) technology. Analysis of quantitative PCR and real‐time quantitative RT‐PCR showed that four copies of hDAF were integrated and 391 copies of hDAF mRNA expressed in the cells of the transgenic pig. The enhancing activity of 5′LTR was approximately 2 fold compared to CMVIE promoter only. The cell viability test showed that more than 80% of ear cells were viable in the presence of 50% human serum. The chromogenic substrate assay and immunocytochemical staining with tail cells showed that the TFPI activity of fusion protein was observed on the cell membrane. The membrane localization of hDAF and hTFPI proteins was observed by immunocytochemical staining, and the expression of transgenes in heart and liver tissues was also confirmed by immunohistochemistry.  相似文献   
69.
Objective To monitor changes in hoof morphology in response to barefoot trimming. Methods Seven horses were trimmed every 6 weeks according to barefoot trimming principles, which involved levelling the hoof to live sole, lowering the heels, bevelling the toe and rounding the peripheral wall, while leaving the sole, frog and bars intact. A 4‐month period was allowed to lower the heels sufficiently to achieve a hoof shape representative of the barefoot trim. This was regarded as the starting point for morphological adaptations in response to maintenance of the trim. Hoof morphology was measured from lateral, dorsal and solar view photographs and lateromedial radiographs taken at 0, 4 and 16 months. Changes from 0 to 4 months represented differences between a natural hoof shape and the trim, while changes from 4 to 16 months represented adaptive effects during hoof growth. Results Establishment of the barefoot trim involved significant shortening of the toe, heel and medial and lateral walls, with increases in angulation at the toe, medial and lateral walls, but not at the heel. Maintenance of the trim resulted in a palmar/plantar migration of the heels, with increases in support length, heel angle and solar angle of the distal phalanx (P3). Conclusions Bevelling the toe and engaging the frog and bars in the weight‐bearing function of the foot resulted in elevation of the heel angle and solar angle of P3. These changes may be beneficial in treating under‐run heels and negative solar plane angulation of P3.  相似文献   
70.
In the Giessen free-air CO2 enrichment (GiFACE) experiment, 5 years of CO2 enrichment led to decreased CH4 uptake rates of the investigated meadow soil. In soils, CH4 is mainly oxidised by methanotrophic bacteria. In the present study, abundances of methanotrophic bacteria and total bacteria in soil samples from the GiFACE experiment were quantified by applying pmoA- and 16S rRNA gene-targeted real-time PCR and fluorescence in situ hybridisation (FISH). Methanotrophic bacteria of the Methylosinus group (Alphaproteobacteria) and the Methylobacter/Methylosarcina group (Gammaproteobacteria) were detectable by real-time PCR as well as by FISH. Both quantitative analytical approaches revealed that abundances of either bacteria or methanotrophic bacteria in soil samples from sites under CO2-enriched atmosphere were decreased. Compared to ambient site, only 46 and 30.5% of methanotrophic bacteria and 38 and 63.2% of total bacterial cell numbers could be detected under CO2-enriched atmosphere by FISH and real-time PCR, respectively. These results suggest that significantly decreased abundances of methanotrophic bacteria could explain reduced CH4 uptake rates.  相似文献   
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