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391.
392.
    
Abstract

Evapotranspiration, water vapour pressure difference, air and canopy temperature in a greenhouse were measured under shading screen materials with different shade factors and air change rate. The highest average evapotranspiration occurred under the screen material LS14, while the average evapotranspiration under the shading screen materials DGT4b and LS16 was equal. The highest water vapour pressure difference was found under DGT4b and the lowest under LS16. Only a small difference in air temperature was found under the screen materials.  相似文献   
393.
The aim of this project was to study the effects of feeding system (dry or wet feeding with whey), dietary lysine level and pre-slaughter routines on technological meat quality in entire male, female and castrated male pigs, which were carriers or non-carriers of the RN ? allele. The feeding system only affected the yield of processed meat, resulting in lower Napole yield (87.5% vs 89.4%) for meat of whey fed pigs. Further, lower dietary lysine levels resulted in higher drip loss of the meat compared with high dietary levels (5.3% vs 4.8%). Mixing of unfamiliar pigs prior to slaughter led to meat with lower internal reflectance values (28.3 vs 32.2) and glucose+G-6-P concentrations of the meat juice (46.3 vs 49.7 μmol/ml) compared with pen-wise slaughtering. In comparison with non-carriers, RN ? carriers had significantly lower ultimate pH, shear force values and water-holding capacity. Mixing of non-carrier pigs prior to slaughter gave higher Napole yield compared with those handled pen-wise. Females had lower ultimate pH and higher Napole yield compared with entire males.  相似文献   
394.
  总被引:1,自引:0,他引:1  
Sixty-eight isolates of Phytophthora infestans were collected from an early planted, fleece-protected potato field in southwest Sweden in May 2001. No infection was observed in the neighbouring fields. In the field investigated, infected plants were found in six discrete foci, with symptoms almost exclusively observed in the lower part of the canopy and numerous infections found on stems and on leaves touching the ground. The structure of the population was analysed based on mating type, mitochondrial haplotype and microsatellites (SSRs) as markers. Both mating types were present and haplotypes Ia and IIa were detected. Among 61 isolates analysed with microsatellite markers, 14 multilocus genotypes were distinguished based on six polymorphic loci. Out of the six foci, three included 3–5 genotypes each. There were unique genotypes in all foci, except two closely situated to each other. These findings strongly suggest that soilborne oosporic inoculum contributed significantly to initiate the late-blight epidemic in the investigated field.  相似文献   
395.
    
Good‐quality semen is a prerequisite for successful and profitable artificial insemination (AI) of modern dairy cattle. Fertility of the bulls is evaluated with andrological examinations and semen analyses, such as morphology. However, little attention has been paid to the inheritance of bull fertility. In this study, we correlated sperm morphology, birth year and station of 695 AI bulls with calving rate (CR). Sperm morphology was clearly associated with CR underlining the usefulness of morphological examination in the assessment of fertility. The correlation between the proportion of normal spermatozoa and CR was significant (p < 0.001). No significant differences were detected between stations or birth years. We also compared the CR of 695 AI bulls with the CR of their 27 sires to study the inheritance of fertility. Sire's CR did not correlate with the CR of the sons (p = 0.218). This result indicates that at least when sires of acceptable CR are used to produce sons for use in AI the inheritance of CR is not significantly correlated.  相似文献   
396.
In the last few years special interest has been focused on enteric diseases localized to the lower alimentary tract, especially the ileum of weaned pigs. An increasing frequency of disorders of unknown aetiology described as regional ileitis (Emsbo 1951), necrotic enteritis (Jubb & Kennedy 1970), and intestinal adenomatosis (Rowland et al. 1973) has been reported. The changes include thickening of the ileal mucosa with hypertrophy of the muscular wall. The normal structure of villi is replaced by a proliferation of crypt cells. Necrosis of the mucosa and granulation-tissue proliferation in the submucosa occur in later stages. Regional ileitis in man (Crohn et al. 1932) which is described as a chronic enteric disease with granulomatous inflammatory changes localized to segments of the ileum is also attracting increasing attention in medical research (Liljefors 1972). The lesions are also found in the colon, and the presence of a transmissible agent involved in the aetiology of Crohn''s disease has been discussed on the basis of animal experiments (Cave et al. 1973). The disease in pigs is accompanied by haematological changes, including decreased concentration of total serum protein, albumin, alkaline phosphatase, and zinc (Martinsson et al. 1974, 1976).  相似文献   
397.
Samples from three different oat (Avena sativa L.) cultivars, Vista, Gem and Dane were steeped and germinated in a pilot plant malting system. The content of avenanthramides, antioxidant compounds unique to oats, and some unknown compounds as well as the activities of the avenanthramide-synthesising enzyme hydroxycinnamoyl-CoA:hydroxyanthranilate N-hydroxycinnamoyl transferase (HHT) and the avenanthramide-oxidizing enzyme phenoloxidase (PO) were measured. An increase in avenanthramide content of germinated seeds, as compared to raw grains, was observed for Dane (125%, p < 0.001) and for Vista (29%, p = 0.007). The HHT activity increased 62% (p = 0.014) in Dane, whereas no change was detected in Vista and Gem. The PO activity decreased slightly during the germination process for Gem (p < 0.001) and Vista (p = 0.005). Many of the unknown compounds increased significantly during germination in all three cultivars, and one of them was identified to be the avenanthramide N-(4′-hydroxy-3′-methoxy-(E)-cinnamoyl)-5-hydroxy-4-methoxyanthranilic acid. This study indicates that a highly controlled steeping and germination process can be a valuable method to increase the content of endogenous avenanthramides in oats.  相似文献   
398.
    
The expansion of spruce-dominated forestry in Southern Sweden during the twentieth century has led to a considerable amount of oak (Quercus robur L.) woodlands being converted into stands dominated by planted spruce. The thinning of spruces around oak trees is currently done in Sweden to improve local diversity of insects, oak growing conditions and eventually decrease their mortality. To evaluate the effect of these treatments, we dendrochronologically studied growth of old (100–200 years old) oaks subjected to thinning of different intensity at nine locations in southern Sweden, and compared them to oaks located in nearby pastures. The overall pattern suggests that commonly adopted thinning intensities do not significantly affect oak growth. Oak growth was positively related to oak age and negatively to the amount of dead oak crown. Analyses of correlations between oak growth and summer drought conditions, as reflected by location-specific chronologies of the Monthly Drought Code (MDC), indicated that older trees exhibited generally negative correlations, whereas the correlation remained generally positive for the younger trees, both inside and outside forest stands. We propose that removal of spruces should be primarily done around older and healthier-looking trees.  相似文献   
399.
Embryos in freshly matured seeds of the facultative winter annual Papaver rhoeas are underdeveloped and physiologically dormant; thus, seeds have morphophysiological dormancy (MPD). Seeds lost physiological dormancy during 12 weeks of burial in moist soil at 12 h/12 h daily alternating temperature regimes of 15/5°C, 20/10 °C and 25/15 °C but not at 1 °C. Physiological dormancy was not broken in seeds stored dry at room temperature for 12 weeks. After physiological dormancy was broken, seeds required light for embryo growth (i.e. for loss of morphological dormancy) and consequently for germination. After a 12-week period of burial in soil at 25/15 °C, seeds that matured in 1997 germinated to 100% in light at 25/15 °C, demonstrating that cold stragification temperatures (≈ 0.5–10 °C) are not required for embryo growth. Thus, seeds have non-deep simple MPD. During exposure to low winter temperatures (5/1 °C, 1 °C), 52% of the seeds with physiologically non-dormant embryos entered conditional dormancy and thus lost the ability to germinate at 25/15 °C but not at 15/5 °C or 20/10 °C. The peak of germination for seeds sown in southern Sweden was in autumn, but some also germinated in spring. A higher percentage of seeds that matured in a relatively warm, dry year (1997) came out of MPD and germinated than did those that matured in a relatively cool, wet year (1998) at the same site.  相似文献   
400.
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