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901.
Bjorn Roth Albert Imsland Lars Helge Stien Rian Schelvis-Smit Snorri Gunnarsson Atle Foss 《Aquaculture International》2010,18(3):461-474
In order to test seasonal, rearing, maturing and anaerobic muscle activity effect on the flesh quality of turbot (Scophthalmus maximus) a total of 80 farmed turbot from three different strains from reared under natural or continuous light were killed by a
percussive blow to the head in November (winter, Icelandic strain), March (spring, Portuguese strain) and June (summer, domesticated
strain (France turbot)). To test the effect of anaerobic muscle activity, 10 fish were on each occasion pre rigor filleted, where one fillet was used as a control, while the other fillet was electrically stimulated using a squared 5 Hz,
10 V pulsed DC for 3 min. All pre rigor fillets were measured for pH, weighed, wrapped in aluminum foil and stored in polystyrene boxes with ice. After 7 days of
storage the fillets were measured instrumentally for pH, drip loss, colour (CIE L* a* b*) and texture properties such as hardness and shear force, while fillet shrinkage and colour (RBG) were evaluated with computer
imaging on photographs from a standard lightbox. Results showed that softness of the flesh was mainly influenced by factors
associated with growth, such as season, photoperiod and maturation. Anaerobic muscle activity simulated with electrical stimulation
caused an increase in drip loss (<1%) and loss of shear force (<4%), but had no effect on hardness or fillet shrinkage. Computer
imaging revealed that muscle contractions related to the electrical stimulus forced out blood from the fillet causing less
reddishness for the entire storage period. We conclude that a pH drop upon slaughter associated with anaerobic muscle activity
has a minor effect on the flesh quality in the short run, while seasonal/alternatively genetic effects are predominant. 相似文献
902.
Mayra L. González-Félix Delbert M. GatlinIII Martin Perez-Velazquez Ken Webb Armando García-Ortega Michael Hume 《Fish physiology and biochemistry》2018,44(5):1319-1331
Sciaenops ocellatus has a long history in aquaculture and many difficulties associated with its commercial culture have been addressed and successfully resolved; nevertheless, further research in lipid nutrition could address more comprehensive questions on the way these nutrients are utilized. The purpose of this study was to evaluate S. ocellatus growth and lipase gene expression in response to increasing dietary lipid supplementation. Four experimental diets were formulated to provide 3, 10, 16, or 23% lipid using menhaden fish oil. Twenty juveniles (mean initial weight 2.3?±?0.1 g) were stocked per aquaria in a recirculating system; each diet was assigned to three aquaria and fed to fish for 6 weeks. At the end of the study, fish fed 3% of dietary lipid were significantly (P?<?0.0001) smaller and showed significantly lower feed efficiency, condition factor, hepatosomatic index, and intraperitoneal fat than fish fed the other diets, but no differences were observed among fish fed 10, 16, or 23% lipid. A straight broken-line regression model for thermal growth coefficient provided an estimated value of 9.4% of dietary lipid as the optimal inclusion level. The bile salt-dependent lipase (BSDL) of red drum was 80.3 kDa. Relative gene expression of BSDL was significantly higher (P?=?0.0007) in fish fed 10% lipid, with no differences among the other dietary treatments. Results provided could help monitor the metabolic status of farmed fish and contribute to optimize diet formulations based on maximum gene expression of BSDL for supplementation of dietary lipid. 相似文献
903.
牛磺酸在动物营养上的研究进展 总被引:2,自引:0,他引:2
牛磺酸广泛存在于动物体各组织器官内,具有多种生物学功能,在动物营养中具有十分重要的作用。通过对牛磺酸理化性质、生物学功能的研究,探讨其作为添加剂在养殖业中的应用。 相似文献
904.
Gobena Ameni Abraham Aseffa Glyn Hewinson Martin Vordermeier 《Tropical animal health and production》2010,42(3):375-383
Host immune responses to Mycobacterium bovis (M. bovis) infection are variable at the different severity stages of pathology of the disease. In countries like Ethiopia, where routine
screening of bovine TB is not undertaken, the use of tests which measure cellular and antibody responses may help for the
maximum detection of infection. In the present study, 701 cattle were tested for bovine tuberculosis (BTB) using comparative
intradermal tuberculin (CIDT) test, interferon (IFN)-γ test, and lateral flow assay. The apparent prevalence was 32% when
all the three tests were used, but varied from 23 to 25% when a pair of tests was used and from 9% to 15% when a single test
was used. Agreement was observed between CIDT and IFN-γ tests both at a cut-off >2 mm (Kappa ± standard Error, k ± SE, 0.129 ± 0.045; 95%CI = 0.041,0.216) and a cut-off >4 mm (k ± SE, 0.094 ± 0.044, 95%CI = 0.008,0.179) while no agreement was observed either between CIDT test and lateral flow assay
(k ± SE, −0.04 ± 0.033; 95%CI = −0.104,0.024) or between IFN-γ tests and lateral flow assay (k ± SE, −0.031 ± 0.032; 95% CI = −0.093,0.031). Thus, the use of more than one test leads to the detection of the maximum number
of infected animals. 相似文献
905.
黄花苜蓿野生种群遗传多样性的初步研究 总被引:2,自引:0,他引:2
对来自我国不同地区的黄花苜蓿野生种群的种子千粒重、发芽率及贮藏蛋白进行了初步研究。结果表明,黄花苜蓿野生种群内和种群间均存在着较大的变异,种子千粒重在1.098~2.012g之间,其中二倍体黄花苜蓿种子千粒重最低,仅为1.098g,是四倍体黄花苜蓿种子平均千粒重的62.01%;种子发芽率也十分不整齐,种皮不经磨擦的自然发芽率十分低,从0~40%不等,平均发芽率仅为16.9%,二倍体种子的自然发芽率为0;种子贮藏蛋白SDS凝胶电泳亦显示出其具有多态性,平均多态位点百分比为37.9%,基因多样性为0.3066,种群分化系数为0.2257。 相似文献
906.
Experimental infection of Black Belly and INRA 401 straight and crossbred sheep with trichostrongyle nematode parasites 总被引:1,自引:0,他引:1
Gruner L Aumont G Getachew T Brunel JC Pery C Cognié Y Guérin Y 《Veterinary parasitology》2003,116(3):239-249
Compared to INRA 401 lambs reared in France, Black Belly (BB) lambs reared in Guadeloupe (F.W.I.) were highly resistant to both primary and secondary experimental infection with Haemonchus contortus. To investigate this huge inter-breed difference, a nucleus flock of BB was constituted, and experiments were conducted to: (i) confirm this difference in lambs born in France, (ii) check whether it was similar for Trichostrongylus colubriformis and Teladorsagia circumcincta, and (iii) find out whether this difference was age-related. Forty BB lambs, 84 F1 lambs (BB siresxINRA 401 ewes) and 88 INRA 401 lambs born in two cohorts were used in an experimental design involving three host breeds, both genders and two age-groups (3.5- and 7-month-old when first infected). The limited availability of BB lambs made the study incomplete. Infection consisted of the administration of two doses of 10,000 infective larvae of one of the nematode species, separated by an anthelmintic treatment and an interval of 1 week before the second dose was administered. Fecal egg counts (FECs) were done on Days 28 and 35 after each infection; ewe lambs of the INRA 401 and F1 breeds were necropsied, the worm burden was established, the length of the female worms measured and the eggs in utero counted. For H. contortus and T. colubriformis, the FEC was lower in the BB than in the INRA 401 lambs, and the FEC found for the F1 lambs was intermediate. For T. circumcincta, only data for the F1 and INRA 401 lambs were available, and the FECs for these breeds were the same. In all three breeds, the FEC determined after the second dose was significantly lower than that found after the first dose in the ewe lambs, but not in the ram lambs. Infecting the lambs when they were 7- instead of 3.5-month-old significantly lowered egg excretion of both parasites in the F1 (P<0.0001), but not the INRA 401 lambs. Worm numbers in the F1 and in the INRA 401 ewe lambs confirmed the FEC data, many F1 lambs being free of T. colubriformis. The H. contortus female worms were shorter and had fewer eggs in utero in the F1 than in the INRA 401 lambs. A higher proportion of T. circumcincta was at the fourth larval stage in the F1 lambs. In conclusion, the BB breed is much more resistant than INRA 401 to H. contortus, with the F1 lambs being more like the BBs after the second dose. This difference was also found for T. colubriformis and, to a lesser extent, for T. circumcincta. 相似文献
907.
Héctor A. Bahamonde P. L. Peri R. Alvarez A. Barneix A. Moretto G. Martínez Pastur 《Agroforestry Systems》2012,84(3):345-360
The role of environmental variables on litter decomposition and its nutrient release in Nothofagus antarctica forest in Patagonia is poorly understood. Moreover, in these forests under silvopastoral use there are few antecedents. Litter
decomposition and nutrient release of grasses and tree leaves were evaluated under different crown cover and two site quality
stands during 480 days. Organic matter decomposition varied with crown cover for both types of litter, achieving mean values
of 23 and 34% for maximal and minimal crown cover, respectively. Total transmitted radiation was the main environmental factor
explaining 61 and 49% of the variation of grass and tree leaves decay rates, respectively. N, P, and Ca were mineralized during
first 60 days in decomposing tree leaves and then immobilized without differences between crown cover. The K was immobilized
during the evaluated period. In decomposing grass leaves the results varied according to site quality and time. There was
a tendency of nutrient mineralization at the first 120 days and then immobilization. The removal of trees for silvopastoral
use of N. antarctica may increase litter decomposition by changing the microclimate, but nutrients release or immobilization was mainly affected
for their concentration in decomposing material. 相似文献
908.
Despite the widely accepted idea that shaded plantations are valuable habitats for Neotropical migrants in disturbed landscapes, little empirical evidence is available in relation to the quality of this habitat for Neotropical-Nearctic migratory birds in the Andes. We evaluated the suitability of shaded plantations for overwintering Neotropical-Nearctic migratory birds by examining diurnal and seasonal variation in body condition of migrants in these agroforests in the Andes. During October to April 2008–2009 and 2009–2010, we mist-netted eight species of Neotropical-Nearctic migrants in shaded plantations in the Colombian Andes. Body condition improved throughout the day for Cerulean Warbler (Setophaga cerulea), Blackburnian Warbler (Setophaga fusca), Tennessee Warbler (Leiothlypis peregrina), and especially Canada Warbler (Cardellina canadensis). Similarly, body condition improved across the season for Tennessee Warbler, Rose-breasted Grosbeak (Pheucticus ludovicianus), and Summer Tanager (Piranga rubra). Our results provided additional evidence that several common Neotropical migrants, including species of conservation concern such as Cerulean Warbler and Canada Warbler, may improve their body condition in shaded plantations. However, about half of the species assessed in this study did not show any significant improvement in their body condition (e.g. Red-eyed Vireo). Furthermore, on average, species were in poor condition (i.e. body condition scores were negative) in these coffee farms. Thus, the extent to which this agricultural system represents high quality habitat should be looked with caution. Overall, our data contribute novel information on daily patterns of body condition improvement for several common migratory birds in Andean shaded plantations. 相似文献
909.
Matthias Vanmaercke Willem Maetens Jean Poesen Benediktas Jankauskas Genovaite Jankauskiene Gert Verstraeten Joris de Vente 《Journal of Soils and Sediments》2012,12(4):586-602
Purpose
This study aims to understand better the relationship between measured soil loss rates due to sheet and rill erosion (SL), predicted SL rates and measured catchment sediment yields (SY) in Europe. 相似文献910.