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排序方式: 共有498条查询结果,搜索用时 484 毫秒
91.
Mawahib K. Khogali Kang Wen Diego Jauregui Huwaida E. E Malik Long Liu Minmeng Zhao Daoqing Gong Tuoyu Geng 《The Journal of Poultry Science》2022,59(3):206
Production of pimpled or sandpaper-shelled eggs (SE) is a major problem in aged hens. Probiotics can improve eggshell quality; however, the relationship between SE production and gut bacteria remains unclear. Here, 1200 450-d-old Hy-line hens were assigned to four groups (300 hens each), with the control group fed basal diet and treatment groups fed basal diet plus 500, 1000, and 1500 mg/kg of Clostridium butyricum and Bacillus subtilis, respectively. After 4 weeks, probiotics significantly decreased the SE rate from 42.51% to 28.02%. To address why probiotics reduced SE rate, the hens that only produced normal eggs (NE) or SE based on a 2-week assessment were assigned to three groups (NE, SE, and SEP groups; 10 hens each), with the NE and SE groups fed a basal diet and SEP group fed a basal diet plus 1000 mg/kg probiotics. After 4 weeks, ileal tissues from eight birds/group were collected for histomorphological and gene expression analyses, and the ileal content was collected from five birds/group for 16S rDNA sequencing analysis. The data showed that probiotics significantly increased the villus length and ratio of villus length to crypt depth. Quantitative PCR analysis indicated that there were no significant differences in the expression of genes related to tight junctions, nutrient transport, and calcium absorption among the groups (except TRPV6, P<0.001). The 16S rDNA sequencing analysis indicated that the alpha-diversity of gut bacteria in the SEP group was the highest among the groups. The Firmicutes phylum was dominant in the NE and SEP groups, whereas the Proteobacteria phylum was dominant in the SE group. Together, these results suggest that probiotics can significantly influence the intestinal structure and composition of the intestinal microbiota, which may lead to a reduction in the SE rate in aged hens. 相似文献
92.
M Alonso E Camus J Rodriguez Diego L Bertaudière J C Tatareau J M Liabeuf 《Revue d'élevage et de médecine vétérinaire des pays tropicaux》1992,45(1):9-14
A serological survey using indirect immunofluorescence (IFAT) for bovine babesiosis (Babesia bovis and B. bigemina) and card test for anaplasmosis, indicates that these haemoparasites are widespread in Martinique. The high prevalences (62% for B. bovis, 52% for B. bigemina and 43% for Anaplasma marginale) lead to the hypothesis of an unstable epizootic situation for these three haemoparasitic diseases. However, the number of smears examined was too low to evaluate their clinical incidence. Both the American and Cuban card tests gave similar results in the detection of antibodies to A. marginale. Theileria mutans is described for the first time in Martinique. Trypanosomosis (Trypanosoma vivax) has disappeared from Martinique, on clinical and serological evidence. 相似文献
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96.
Geovane R. Oliveira Willian K. Oliveira Carla Andrade Antonio Diego B. Melo Fernando B. Luciano Renata E. F. Macedo Leandro B. Costa 《Journal of animal physiology and animal nutrition》2019,103(3):756-765
This study evaluated the antimicrobial effect of essential oils (EO) and organic acids (OA) against Salmonella Enteritidis in chicken feed and during an in vitro model that mimics the chicken digestive process. The minimal inhibitory concentration (MIC) of allyl isothiocyanate (AITC), carvacrol (CV), propionic acid (PROP) and caproic acid (CAP) were individually determined. Then, based on the MICs of each compound, combinations of EOs and/or OAs were tested to evaluate their synergic antimicrobial effect. The synergic effect of AITC and CAP was the most efficient against the bacterial strain tested. Commercial feed was inoculated with a 5‐strain cocktail of S. Enteritidis and treated with different doses of AITC + CAP to evaluate their effect on the growth/survival of the pathogen. In addition, the simulated digestion model was used to access the antimicrobial effect of AITC + CAP added to the feed towards S. Enteritidis and Lactobacillus plantarum. Synergistic effect was found between AITC (0.065 mM) and CAP (17.5 mM) against S. Enteritidis in chicken feed, where S. Enteritidis was reduced to undetectable levels (<1.00 log CFU/g). AITC (1.95 mM) + CAP (45 mM) also decreased (p < 0.05) the population of S. Enteritidis in the simulated digestion, while the growth of L. plantarum was not affected. Therefore, the addition of AITC + CAP in feed might be a potential natural antimicrobial able to prevent economic losses caused for Salmonella in chicken. 相似文献
97.
Diego F. Varela-Ortiz José E. Barboza-Corona Joaquín González-Marrero Ma. Fabiola León-Galván Mauricio Valencia-Posadas Alma A. Lechuga-Arana Cynthia G. Sánchez-Felipe Fernanda Ledezma-García Abner J. Gutiérrez-Chávez 《Veterinary research communications》2018,42(3):243-250
Staphylococcus aureus is an opportunistic pathogen that may cause severe infections in livestock, and represents the major cause of mastitis in dairy cows. Currently, instead of using antibiotics, new strategies are sought to reduce this clinical health problem. The aim of this study was to determine the efficacy of phage therapy to kill S. aureus strains obtained from farms located at the State of Guanajuato, México. Thirty-six S. aureus strains from cow milk with subclinical mastitis were isolated and identified, and the susceptibility to antibiotics and four phages also isolated in this work was tested. It was found that more of 90% of S. aureus isolates were not susceptible to six or more antibiotics, and 100% were resistant to penicillin, dicloxacillin, cefotaxime, ampicillin and cephalothin, and 81 and 77%, to tetracycline and cefuroxime, respectively. Fortunately, 100% of S. aureus isolates were susceptible to phages used in this work, which was detected as clear zones using specific phage. It was shown for the first time, that phages used in this study are active against pathogenic S. aureus and might be incorporated into the therapy as an important tool for the control of staphylococcal bovine mastitis, specially to antibiotic-resistant S. aureus strains isolated in farm located at the state of Guanajuato, México; and its use might be extended to other regions inside or outside the country. 相似文献
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99.
Diego del Villar‐Guerra Kim Aarestrup Christian Skov Anders Koed 《Ecology of Freshwater Fish》2014,23(4):594-603
Partial migration is a common phenomenon in many fish species. Trout (Salmo trutta) is a partially migratory species where some part of the population migrate to the marine environment, while another remains in freshwater. In the years 2008 and 2009, a total of 159 wild sea trout smolts were tagged with acoustic and PIT‐tags in the river Villestrup (Denmark) to study the initial postsmolt marine behaviour within a fjord system. We found that the strategies of the sea migrants vary: some stay in the fjord, while others migrate to the sea, suggesting that partial migration occurs even in the marine environments. Overall, a total of 53% of the tagged smolts migrated from the fjord to the sea, and 47% stayed (or potentially died) in the fjord. The ratios of fjord‐resident versus sea‐migrating postsmolts were consistent at the study times, and no differences between the early and late migration periods of the smolts were observed. The individual's size or body condition at the time of tagging did not affect survival or the migratory decisions in the fjord. High overall initial survival (74%) was found 30 days after the fjord entry. We suggest that within a continuum of migration to sea, there is a migratory decision point when sea trout postsmolts encounter a fjord system. At this point, postsmolts will assess the possibility of migration versus the alternative of fjord residency. 相似文献
100.
Diego Corrêa Alves Lilian Paula Vasconcelos Robson Marcelo Rossi Sidnei E. Lima-Junior Yzel R. Súarez 《Ecology of Freshwater Fish》2020,29(4):574-587
Bayesian inference was used to estimate the main population parameters (sex ratio, L50, LWR and somatic growth) and to evaluate sexual dimorphism and growth patterns (isometric/allometric and monophasic/biphasic growth) of Astyanax paranae of the Upper Paraná River. This study brings three statistical differentials: (a) the reparametrisation of the logistic model as a function of L50; (b) the reparameterisations of the LWR models based on the exponential of a piecewise linear regression to evaluate the hypotheses of polyphase growth; and (c) the first application of the recently proposed somatic growth models based only on length data to real data, as well as its expansion and generalisation. The models estimated L50 of females at 37.75 mm and sex ratio at 1.4 females per male. LWR models showed that both sexes presented biphasic growth with a lower increase in weight for males in first stanza. In second stanza, both sexes presented a greater increase in weight. Growth models showed that the growth rates were low, equal for both sexes in early life and slightly higher for females after the eighteenth months old. The studied population inhabits streams, therefore being exposed to constraining conditions that can limit the expression of their whole growth potential since they prioritise energy allocation for reproduction and survival, including reducing L50 in order to ensure the maintenance of the population. Finally, the complex biological patterns that arose from the proposed LWR and growth models demonstrated high potential and applicability for population studies. 相似文献