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71.
This study was conducted to evaluate the effects of single or carbohydrases cocktail in low-nutrient-density diets on growth performance, nutrient digestibility, blood characteristics, and carcass traits of growing–finishing pigs. A total of 96 pigs with an average initial BW of 47.50 ± 1.25 kg were used in this 8-week growth trial. Pigs were randomly allocated to 1 of the 4 treatments according to its BW and sex (4 pigs/pen, 6 replicate pens/treatment). The diets included: 1) control (CON) corn–soybean meal diet (DE, 3400 kcal/kg; CP, 17%), 2) low-nutrient-density (LC) diet with 6% DDGS and 5% tapioca (DE, 3280 kcal/kg; CP, 15%), 3) LC + 0.05% β-mannanase (LCS), and 4) LC + 0.05% enzyme mixture (LCM). The LC treatment had a lower ADG, and G/F compared to the other treatments in 0–4 weeks and the overall period of the feeding trial (P < 0.05). The ADFI were decreased in LC, LCS, and LCM groups related to CON (P < 0.05). The LCS treatment had higher DM digestibility than pigs in both the LC and LCM groups (P < 0.05) on 4 weeks while LCM improved N and energy digestibility compared to LC treatment. Blood urea nitrogen and creatinine values were not affected by the experimental treatments. After the feeding period, pigs (2 per pen) which reached marketing BW were collected meat samples from slaughter house. Backfat thickness was decreased in LC, LCS and LCM groups (P < 0.05). No numerical differences were observed in meat color, pH value and water holding capacity among four treatments. In conclusion, the results of this study indicate that single or carbohydrases cocktail in low-density diets can partially improve ADG, G/F, nutrient digestibility, and meat quality in finishing pigs, which can counteract the negative effects caused by the decreased nutrient concentration.  相似文献   
72.
Seo KS  Lim JY  Yoo HS  Bae WK  Park YH 《Veterinary microbiology》2005,106(3-4):225-233
Vancomycin-resistant enterococci (VRE) have emerged as an important nosocomial pathogen. Since 1989, a rapid increase in the incidence of enterococcal bacteremia and endocarditis by VRE has been reported. The use of avoparcin in animal husbandry is reportedly associated with the appearance of VRE. In this study, a multiplex polymerase chain reaction (PCR) method was established to detect and differentiate resistant types of enterococci, which specifically amplify the four van genes that encode vancomycin resistance elements. Using this method, we investigated the incidence rates and types of VRE from two types of farms: those that had used avoparcin and those that had not used avoparcin. A total of 1091 animal fecal samples were collected from 70 pig farms and 32 poultry farms. A total of 425 enterococci were isolated from the fecal samples. Among the 425 isolates, six showed a pattern of high-level vancomycin resistance (Minimal Inhibitory Concentration, MIC: 64-256 microg/ml). Out of six high-level VRE, three were isolated from poultry farms that had used avoparcin and three were not. The six high-level VRE harbored the vanA gene. Sixty-seven of 425 isolates that showed a pattern of low-level vancomycin resistance (MIC: 4-8 microg/ml) were associated with the presence of vanC-1 or vanC-2/3 gene. We also performed a repetitive extragenic palindromic PCR (rep-PCR) method to compare the genetic relatedness between the high-level VRE of six animal isolates and 31 human isolates. None of the animal isolates had a similar rep-PCR pattern as the human isolates but similarities between human VRE isolates were observed.  相似文献   
73.
Cyclodextrin glucanotransferase from Bacillus stearothermophilus ET1 (CGTase ET1) is a potential antistaling enzyme with cyclodextrin (CD)-forming activity. To reduce cyclization activity of CGTase ET1, phenylalanine residues at 191 and 255 were replaced with a glycine (F191G-CGTase ET1) and an isoleucine (F255I-CGTase ET1), respectively. Temperature optima of both mutant enzymes were lower than that of the wild-type. Cyclization activities of both mutants decreased dramatically, but F255I-CGTase ET1 showed a 2-fold higher hydrolytic activity than the wild-type enzyme. CD content of bread loaf treated with F191G-CGTase ET1 was 28.6% of that treated with wild-type, whereas no CD was detected in the loaf treated with F255I-CGTase ET1. Loaves treated with CGTase ET1 or either of the two mutants contained more of the larger maltooligosaccharides such as maltopentaose and maltohexaose than the control and the commercial antistaling enzyme-treated loaves. Retrogradation rates decreased significantly in the loaves treated with either mutant, which indicates the applicability of CGTase ET1 in the bread industry by modulating the cyclizing and hydrolyzing activities of the enzyme.  相似文献   
74.
用辣椒品种ECW123R(C.annuum)与CM334(C.annuum)杂交,对其121个F2代单株进行的检测表明,辣椒素合成酶基因(CS)与C位点的共分离控制了辣味的表达.故我们认为CS与C紧密连锁.对四个辣味型品种和四个无辣味型品种的测序分析表明,无辣味型品种在CS的5'上游区有一长度为2529bp的缺失(基因序列)存在.我们已研究出该C位点的分子标记,可在植株苗期检测其辣度.根据该缺失序列,我们开发了5个SCAR标志,其中有两个为共显性.这些SCAR标记对早期检测无辣味型个体既方便又准确.  相似文献   
75.
Spontaneously hypertensive rats (SHRs) are widely accepted in medical research because this model has been used for studies in neurodegenerative diseases such as vascular dementia and stroke. In the present study, we observed newly generated neuronal precursors using doublecortin (DCX, a marker of neural proliferation and differentiation) in the subgranular zone of the dentate gyrus in SHRs compared to Sprague-Dawley rats (SDRs) at various age stages. DCX immunoreactivity, immunoreactive cell numbers and its protein level in the dentate gyrus of the SHRs were higher than those in the SDRs at postnatal month 1 (PM 1). At PM 8, DCX immunoreactivity, immunoreactive cell numbers and protein levels in both groups were markedly decreased compared to those at PM 1; however, they were higher than those in the SDRs. They were decreased in the both groups with age: DCX immunoreactive cells in the SDRs were few at PM 12. Our results indicate that newly generated neuronal precursors are more abundant in SHRs than in SDRs during their life.  相似文献   
76.
Reactive oxygen species have been long associated with oxidative stress relevant to many pathological damages. In brain, 4-hydroxy-2E-nonenal (HNE), a major cytotoxic end product of lipid peroxidation, is produced. In contrast, superoxide dismutase (SOD), one of the major antioxidant enzymes, protects neurons from oxidative stress. The aim of this study is to observe differences in the distribution of HNE and Cu,Zn-superoxide dismutase (SOD1) in the hippocampal CA1 region of adult (2-3 years of age) and aged (10-12 years of age) dogs. The HNE immunoreactivity and protein level in the CA1 region were significantly high in the aged dogs compared to those in the adult dogs. SOD1 immunoreactivity and its protein level were also higher in the aged dogs than those in the adult dogs. However, there were not significant differences in NeuN (a neuron-specific soluble nuclear antigen) immunoreactivity in CA1 neurons between the adult and aged dogs. These differences may be associated with oxidative stress in aged dogs compared to that in adult dogs.  相似文献   
77.
Fowl typhoid is a disease of adult chickens and is caused by Salmonella Gallinarum infection via the alimentary tract. The experimental reproduction of fowl typhoid per os (PO) requires artificial conditions to minimize the effect of gastric acid, and several Salmonella serovars have been known to be transmitted via the respiratory route. Therefore, we have hypothesized the existence of a respiratory route for Salmonella Gallinarum infection and have attempted to reproduce fowl typhoid via intratracheal challenge. In accordance with our hypothesis, the intratracheal challenges of Salmonella Gallinarum reproduced exactly same lesions as fowl typhoid and induced higher mortality and morbidity than those of the PO challenge. Therefore, this study represents the first reproduction of fowl typhoid via respiratory route, and our findings may be useful for understanding the transmission of Salmonella Gallinarum in the field.  相似文献   
78.
Biological monitoring is performed to detect and analyze microorganisms that have continuously made an effort to survive in the environment. Of such microorganisms, Staphylococcus spp. is considered a common cause of nosocomial and environmental infections., Microbial Surface Components Recognizing Adhesive Matrix Molecules (MSCRAMMs) are required for the adhesion and biofilm formation of Staphylococci. Thirty-six and thirty-five Staphylococci isolated from animals and air, respectively, were analyzed. Biofilm formation and ten MSCRAMM genes were investigated using Congo red agar, tissue culture plate methods, and PCR. Airborne isolates were shown to have higher adherence and stronger biofilm formation than those from animals. The prevalence of MSCRAMM genes from air isolates was also higher than those from animals. Of the genes, eno was mainly associated with biofilm formation in both animals and airborne isolates (P < 0.05). Moreover, the rate of airborne isolates harboring the eno gene was higher than in animal isolates. These results indicated that analysis of MSCRAMM genes with a phenotypic assay might be a helpful bacterial control system for the environment.  相似文献   
79.
Sulfur (S) nutrition has a strong influence on onion pungency, and the production of sweet onions in the high-sulfur soil of Texas is a challenge to growers. This study was performed to determine the effects of S applications to fields already having sufficient levels of soil S on pungency and related compounds in four shortday onion cultivars. The onion cultivars ‘Cougar’, ‘Legend’, ‘Texas Early White’, and ‘Texas Grano 1015Y’ were grown in three commercial fields at Edinburg, Mercedes, and Weslaco of the Rio Grande Valley of South Texas with applications of sulfur at 0, 13, and 26 kg S/ha. Pyruvic acid, bulb weight, extractable S in soil and total S in bulb, soluble solids content (SSC), flavor precursor compounds [also called S-alk(en)yl-l-cysteine-sulfoxides (ACSOs)], and total sugars were measured. The pyruvic acid level of onions was not increased by the S applications and showed no significant correlation with soil S levels in any of the cultivars at locations having 30 or 235 ppm S. The SSC, total S in bulbs, total sugars, and total ACSO content also showed no correlation with the S applications and soil S levels. Onion pungency and content of flavor precursor compounds were significantly influenced by cultivar and cultivar × location interaction. We conclude that onion pungency is not increased by application of extra S fertilizer to commercial fields already containing sufficient levels of soil sulfur.  相似文献   
80.
Pectin gels were induced by monovalent salts (0.2 M) concurrently with deesterification of high methoxy pectin using a salt-independent orange pectin methylesterase (PME). Constant pH was maintained during deesterification and gelation. If salt or PME was absent, the pectin did not form a gel. The gel strength was influenced by both pH and species of monovalent cation. At pH 5.0, the pectin gel induced by KCl was significantly stronger than the NaCl-induced gel. In contrast, a much stronger gel was produced in the presence of NaCl as compared to KCl at pH 7.0. LiCl did not induce pectin gelation at either pH. Molecular weights of pectins increased from 1.38 x 10(5) to 2.26 x 10(5) during NaCl-induced gelation at pH 7. One proposal to explain these pectin molecular weight changes is a hypothetical PME transacylation mechanism. However, these pectin molecular weight changes can also be explained by metastable aggregation of the enzymatically deesterified low methoxy pectin. We postulate that gelation was induced by a slow deesterification of pectin under conditions that would normally salt out (precipitate) low methoxy pectin in the absence of PME.  相似文献   
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