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61.
The objectives were to evaluate the effect of (1) supplementing concentrates to multiparous Holstein cows during the dry period on colostral and milk immunoglobulin G (IgG) concentration; and (2) feeding calves colostrum at either 5 or 10% of their body weight (BW) on passive transfer of immunity, health, and performance. Holstein multiparous cows (n = 37) were assigned to 1 of 2 nutritional treatments during an 8-wk dry period: (1) offered ad libitum grass silage only (GS) or (2) offered ad libitum access to the same grass silage plus concentrate [total mixed ration in a 75:25 dry matter (DM) ratio], providing a mean concentrate DM intake of 3.0 kg/cow per day (GSC). Both treatment groups were offered identical levels of mineral and vitamin supplementation. Calves from these cows were weighed immediately after birth and fed either 5% (5BW) or 10% (10BW) of their BW in colostrum from their own dams within 2.5 h of birth. Calves in the 10BW group received their second feed of colostrum from first-milking colostrum. Concentrate supplementation during the dry period had no effect on colostral IgG concentration, first-milking IgG yield, or fat, protein, and lactose contents. However, cows in GSC produced a greater mean milk yield over the first 8 milkings compared with cows in the GS group. Concentrate supplementation had no effect on calf BW or BW gain, serum IgG, or apparent efficiency of absorption (AEA) at 24 h after birth. However, offspring from the GSC group had fewer cases of enteritis during the first 56 d of life compared with offspring from the GS group. Calves in the 10BW group had greater mean serum IgG concentration for the first 3 d following birth; however, at 24 h after birth, we observed no treatment effect on AEA. The rate of enteritis was greater for calves in the 5BW treatment compared with 10BW. The colostrum-feeding regimen had no effect on BW gain or on the incidence of pneumonia among calf treatment groups. In conclusion, concentrate supplementation regimens offered during the dry period had a positive effect on colostrum yield, and offspring from the GSC group had a reduced rate of enteritis. Feeding 10% of BW of colostrum versus 5% of BW resulted in a greater serum IgG concentration for the first 3 d postpartum, and 10BW calves had a reduced rate of enteritis. Overall, to achieve successful passive transfer, decrease the rate of enteritis, and increase efficiency in the dairy calf, we recommend that dairy calves be fed 10% of their BW in colostrum as soon as possible after birth.  相似文献   
62.
Whereas whole first-milked colostrum IgG1 variation is documented, the IgG1 difference between the quarter mammary glands of dairy animals is unknown. First colostrum was quarter-collected from healthy udders of 8 multiparous dairy cows, all within 3 h of parturition. Weight of colostrum produced by individual quarters was determined and a sample of each was frozen for subsequent analysis. Immunoglobulin G1 concentration (mg/mL) was measured by ELISA and total mass (g) was calculated. Standard addition method was used to overcome colostrum matrix effects and validate the standard ELISA measures. Analysis of the data showed that cow and quarter (cow) were significantly different in both concentration and total mass per quarter. Analysis of the mean IgG1 concentration of the front and rear quarters showed that this was not different, but the large variation in individual quarters confounds the analysis. This quarter difference finding indicates that each mammary gland develops a different capacity to accumulate precolostrum IgG1, whereas the circulating hormone concentrations that induce colostrogenesis reach the 4 glands similarly. This finding also shows that the variation in quarter colostrum production is a contributor to the vast variation in first milking colostrum IgG1 content. Finally, the data suggests other factors, such as locally acting autocrine or paracrine, epigenetic, or stochasticity, in gene regulation mechanisms may impinge on colostrogenesis capacity.  相似文献   
63.
The primary objective of this study was to investigate the effects of supplementing a commercial colostrum replacer (CR) with gut active carbohydrates (GAC) on passive transfer of IgG in commercial dairy calves. A secondary objective was to evaluate the effect of treatment on preweaning health and growth. A total of 240 newborn Holstein dairy calves on a commercial dairy farm were enrolled in this study. Newborn heifer and bull calves were weighed and then randomly assigned to either the treated group [GAC: 30 g of GAC mixed into 1.5 doses (150 g of IgG) of commercial colostrum replacer; n = 119] or the control group [CON: 1.5 doses (150 g of IgG) of CR; n = 121]. The assigned CR treatment was fed within 3.5 h of birth using an esophageal tube feeder. Venous blood samples were collected at 0 and 24 h of age and used to measure serum IgG (mg/mL) and serum total protein (g/dL) concentrations and to estimate the apparent efficiency of absorption of IgG (%). The 129 heifers calves enrolled (CON = 60; GAC = 69) were also followed until weaning to assess the effect of GAC addition on preweaning health and growth. Multivariable linear regression showed that the addition of GAC to CR did not influence passive transfer of IgG, as measured by apparent efficiency of absorption at 24 h of age (CON = 54.0 vs. GAC = 54.3%), serum IgG (CON = 20.3 vs. GAC = 20.2 mg/mL), and serum total protein (CON = 5.69 vs. GAC = 5.68 g/dL). Although study sample sizes were not originally derived to evaluate health outcomes, treatment had no effect on weight gain or incidence of health events (diarrhea, pneumonia, mortality) for heifer calves between birth and 7 wk of age.  相似文献   
64.
Eighty Holstein and Holstein cross dairy calves were blocked by birth date and randomly assigned to 1 of 8 treatments within each block to examine the effect of a colostrum replacer (CR) feeding regimen, supplementation of CR with sodium bicarbonate (NaHCO3), and provision of a milk replacer (MR) feeding on IgG absorption. Calves were offered a CR containing 184.5 g/L of IgG in either 1 feeding at 0 h (within 30 min of birth), with or without 30 g of NaHCO3, with or without a feeding of MR at 6 h of age, or 2 feedings of CR (123 g of IgG at 0 h with or without 20 g of NaHCO3 and 61.5 g of IgG at 6 h with or without 10 g of NaHCO3), with or without a MR feeding at 12 h. Therefore, treatments were (1) 1 feeding of CR; (2) 2 feedings of CR; (3) 1 feeding of CR + 30 g of NaHCO3; (4) 2 feedings of CR + 30 g of NaHCO3; (5) 1 feeding of CR + MR feeding; (6) 2 feedings of CR + MR feeding; (7) 1 feeding of CR + 30 g NaHCO3 + MR feeding; and (8) 2 feedings of CR + 30 g NaHCO3 + MR feeding. Blood samples were obtained at 0, 6, 12, 18, and 24 h after birth and were analyzed for IgG via radial immunoassay. Results indicated that CR feeding schedule, MR feeding, and the interactions CR × Na, CR × MR, and CR × Na × MR were similar for 24-h serum IgG, apparent efficiency of absorption, or area under the curve. Serum IgG at 24 h, apparent efficiency of absorption, and area under the curve were decreased with addition of NaHCO3 compared with calves not supplemented with NaHCO3. These data indicate that supplementation of CR with NaHCO3 is not beneficial to IgG absorption and feeding MR within 6 h of CR feeding does not affect IgG absorption.  相似文献   
65.
The objective of this study was to identify herd-level colostrum management factors associated with the adequate transfer of passive immunity (TPI; defined as serum Brix refractance ≥8.4% in the first week of life). A total of 59 commercial Holstein dairy farms were included in this observational cross-sectional study. In every participating herd, a minimum of 14 Holstein calves were sampled to measure their TPI using a digital Brix refractometer. Colostrum samples fed to each of these calves were collected to estimate IgG concentration (colostrum quality) using a digital Brix refractometer and bacterial contamination using the Petrifilm (3M, St. Paul, MN) culture system. Dairy producers completed a questionnaire on colostrum management to assess on-farm practices. The study outcome was the prevalence of adequate TPI calculated based on the proportion of adequate TPI (defined with an individual threshold ≥8.4% Brix) on the total samples tested within each herd. According to the threshold determined in a previous study investigating the influencing colostrum management factors to achieve adequate TPI at the calf level, the prevalence of an adequate colostrum volume fed at first meal (≥2.5 L), the prevalence of adequate colostrum quality (≥24.5% Brix), the prevalence of an adequate time to first feeding (delay between birth and the first colostrum meal, ≤3 h), the prevalence of low aerobic bacterial contamination (≤20,000 cfu/mL), the prevalence of low coliform contamination (≤1,000 cfu/mL), and the prevalence of females were calculated. The herd-level prevalence of adequate TPI ranged from 24% to 100%, with a median of 68%. The median herd prevalences of an adequate colostrum volume fed at first meal, of adequate colostrum quality, of an adequate time to first feeding, of low aerobic bacterial contamination, of low coliform contamination, and of females, were 71, 42, 41, 64, 88, and 61%, respectively. In the final model, the prevalence of adequate TPI was associated with the prevalence of an adequate colostrum volume fed at first meal and the prevalence of an adequate time to first feeding. In summary, management practices varied greatly between farms and influenced the prevalence of adequate TPI.  相似文献   
66.
初乳中低分子量部分的抗炎活性   总被引:9,自引:0,他引:9  
以大鼠足跖肿胀为模型,研究了牛初乳(72 h泌乳混合物)低分子量部分(小于10000)的抗炎作用,研究结果表明,牛初乳乳清10 ku(1 D=1 u)超滤物对角叉莱胶所致的大鼠足跖胀肿具有显著的抑制作用,这一作用具有一定的剂量效应;同时,较高剂量(大于500 mg/kg体重,口胶)的超滤物可以显著降低炎性组织中前列腺素E2(PGE2)的含量.这一结果说明了初乳中含有低分子量的抗炎活性物质,这些物质对新生儿具有一定的生物学意义.  相似文献   
67.
The objective of this study was to identify the critical temperature, at or below which heat-treatment of bovine colostrum would produce no significant changes in viscosity, IgG concentration, or Ig activity. Results of preliminary work, using a Rapid Visco Analyzer (RVA) to heat 50-mL aliquots from 6 unique batches of bovine colostrum at 59, 60, 61, 62, and 63°C, suggested that colostrum could be heated to 60°C for up to 120 min without changing viscosity or IgG concentration. This finding was confirmed by heating 50-mL aliquots from 30 unique batches of colostrum in an RVA for 120 min at 60 and 63°C. Heating colostrum to 63°C resulted in an estimated 34% decrease in IgG concentration and 33% increase in viscosity. However, there was no difference in IgG concentration between preheat-treated (73.4 ± 26.5 mg/mL) and post-heat-treated (74.5 ± 24.3 mg/mL) samples after heating colostrum to 60°C in an RVA for 120 min. Similarly, viscosity was unaffected after heating colostrum to 60°C in an RVA for 120 min. High quality colostrum (≥73.0 mg/mL) suffered greater losses of IgG and greater viscosity changes when heated to 63°C than did moderate quality colostrum (<73.0 mg/mL). However, the effects of colostrum quality were minor if high quality colostrum was only heated to 60°C. The results of a bovine viral diarrhea serum neutralization assay suggested that antibody activity was unchanged after heating colostrum to either 60 or 63°C. However, these results were interpreted as being inconclusive due to a high proportion of missing results because of the congealing of many samples after heat treatment. The results of this study indicate that 50-mL volumes of bovine colostrum can be heat treated at 60°C for up to 120 min in an RVA without affecting IgG concentration or viscosity.  相似文献   
68.
Batches (30-L) of first-milking bovine colostrum, inoculated with Mycoplasma bovis (108 cfu/mL), Listeria monocytogenes (106 cfu/mL), Escherichia coli O157:H7 (106 cfu/mL), Salmonella enteritidis (106 cfu/mL), and Mycobacterium avium subsp. paratuberculosis (Map; 103 cfu/mL), were heat-treated at 60°C for 120 min in a commercial on-farm batch pasteurizer system. Duplicate 50-mL subsamples of colostrum were collected at 15-min intervals throughout the heat-treatment process for the purpose of bacterial culture and for measurement of IgG concentration (mg/mL) and antibody activity [log2(bovine viral diarrhea virus type 1 serum neutralization titer)]. Four replicate batches of colostrum were run for each of the 5 pathogens studied. There was no effect of heating moderate- to high-quality colostrum at 60°C for at least 120 min on mean IgG concentration (pre = 60.5 mg/mL; post = 59.1 mg/mL). Similarly, there was no effect of heat-treatment on the mean log2 bovine viral diarrhea virus type 1 serum neutralization titer (pre = 12.3; post = 12.0). Viable M. bovis, L. monocytogenes, E. coli O157:H7, and S. enteritidis added to colostrum could not be detected after the colostrum was heat-treated at 60°C for 30 min. Average bacteria counts showed that Map was not detected when batches were heated at 60°C for 60 min. Although the authors believe that heat-treating colostrum at 60°C for 60 min should be sufficient to eliminate Map from colostrum in most situations, further research is needed to determine whether these findings may be replicated, given that variability was observed in Map culture results.  相似文献   
69.
A study was conducted to identify the optimal temperature and time at which heat treatment of bovine colostrum would least change viscosity and IgG concentrations yet reduce bacterial count. First-milking colostrum with >50 g of immunoglobulins/L (measured by colostrometer) was collected from 30 Holstein cows. Aliquots of colostrum were heated for 0, 30, 60, or 90 min at 57, 60, or 63°C in a water bath. Samples were examined for viscosity, IgG1, and IgG2 concentrations, standard plate count, coagulase-negative staphylococci, environmental streptococci, coliform, gram-negative noncoliform, Streptococcus agalactiae, and Staphylococcus aureus counts. All heat treatments reduced counts of all bacteria groups measured compared with untreated colostrum samples. Heat treatment at ≥60°C denatured IgG1 compared with untreated colostrum; however, colostral IgG2 levels were not reduced when temperature was held at 60°C for <60 min. Viscosity was not affected when temperature was held at 60°C for <60 min. In this study, heat treatment of bovine colostrum at 60°C for 30 or 60 min reduced bacterial count, slightly reduced IgG concentration, and did not affect viscosity.  相似文献   
70.
BACKGROUND: Colostrum is the breast milk of female mammals produced within in a short time after giving birth. It is thought to protect neonates from infection as well as to facilitate immune system maturation. In this study the effect of bovine colostrum on the proliferation and differentiation of human leukemic U937 cells was investigated to understand more about its immunomodulatory activity. RESULTS: Human mononuclear cells (MNCs) were stimulated with bovine colostrum (CS) and then filtered to obtain a conditioned medium (CM) (CS‐MNC‐CM). CS‐MNC‐CMs prepared with day 1 to day 4 colostrums inhibited U937 cells by 39.4–64.4%. The expressions of surface markers CD11b and CD14 on U937 cells in the treated groups were 30.6–33.5% and 40.0–42.6% respectively. High levels of cytokines IL‐1β, IFN‐γ and TNF‐α were detected in CS‐MNC‐CMs. CONCLUSION: Evidence indicates that colostrums stimulate human MNCs to secrete cytokines IL‐1β, IFN‐γ and TNF‐α which subsequently inhibit the growth of U937 cells and induce their differentiation into mature monocytes and macrophages. There is a possibility for bovine colostrum to be processed into an anti‐leukemia ingredient for use in health foods. Copyright © 2009 Society of Chemical Industry  相似文献   
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