共查询到13条相似文献,搜索用时 0 毫秒
1.
The detrimental effect of bluetongue virus serotype 8 (BTV-8) on fertility was quantified in seroconverting cows. Although the effect on individual cows provides information regarding the potential biological burden of infection, losses at a herd level are also dependent on the proportion of infected cows within the herd. The objectives of this study were to quantify the average effect of BTV-8 exposure in field conditions on the fertility of dairy cows in previously naïve herds, and to determine the at-risk period of decreased fertility related to the date of detection of the disease in the herd. The effect of BTV-8 exposure on fertility was assessed using the 90-d-return-to-service rates after the first artificial insemination (AI) calculated for cows in exposed herds (during the 2007 epizootic in France) and compared with that for cows in unexposed herds. Only herds with a confirmed detection that were reported after clinical suspicion were included. To determine the at-risk period of decreased fertility, variations of fertility in exposed herds were quantified according to the time interval between the date of AI for individual cows and the date that disease was detected in the herd. Survival analyses were used to assess the risk of decreased fertility associated with BTV-8 exposure, adjusting for the main factors known to influence fertility. The episode at risk for decreased fertility depended on the month of disease detection in the herd. For herds detected early in the epizootic, fertility was decreased for cows inseminated from 1 mo before to 1 mo after the date of disease detection in the herd. Depending on time interval between the date of AI of cows and the date of detection in the herd, the increase of return-to-service rate associated with BTV-8 exposure varied from 8 to 21 percentage points of 90-d return to service. The episode of decreased fertility is likely due to a combination of the effect of the infection at different stages of conception and early pregnancy and the delayed exposure of cows due to the spreading of the virus within herds. For herds detected during the second half of the epizootic, fertility was decreased for cows inseminated more than 2 mo before detection, which suggests a delay in the detection of clinical signs following virus introduction in the herd. No correlation was observed between the effect of BTV-8 exposure on fertility and the incidence of BTV-8 in the local geographical area. Given the duration of the period that cows were at risk for decreased fertility and the magnitude of the effect, the average BTV-8 exposure in naïve herds led to major losses. 相似文献
2.
Anas AI-Nabulsi Reyad Shaker Tareq Osaili Mahmoud Al-Taani Amin Olaimat Saddam Awaisheh Aisha Abushelaibi Richard Holley 《食品科学与工程:英文版(2...》2014,(1):27-35
Soy yogurt has gained significant popularity due to its nutritional health benefits. The objectives of this study were to develop flavored yogurt from soybean milk with reduced soy aftertaste by the addition of 30% (wt/wt) strawberry or orange jam in conjunction with a lactic acid fermentation. Soy milk-based yogurt products were assessed for microbial quality and for acceptability by a panel of Jordanian and Malaysian consumers. Sixty-one individuals, of whom 75.4% (n = 46) were Jordanian and 24.6% (n = 15) were Malaysian, evaluated the plain and flavored soy milk-based yogurt. The overall acceptability of orange and strawberry soy yogurt was rated significantly higher than plain soy yogurt. In general, the orange and strawberry soy yogurt received higher sensory ratings from Malaysian than Jordanian consumers. In addition, formulations with orange jam received higher scores than those flavored with strawberry. Shelf life tests showed that soy yogurt was acceptable for at least 8 d without perceptible spoilage. Therefore, the approach used yielded flavored products with better acceptability and improved sensory attributes, including decreased intensity of off flavor, with suitable shelf life at 4 ℃. 相似文献
3.
Piyada Songsermsakul Endo Pornphairin Supatra Porasuphatana 《International Journal of Food Properties》2013,16(3):643-648
Antioxidant activity of a potent antioxidant, grape seed extract, and fruits containing high β-carotene, vitamin C, and vitamin E was measured and compared by 2,2-diphengl-1-picrylhydrazyl radical and ferric reducing antioxidant power assay. The results showed that antioxidant activity of a 20-mg capsule of grape seed extract was approximately 10 to 20 times greater than 1 g of tomato, papaya, banana, and mango. However, if antioxidant activity was calculated per fruit or piece of fruit, the values were comparable. Therefore, consumption of fruit could be a cost-effective way of healthy eating when the price of a dietary supplement is relatively high. 相似文献
4.
《Food chemistry》1986,21(2):83-92
The relationship between lipophilicity, structure and bitterness of phenyl β-d-glucopyranosides and their methyl ether derivatives was examined quantitatively using lipophilic and STERIMOL parameters, and selected indicator variables to assess position-specific substituent effects. The results indicate that the partial lipophilicity of the methoxyl groups is different for each substituent position of the glucose moiety and that the lipophilicity of a methoxyl group at position 2 is the largest. The results also show that the bitterness of phenyl β-d-glucopyranosides is determined primarily by the presence or absence of the methoxyl group at position 2 of the glucose moiety, not by the lipophilicity of the entire molecule. 相似文献
5.
Schuster JK Gioia R Moeckel C Agarwal T Bucheli TD Breivik K Steinnes E Jones KC 《Environmental science & technology》2011,45(17):7291-7297
Background soils were collected from 70 locations on a latitudinal transect in the United Kingdom and Norway in 2008, ten years after they had first been sampled in 1998. The soils were analyzed for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (OCs), to see whether there had been any change in the loadings or distributions of these persistent organic pollutants (POPs). The same transect has also been used to sample air between the mid-1990s and the present, so the air and soil spatial and temporal trends provide information on air-soil transfers, source-receptor relationships, long-range atmospheric transport (LRAT), and recycling phenomena. Comparisons of the 2008 and 1998 data sets show a general decline for PBDEs in surface soil, and a smaller averaged net decline of PCBs. Changes between the years were observed for total POP concentrations in soil and also for correlations with site and sample characteristics assumed to affect those concentrations. POP concentrations were correlated to distance and strength of possible sources, a relationship that became weaker in the 2008 data. Fractionation, a commonly discussed process for the global cycling of POPs was also lost in the 2008 data. As in 1998, soil organic matter content continues to have a strong influence on the loadings of POPs in surface soils, but changes in the PCB loads were noted. These factors indicate an approach to air-surface soil equilibrium and a lessening of the influence of primary sources on POP concentrations in soil between 1998 and 2008. 相似文献
6.
Comparison of structure and performance of Tianzhu white yak dress hair,tail hair and human hair北大核心
In order to provide a scientific basis to develop and utilize the tail hair and dress hair of the Tianzhu white yak, the hair fiber structure and the similarities and differences of Tianzhu white yak was compared with human hair. Using optical microscopy, scanning electron microscopy, and ultrastructure of the performance of the amino acid analyzer, spectrum analyzer, the Tianzhu White yak dress hair, tail hair and human hair were observed. The results showed that the range of the tail hair, dress hair and human hair fiber fineness are from 52. 5 pun to 109. 8 pim, the content of the marrow wool is 1. 8% to 17% ; the breaking force and elongation of the single fiber is greater than or equal to 60cN and 50% , respectively, three fibers are composed of 18 kinds of amino acids. The scales were arranged like clutter and the cross-section is oval or nearly circular. The performance and structure of the dress hair and tail hair of the Tianzhu white yak is similar to the human hair, the dress hair is more similar to the human hair, the is an ideal raw material, which to produce the ideal of high-end wig and suit lining raw materials. 相似文献
7.
Jin-Song He Tai-Hua Mu Xishan Guo Songming Zhu Norihiro Azuma Choemon Kanno 《Food Hydrocolloids》2013
α-Lactalbumin (α-La) and lysozyme (LZM) each contain four disulfide bonds but no free SH group, whereas myoglobin (Mb) possesses no disulfide bond or free SH group. In this work, the pressure-induced gelation of α-La, LZM and Mb in the absence and in the presence of β-lactoglobulin (β-Lg) was studied. Solutions of α-La, LZM and Mb (1–24%, w/v) did not form a gel when subjected to a pressure of 800 MPa and circular dichroism analysis revealed that both α-La and LZM are pressure-resistant proteins. In the presence of β-Lg (5%, w/v), however, a pressure-induced gel formed for α-La and LZM (each 15%, w/v) but not for Mb (15%, w/v). One- and two-dimensional SDS-PAGE demonstrated the disulfide cross-linking of proteins was responsible for the gelation. Although α-La and LZM are homologous and have the same disulfide bond arrangement, the texture and appearance of the gels formed from α-La/β-Lg and LZM/β-Lg were markedly different even when induced under the same experimental conditions. Microscopic analysis indicated that phase separation occurs during the gelation of LZM/β-Lg but not during the gelation of α-La/β-Lg. NMR relaxation measurement revealed that the association of water molecules with the protein matrix in the α-La/β-Lg gel is tighter compared to that in the LZM/β-Lg gel. These results indicate that the gel-forming ability of a globular protein under high pressure is related to the primary structure of the protein, and that the gel properties depend on the cross-linking reaction and on the phase behavior of protein dispersion under high pressure. 相似文献
8.
G Su RF Brøndum P Ma B Guldbrandtsen GP Aamand MS Lund 《Journal of dairy science》2012,95(8):4657-4665
This study investigated genomic prediction using medium-density (~54,000; 54K) and high-density marker panels (~777,000; 777K), based on data from Nordic Holstein and Red Dairy Cattle (RDC). The Holstein data comprised 4,539 progeny-tested bulls, and the RDC data 4,403 progeny-tested bulls. The data were divided into reference data and test data using October 1, 2001, as a cut-off date (birth date of the bulls). This resulted in about 25% genotyped bulls in the Holstein test data and 20% in the RDC test data. For each breed, 3 data sets of markers were used to predict breeding values: (1) 54K data set with missing genotypes, (2) 54K data set where missing genotypes were imputed, and (3) imputed high-density (HD) marker data set created by imputing the 54K data to the HD data based on 557 bulls genotyped using a 777K single nucleotide polymorphism chip in Holstein, and 706 bulls in RDC. Based on the 3 marker data sets, direct genomic breeding values (DGV) for protein, fertility, and udder health were predicted using a genomic BLUP model (GBLUP) and a Bayesian mixture model with 2 normal distributions. Reliability of DGV was measured as squared correlations between deregressed proofs (DRP) and DGV corrected for reliability of DRP. Unbiasedness was assessed by regression of DRP on DGV, based on the bulls in the test data sets. Averaged over the 3 traits, reliability of DGV based on the HD markers was 0.5% higher than that based on the 54K data in Holstein, and 1.0% higher than that in RDC. In addition, the HD markers led to an improvement of unbiasedness of DGV. The Bayesian mixture model led to 0.5% higher reliability than the GBLUP model in Holstein, but not in RDC. Imputing missing genotypes in the 54K marker data did not improve genomic predictions for most of the traits. 相似文献
9.
Wang G Kawamura K Cheng C Li J Cao J Zhang R Zhang T Liu S Zhao Z 《Environmental science & technology》2012,46(9):4783-4791
Size-resolved airborne particles (9-stages) in urban Xi'an, China, during summer and winter were measured for molecular distributions and stable carbon isotopic compositions of dicarboxylic acids, ketocarboxylic acids, and α-dicarbonyls. To our best knowledge, we report for the first time the size-resolved differences in stable carbon isotopic compositions of diacids and related compounds in continental organic aerosols. High ambient concentrations of terephthalic (tPh, 379 ± 200 ng m(-3)) and glyoxylic acids (ωC(2), 235 ± 134 ng m(-3)) in Xi'an aerosols during winter compared to those in other Chinese cities suggest significant emissions from plastic waste burning and coal combustions. Most of the target compounds are enriched in the fine mode (<2.1 μm) in both seasons peaking at 0.7-2.1 μm. However, summertime concentrations of malonic (C(3)), succinic (C(4)), azelaic (C(9)), phthalic (Ph), pyruvic (Pyr), 4-oxobutanoic (ωC(4)), and 9-oxononanoic (ωC(9)) acids, and glyoxal (Gly) in the coarse mode (>2.1 μm) are comparable to and even higher than those in the fine mode (<2.1 μm). Stable carbon isotopic compositions of the major organics are higher in winter than in summer, except oxalic acid (C(2)), ωC(4), and Ph. δ(13)C of C(2) showed a clear difference in sizes during summer, with higher values in fine mode (ranging from -22.8‰ to -21.9‰) and lower values in coarse mode (-27.1‰ to -23.6‰). The lower δ(13)C of C(2) in coarse particles indicate that coarse mode of the compound originates from evaporation from fine mode and subsequent condensation/adsorption onto pre-existing coarse particles. Positive linear correlations of C(2), sulfate and ωC(2) and their δ(13)C values suggest that ωC(2) is a key intermediate, which is formed in aqueous-phase via photooxidation of precursors (e.g., Gly and Pyr), followed by a further oxidation to produce C(2). 相似文献
10.
S. Ivemeyer C. Simantke A. Ebinghaus P.H. Poulsen J.T. Sorensen T. Rousing R. Palme U. Knierim 《Journal of dairy science》2018,101(8):7361-7374
Impact patterns of human–animal relationship (HAR) and herd stress level on udder health were investigated in a cross-sectional study on 30 German and Danish organic dairy herds also taking into account influencing factors regarding housing and management. Cow behavior (avoidance distance, tolerance to tactile interaction, release behavior) was assessed in tests, milkers' behavior recorded during milking, and information about contacts with animals during routine work gathered by interview. Additionally, stockpersons' attitudes were recorded via questionnaires. Fecal cortisol metabolites were measured in approximately 30 focal cows on each farm and used as a proxy to determine the level of distress within the herd. Management and housing were assessed on-farm. The following herd udder health indicators were calculated: the prevalence of mastitis quarters (≥100,000 cells/mL), and, from milk recording data over 1 yr retrospectively, the average somatic cell score and the self-cure rates during lactation per herd. Multivariable regression models with stepwise selection were calculated at herd level. The following HAR-related factors were associated with better udder health (in at least 1 of the final models): stockpersons' higher agreement on patience being important when moving the cows and on necessary contact to cows being pleasant, higher amount of positive interactions with cows during milking, more docile cows in the release behavior test, no routine change of milkers, more contact time during routine work, no active heifer habituation to milking, and performance of barn controls beyond routine work. Lower fecal cortisol metabolite levels were related to higher self-cure rates during lactation. Concerning housing, management, and herd characteristics, the following known factors were related to impaired udder health for at least 1 of the indicators: straw yards, automatic milking system, higher average lactation number, and less antibiotic udder treatments. The results confirm earlier findings that HAR is associated with udder health and should therefore be considered in future research and mastitis control programs. First indications of negative associations between herd stress level and mastitis curing capacity should be followed up in future studies. 相似文献
11.
The lignans isolariciresinol, medioresinol, matairesinol, pinoresinol, secoisolariciresinol and syringaresinol were detected and quantified for the first time in pomegranate (Punica granatum L.) and in commercial pomegranate juices by means of GC–MS. The total lignan content in the different plant parts was estimated as follows: 36.1 ± 0.3 μg/g in seeds, 17.8 ± 0.2 μg/g in wood knots, 11.2 ± 0.2 μg/g in fruit pulp, 3.3 ± 0.1 μg/g in endocarp. Secondary metabolite distribution varied greatly in the evaluated samples, with syringaresinol being the most abundant contributor in seeds (23.5 ± 0.4 μg/g) and pinoresinol in knots, pulp, endocarp and juice (8.9 ± 0.3, 7.4 ± 0.2, 3.3 ± 0.1 and 2.1 ± 0.2 μg/g, respectively). A survey on two concentrated juices and three commercial pomegranate beverages evidenced the presence of lignans in all of them, with values ranging from 0.4 ± 0.1 to 4.4 ± 0.1 μg/g. Lignans may be relevant contributors to the purported dietary beneficial properties of pomegranate juice and their considerable abundance in agro-industrial waste materials could render P. granatum by-products an inexpensive and renewable natural source of these healthy compounds. 相似文献
12.
Whey proteins are widely used food ingredients due to their nutritional and functional properties (gelling, emulsifying, foaming). Owning to their structure (free thiol group, lysine residues, hydrophobic pocket), they can also be used as carriers for bioactives. In this study, conjugates between β-lactoglobulin (β-lg), and a bioactive metabolite from Brassicaceae vegetables, allyl isothiocyanate (AITC) were formed. Heat aggregation behavior (85 °C, 15 min), foaming and emulsifying properties of conjugates, at pH 4.0 and 7.1, were evaluated. 相似文献
13.
Objective colour evaluation was determined for 33 samples of “chorizo de Pamplona” using the CIE L*a*b* and the Hunter system with two illuminants (D65 and C). Highly significant differences between the measures obtained with the two illuminants were found for the three colour co-ordinates (L*a*b* and Lab) in both systems. The highest coefficient of variation in b was with the Hunter system and in a was with the CIE L*a*b* system, suggesting that the CIE system is better for separating samples according to yellowness, while the Hunter system is better for separating samples according to redness. Correlations with sensory evaluation were similar for both systems and illuminants, the lowest values being for yellowness. 相似文献