true protein

真正的蛋白质
  • 文章类型: Journal Article
    小麦秸秆含有大量的木质素,阻碍纤维素酶和半纤维素酶的作用,导致动物从秸秆饲料中吸收营养的困难。然而,目前,秸秆的生物处理主要依靠真菌降解,不能直接用于制备家畜饲料。本研究的重点是小麦秸秆的酶共发酵生产高蛋白,低纤维素生物饲料,将木质素降解与饲料生产相结合,从而简化了饲料生产过程。在使用Box-BehnkenDesign对饲料配方进行优化后,添加2.46%的葡萄糖氧化酶,漆酶添加量为3.4%,和丙二酸添加0.6%,本实验制备的麦草饲料的真实蛋白质含量为9.35%。与非发酵状态相比,这增加了四倍,小麦秸秆的木质纤维素降解率达到45.42%。这些结果不仅突出了蛋白质含量的实质性增加,而且强调了木质纤维素分解的显着进步。这种配方显著提高了秸秆饲料的适口性和营养价值,促进秸秆饲料的产业化发展。
    Wheat straw contains a high amount of lignin, hindering the action of cellulase and hemicellulase enzymes, leading to difficulties in nutrient absorption by animals from straw feed. However, currently, the biological treatment of straw relies primarily on fungal degradation and cannot be directly utilized for the preparation of livestock feed. This study focuses on enzymatic co-fermentation of wheat straw to produce high-protein, low-cellulose biological feed, integrating lignin degradation with feed manufacturing, thereby simplifying the feed production process. After the optimization using Box-Behnken Design for the feed formulation, with a glucose oxidase addition of 2.46%, laccase addition of 3.4%, and malonic acid addition of 0.6%, the wheat straw feed prepared in this experiment exhibited a true protein content of 9.35%. This represented a fourfold increase compared to the non-fermented state, and the lignocellulose degradation rate of wheat straw reached 45.42%. These results not only highlight the substantial enhancement in protein content but also underscore the significant advancement in lignocellulose breakdown. This formulation significantly enhanced the palatability and nutritional value of the straw feed, contributing to the industrial development of straw feed.
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  • 文章类型: Journal Article
    目的是评估瘤胃后吸收尿素在补充季节性牧场饲养的生长Nellore牛中的作用。对于这项研究,进行了两个实验。在实验1中,使用八只瘤胃插管的Nellore公牛评估了瘤胃和血液参数,其初始体重(BW)为763±44kg,分布在4×4的双拉丁正方形中。在实验2中,使用120辆初始BW为380±35kg的Nellore舵机进行性能评估,分布在随机区组设计(阻断因子或初始BW)中。评估的处理方法为1:(TP-U)(对照)=补充24%含尿素的粗蛋白(CP)作为非蛋白氮(NPN;3%)和豆粕的来源,2:(TP-PRU)=24%CP补充剂含有瘤胃后尿素(PRU;3.6%)和豆粕;3:(NPN-U-PRU)=24%CP补充剂含有尿素+瘤胃后尿素(U=3%,PRU=3.9%),不含豆粕;4:(NPN-PRU)=补充24%CP,含有瘤胃后尿素(7.5%),没有豆粕。补充剂以每只动物3克/千克体重提供,daily,一天一次.所有动物都饲养在Urochloabrizanthacv上。Marandu牧场.使用SASPROCMIXED进行统计分析,并通过以下对比评估数据:C1=TP-U/TP-PRUvs.NPN-U-PRU/NPN-PRU(NPN替代豆粕);C2=TP-Uvs.TP-PRU(常规尿素与免疫后尿素);C3=NPN-U-PRUvs.NPN-PRU(瘤胃后尿素-PRU水平低和高)。干物质的消化率,有机物,当豆粕被非蛋白氮替代时,NDF较低,补品中使用的瘤胃后尿素水平也不同。当大豆粉被NPN替代时,瘤胃pH是不同的(p=0.003)。短链脂肪酸的总浓度,异丁酸的浓度(p=0.003),戊酸(p=0.001),和异戊酸(p=0.001)是不同的,当豆粕被NPN替代时,血液尿素有所不同(p=0.006)。在补充TP-U的动物瘤胃中,辛普森的多样性指数高于补充TP-PRU的动物(p=0.05)。共27门,234个家庭,并鉴定了488属。仅在补充有TP-PRU的牛的瘤胃中就检测到了Nitrosirota和Gemmaatimonadota。性能(最终BW,动物的体重增加和每面积的增加)是不同的,在补充大豆粉的动物中更高(p=0.04),与NPN相比。从补充剂中去除豆粕并用常规尿素加瘤胃后尿素或仅瘤胃后尿素代替豆粕会损害动物的性能。瘤胃后尿素包合水平越低,干物质的表观消化率越低,有机物,NDF,与补充较高水平的动物相比。
    The objective was to evaluate the effects of urea with post-ruminal absorption in the supplementation of growing Nellore cattle reared on pasture during a seasonal period. For the study, two experiments were conducted. In experiment 1, rumen and blood parameters were evaluated using eight rumen-cannulated Nellore bulls with initial body weight (BW) of 763 ± 44 kg, distributed in a double Latin square 4 × 4. In experiment 2, 120 Nellore steers with initial BW of 380 ± 35 kg were used for performance evaluation, distributed in a randomized block design (blocking factor or initial BW). The evaluated treatments were 1: (TP-U) (control) = supplement with 24% crude protein (CP) containing urea as a source of non-protein nitrogen (NPN; 3%) and soybean meal, 2: (TP-PRU) = 24% CP supplement containing post-ruminal urea (PRU; 3.6%) and soybean meal; 3: (NPN-U-PRU) = 24% CP supplement containing urea + post-ruminal urea (U = 3% and PRU = 3.9%), without soybean meal; 4: (NPN-PRU) = supplement with 24% CP containing post-ruminal urea (7.5%), without soybean meal. The supplement was offered at 3 g/kg BW per animal, daily, once a day. All animals were kept on Urochloa brizantha cv. Marandu pasture. Statistical analyses were performed using the SAS PROC MIXED, and the data were evaluated by the following contrasts: C1 = TP-U/TP-PRU vs. NPN-U-PRU/NPN-PRU (Soybean meal replacement by NPN); C2 = TP-U vs. TP-PRU (conventional urea vs. post-immune urea); C3 = NPN-U-PRU vs. NPN-PRU (low and high post-ruminal urea-PRU level). The digestibility of dry matter, organic matter, and NDF was lower when soybean meal was replaced by non-protein nitrogen, also being different between the levels of post-ruminal urea used in the supplement. Ruminal pH was different when soybean meal was replaced by NPN (p = 0.003). Total concentration of short-chain fatty acids, concentrations of isobutyrate (p = 0.003), valerate (p = 0.001), and isovalerate (p = 0.001) were different, and blood urea was different when soybean meal was replaced by NPN (p = 0.006). Simpson\'s diversity index was higher in the rumen of animals supplemented with TP-U than in those supplemented with TP-PRU (p = 0.05). A total of 27 phyla, 234 families, and 488 genera were identified. Nitrospirota and Gemmatimonadota phyla were detected just in the rumen of steers supplemented with TP-PRU. The performance (final BW, weight gain and gain per area) of the animals was different, being higher (p = 0.04) in animals supplemented with soybean meal, compared to NPN. The removal of soybean meal from the supplement and its replacement with either conventional urea plus post-ruminal urea or only post-ruminal urea compromises the performance of the animals. The lower the post-ruminal urea inclusion level, the lower the apparent digestibility of dry matter, organic matter, and NDF, when compared to animals supplemented with higher levels.
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  • 文章类型: Journal Article
    Moringa oleifera Lam. (MO) is a fast-growing multi-purpose deciduous tree with high biomass and nutritional value. However, the presence of antinutritional factors, poor palatability, and indigestibility of Moringa oleifera leaf meal (MOLM) restrict its application to animal feed. This study aimed to obtain high-quality protein feeds via solid-state fermentation (SSF) of MOLM. The process conditions for increasing the true protein (TP) content using Aspergillus niger, Candida utilis and Bacillus subtilis co-cultures were optimized, and the chemical composition of MOLM was compared before and after fermentation. The results of this study showed that the highest TP content could be obtained through mixed-strain culture of A. niger, C. utilis and B. subtilis at a ratio of 1:1:2. The MOLM was inoculated with A. niger, followed by C. utilis and B. subtilis 24 h later. The optimized co-culture parameters were as follows: total inoculation size, 24%; temperature, 32 °C; fermentation time, 6.5 days; and initial water content, 60%. The maximum TP yield was 28.37%. Notably, in the fermented MOLM (FMOLM), the content of nutrients such as crude protein (CP), small peptides, and total amino acids (AAs) were significantly increased relative to unfermented MOLM, whereas the contents of crude fiber (CF), tannin, and phytic acid were significantly decreased. MOLM analysis using scanning electron microscopy (SEM) revealed that SSF disrupted the surface structure of MOLM, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) indicated that macromolecular proteins were degraded. The in vitro protein digestibility (IVPD) of FMOLM was also improved significantly. Our findings suggest that multi-strain fermentation with A. niger, C. utilis and B. subtilis improves the nutritional quality of MOLM, rendering it a viable functional feedstuff for use in livestock industries in the future.
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  • 文章类型: Journal Article
    随着世界范围内对动物蛋白的需求不断增加,昆虫正在成为肉类蛋白质替代品的一种有希望的可持续选择。然而,当计算为“粗蛋白”=6.25×氮含量(N)时,报告的昆虫蛋白质含量通常被高估,与从氨基酸(AA)残基总和定量的真实蛋白质含量相比。在这项研究中,根据真实蛋白质/总氮和真实蛋白质/蛋白质氮确定了通常的两种类型的氮到蛋白质转换因子kp和kA,分别,重点是在瑞士食品市场上合法出售的三种昆虫。墨虫(粉虫幼虫),A.domesticus(房屋of),和L.migratoria(蝗虫)从不同的育种者进行了分析的总氮和酰胺氮,甲壳素,和AA成分。对掺入蛋白质标准品的昆虫样品进行了仔细的对照实验,以建立真正蛋白质的回收率,这是>95%优秀。粉虫,板球,蝗虫表现出相似的AA谱和51、55和47g/100g(干重)的真实蛋白质含量,分别。特定转换因子kp显示三种昆虫之间的变异性很小,粉虫分别为5.41、5.25和5.33,板球,还有蝗虫,分别,并确认使用6.25×N时蛋白质含量平均高估了约17%。提取的文献数据支持确定的平均kp为5.33,建议一般使用代替6.25×N,以计算更准确的昆虫蛋白质含量,而建议在昆虫蛋白分离株的情况下使用平均纯蛋白转换因子kA为5.6。
    With an increasing worldwide demand for animal protein, insects are becoming a promising sustainable option for meat protein replacement. However, reported protein contents of insects are often overestimated when calculated as \"crude protein\" = 6.25 × nitrogen content (N), compared to true protein contents quantified from the sum of amino acid (AA) residues. In this study, the main two types of usual nitrogen-to-protein conversion factors k p and k A were determined on the basis of true protein/total nitrogen and true protein/protein nitrogen, respectively, with focus on the three insect species legally sold on the Swiss food market. T. molitor (mealworm larvae), A. domesticus (house crickets), and L. migratoria (locusts) from various breeders were analyzed for total and amide nitrogen, chitin, and AA composition. Careful control experiments of insect samples spiked with a protein standard were conducted to establish the recovery of true protein, which was with >95% excellent. Mealworms, crickets, and locusts exhibited similar AA-profiles and true protein contents of 51, 55, and 47 g/100 g (dry weight basis), respectively. Specific conversion factors k p showed little variability between the three insect species with 5.41, 5.25, and 5.33 for mealworms, crickets, and locusts, respectively, and confirmed an average ~17% overestimation of protein contents when using 6.25 × N. The determined average k p of 5.33 is supported by extracted literature data and is suggested for general use instead of 6.25 × N to calculate more accurate insect protein contents, whereas the average pure protein conversion factor k A of 5.6 is proposed for use in the case of insect protein isolates.
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  • 文章类型: Journal Article
    Multi-strain mixed fermentation can provide a relatively complete lignocellulosic enzyme system compared with single-strain fermentation. This study was firstly to screen strains which have a strong ability to hydrolyse rice straw (RS) enzymatically and enrich true protein (TP). Then, the conditions in the process of SSF, including the optimum inoculum size of mixed strains, inoculation ratio, and different inoculation time of N. crassa 14-8, were optimized. The experimental results showed that the highest TP content could be obtained by using N. crassa 14-8, C. utilis, and P. chrysosporium as mixed strains, and 5 mM Mn2+ and 50 mM veratryl alcohol were used as inducers of lignin peroxidase (LiP) to improve the efficiency of enzymatic hydrolysis. When N. crassa 14-8 was inoculated 1 day later than P. chrysosporium, the total inoculum size was 10%, and the optimum ratio of N. crassa 14-8 to P. chrysosporium was 1:2, the maximum TP yield (8.89%) was obtained, with 123.37% of its increase rate. This work proposed a technique with potential application in large-scale feedstuff protein conversion.
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  • 文章类型: Journal Article
    This study investigated the effect of cation optimization by mixed cultures of Neurospora crassa and Candida utilis on the true protein (TP) content. Firstly, to enhance the nutritional contents of rice straw (RS), two fermentation parameters (effect of inoculation ratio and inoculation time) were optimized. It was found that when C. utilis was inoculated 60 h later than N. crassa with the inoculation ratio of 1:5 (N. crassa to C. utilis), the maximum TP yield was obtained. In order to further optimize TP content, Plackett-Burman design (PBD) and Box-Behnken design (BBD) of response surface methodology (RSM) were adopted. The results of PBD indicated that Mn2+, Zn2+, and Cu2+ were the significant variables. The optimum values for the three cations determined by the BBD were as follows: Mn2+ 0.06 g/L, Zn2+ 0.15 g/L, and Cu2+ 0.2 g/L. After the optimization of RSM, a model was proposed to predict the optimum value 10.36% confirmed by the experimental result 9.84%. The TP content increased from 3.98 to 9.84%, with 147.24% of its increase rate. This study proposed an ecofriendly and economical way to convert RS into protein-enriched livestock feed.
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  • 文章类型: Journal Article
    This study investigated the relationship of management practices, dietary characteristics, milk composition, and lactation performance with de novo fatty acid (FA) concentration in bulk tank milk from commercial dairy farms with Holstein, Jersey, and mixed-breed cows. It was hypothesized that farms with higher de novo milk FA concentrations would more commonly use management and nutrition practices known to optimize ruminal conditions that enhance de novo synthesis of milk FA. Farms (n=44) located in Vermont and northeastern New York were selected based on a history of high de novo (HDN; 26.18±0.94g/100g of FA; mean ± standard deviation) or low de novo (LDN; 24.19±1.22g/100g of FA) FA in bulk tank milk. Management practices were assessed during one visit to each farm in March or April, 2014. Total mixed ration samples were collected and analyzed for chemical composition using near infrared spectroscopy. We found no differences in days in milk at the farm level. Yield of milk fat, true protein, and de novo FA per cow per day were higher for HDN versus LDN farms. The HDN farms had lower freestall stocking density (cows/stall) than LDN farms. Additionally, tiestall feeding frequency was higher for HDN than LDN farms. No differences between HDN and LDN farms were detected for dietary dry matter, crude protein, neutral detergent fiber, starch, or percentage of forage in the diet. However, dietary ether extract was lower for HDN than LDN farms. This research indicates that overcrowded freestalls, reduced feeding frequency, and greater dietary ether extract content are associated with lower de novo FA synthesis and reduced milk fat and true protein yields on commercial dairy farms.
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  • 文章类型: Review
    任何来源的蛋白质含量都是通过Kjeldahl方法对其100多年的氮含量进行分析来确定的,并将获得的结果乘以称为氮转换因子(NCF)的数字。NCF的值与蛋白质源的氨基酸组成以及与蛋白质链的一些氨基酸共价结合的侧基的最终存在有关。因此,所有食物蛋白质来源的NCF值不能相同。本文的目的是回顾有关婴儿食品配方中两种允许的蛋白质来源的可用知识,牛奶和大豆,以便为修订欧洲立法和婴儿配方食品法典标准提供正确的科学依据。
    Protein content of any source is classically determined through the analysis of its nitrogen content done for more 100 years by the Kjeldahl method, and the obtained result is multiplied by a number named nitrogen conversion factor (NCF). The value of NCF is related to the amino acid composition of the protein source and to the eventual presence of side groups covalently bound to some amino acids of the protein chain. Consequently, the value of NCF cannot be identical for all sources of food proteins. The aim of this paper is to review the available knowledge on the two allowed protein sources for infant food formulas, milk and soybean, in order to bring the right scientific basis which should be used for the revision of both European legislation and Codex Standard for Infant Formulas.
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  • 文章类型: Journal Article
    The objective of this study was to determine the possibility of using molecular spectroscopy with multivariate technique as a fast method to detect the source effects among original feedstock sources of wheat and their corresponding co-products, wheat DDGS, from bioethanol production. Different sources of the bioethanol feedstock and their corresponding bioethanol co-products, three samples per source, were collected from the same newly-built bioethanol plant with current bioethanol processing technology. Multivariate molecular spectral analyses were carried out using agglomerative hierarchical cluster analysis (AHCA) and principal component analysis (PCA). The molecular spectral data of different feedstock sources and their corresponding co-products were compared at four different regions of ca. 1800-1725 cm(-1) (carbonyl CO ester, mainly related to lipid structure conformation), ca. 1725-1482 cm(-1) (amide I and amide II region mainly related to protein structure conformation), ca. 1482-1180 cm(-1) (mainly associated with structural carbohydrate) and ca. 1180-800 cm(-1) (mainly related to carbohydrates) in complex plant-based system. The results showed that the molecular spectroscopy with multivariate technique could reveal the structural differences among the bioethanol feedstock sources and among their corresponding co-products. The AHCA and PCA analyses were able to distinguish the molecular structure differences associated with chemical functional groups among the different sources of the feedstock and their corresponding co-products. The molecular spectral differences indicated the differences in functional, biomolecular and biopolymer groups which were confirmed by wet chemical analysis. These biomolecular and biopolymer structural differences were associated with chemical and nutrient profiles and nutrient utilization and availability. Molecular spectral analyses had the potential to identify molecular structure difference among bioethanol feedstock sources and their corresponding co-products.
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