Prediction of Injection-Production Ratio with BP Neural Network

Injection of water to enhance oil production is commonplace, and improvements in understanding the process are economically important. This study examines predictive models of the injection-to-production ratio. Firstly, the error between the fitting and actual injection-production ratio is calculated with such methods as the injection-production ratio and water-oil ratio method, the material balance method, the multiple regression method, the gray theory GM (1,1) model and the back-propogation (BP) neural network method by computer applications in this paper. The relative average errors calculated are respectively 1.67%, 1.08%, 19.2%, 1.38% and 0.88%. Secondly, the reasons for the errors from different prediction methods are analyzed theoretically, indicating that the prediction precision of the BP neural network method is high, and that it has a better self-adaptability, so that it can reflect the internal relationship between the injection-production ratio and the influencing factors. Therefore, the BP neural network method is suitable to the prediction of injection-production ratio.

Yields,growth and water use under chemical topping in relations to row configuration and plant density in drip-irrigated cotton

Background Water deficit is an important problem in agricultural production in arid regions.With the advent of wholly mechanized technology for cotton planting in Xinjiang,it is important to determine which planting mode could achieve high yield,fiber quality and water use efficiency(WUE).This study aimed to explore if chemical topping affected cotton yield,quality and water use in relation to row configuration and plant densities.Results Experiments were carried out in Xinjiang China,in 2020 and 2021 with two topping method,manual topping and chemical topping,two plant densities,low and high,and two row configurations,i.e.,76 cm equal rows and 10+66 cm narrow-wide rows,which were commonly applied in matching harvest machine.Chemical topping increased seed cotton yield,but did not affect cotton fiber quality comparing to traditional manual topping.Under equal row spacing,the WUE in higher density was 62.4%higher than in the lower one.However,under narrow-wide row spacing,the WUE in lower density was 53.3%higher than in higher one(farmers’practice).For machine-harvest cotton in Xinjiang,the optimal row configuration and plant density for chemical topping was narrow-wide rows with 15 plants m-2 or equal rows with 18 plants m-2.Conclusion The plant density recommended in narrow-wide rows was less than farmers’practice and the density in equal rows was moderate with local practice.Our results provide new knowledge on optimizing agronomic managements of machine-harvested cotton for both high yield and water efficient.

Effects of Different Protein Energy Ratios on Fattening Performance,Slaughter Performance and Meat Quality of Pigs

[Objectives]Protein energy ratio refers to the proportional relationship between protein and energy levels in animal diets,i.e.,the grams of crude protein corresponding to every megacalorie of energy,which is generally expressed as CP:ME or CP:DE.This study was conducted to investigate the effects of different diets on fattening and slaughter performance and meat quality traits for"L(Large Yorkshire)×L(Landrace)"crossbred pigs.[Methods]Eighteen piglets of L×L crossbred with similar body weights about 51 kg were selected.The piglets were divided into 3 groups randomly and each group was assigned to 3 replicates with 2 piglets in a replicate.Group A was fed diet Ⅰ (control diet),group B was fed the same diet of group A in the first month of the trial but fed diet Ⅱ in second month,and group C consumed diet Ⅲ.All the pigs were fed in the same feeding condition for two months except the different diets during the trial.One pig in similar body weight from each replicate was slaughtered for the determination of slaughter performance and meat quality traits in the end of the trial.[Results]The average daily feed intake(ADFI)of pigs from group B was only(2.32±0.52)kg and significantly lower than those from group A and group C(P<0.05),but no difference was found in average daily gain(ADG) and feed/gain(P>0.05).Also,no differences occurred in the carcass length,back fat thickness,longissimus muscle (LM) area and dressing percentage(P>0.05).In addition,no differences were found in the meat quality traits of shear force,meat color,pH_(45 min),pH_(24 h) and cooking loss(P>0.05).However,the water-holding capacity of meat from group C was(2.58±0.02)ms and significantly lower than that of(2.80±0.20)ms from group A(P<0.05).Although the contents of glutamic acid and cystine in LM from group B was significantly lower than those from group A and group C(P<0.05),no differences occurred in the contents of other amino acids,the total amino acid and total flavor amino acid among the three groups(P>0.05).However,the inosine monophosphate content of LM from group C was only(331.80±11.53)mg/100 g and significantly lower than those of(361.00±6.36)and(366.37±4.80)mg/100 g from group A and B(P<0.05).Even though no differences were found in the contents of DM and CP in LM among the three groups of pigs,the content of intramuscular fat(IMF)in LM from group B and group C was increased by 45.6%and 46.58%respectively from that of group A(P<0.05),but no difference occurred between group B and C(P>0.05).[Conclusions]DietsⅡ and Ⅲ in this study caused no differences in fattening and slaughter performance of L×L crossbred pigs,but the effects on some meat traits were still significant,especially on the improvement of intramuscular fat in experimental pigs.Therefore,they could improve the meat quality of crossbred pigs to a certain extent.

Assessment of water quality suitability for agriculture in a potentially leachate-contaminated region

Dump sites pose a significant threat to groundwater resources due to the possibility of leachate leakage into the aquifer.This study investigated the impact of leachate on groundwater quality in the southwest region of Zanjan City,Iran,where groundwater is utilized for drinking,agricultural,and industrial purposes.We analyzed 18 parameters of dump site leachate,including physicochemical,heavy metals,and bacterial properties,alongside 13 groundwater samples.Sampling was conducted twice,in November 2020 and June 2021,within a five-kilometer radius of the Zanjan dump site.We utilized the Leachate Pollution Index(LPI)to evaluate potential groundwater contamination by leachate leakage from nearby dumpsite.Additionally,due to the predominant agricultural activities in the study area,various indices were employed to assess groundwater quality for agricultural purposes,such as Sodium Adsorption Ratio(SAR),Soluble Sodium Index(SSI),Kelly Ratio(KR),and Permeability Index(PI).Our analysis revealed no observed contamination related to leachate in the study area according to the LPI results.However,with the persistent pollution threat,implementing sanitary measures at the dump site is crucial to prevent potential impacts on groundwater quality.Moreover,the assessment of groundwater quality adequacy for irrigation yielded satisfactory results for SAR,KR,and PI indices.However,during both the dry(November 2020)and wet seasons(June 2021),the SSP index indicated that 80%of the samples were not classified as excellent,suggesting groundwater may not be suitable for agriculture.Overal,our qualitative study highlights the significant impact of the dry season on groundwater quality in the study area,attributed to elevated concentration levels of the investigated parameters within groundwater sources during the dry season.

Estimation of quality factors by energy ratio method

The quality factor Q, which reflects the energy attenuation of seismic waves in subsurface media, is a diagnostic tool for hydrocarbon detection and reservoir characterization. In this paper, we propose a new Q extraction method based on the energy ratio before and after the wavelet attenuation, named the energy-ratio method（ERM）. The proposed method uses multipoint signal data in the time domain to estimate the wavelet energy without invoking the source wavelet spectrum, which is necessary in conventional Q extraction methods, and is applicable to any source wavelet spectrum; however, it requires high-precision seismic data. Forward zero-offset VSP modeling suggests that the ERM can be used for reliable Q inversion after nonintrinsic attenuation（geometric dispersion, refl ection, and transmission loss） compensation. The application to real zero-offset VSP data shows that the Q values extracted by the ERM and spectral ratio methods are identical, which proves the reliability of the new method.

Effects of dietary protein/energy ratio on growth performance,carcass trait,meat quality,and plasma metabolites in pigs of different genotypes

Background： The protein/energy ratio is important for the production performance and utilization of available feed resources by animals. Increased protein consumption by mammals leads to elevated feed costs and increased nitrogen release into the environment. This study aimed to evaluate the effects of dietary protein/energy ratio on the growth performance, carcass traits, meat quality, and plasma metabolites of pigs of different genotypes. Methods： Bama mini-pigs and Landrace pigs were randomly assigned to two dietary treatment groups （Chinese conventional diet with low protein/energy ratio or National Research Council diet with high protein/energy ratio; n = 24 per treatment） in a 2 x 2 factorial arrangement. Blood and muscle samples were collected at the end of the nursery, growing, and finishing phases. Results： We observed significant interactions （P 〈 0.05） between breed and diet for total fat percentage, intramuscular fat （IMF） content, protein content in biceps femoris （BF） muscle, and plasma urea nitrogen （UN） concentration in the nursery phase; for average daily gain （ADG）, average daily feed intake （ADFI）, dry matter, IMF content in psoas major （PM） muscle, and plasma total protein and albumin concentrations in the growing phase; and for drip loss and plasma UN concentration in the finishing phase. Breed influenced （P 〈 0.05） growth performance, carcass traits, and meat quality, but not plasma metabolites. Throughout the trial, Landrace pigs showed significantly higher （P 〈 0.0_5） ADG, ADFI, dressing percentage, lean mass rate, and loin-eye area than did Bama mini-pigs, but significantly lower （P 〈 0.0.5） feed/gain ratio, fat percentage, backfat thickness, and IMF content. Dietary protein/energy ratio influenced the pH value, chemical composition of BF and PM muscles, and plasma activities of glutamic-pyruvic transaminase and gamma-glutamyl transpeptidase, and plasma concentration of UN. Conclusions： Compared with Landrace pigs, Bama mini-pigs showed slower growth and lower carcass performance, but had better meat quality. Moreover, unlike Landrace pigs, the dietary protein/energy ratio did not affect the growth performance of Bama mini-pigs. These results suggest that, in swine production, low dietary protein/energy ratio may be useful for reducing feed costs and minimizing the adverse effects of ammonia release into the environment.

Effect of carbon and nitrogen ratio control on Artemia growth, water quality, biofloc microbial diversity under high salinity and zero-water exchange culture condition

Biofloc technology has been applied successfully in the intensive aquaculture of several fish and shrimp species. The growth of heterotrophic microorganisms can be stimulated through adding extra carbon, which reduces the nitrogen level in the water and provides microbial protein to the animals. However, most of the studies and practical applications have been conducted in freshwater and marine environment. This paper focused on brine shrimp Artemia that lives in high salinity environment together with other halophilic or halotolerant microorganisms. The effect of carbon supplementation on Artemia growth, water quality, and microbial diversity of biofl ocs was studied in the closed culture condition without any water exchange. The salinity of the culture medium was 100. A 24-d culture trial was conducted through supplementing sucrose at carbon/nitrogen (C/N) ratio of 5, 15, and 30 (Su5, Su15, and Su30), respectively. The culture without adding sucrose was used as a control. Artemia was fed formulated feed at a feeding ration of 60% recommended feeding level. The results showed that sucrose supplementation at higher C/N ratio (15 and 30) signifi cantly improved the Artemia survival, growth and water quality ( P <0.05). Addition of sucrose at C/N ratio of 15 and 30 significantly increased biofloc volume (BFV)( P <0.05). The Illumina MiSeq sequencing analysis showed that supplementing carbon at C/N ratio of 15 had a better total bacterial diversity and richness, and shaped the microbial composition at genera level. This study should provide information for studying the mechanism of biofloc technology and its application in high salinity culture conditions.

Effect of Shoot-Fruit Ratio on Grape Yield,Quality and Storage Nutrient

With the grape variety ＂Summer Black＂ as the test material, the effects of different shoot-fruit ratios on grape yield, fruit quality and grapevine storage nutrient were investigated for 2 consecutive years, so as to determine the optimized load for Summer Black grapes in Shandong. The results showed that the grapes with shoot-fruit ratio of 1∶ 1 had the highest soluble solid content, vitamin C content and grapevine storage nutrient. Based on the comprehensive analysis, the shoot-fruit ratio of 1∶ 1 was the optimized load for Summer Black grapes in Tai an of Shandong Province, and the yield was 1 179.37-1 288.63 kg per 667 m^2.

Injection-production parameters optimization research SAGD production stage

Steam assisted gravity drainage （SAGD） technology has been industrialized popularization and application in our country, according to the characteristics of Xing group I SAGD experimental zone in liaohe oilfield, SAGD production stage injection-production parameters such as the operating pressure, Sub - Cool control, steam injection rate, steam dryness, production factor are studied and selected.

Stability evaluation method of large cross-section tunnel considering modification of thickness-span ratio in mechanized operation

Purpose-This study aims to research the large cross-section tunnel stability evaluation method corrected after considering the thickness-span ratio.Design/methodology/approach-First,taking the Liuyuan Tunnel of Huanggang-Huangmei High-Speed Railway as an example and taking deflection of the third principal stress of the surrounding rock at a vault after tunnel excavation as the criterion,the critical buried depth of the large section tunnel was determined.Then,the strength reduction method was employed to calculate the tunnel safety factor under different rock classes and thickness-span ratios,and mathematical statistics was conducted to identify the relationships of the tunnel safety factor with the thickness-span ratio and the basic quality(BQ)index of the rock for different rock classes.Finally,the influences of thickness-span ratio,groundwater,initial stress of rock and structural attitude factors were considered to obtain the corrected BQ,based on which the stability of a large cross-section tunnel with a depth of more than 100 m during mechanized operation was analyzed.This evaluation method was then applied to Liuyuan Tunnel and Cimushan No.2 Tunnel of Chongqing Urban Expressway for verification.Findings-This study shows that under different rock classes,the tunnel safety factor is a strict power function of the thickness-span ratio,while a linear function of the BQ to some extent.It is more suitable to use the corrected BQ as a quantitative index to evaluate tunnel stability according to the actual conditions of the site.Originality/value-The existing industry standards do not consider the influence of buried depth and span in the evaluation of tunnel stability.The stability evaluation method of large section tunnel considering the correction of overburden span ratio proposed in this paper achieves higher accuracy for the stability evaluation of surrounding rock in a full or large-section mechanized excavation of double line high-speed railway tunnels.

自主研发高分辨盆腔专用线圈在3.0 T磁共振设备成像价值的评估

目的探讨自主研发的16通道高分辨盆腔专用线圈(16C)在3.0 T盆腔MRI中的应用价值。材料和方法前瞻性招募35例行盆腔MRI的患者,分别用16C线圈和32通道的体部线圈(32C)采集相同的轴位和矢状位T2WI序列。比较相同序列图像中第三骶椎、子宫肌层、前列腺外周带、直肠壁和闭孔内肌的信噪比(signal to noise ratio,SNR)及对比噪声比(contrast to noise ratio,CNR)。由两位诊断医师各自对两组图像质量和直肠轴位图像直肠壁分层结构的显示度进行主观评分。结果两组线圈相同序列的T2WI矢状位第三骶椎、子宫肌层、前列腺外周带和轴位闭孔内肌的SNR差异具有统计学意义(P<0.05),矢状位第三骶椎、子宫肌层和轴位直肠壁对肌肉的CNR差异具有统计学意义(P<0.05),16C组高于32C组。两组线圈相同序列的T2WI图像质量主观评价差异具有统计学意义(P<0.05),16C组图像质量更优。在轴位T2WI直肠壁分层结构的显示度评价方面两组图像差异具有统计学意义(P<0.05),16C组更优。结论16C线圈在3.0 T磁共振设备上成像质量更好,更有利于盆腔疾病的诊断。

氮肥运筹对晚播强筋小麦产量及品质的效应

为探索适宜的稻茬晚播小麦高产优质栽培技术,于2019-2021年在晚播条件下(较适播期推迟20 d播种),以强筋小麦扬麦29为材料,设置二因素随机区组试验,探究两种施氮量(210 kg·hm^(-2)和270 kg·hm^(-2))和3种基追比(基肥∶分蘖肥∶拔节肥分别为7∶1∶2、5∶1∶4和3∶3∶4)对晚播强筋小麦籽粒产量和品质的影响及其较优组合。结果表明,施氮量和氮肥基追比对扬麦29籽粒产量的影响均达极显著水平(P<0.01)。施氮量由210 kg·hm^(-2)增至270 kg·hm^(-2),扬麦29穗数、穗粒数及产量增加;随氮肥后移,穗粒数、千粒重、产量均呈增加趋势,其中基追比3∶3∶4处理两年平均产量分别比5∶1∶4和7∶1∶2高2.27%和7.69%。施氮量和氮肥基追比对蛋白质含量、湿面筋含量、面团形成时间、稳定时间、面包体积和面包评分等品质指标有极显著影响,而对籽粒硬度、吸水率、水SRC和蔗糖SRC影响不显著。增加施氮量或氮肥后移有利于提高蛋白质含量、湿面筋含量、面团形成时间、稳定时间、面包体积和面包评分等指标,在270 kg·hm^(-2)施氮量或210 kg·hm^(-2)施氮量、基追比3∶3∶4运筹下的面包评分均大于80分,达到优质强筋小麦标准。综上所述,晚播条件下,强筋小麦扬麦29在施氮量270 kg·hm^(-2)、基肥:壮蘖肥:拔节肥为3∶3∶4可实现产量与品质的协同提高。

斑块质量对沙蒿金叶甲种群特征的影响

黑沙蒿(Artemisia ordosica)是我国西北荒漠沙化区主要的防风固沙植物,对控制土壤沙化、保护和改善生态环境、稳定生态平衡具有非常积极的作用。沙蒿金叶甲是黑沙蒿的一种重要食叶类害虫。试验选取位于宁夏灵武白芨滩国家级自然保护区的古窑子(GYZ-A、GYZ-B)、长流水(CLS)及刘家寨(LJZ)4个黑沙蒿植物斑块,于2020年6月—9月期间调查了不同生境中沙蒿金叶甲的种群数量,分析了不同生境斑块中沙蒿金叶甲的形态学特征、性比差异及环境因子对沙蒿金叶甲种群数量、有虫株率的影响。结果显示不同斑块内沙蒿金叶甲成虫种群数量及有虫株率差异显著(P<0.05),种群数量2.28头·株^(-1)—10.43头·株^(-1)、有虫株率56.02%—90.56%。不同斑块内沙蒿金叶甲成虫雌虫数量均多于雄虫(P<0.05),雌雄性比分别为1.38:1、1.05:1、1.2:1、1.23:1。斑块间沙蒿金叶甲体重(0.03 g—0.05 g)、体长(6.89mm—3.76 mm)、体宽(4.09 mm—4.71 mm)均差异显著(P<0.05)。多元逐步回归分析显示沙蒿金叶甲种群数量、有虫株率与植物的丰富度指数(P<0.05)、沙蒿的长势(P<0.01)、土壤全氮(P<0.05)具有显著相关性。沙蒿的盖度、土壤有机质是影响种群结构特征的关键因子。

CT大重建矩阵联合重建算法对肺结节的诊断价值

目的探讨CT大重建矩阵1024×1024联合Karl迭代重建算法对肺结节的诊断价值。资料与方法前瞻性收集2021年10月—2022年5月于大连医科大学附属第一医院行胸部CT检查的500例患者,对CT扫描图像原始数据进行分组重建。A组采用常规512×512矩阵结合Karl 5级重建;B组采用1024×1024大重建矩阵结合不同等级Karl算法重建,获得B1(Karl 6)、B2(Karl 7)、B3(Karl 8)、B4(Karl 9)4个亚组。测量主动脉弓上方的气管腔内(气管区)及左肺上叶无血管区(肺实质)的CT值和噪声值,计算信噪比。由2位医师评价A、B组肺部总体图像质量。比较B组中图像质量最佳亚组与A组病灶显示情况,依据手术病理结果,分析诊断效能。结果B组组内随Karl等级升高,气管和肺实质标准差值逐渐下降,信噪比逐渐升高(F=675.002~2020.903,P<0.05)。B组各项主观评分均高于A组(Z=-15.361~-6.465,P<0.05),B4组主观评分最高。A组和B4组部分实性结节(≤3 mm)和实性结节(6.1 mm~≤3 cm)显示清晰度差异无统计学意义(Z=-2.000、-0.378,P>0.05);与A组相比,B4组结节显示清晰率提升12%~100%;胸膜凹陷征显示差异无统计学意义(χ^(2)=2.143,P>0.05)。以43例手术病理结果为诊断金标准,B4组诊断准确度为65.12%,优于A组的41.86%(χ^(2)=4.674,P<0.05)。结论大重建矩阵联合Karl算法可以获得较好的图像质量,有利于诊断肺结节。

不同对比剂流速对肝癌患者CT增强扫描图像的影响

目的 探讨不同对比剂流速对肝癌患者CT增强扫描图像的影响。方法 选取2019年1月至2022年12月于医院收治的156例肝癌患者为研究对象,根据随机数字表法分为试验组与对照组,每组78例。所有患者均行CT增强扫描,碘海醇注射液剂量为100 ml,试验组对比剂流速为2.0~2.5 ml/s,对照组对比剂流速为3.5~4.0 ml/s,记录两组不良反应发生情况、影像学特征、辐射剂量与图像质量。结果 试验组不良反应发生率低于对照组(P <0.05);所有患者图像均能显示4~6级肝血管分支;两组图像质量评分比较,差异无统计学意义(P>0.05)。试验组图像信噪比和对比噪声比低于对照组(P<0.05);两组剂量长度乘积与有效剂量比较,差异无统计学意义(P>0.05)。两组动脉期、门脉期、平衡期的病灶检出率比较,差异无统计学意义(P>0.05)。结论 CT增强扫描中对比剂流速降低不会影响图像质量及病灶检出率,且不增加辐射剂量,但可降低不良反应发生率、图像信噪比和对比噪声比。

基于秩和比分档法的护理质量综合评价与影响因素分析模型

目的建立基于秩和比分档法的护理质量综合评价与影响因素分析模型。方法应用基于秩和比分档法分析某三甲医院2018年24个科室11个反映护理质量的合格率评价指标观测值,对24个科室的护理质量进行客观评价,将计算得到的列秩和比进行分档分析,找出影响该院护理质量的因素。结果将该医院护理质量分为5个等级,4个科室属于“差”等级,9个“较差”等级,7个“中等”等级,2个“较好”等级,2个“好”等级。从护理质量的影响因素看,危重护理合格率、病区管理合格率、一级护理合格率、基础护理合格率为高影响程度指标,静疗护理合格率、文件书写合格率为中影响程度指标。结论应用基于秩和比分档法建立的护理质量综合评价与影响因素分析模型简明易懂,原理自明。

荧光粉配比和激发波长对高品质白光LED的影响

随着人们对照明光源品质要求的不断提高,单一的指标参数已不能完全满足对LED的评价。本文研究了荧光粉配比和激发波长对白光LED的显色指数、光谱功率分布的蓝光危害占比指数、光谱连续度和光效等参数的影响。研究发现,合适的荧光粉种类和配比可以降低荧光粉之间的二次吸收、减少能量损失、光线衰减以及光谱的畸变,实现白光LED品质的提升。此外,不同波长蓝光LED激发荧光粉的优势各不相同,通过组合使用,可提高白光LED的显色指数、光谱连续度,降低光谱功率分布的蓝光危害占比指数。本文采用普通商用450 nm和460 nm的蓝光LED芯片激发优化后的荧光粉,显著提高了白光LED的品质,其显色指数、光谱功率分布的蓝光危害占比指数、光谱连续度和光效分别为97.4、26.3%、93.6%和98.75 lm/W。本研究为高品质白光LED的制备提供了完备的参考依据,有利于推动高品质白光LED的普及。

清梳效果的评估与改进

为合理控制纺纱半制品质量、提高成纱品质,详细介绍清梳效果评估的目的、方法及标准,结合实际生产经验及乌斯特公报数据,重点从半制品棉结、杂质、短绒及纤维伸直度等方面对清梳效果进行评估,分析问题及成因,并对梳棉、清梳等重点工序及部位提出改进方法。指出:清梳效果的评估与改进应依据半制品结杂、短绒、伸直度变化规律,分析判断清梳联各工序的清梳效果,结合落棉率的分配及落物对具体问题进行分析,及时调整不达标工序和部位,充分发挥器材专件作用。

不同基质配比对戈壁温室黄瓜生理代谢和产量及品质的影响

基质是黄瓜生长的基础,对其产量品质影响巨大,为得到戈壁温室有机生态型无土栽培中高品质黄瓜生产的最适基质配比,以当前生产中常用基质配比为对照,研究了5种不同配方的基质对黄瓜叶片叶绿素荧光参数及产量品质影响,并比较了不同处理下黄瓜生长生理及产量品质指标。结果表明,采用配方为腐熟牛粪、粉碎玉米秸秆、菌渣、草炭、蛭石体积比为3∶2∶2∶2∶1的基质栽培时,黄瓜叶片最大量子产额(Fv/Fm)与生长潜在活性(Fv/Fo)的值最大,分别为0.76、3.18;黄瓜株高196.15 cm、茎粗0.92 cm、叶片数38.31片、单株结瓜数17.65个、单株产量3.58 kg、折合产量155508.90 kg/hm^(2),均高于其他处理。采用该基质配比时黄瓜果实的Vc含量与可溶性糖含量均最高,分别为167.28、19.83 mg/g FW;硝酸盐含量最低,为78.94μg/g FW。可见,使用腐熟牛粪、粉碎玉米秸秆、菌渣、草炭、蛭石体积比为3∶2∶2∶2∶1的基质配方时黄瓜综合表现最佳,产量及品质最优。

反刍动物日粮精粗比和非纤维性碳水化合物/中性洗涤纤维的研究进展

反刍动物的生长发育受日粮精料水平的影响。日粮精粗比和非纤维性碳水化合物/中性洗涤纤维(NFC/NDF)是反映日粮精料水平的2个常用指标。适宜的精粗比和NFC/NDF可以提高反刍动物的生产性能,维持瘤胃健康,提高经济效益。本文主要综述日粮精粗比和NFC/NDF对反刍动物生产性能、消化代谢和产品品质的影响,以期为反刍动物的日粮配制及健康生产提供参考。