Loading...

Table of Content

    16 January 2020, Volume 53 Issue 2
    Crop Genetics & Breeding·Germplasm Resources·Molecular Genetics
    QTL Mapping for Grain Size Related Traits Based on a High-Density Map in Rice
    ZHANG Jian,YANG Jing,WANG Hao,LI DongXiu,YANG GuiLi,HUANG CuiHong,ZHOU DanHua,GUO Tao,CHEN ZhiQiang,WANG Hui
    Scientia Agricultura Sinica. 2020, 53(2):  225-238.  doi:10.3864/j.issn.0578-1752.2020.02.001
    Abstract ( 396 )   HTML ( 44 )   PDF (3549KB) ( 307 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】Combine QTL mapping for grain size and related traits and screening for candidate genes to lay a good foundation for dissecting genes regulating rice grain size and related traits.【Method】A dwarf mutant CHA-1 screened from the progeny of the indica rice variety Tehuazhan carried by high altitude balloon was hybridized with another mutant H335 selected from the progeny of the indica rice variety Hanghui 7 induced by “Shenzhou 8” spaceflight. A population of 275 recombinant inbred lines (RILs) was structured from CHA-1 ×H335. A high-density genetic map was constructed using genotyping by sequencing (GBS) technology. The RIL population and parents were grown in the experimental base of South China Agricultural University consecutively in the early and late season in 2017. After ripening, rice grain images were scanned, and the grain size and related traits was obtained by SmartGrain software. QTL mapping for rice grain size and related traits was done with QTL IciMapping v 4.0 software based on inclusive composite interval mapping (ICIM).【Result】The constructed high-density genetic map contains 2498 Bin markers ,and all the markers covers 2371.84 cM with an average genetic distance of 0.95 cM/marker. A total of 26 grain-size related QTLs were repeatedly detected on Chr.1, Chr.2, Chr.3, Chr.4, Chr.7 and Chr.9 in the two seasons with single QTL contribution rate ranged from 0.16% to 14.41%. Five QTL clusters (qGS1, qGS2, qGS3-1, qGS3-2, qGS7) were detected on Chr.1, Chr.2, Chr.3, and Chr.7. Among them, qGS1, qGS3-2, and qGS7 have been previously reported. qGS2 and qGS3-1 were novel grain-size related QTLs. qGS2 was repeatedly detected in the same marker interval in the two seasons, and its LOD values in the early and late season were 8.08 and 4.00 with the phenotypic contribution rate 11.38% and 6.67%, respectively. qGS3-1 was detected to be correlated with grain thickness in the two seasons, and its LOD values in the early and late season were 2.94 and 8.59 with the phenotypic contribution rates 4.69% and 14.41%, respectively. Combined with functional annotation and CREP database of gene expression profiles, four candidate grain-size related genes including LOC_Os02g42310, LOC_Os02g42314, LOC_Os02g42370 and LOC_Os02g42380 were screened out in the qGS2 locus. LOC_Os02g42310 encodes a serine carboxypeptidase homologue; LOC_Os02g42314 encodes a ubiquitin-conjugating enzyme; LOC_Os02g42370 encodes a protein kinase domain containing protein; LOC_Os02g42380 encodes a TCP domain containing protein. Three candidate grain-size related genes including LOC_Os03g39020, LOC_Os03g39150 and LOC_Os03g39230 were screened out in the qGS3-1 locus. LOC_Os03g39020 encodes a kinesin motor domain containing protein; LOC_Os03g39150 encodes a protein kinase domain containing protein; LOC_Os03g39230 encodes an OTU-like cysteine protease family protein. Among the genes, LOC_Os02g42314 and LOC_Os03g39020 were highly expressed in the young panicle and endosperm after pollination and recognized as the most possible candidate genes for regulating grain size.【Conclusion】 26 rice grain-size related QTLs were detected. Five QTL clusters (qGS1, qGS2, qGS3-1, qGS3-2, qGS7) were detected on Chr1, Chr.2, Chr.3, and Chr.7, and qGS2 and qGS3-1 were novel QTLs for regulating grain size, and two candidate genes were screened out in this locus.

    Genetic Correlation Coefficients of Foxtail Millet Traits Between Parents and Hybrids
    LI HuiXia,TIAN Gang,WANG YuWen,LIU Xin,LIU Hong
    Scientia Agricultura Sinica. 2020, 53(2):  239-246.  doi:10.3864/j.issn.0578-1752.2020.02.002
    Abstract ( 277 )   HTML ( 20 )   PDF (387KB) ( 266 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 Genetic correlation of millet traits between hybrids and parents was studied in order to select parental materials on purpose and provide theoretical basis for optimizing the grouping of hybrid. 【Method】 Six highly-male-sterile lines were hybridized with ten sethoxydim resistant restorer lines, and sixty hybrids were obtained. These hybrids were planted with their parents in 2017. By evaluating their agronomic traits through statistical analysis, 7 advantageous combinations with their 4 female parents (Gu 3A, Jin 29A, 51A and 910A) and 7 male parents (K34, M22, K650, K154, K410, K391 and K47) were screened to plant in 2018. 10 agronomic and yield traits of them were surveyed. They were tiller number, plant height, panicle stem length, panicle length, panicle diameter, panicle weight, panicle grain weight, thousand seed weight, days to heading and plot yield. Genetic correlation had been analyzed between millet parents and hybrids in the same traits. And genetic correlation between parents traits and hybrids yield traits (panicle weight and panicle grain weight) had also been analyzed.【Result】The hybrids had some heterobeltiosis in two traits of panicle stem length and heading period, and had distinctly heterobeltiosis in trait of panicle length. Correlation analysis of hybrids and parents in two years indicated the following results. There were significant positive correlations in terms of plant height, heading period and panicle length between hybrids and their females. According to the analysis in 2018, the genetic correlation coefficients were 0.8841, 0.9117 and 0.8263, respectively. The first two items reached extremely significant level. There were significantly positive correlations between hybrids and their males in tiller number, plant height, panicle stem length, panicle diameter and thousand seed weight. According to the analysis in 2018, the genetic correlation coefficients were 0.8267, 0.9618, 0.8234, 0.7770 and 0.8404. Among them, the correlation of plant height was extremely significant. Tiller number, plant height, heading period of females were positively correlated with panicle weight and panicle grain weight of hybrids. The correlation coefficients of panicle weight were 0.3327, 0.5439 and 0.4436, respectively. The correlation coefficients of panicle grain weight were 0.4238, 0.4642 and 0.3487, respectively. Panicle length of females were positively correlated with panicle grain weight of hybrids with the correlation coefficient of 0.3698. Tiller number, plant height, heading period and panicle diameter of males were positively correlated with panicle weight and panicle grain weight of hybrids. The correlation coefficients of panicle weight were 0.4986, 0.4598, 0.3367 and 0.5348, respectively. The correlation coefficients of panicle grain weight were 0.5568, 0.4253, 0.3659 and 0.4236, respectively. The correlations between tiller number of males and panicle weight and panicle grain weight of hybrid reached extremely significant levels. 【Conclusion】There were positive correlations between parents and hybrids in tiller number, plant height, panicle stem length, panicle diameter, thousand seed weight and so on. Good agronomic traits and yield traits of hybrids can be indirectly selected based on the traits of the parents. Excellent high yield hybrids can be selected by this method.

    Cloning MsSQE1 from Alfalfa and Functional Analysis in Saponin Synthesis
    KANG JunMei,ZHANG QiaoYan,JIANG Xu,WANG Zhen,ZHANG TieJun,LONG RuiCai,CUI HuiTing,YANG QingChuan
    Scientia Agricultura Sinica. 2020, 53(2):  247-260.  doi:10.3864/j.issn.0578-1752.2020.02.003
    Abstract ( 308 )   HTML ( 26 )   PDF (7501KB) ( 283 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】Squalene epoxidase (SQE) is a rate-limiting enzyme in sterols and triterpenoids biosynthesis pathway, which is closely related to the synthesis of saponins. This study focused on the regulatory function of MsSQE1 on saponin biosynthesis in alfalfa,【Method】MsSQE1 was isolated from alfalfa based on SQE sequence of model plant Medicago truncatula. MEGA software was used for bioinformatic analysis of MsSQE1. Subcellular localization of MsSQE1 protein was examined by micro projectile bombardment. qRT-PCR was used to examine tissue-specific expression and the expression patterns of MsSQE1 under UV radiation, MeJA, ABA and GA3 treatments. The MsSQE1 overexpressing transgenic alfalfa was obtained by Agrobacterium-mediated transformation, and the saponins content of the transgenic plants was determined by spectrophotometer【Result】The cDNA sequence of MsSQE1 was cloned, which contained an ORF of 1 578 bp encoding a protein of 525 amino acids with an isoelectric point of 8.59. Bioinformatic analysis showed that the deduced of MsSQE1 shared high sequence homology with SQE1 from M. truncatula (98.6%) and Arabidopsis thaliana (80%). Subcellular localization indicated that MsSQE1 may be located in the cell membrane of onion epidermis. The expression level of MsSQE1 was highest in leaves compared with stems and roots. MsSQE1 was enhanced by the simulation of UV radiation, ABA and GA3. The expression level of MsSQE1 in leaves was highest in 24 h treated by UV, and in 8 h treated of GA3 (50 μmol·L -1) and ABA(100 μmol·L -1). Moreover, MsSQE1 was upregulated by MeJA, and the enhanced expression of MsSQE1 resulted in the increase of total saponins. Overexpression of MsSQE1 in alfalfa led to the accumulation of total saponins in the transgenic plants and MsSQE1 expression level was correlated with the contents of saponins. The expression level of MsSQE1 in transgenic alfalfa was 3.11-9.45 times of control, and the content of saponins was 14.26%-28.05% higher than control. These findings suggested that the novel identified MsSQE1 encodes epoxidase and it contributes to the synthesis of saponins in alfalfa.【Conclusion】This study reported the cloning and functional characterization of squalene epoxidase (SQE) encoding gene from legume forage alfalfa (MsSQE). Overexpression MsSQE1 in alfalfa improved the content of total saponins suggesting that MsSQE affects the saponin biosynthesis.

    TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY·AGRICULTURE INFORMATION TECHNOLOGY
    High and Stable Yield of Early Indica Rice Varieties with Double-Season Mechanical Direct Seeding
    CHEN LiMing,ZHOU YanZhi,TAN YiQing,WU ZiMing,TAN XueMing,ZENG YongJun,SHI QingHua,PAN XiaoHua,ZENG YanHua
    Scientia Agricultura Sinica. 2020, 53(2):  261-272.  doi:10.3864/j.issn.0578-1752.2020.02.004
    Abstract ( 270 )   HTML ( 14 )   PDF (1219KB) ( 316 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 The study aimed to explore the characteristics of high and stable yield of double-season mechanical direct seeding early rice varieties, and to screen out a batch of early indica rice varieties suitable for mechanical direct seeding in Jiangxi double-season rice region, which provided theoretical basis for breeding and cultivation of southern double-season mechanical direct seeding rice varieties.【Method】With 21 early indica rice varieties as experimental materials, artificial mechanical direct seeding was carried out in three different ecological regions of Jiangxi province (North Jiangxi, Central Jiangxi and South Jiangxi). Cluster analysis, combined variance analysis and GGE biplot were used to systematically study the high and stable yield characteristics of double-season mechanical direct seeding early indica rice varieties. 【Result】 The yield of different cultivars was significantly affected by genotype, environment and interaction effect. Cluster analysis of yield of tested varieties in each ecological region showed that high-yield varieties in North, Middle and South Jiangxi accounted for 38.10%, 19.05% and 23.81% of the total, respectively. Tan Liangyou 83 had the highest yield and the best stability, followed by Wufengyou 286 and Zhuliangyou 171 varieties, and Yong 3 Youhua had the lowest yield, while Liangyou 287 had good high yield but poor stable yield. Compared with medium and low yield varieties, the effective panicle, grain number per panicle and total spikelet number of high yield varieties increased significantly, and 1000-grain weight and daily output had significant advantages. It showed better ability of early growth and rapid development. The tiller growth rate, peak seedling number and panicle formation rate were significantly increased, and the tiller decline rate was significantly reduced. Dry matter production at heading stage and maturity stage was significantly higher for high-yield varieties than that for medium and low-yield varieties, and high-yield varieties have significant advantages in dry matter output rate, apparent conversion rate and apparent conversion rate.【Conclusion】Under the condition of machine direct seeding, the early indica rice varieties with high and stable yield had the characteristics of moderate growth period, good early onset, high tillering and ear formation rate, large total spikelet number, large dry matter production after flowering, high dry matter output and transportation efficiency, and high daily output, etc. According to the comprehensive characteristics of various varieties, Tan Liangyou 83, Wu Fengyou 286, Zhu Liangyou 171 and Yong You 9380 had good high yield and stability, and moderate maturity, which was suitable for direct seeding of early rice in Jiangxi double cropping rice region.

    Effects of Different Covering Planting Patterns on Soil Moisture, Temperature Characteristics and Maize Yield in Semi-Arid Region of the Loess Plateau
    DENG HaoLiang,ZHANG HengJia,XIAO Rang,ZHANG YongLing,TIAN JianLiang,LI FuQiang,WANG YuCai,ZHOU Hong,LI Xuan
    Scientia Agricultura Sinica. 2020, 53(2):  273-287.  doi:10.3864/j.issn.0578-1752.2020.02.005
    Abstract ( 299 )   HTML ( 17 )   PDF (1490KB) ( 306 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 This experiment explored the dynamic changes of soil water and thermal environment and spring maize yield and water use efficiency in semi-arid areas of the Loess Plateau, which provided a theoretical basis for optimizing the soil water and heat environment and improving the crop yield of spring maize field in the dry farming area in central Gansu. 【Method】 The field positioning experiments were carried out in Yuzhong Agricultural Technology Promotion Center of Gansu from 2017 to 2018, which were set up 6 planting methods, including non-contoured seedbed with film mulching (WM), non-contoured seedbed with half film mulching (HM), ridge-furrow with polyethylene film and straw mulching (MRM), ridge-furrow with full film mulching (WRF), ridge-furrow with straw mulching (SM) and non-contoured seedbed without mulching (CK). Based on the experiments, the water and heat conditions of soil layers profiles in different fertility period of spring maize, phenological characteristics, yield and water use efficiency during harvest period were measured and analyzed. 【Result】 In this study, the film mulching treatment had a warming effect compared with CK, the average soil temperature during the whole growth period was 2.42 °C, while the SM showed a cooling effect with an average temperature drop of 0.36 °C, and the adjustment of soil temperature by the planting method was mainly manifested in the seedling stage, the effect of temperature regulation gradually weakened with the progress of growth period. MRM, WRF, HM and SM had significant effect on the preservation of spring maize during the whole growth period, while WM was not conducive to precipitation collection. It only had the effect of preserving in the early stage of spring maize growth, while the water consumption in the middle and later stages increased with the crop growth, and the soil moisture content was lower than that under CK. The most water consumed of spring maize was in the middle growth stage (jointing to silking), followed by the later growth stage (silking to maturity), and the least was in the early growth stage (budding to jointing), in which the water consumption of plastic film mulching was greater than straw mulching, and full film mulching was greater than half film mulching. Plastic film mulching planting method could improve biomass water use efficiency of spring maize least and middle growth stage significantly. The improvement was highest (up to 250.68%) at early growth stage of HM and at the middle stage of WRF (up to 61.30%), compared with CK. Plastic film mulching planting method resulted in increased soil temperatures and improved soil water consumption, therefore, these treatments extended the growing period for spring maize and increased the dry matter weight per plant, the final performance was the improvement of yield and water use efficiency. The most significant effect on increasing yield and water use efficiency was WRF and MRM, increased yield by 171.40% and 155.05%, respectively, and increased water use efficiency by 142.80% and 125.44%, respectively, compared with CK. 【Conclusion】 The plastic film mulched ridge and sowing furrow planting changed the soil water and thermal environment and increased dry matter accumulation in semi-arid areas of the Loess Plateau. The yield and water use efficiency of the ridge-furrow with full film mulching planting method was the best under these treatments.

    PLANT PROTECTION
    Reorganization of Maize Disease and Causal Agent Names and Disscution on Their Standardized Translation of Chinese Names
    WANG XiaoMing,DUAN CanXing
    Scientia Agricultura Sinica. 2020, 53(2):  288-316.  doi:10.3864/j.issn.0578-1752.2020.02.006
    Abstract ( 523 )   HTML ( 28 )   PDF (732KB) ( 446 )   Save
    Figures and Tables | References | Related Articles | Metrics

    By reorganization of maize diseases and causal agents reported worldwide, a proposal for standardized translation of Chinese names of maize diseases and pathogens has been given in this article. A total of 185 fungal, oomycete, bacterial, viral and nematode diseases and 380 species/times causal agents in maize were gathered from books, including Compendium of Corn Diseases (4th edition, MUNKVOLD G P and WHITE D G, 2016), Maize Diseases (MCGEE D C, 1988), Field Crop Diseases (NYVALL R F, 1999), Illustrated Handbook of Maize Diseases, Insect Pests and Weeds in China (WANG X M and WANG Z Y, 2018), The American Phytopathological Society (APSnet, 2019), and some research articles. Some English names of maize diseases were originated from their pathogen species names. Accompanied by advances on scientific knowledge and identification techniques, 62 pathogen species were changed to new taxonomic category, which is different from the old taxonomic name, so the old disease name is not related with the new pathogen name that it will cause the confusion in practice. For international communication on maize diseases with universality, scientificity and normativity, 27 English names of maize diseases are proposed to modify with their new taxonomic names. 185 infectious diseases on maize were collected and reorganized including 123, 20, 26 and 16 diseases caused by fungi/oomycetes, bacteria, viruses and nematodes, respectively. The 185 maize diseases were caused by 286 pathogenic species/subspecies/varieries/pathovars, included 147 fungi, 34 oomycetes, 20 bacteria and 3 spitoplasm/phytoplasm, 38 viruses and 44 nematodes. The 185 Chinese names of maize diseases have been revised based on the principle of respecting the names published in historical and classic works of Chinese maize diseases or widely adopted in practice, including 96 new Chinese names based on the causal agent names and typical symptoms on maize. For the Chinese name of the maize pathogens, it should be given priority to the name of fungi, bacteria, viruses or nematodes in published plant and medical pathogen monographs, Flora Fungorum Sinicorum and research articles, and to give Chinese name first for the pathogen without Chinese name before based on the original meaning of pathogen’s Latin genus name and species epithet (English in virus). Standardized English names of maize diseases and determined taxonomic status of pathogens will be of benefit to scientific communication among maize disease researchers worldwide and to promote new researches. Under the determination of Chinese names of maize diseases and pathogens, the standardized names will be widely used for preventing translation between English-Chinese name of maize disease and pathogen optionally, and it will provide a correct list for research and teaching on maize diseases to avoid various ambiguities of the names and mistakes of disease-to-pathogen.

    SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT
    Research Progress of SOC Functions and Transformation Mechanisms
    ZHANG WeiLi,KOLBE H,ZHANG RenLian
    Scientia Agricultura Sinica. 2020, 53(2):  317-331.  doi:10.3864/j.issn.0578-1752.2020.02.007
    Abstract ( 2213 )   HTML ( 98 )   PDF (2654KB) ( 1523 )   Save
    Figures and Tables | References | Related Articles | Metrics

    Up to end of last century, studies on SOC were mainly concentrated in identifying chemical structures of different organic materials in soil, such as structural characteristics of humic or fulvic acids and their related functions for soil quality. In recent years, focus on SOC has been laid on SOC transformation characteristics in soil, trying to establish the relationship between SOC functions and the grouping according to SOC transformation characteristics. According to the transformation properties, SOC can be divided into two groups, including the stable SOC and the active SOC. The first one refers mainly to the SOC closely combined with clay or fine silt and it is difficult to be decomposed and mineralized by soil microorganisms. Stable SOC belongs to passive and inert SOC pool in soil. The second one refers to SOC, which mainly consists of crop residues and roots after harvesting, crop straws returned to farmland and organic manures applied. The active SOC belongs to nutritive and labile SOC pool in soil. This part of SOC is of great importance to soil fertility. SOC concentration is actually the expression of dynamic equilibrium of two processes. One is the input of organic materials to soil and the other one is the decomposition and mineralization of SOC. When the amount of organic material input is less than the mineralized amount, the SOC concentration and soil fertility will decrease. When the annual input of organic carbon is greater than the annual mineralization amount, the SOC concentration will keep rising until the annual input is equal to the annual mineralized amount. At this moment, SOC concentration will no longer increase and reaches the equilibrium point. Under normal agricultural production conditions, the duration for reaching equilibrium point needs 20 to 30 years. If the active SOC input is in very high level, the dynamic equilibrium system will also lead to a high amount of SOC mineralization annually. In such case, it might lead to a loss of mineral nutrients from soil into water and atmospheric environments, especially mineral nitrogen loss. For the purposes of soil fertility improvement and environmental protection, the active SOC input for farmland should be controlled to the level equal to the annual SOC mineralization amount, sustaining the so-called balance with positive zero. New research shows that the active SOC, after entering soil, is decomposed into a series of short-chain chemical compounds by soil organisms. These short-chain chemical compounds combine with soil mineral particles and form soil organic-mineral aggregates through bioturbation. A lot of soil fertility properties are positively affected by formation of these aggregates. Influenced by humification, decomposition and other processes of SOC, aggregation and disaggregation in soil occur simultaneously and consistently. In order to maintain stability of the total aggregates in soil and to increase soil fertility, sustained and abundant active SOC should be inputted to soil. Variation of SOC concentration depends mainly on climate, soil texture and land use forms. Among the artificial influences, land use form changing has the greatest impact on SOC concentration. In comparison, farming managements, such as fertilization, straw returning, tillage and crop rotation, have much less impacts on SOC concentration. In arable land, crops with different growth periods, tillage and harvesting managements will produce different amounts of above ground residues and root residues after harvesting. Depending on residue quantity and quality, different crops are of different capacity for SOC reproduction. According to the differentiated SOC reproduction capacities, field crops can be divided into two types: SOC increasing crops and SOC consuming crops. For farmland with SOC consuming crops, it is very important to introduce SOC increasing crops in rotation or to apply organic manure or organic materials to field, in order to sustain soil fertility.

    Soil Organic Carbon Management and Farmland Organic Matter Balance Method
    ZHANG WeiLi,KOLBE H,ZHANG RenLian,JI HongJie
    Scientia Agricultura Sinica. 2020, 53(2):  332-345.  doi:10.3864/j.issn.0578-1752.2020.02.008
    Abstract ( 407 )   HTML ( 20 )   PDF (773KB) ( 372 )   Save
    Figures and Tables | References | Related Articles | Metrics

    Progress of soil and fertilizer research work has promoted establishment of scientific recommendation for mineral nutrient requirements of major crops in different regions and counties. These quantitative and precise indicators have become the basis of scientific fertilization and ensured yield, income, and fertilizer efficiency increase and environmental safety. While application of organic manure, green manure and straw returning are the main measures to fertilize soil, studies have showed that excessive organic manure application will result in not only energy and resource waste, but also nutrient release and environmental pollution. Up to now, however, there are still no scientific and quantitative indicators for farmland fertilization in international arena. In recent years, a new method tried in Germany might break the deadlock. The purpose of this paper was to introduce the principle, application scope and examples of the method, so as to provide useful experience for China. The scientific basis of the method is the humus equivalent values (Heq) of crops and organic manures, and materials derived from long-term experiments in different regions. The Heq values of different crops is applied to identify the SOC changes caused by different crops under their typical production conditions. The Heq values of different manures and organic materials is applied to characterize the soil humus producing capacity after these materials applied to farmland. Through Heq value, the deficit or surplus of soil humus caused by crops and the increase of soil humus caused by straw returning or organic manure application can be analyzed and calculated on one unified dimension basis. In many states of Germany and in Austria, the method has been used as officially recommended approach. It was suitable for both integrated farming system and organic farming system. For organic farming system, where mineral nitrogen fertilizers were not allowed to apply, the method could also be used as nitrogen nutrient management approach. A large amount of field tests showed that yield increases arrived to 50%-150%, when SOC management level raised from "low" to "balanced" by using the method. Organic matter balance method, specifically designed for farmers, is a region condition identified, group classified and accurately quantified farming’s management approach. A five-grade evaluation, which was consistent with other methods designed for farmers in Germany, was also adopted in the method. In the five grade evaluation system, name, definitions and interpretation of each grade were nation-wide unified. This was achieved by summarizing a large amount of long-term experiments and farmers surveys from all of the major agricultural areas with different climate, soil and crop production conditions. The unified name and definitions were validated in different regions to ensure the stability of the evaluation indexes. This simplified, unified, and stable evaluation system has showed strong advantages both for learning by farmers and for making relationships between farming’s management measures in practice and subsidy policies for environment. Names, definitions and interpretation of the five grades were the front indexes of the method. The ranges of Heq values in corresponding to the five grades, the Heq values of different crops, manures and organic materials were regarded as the professional indexes or parameters to support the front indexes. These professional parameters were allowed to be adjusted in accordance with local conditions by agricultural research institutions without changing of the unified front indexes. By this way, the method stability, expansibility, scientificity and extensibility in farming’s practice were improved greatly. The architecture composed of front and background indexes designed for farmers for farming’s management is also worthy of our reference. For application of the approach in China, main difficulty is to develop Heq values suitable for crops and agricultural condition in China. Since the sum of qualified long-term experiments in China are limited, we can try to develop the Heq values by use of the available long-term experiments in combination with short-term experiments, simulation experiments as well as site-specific farmland survey in different major agricultural regions in China. To speed up the work, parameter development, calibration, improvement and field demonstration might be done simultaneously.

    SPECIAL FOCUS: TEA
    Effects of LED Light Withering at Different Temperatures on Expression of Key Genes in the Upstream of MEP and Formation of Volatiles in Tieguanyin Tea
    YOU FangNing,DENG HuiLi,HU Juan,YAO ZhiLing,WU ShuaiQiang,QIN YiJia,TANG TongHua,SUN Yun
    Scientia Agricultura Sinica. 2020, 53(2):  346-356.  doi:10.3864/j.issn.0578-1752.2020.02.009
    Abstract ( 221 )   HTML ( 11 )   PDF (515KB) ( 167 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】Terpenoids are important aroma components of oolong tea, and the key upstream genes of the MEP are directly involved in the regulation of the synthesis of terpenoid precursors. Withering, a process closely related to the aroma formation of oolong tea, is affected by many factors such as light exposure and temperature. The present study was aimed at investigating the effects of LED light and temperature on the aroma formation of oolong tea during withering process and to provide reference for improving aroma quality of withered leaves of Oolong tea. 【Method】 Firstly, the key upstream genes of MEP (DXS, DXR, HDS, and HDR) in tea which responded to light were selected according to our previous transcriptome data and KEGG pathways. The tea cultivar Tieguanyin was chosen as test materials, which were plucked in Tea Science Teaching and Research Base of Fujian Agriculture and Forestry University with one bud and three leaves. The freshly plucked leaves were treated under white LED light coupling with series temperature ((20℃ (L20), 25℃ (L25), 30℃ (L30), 35℃ (L35) and 40℃ (L40) ), Dark treatment (20℃ (D20), 25℃ (D25), 30℃ (D30), 35℃ (D35), and 40℃ (D40) ), and then the aroma contents and key upstream gene of MEP of withered leaves were determined.【Result】Under L30 treatment, DXS, DXR, HDS and HDR genes in the withered leaves were reached maximum, and which was 4.31, 5.28, 11.77, and 1.59 fold of XY (CK), respectively; these genes in L30 were 2.24, 2.39, 1.86 and 1.60 fold compared to D30 treatment; these genes expression were highest in D30 among Dark group and was 1.92, 2.21, 6.34 and 0.99 fold of XY, respectively. The contents of α-Farnesene and Linalool oxide (I, II) of L20 was the highest, which were increased by 15.05%, 4.92% and 15.13%, respectively, compared to XY. The highest content of Nerolidol, Linalool and Geraniol were occurred in L30 treatment, which were increased by 3.71%, 6.14% and 15.28%, respectively, compared with XY. The content of main aroma components in the LED group of Tieguanyin withered leaves was higher than that of temperature group. The mathematical model was established by principal component analysis method and the aroma components of the withered leaves were evaluated. It was found that the L20 treatment had the highest score and followed by L30, which were consistent with the aroma analysis. 【Conclusion】According to the comprehensive test results, there was no synchronization between the expression of the genes and the aroma contents of Tieguanyin, The gene expression under L30 treatment, aroma contents and principal component analysis scores were higher than that under other treatments. These results were consistent with the withering temperature in Tieguanyin production: when withering temperature was too high (40℃), the related gene expression and the formation of terpenoids in the withered leaves were prohibited.

    Metabolic Changes in the Processing of Yunkang 10 Sun-Dried Green Tea based on Metabolomics
    DAI YuQiao,Lü CaiYou,HE LuNan,YI Chao,LIU XueYan,HUANG Wen,CHEN JiaMin
    Scientia Agricultura Sinica. 2020, 53(2):  357-370.  doi:10.3864/j.issn.0578-1752.2020.02.010
    Abstract ( 336 )   HTML ( 13 )   PDF (3096KB) ( 329 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The ultrahigh phase liquid chromatography/mass spectrometry (LC-MS) combined technique of metabolomics was used to explore the changes of metabolites in the processing of sun-dried green tea of Camellia sinenis var. assamica cv. Yunkang 10, and to find the iconic metabolites affecting the formation of sun-dried green tea quality. Further study on the change path of these substances would lay a foundation for understanding the formation mechanism of sun-dried green tea quality. 【Method】In the process of making Yunkang 10 sun-dried green tea, 3 samples of fresh leaves, rolled leaves and sun-dried leaves were taken respectively. After the samples were pretreated, the metabolites in the three groups of samples were detected by LC-MS and identified by mass spectrometry database. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were used to analyze the detection data of three groups of samples. Metabolites with significant differences were screened out by PLS-DA method. 【Result】LC-MS analysis method for the endogenous metabolites of Yunkang 10 fresh leaves, rolled leaves and sun-dried leaves was established, and commercial mass spectrometry database was used for rapid identification of the detected metabolites. The metabolome data were imported into SIMCA-P software for principal component analysis and partial least squares discriminant analysis, and the metabolome data could be used to distinguish the three groups of samples. By LC/MS technique on Yunkang 10 sun-dried green tea and its processing tea, in combination with multivariate statistical analysis, there were 701 kinds of metabolites were significant differences among the fresh leaves, rolling leaves and sun-dried leaves, and 116 kinds metabolites between fresh leaves and rolling leaves, 158 kinds of metabolites between sun-dried leaves and fresh leaves, and 48 kinds of metabolites between sun-dried leaves and rolling leaves were found. By searching KEGG database to analyze metabolites, these metabolites were mainly related to amino acid metabolism, polyphenol metabolism and other energy metabolism pathways. 【Conclusion】LC-MS technique could be used to distinguish fresh leaf group, rolled leaf group and sun-dried leaf group of Yunkang 10, which proved that metabolomics technology could reveal the chemical changes of metabolites in sun-dried green tea to some extent. The key metabolites were found in the study could provide a theoretical basis for evaluating the quality of sun-dried green tea, and lay a theoretical foundation for exploring the formation of "sunburn taste" of sun-dried green tea and the formation mechanism of sun-dried green tea quality.

    Typical Yellow Tea Taste Characteristic and Its Related Taste-Chemical Compositions
    FAN FangYuan,TANG GuiZhen,GONG ShuYing,ZONG BangZheng,GUO HaoWei,LI ChunLin
    Scientia Agricultura Sinica. 2020, 53(2):  371-382.  doi:10.3864/j.issn.0578-1752.2020.02.011
    Abstract ( 341 )   HTML ( 49 )   PDF (3631KB) ( 331 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】Yellow tea is a unique Chinese traditional tea, which has a special taste characteristic produced by a unique processing step, namely “sealed yellowing”. Studies about the associations of yellow tea taste characteristic attributes and their related chemical compositions would create the conditions for elucidating the chemical-acting mechanism of formation of yellow tea taste characteristic. Meanwhile, it would provide important evidence for standardization production of yellow tea. 【Method】 In this study, the taste characteristic attributes of yellow teas from China traditional yellow-tea producing areas and their related taste-chemical compositions were explored by sensory evaluation, chemical detection and chemometrics analysis 【Result】This research showed that mellow taste and sweet taste were the common characteristic attributes of yellow teas. It had different performance of umami, thickness, astringency and coarse taste in yellow teas from different tea producing areas. There were significant differences on the content of taste chemical compositions among yellow teas from different tea producing areas. In this study, the correlation was closer between thickness and astringency. The coarse taste attribute was an important contributor to separating Anhui yellow big tea from other types of yellow teas, which was due to the lower tenderness of fresh leave materials. The correlation analysis showed that gallic acid, gallic acid/flavone ratio (GA/Fla), gallic acid/catechins ratio (GA/Ca) and gallic acid/alkaloids ratio (GA/Alk) had a high correlation with coarse taste characteristic, which presumably was due to the high content of gallic acid in the yellow tea made from mature leaves under the experimental conditions. Amino acids are the important contributors for the umami taste in yellow teas, especially like glutamic acid, theanine/amino acids ratio (Thea/aa) and umami/total amino acids ratio (Umami/aa) under this experimental condition. 【Conclusion】 The mellow and sweet taste attributes were the taste characteristic common attributes of yellow teas. The coarse taste was typical taste characteristic attribute of yellow big teas. In this study, the gallic acid, GA/Fla, GA/Ca and GA/Alk were closely relation with coarse taste based on the characteristics of these experimental samples, and the glutamic acid, Thea/aa, Umami/aa were highly correlated with umami taste in yellow teas.

    Taste Characteristic and Main Contributing Compounds of Different Origin Black tea
    SONG ChuJun,FAN FangYuan,GONG ShuYing,GUO HaoWei,LI ChunLin,ZONG BangZheng
    Scientia Agricultura Sinica. 2020, 53(2):  383-394.  doi:10.3864/j.issn.0578-1752.2020.02.012
    Abstract ( 802 )   HTML ( 40 )   PDF (2487KB) ( 539 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 This study focused on the taste characteristic of typical black tea from main black tea producing areas in China. The important taste compounds of black tea were detected, and the correlation between the main contributing compounds and the taste characteristic of black tea was analyzed. 【Method】 In this study, the black tea samples were collected from Shandong, Hubei, Anhui, Henan, Zhejiang, Hunan, Fujian, Guizhou, Sichuan and Yunnan, named by Shandong Linyi black tea, Hubei Hongan black tea, Anhui Qimen black tea, Henan Xinyang black tea, Zhejiang Shaoxing black tea, Hunan Guzhang black tea, Fujian Wuyishan black tea, Guizhou Puan black tea, Sichuan Yaan black tea and Yunnan Fengqing black tea, respectively. The taste characteristic of black teas were analyzed and compared by sensory evaluation according national standard. High performance liquid chromatography (HPLC) and ultrahigh performance liquid chromatography-mass spectrometry (UPLC-MS) were used for the determination of 65 compounds including catechins, alkaiods, flavonoids, amino acids and gallic acid, sugars and organic acids. The correlation between the compounds and the taste characteristic of black teas were analyzed by principal component analysis (PCA) based on IBM SPSS Statistics 25. 【Result】 There were obvious difference on taste characteristic of black teas from 10 tea producing areas in China. Black teas from Yunnan and Guizhou were belong to large leaf teas, which were considered by the taste of mellow, thick, and umami, while the taste characteristic of black teas from other 8 tea producing areas were mainly reflected in fresh and umami. The PCA results showed that the taste constituents directly were responsible for discrimination of black teas from different sources. The clear separation of large-leaf black teas from small leaf-black teas could be found based on PC1. Black teas with taste characteristic of fresh and umami could be divided into two categories based on PC2, among which Shandong Linyi black tea, Anhui Qimen black tea and Zhejiang Shaoxing black tea with more fresh taste scored higher. According to the loading plot of principal component analysis, fumaric acid, total catechins, Myr-3-O-glu, theophylline, theobromine and theaflavins with high scores on the positive of PC1, two kaempferol triglucosides and total flavonol glycosides with high scores on the negative of PC1 and most of the free amino acids with high scores on the positive of PC2, were presumed to make important contribution for classification of geological black teas. Further chemical content analysis showed that the content of fumaric acid, total catechins, Myr-3-O-glu, theophylline, theobromine and theaflavins in large-leaf black teas were higher than that in other samples, with average value of about 7.6, 554, 1.3, 7.9, 205, and 15 μg?mL -1, respectively. Conversely, the contents of two kaempferol triglucosides and total flavonol glycosides were higher in small-leaf black teas than that in the big-leaf ones. Hubei Hongan black tea had the highest amounts of total flavonol glycosides, up to 80 μg?mL -1, which was four times as much as that in large leaf black teas. Black tea numbered 1, 3, and 5 had strong umami taste characteristic based on sensory evaluation, in which the content of free amino acids reached 300 μg?mL -1. 【Conclusion】 In conclusion, there were significant differences in the taste characteristic of 10 representative black tea producing areas in China. The taste characteristic of large-leaf black teas was mellow, thick and umami, while that of small-leaf black teas was fresh and umami. Alkaloids, organic acids, catechins and its oxides were the important contributors for taste characteristic of mellow and thick in black teas. The taste characteristic of fresh and umami in black teas maybe caused by free amino acids.

    SPECIAL FOCUS: young ruminant rearing research
    Scientific Rearing of Preruminants is the Basis of Sustainable Development of Livestock Industry
    DIAO QiYu,TU Yan
    Scientia Agricultura Sinica. 2020, 53(2):  395-397.  doi:10.3864/j.issn.0578-1752.2020.02.013
    Abstract ( 194 )   HTML ( 16 )   PDF (315KB) ( 201 )   Save
    References | Related Articles | Metrics
    SPECIAL FOCUS: YOUNG RUMINANT REARING RESEARCH
    Effects of Adding Mannan Oligosaccharides to Milk Replacer on the Development of Gastrointestinal Tract of 7-28 Days Old Hu Lambs
    ZHENG Chen,LI FaDi,LI Fei,ZHOU JuWang,DUAN PengWei,LIU HuiHui,FAN HaiMiao,ZHU WeiLi,LIU Ting
    Scientia Agricultura Sinica. 2020, 53(2):  398-408.  doi:10.3864/j.issn.0578-1752.2020.02.014
    Abstract ( 209 )   HTML ( 16 )   PDF (527KB) ( 212 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】This study was conducted to investigate the effects of mannan oligosaccharides (MOS) supplementation to milk replacer on the development of gastrointestinal tract of 7-28 day-old Hu lambs. 【Method】 Thirty 7 day-old Hu male lambs were chosen and divided into 2 groups randomly, fifteen lambs in each group and each lamb as a repeat. Lambs were fed milk replacer with or without 0.2 % MOS, respectively. The test lasted for 21 days. Eight lambs were selected from each group randomly and slaughtered at 28 day-old. The weights of the compound stomach and the intestinal tract with and without content, and lengths of the intestinal tract were measured, and the relative quality and length were calculated. While the tissue samples from fundus gland region of the abomasum, the middle part of duodenum, jejunum and ileum were fixed in paraformaldehyde to analyse the histomorphology, and the apoptotic rate of intestinal epithelial cells as well. And the mRNA expression of claudin 1, zonula occludens-1 (ZO-1), and occludin protein of duodenum, jejunum and ileum mucosa were measured.【Result】The results showed that except relative length of jejunum (P=0.040), the relative weights (% body weight, % stomach weight, % intestinal tract weight, and % gastrointestinal tract weight), relative lengths (% intestinal tract length), content of stomach and intestinal tract (% body weight, % stomach content weight, % intestinal tract content weight, and % gastrointestinal tract content weight), the apoptotic rate of intestinal epithelial cells and mRNA expression of claudin 1 protein in intestinal tract of lambs were not affected by MOS (P>0.05). However, MOS elongated the villus height and the muscular thickness, and decreased the villus width of lamb duodenum significantly (P=0.033, P=0.047, P=0.015). MOS also up-regulated the mRNA expression of ZO-1 protein of lamb jejunum significantly (P=0.028). And there was a tendency that MOS elongated villus height, width and crypt depth of ileum, muscular thickness of abomasum, and mRNA expression of occludin protein of ileum (P=0.075, P=0.078, P=0.085, P=0.084, P=0.052).【Conclusion】MOS almost did not affect the relative weights, lengths, and content distribution of gastrointestinal tract of 7-28 days old Hu lambs, but improved the histomorphology of duodenum and ileum, indicating it could maintain barrier function of intestinal tract and benefit to nutrients digestibility.

    Effects of Milk Replacer Feeding Level on Hematology Index and Gut Barrier Function in Lambs
    LI YanJun,NIU XiaoLin,ZHANG Qian,WANG GuoXiu,LI FaDi,LI Fei,LI Chong,PANG Xin,JIA Li,FAN HaiMiao
    Scientia Agricultura Sinica. 2020, 53(2):  409-417.  doi:10.3864/j.issn.0578-1752.2020.02.015
    Abstract ( 202 )   HTML ( 14 )   PDF (466KB) ( 265 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Background】 The application of milk replacer powder has important significance for improving the health and survival rate of lambs. However, the effects of milk replacer feeding levels on immune function and intestinal barrier function of lambs were still unclear. The optimal level of milk replacer for development of immune function and intestinal health is still inconclusive. 【Objective】 The objective of this experiment was to analyze the effects of the milk replacer feeding level on the immune function and intestinal barrier function of lambs through the dynamic of hematological indicators, the morphology of ileum and colon, antioxidant index, immune index and expression of intestinal barrier function related genes.【Method】16 newborn lambs were randomly divided into two groups: the control group (CON, milk replacer feeding level was 2% of average body weight) and the intensive feeding group (H, milk replacer feeding level was 4% of their average body weight). All lambs were fed milk replacer from the 7th day of age and were slaughtered at 49 days of age. 【Result】The results showed that the milk replacer feeding level had no significant effects on leukocyte count, lymphocyte count, neutrophil count, red blood cell count and hemoglobin concentration (P>0.05). The number of lymphocytes, red blood cells and hemoglobin in the 21-49d lambs increased gradually with age, significantly higher at 49 days of age (P<0.05), while neutrophil lymphocytes were significantly lower than at 49 days (P<0.05). The ileal villus height of the H group was significantly higher than that of the CON group (P<0.05), the ileum and colon crypt depth was significantly lower than that of the CON group (P<0.05), the ileal and colonic malondialdehyde (MDA) content and immunoglobulin A (The content of IgA) was significantly lower than that of CON group (P<0.05). The expression of Claudin4 in colon was significantly lower than that in CON group (P<0.05), and the expression of tumor necrosis factor (TNF-α) in ileum and colon was significantly lower than that in CON group (P<0.05). 【Conclusion】The intensive milk replacer feeding could reduce intestinal oxidative damage, promote intestinal villus development, reduce intestinal physical barrier damage and reduce intestinal immune response. In the sheep production, an intensive milk replacer-feeding program benefits to the healthy intestinal development.

    Effects of Amino Acid Deficiency on Growth Development, Dietary Nutrients Digestion and Metabolism in Heifers
    KONG FanLin,LI Yuan,TANG MengQi,MA ManPeng,FU Tong,DIAO QiYu,CHENG SiYuan,TU Yan
    Scientia Agricultura Sinica. 2020, 53(2):  418-430.  doi:10.3864/j.issn.0578-1752.2020.02.016
    Abstract ( 164 )   HTML ( 23 )   PDF (490KB) ( 293 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The objective of this study was to evaluate the effects of deleting dietary lysine (Lys), methionine (Met) and threonine (Thr) on growth performance, and nutrients digestion and metabolism in 3-6 month-old Chinese Holstein heifers. It can provide not only the evidences for diagnosing the deficiency disease of amino acid of heifers in production, but also the guidance for determining amino acid requirements of heifers in the future.【Method】The experiment was conducted for 90 days with 72 Holstein heifers aged about 84 day-old fed in restricted amounts. Following a 7-day covariate period, heifers were allocated to 4 groups according to date of birth and body weight: 30% Lys reducing treatment (PC-Lys), 30% Met reducing treatment (PC-Met), 30% Thr reducing treatment (PC-Thr) and theoretical amino acid balanced treatment (PC). Body weight, body size and length of nipples were measured on 1, 30, 60 and 90 day. Six healthy calves were selected from each group at the ages of 132-138 and 173-179 day for twice and metabolism test. Feces, urine and feeds samples were collected to determine the apparent digestibility of nutrients and nitrogen metabolism. Dry matter intake was recorded daily throughout the whole trial period. 【Result】Compared with PC, the results showed that (1) Lys deficiency significantly decreased Gain/Feed (G/F) in 90 to 180 day-old heifers (P<0.05). Average daily gain (ADG) of PC-Lys group was lowest among four groups in 90 to 180 day-old heifers (P>0.05). ADG and G/F were not influenced by Met and Thr deficiency in 90 to 180 day-old heifers (P>0.05); (2) No differences of diarrhea rate were found among four groups (P>0.05), while diarrhea rate was highest in PC-Lys group (P>0.05). However, Lys and Thr deficiency decreased fecal score (P<0.05); (3) Lys, Met and Thr deficiency did not affect body size (P>0.05), but the growth rate of nipples of PC-Lys group were lower than that of PC group (P<0.05); (4) The apparent digestibility of nutrients were not influenced by different treatments. Retained N of intake N and biological value of N were significantly decreased in PC-Lys group (P<0.05). 【Conclusion】On the basis of the theoretical amino acid balanced diet, reducing 30% dietary Lys had adverse effect on growth performance and nitrogen metabolism, and reducing 30% dietary Thr could deteriorate diarrhea, while reducing 30% dietary Met had no effects in heifers.

    The Slaughter Characteristics and Meat Quality of Holstein Bulls Grain-Fed Under Different Dietary Crude Protein Levels
    ZHAO YangYang,LI Yan,HAN YongSheng,WANG XiaoLing,LI JianGuo,GAO YanXia,CAO YuFeng,LI QiuFeng
    Scientia Agricultura Sinica. 2020, 53(2):  431-439.  doi:10.3864/j.issn.0578-1752.2020.02.017
    Abstract ( 340 )   HTML ( 23 )   PDF (441KB) ( 366 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 The purpose of this experiment was to study the slaughter characteristics and meat quality of Holstein bulls grain-fed under different dietary crude protein levels. To provide a reference for improving beef quality research.【Method】 Ninety Holstein bulls with body weight of about 197 kg and similar body condition were randomly divided into three groups with 30 calves in each group. Group I, II and III were fed diets with low, medium and high crude protein level, respectively. The dietary comprehensive net energy level in each group was the same, and the ratio of concentrate to roughage (dry matter basis) was 90﹕10. The pre-trial period lasted 10 d and the formal trial period lasted 193 d. 【Result】 The results showed as follows: (1) The longissimus muscle area in group III was significantly increased by 6.69% (P>0.05) compared with group I, while there were no effects on dressing, meat-bone ratio, net meat percentage and carcass yield among the groups (P>0.05). (2) The dehydration rates in group Ⅲ were significantly lower than those in group I by 9.01% (P<0.05); with the increasing of dietary crude protein level, the shear stress and cooking loss decreased slightly, but the difference was not significant (P>0.05), and there were no significant differences in meat pH, meat color, chroma and hue angle among groups (P>0.05). (3) Dietary crude protein levels had no significant effect on conventional ingredients of longissimus muscle (P>0.05). (4) The concentration of saturated fatty acid (SFA) of longissimus dorsi in group III was 14.58% (P<0.01) and 9.68% (P<0.05) lower than that in group I and group II, respectively, and the palmitic acid (C16:0) concentration in group III was significantly lower than that in group I (P<0.05). Compared with groupⅠ, the concentration of monounsaturated fatty acid (MUFA) in group II and group III was increased by 14.16% and 17.42% (P<0.01), respectively, and the oleic acid (C18:1n9c) concentration was increased by 28.89% and 30.19% (P<0.01), respectively; the ratio of monounsaturated fatty acids to saturated fatty acids (M/S) in group II was significantly higher than that in groupⅠ(P<0.05), and the M/S in group III was significantly higher than that in groupⅠ(P<0.01).【Conclusion】In conclusion, under the experimental conditions, diets with high crude protein level could increase longissimus muscle area of Holstein bulls, increase MUFA content and decrease SFA content of longissimus dorsi, and improve meat quality in dairy bulls.

    Effects of NDF Level of Starter on Growth Performance, Serum Biochemical Parameters and Antioxidant Indices in Calves
    REN ChunYan,BI YanLiang,GUO YanLi,DU HanChang,YU Bo,TU Yan,DIAO QiYu
    Scientia Agricultura Sinica. 2020, 53(2):  440-450.  doi:10.3864/j.issn.0578-1752.2020.02.018
    Abstract ( 232 )   HTML ( 31 )   PDF (435KB) ( 222 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 The objective of this study was to determine the effects of different neutral detergent fiber (NDF) levels of starter on growth performance, blood biochemical and antioxidant indices of calves.【Method】Sixty new born dairy calves (24 females and 36 males) with body weight (42 ± 2.5) kg were randomly assigned to four treatment groups (10N, 15N, 20N and 25N) with nine male calves and six female calves each. Each group was fed one of the four starters which had different NDF levels (10%,15%, 20% and 25%, respectively). Starter intake was measured daily, and body weight of calves was measured every two weeks. The body sizes of calves were measured at 35 and 112 days of age, respectively. The concentrations of serum biochemical and antioxidant indices were determined at 35, 70, 90 and 112 days of age prior to morning feeding.【Result】 (1) At the age of 70-112 days, the starter intake of calve in 10N group was significantly lower than that in 25N group (P<0.5). At the age of 42-70 days, the NDF intake of calf in 20N and 25N groups were significantly higher than that of the 10N and 15N groups (P<0.05). The NDF intake of calve increased significantly with the dietary NDF level increasing during the 70-112 days (P<0.05). (2) At the age of 70-112 days and 15-112 days, the body weight gain was increased by 12.67%, 43.56%, 30.17% and 6.16%, 18.09%, 15.16%, respectively in group II than that in group 10N, 20N and 25N (P<0.05). The wither height was significantly higher in group 15N than that in group 20N and 25N (P<0.05). The body length and heart girth were significantly higher in group 15N than in group 25N (P<0.05). (3) At 90 days of age, serum globulin content of group 15N was significantly higher than that of the other three groups, and ALB/GLB value was significantly lower than that of the other three groups (P<0.05). At 112 days of age, serum glutamic-pyruvic transaminase, glutamic oxalacetic transaminase and alkaline phosphatase were significantly decreased with improved NDF level (P<0.05). (4) At 35, 70 and 112 days of calf age, the activities of superoxide dismutase of serum in group 15N, 20N and 25N were significantly higher than that in group 10N (P<0.05), and the content of malondialdehyde in serum of group15N, 20N and 25N were significantly lower than that of group 10N (P<0.05).【Conclusion】The content of NDF in starter diets had a direct influence on intake and body weight gain of calf, and the optimum level of NDF in starter of calves aged15-112 days was 15%.

    Growth Performance, Nutrient Digestibility and Serum Parameters in 0-2 Months Old Hu Lambs
    WANG ShiQin,BI YanLiang,ZHAO GuoHong,CUI Kai,HUANG WenQin,ZHANG NaiFeng,LI FaDi,TU Yan,DIAO QiYu
    Scientia Agricultura Sinica. 2020, 53(2):  451-460.  doi:10.3864/j.issn.0578-1752.2020.02.019
    Abstract ( 267 )   HTML ( 43 )   PDF (478KB) ( 238 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 The study was conducted to evaluate the effects of Resveratrol and Bacillus licheniformis on growth performance, nutrient digestibility and serological parameters in lambs.【Method】A total of 120 neonatal Hu lambs ((3.82±0.46) kg of BW) randomly divided into four groups, including CON group (lambs were conventional weaned at 49 days of age), EW group (lambs were early weaned at 21 days of age), RSV group (lambs were supplemented with 10 mg·kg -1 BW Resveratrol and early weaned) and BL group (lambs were supplemented with 60 mg·kg -1 BW Bacillus licheniformis with ≥4.0×10 9 CFU/g live bacteria and early weaned). Each group had 3 replicates with 10 lambs in each replicate. The digestion trial was carried out during day 56-63, and serum parameters were determined on day 63. The experiment lasted 63 d.【Result】There were no differences in body weight (BW) at day 21, average daily gain (ADG ) and solid feed intake during day 1 to day 21 between the groups (P>0.05). The BW of day 21 and day 49 were significantly lower (P<0.01) but solid feed intake of day 21-49 were significantly higher (P<0.01) in EW, RSV and BL groups than that in CON group. During the whole experiment, the ADG of ER, RSV, and BL groups were significantly lower than that of CON group (P<0.01), which were relatively decreased by 18.5%, 15.1% and 20.5%, respectively. The digestibility of dry matter (DM) and organic matter (OM) were significantly higher in CON and EW group than that in RSV group (P<0.05), and the OM digestibility was significantly higher in EW group than that in RSV group (P<0.05). The apparent digestibility of CP, EE, Ca and P were not significantly different among the groups (P>0.05). The digestibility of NDF and ADF were significantly higher in EW group than that in RSV group (P<0.05), but there was no significant difference between the other groups (P>0.05). There were no significant differences in serum anti-oxidation, immunity and inflammation parameters of lambs between groups (P>0.05).【Conclusion】 The results showed that weaning at 21 days of age and directly switching them to solid feed had negative effects on lambs’ growth performance with the BW reducing by about 15% at 63 days of age. The supplementation of Resveratrol and Bacillus licheniformis seemed no influence on growth performance, nutrient digestibility, serum antioxidants and immunity parameters in Hu lambs.