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2020 Vol.37(12)

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2020, (12): 1-12.
[Abstract](2335) [FullText HTML] (608) [PDF 629KB](21)
2020, (12): 1-4.
[Abstract](1982) [FullText HTML] (560) [PDF 0KB](27)
Characteristics of soil enzyme activities in different degraded gradient grasslands on the Tibetan Plateau
LI Shaoyu, SUN Jian, WANG Yi, QIN Xiaojing, YE Chongchong
2020, 37(12): 2389-2402. doi: 10.11829/j.issn.1001-0629.2020-0218
[Abstract](2389) [FullText HTML] (824) [PDF 1313KB](56)
Soil enzymes are important in nutrient cycling, material circulation, energy flow, and metabolism in the ecosystem. We determined the soil physical and chemical properties, and enzyme stoichiometry, and explored the driving mechanism along a degraded gradient on Tibetan Plateau alpine meadow and steppe. The results showed that: 1) Soil total nitrogen, total carbon, total phosphorus, organic carbon, compactness, moisture content, β-1,4-N-acetylglucosaminidase, leucine aminopeptidase, and β-1,4-glucosidase exhibited a decreasing trend, while soil temperature and pH increased with the aggravation of degradation in both alpine meadow and steppe; 2) Pearson correlation analysis showed that pH was significantly negatively correlated with β-1,4-glucosidase activity and lignin peroxidase, while organic carbon and total carbon were positively correlated with β-1,4-glucosidase and lignin peroxidase in alpine meadow. The moisture content and compactness in alpine steppe were positively correlated with leucine aminopeptidase, alkaline phosphatase, urease, and β-1,4-N-acetylglucosaminidase. The study provides a theoretical basis for exploring the variation mechanism of soil physical and chemical properties and enzyme activity under different degradation gradients, and grassland ecosystem restoration in Tibetan Plateau.
Fractal features of soil and their relationship with soil nutrients under desert shrubs in the West Ordos region
DONG Xue, CHI Yuechun, XU Dehao, HAO Yuguang, DUAN Ruibing, ZHANG Shuai, HUANG Yaru, SUN Fei
2020, 37(12): 2403-2413. doi: 10.11829/j.issn.1001-0629.2020-0222
[Abstract](2106) [FullText HTML] (757) [PDF 997KB](40)
Survival and adequate growth of plants require ideal soil mechanical composition and nutrient conditions. The fractal dimension of soil and the distribution characteristics of nutrients and their relationships play an important role for the stability of soil structure, resistance to wind erosion, and movement of water and fertilizer. Ammopiptanthus mongolicus, Tetraena mongolica Maxim, and Zygophyllum xanthoxylum Bunge are typical shrubs that are widely distributed in the West Ordos region. They are important natural resources and natural ecological barriers which are crucial for the stability of arid steppe ecosystems. In this study, we examined soils under three shrubs. The vertical distribution of soil particle mechanical composition, soil volume fractal dimension, and soil nutrients in 0– 60 cm soil depth were analyzed to explore the relationships between soil fractal characteristics and soil fertility and to reveal the mechanisms of survival and diffusion of shrub vegetation in an arid steppe. The results showed significant differences in the morphologies of the three typical shrubs, which resulted in different grain size characteristics of the soil underneath the shrubs after intercepting the sand flow. The volume of clay and silt content and fractal dimension differed significantly among shrub species (P < 0.05). The soil fractal dimension was significantly different (P < 0.05), i.e., T. mongolica (2.432 ± 0.041) > A. mongolicus (2.391 ± 0.046) > Z. xanthoxylum (2.276 ± 0.034) > bare sand (2.218 ± 0.059). The soil fractal dimension was correlated with < 0.5 mm particles such as clay and silt (< 0.05 mm), very fine sand (0.05~0.1 mm), fine sand (0.1~0.25 mm), and medium sand (0.25~0.5 mm). The 0.1 mm particle size was the critical size determining the soil fractal dimension under shrubs in the study area. The soil fractal dimension increased with increasing < 0.1 mm diameter content (such as content of clay, silt, and very fine sand). Soil rapidly available potassium content decreased with increasing soil depth, and soil organic matter, available nitrogen, and available phosphorus fluctuated over soil layers. Differences in soil nutrients among species were significant (P < 0.05). The soil structure and fertility of shrub-covered land were significantly improved compared with those of bare sand. A highly significant positive correlation of soil organic matter content and soil available nitrogen content with soil fractal dimension was observed (P < 0.01), and a significant positive correlation of soil available phosphorus content and soil rapidly available potassium content with soil fractal dimension was found (P < 0.05). The results indicate that soil fractal dimensions can be used to describe eolian sandy soil properties in the West Ordos arid steppe. Appropriate inclusion of T. mongolica and A. Mongolicus in the shrub community of this environment can improve soil particle status, promote soil quality in partial desert areas, and curb continuous coarsening and deterioration of surface sand. This study provides a scientific research basis for quantitative evaluation of desert shrub functions such as windbreaking, sand fixation, and soil conservation.
Effect of fencing on vegetation carbon storage in the Qinghai Haibei alpine meadows
SONG Shanshan, ZHANG Jiansheng, ZHENG Tianli, ZHANG Fan, ZHU Jianxiao
2020, 37(12): 2414-2421. doi: 10.11829/j.issn.1001-0629.2020-0235
[Abstract](1877) [FullText HTML] (722) [PDF 967KB](49)
This study was performed to compare differences in vegetation carbon storage between five fencing treatments (2, 4, 9, 11, and 20 years) and their corresponding grazing treatments (control) in alpine meadows of Haibei. Short-term fencing (2 and 4 years) had no significant effect on vegetation carbon storage (P > 0.05), whereas long-term fencing (9, 11, and 20 years) significantly reduced vegetation carbon storage (P < 0.05). Fencing changed the relative contribution of different functional groups to the above-ground biomass carbon storage. Short-term fencing significantly increased above-ground biomass carbon storage of forbs (P < 0.05), whereas long-term fencing significantly reduced above-ground biomass carbon storage of grasses, legumes, and sedges (P < 0.05). Long-term fencing decreased carbon vegetation storage mainly by reducing below-ground biomass (root system levels, 0 – 50 cm soil depth). These results suggest that long-term fencing was not conducive to the accumulation of biomass carbon storage in alpine meadows of Haibei on the Qinghai-Tibetan Plateau, especially to the stock of below-ground root carbon storage.
Variation characteristics of plant communities in black soil shoals with different establishment years in the source area of the Yellow River
WANG Chao, WANG Xiaoli, SHI Jianjun, XING Yunfei, WU Jianli, Cairangzhongga, Maolanzhuoma
2020, 37(12): 2422-2430. doi: 10.11829/j.issn.1001-0629.2020-0291
[Abstract](1613) [FullText HTML] (633) [PDF 1624KB](27)
To evaluate the effects of vegetation restoration on the degraded "black soil beach" grassland in the source area of the Yellow River, we focused on the plant community characteristics of the "black soil beach" cultivated grasslands. Three cultivated Elymus nutans grasslands with different years since establishment (19, 15, 13) were selected in Maqin County, Qinghai Province. The extremely degraded "black soil beach" grassland was regarded as the control (CK) group. The results showed that: 1) the coverage of the gramineous forage and aboveground biomass in the three types of cultivated grasslands were significantly higher than those in CK (P < 0.05). However, the forbs coverage and biomass in the three types of cultivated grasslands were significantly lower than those in CK (P < 0.05). Establishing cultivated grasslands had obvious restoration effects on the extremely degraded black soil beach. 2) The coverage and biomass of gramineous forage and forbs in the grassland decreased significantly (P < 0.05) with the establishment years. The species richness, Simpson index, Shannon-Wiener index, and Pielou index of the plant community showed upward trends. 3) The principal component analysis (PCA) results showed that the dominance of Elymus nutans, Poa pratensis, and Koeleria macrantha in the plant community of the degraded black soil beach grassland improved after the establishment of cultivated grassland. In addition, the percentage of forbs dominated by A. nanschanica, A. sacrorum, and M. kokonorica significantly reduced. The research indicated that the cultivated grassland of the black soil beach in the source area of the Yellow River gradually changed to an ecological restoration grassland with an increase in the establishment time.
Soil seed bank characteristics of grasslands with different desertification degrees in a high-cold region
ZHAO Xiaonan, TANG Jinnian, FAN Baoli, LI Yinke, WANG Qi, JIN Hongxi, ZHANG Yinghua, YANG Xuemei, HE Fanglan, LIU Youjun, LIU Zhenheng
2020, 37(12): 2431-2443. doi: 10.11829/j.issn.1001-0629.2020-0184
[Abstract](2857) [FullText HTML] (690) [PDF 778KB](47)
To understand the response of soil seed banks to grassland desertification in alpine regions, the characteristics and dynamic changes in soil seed banks located in non-desertified alpine meadows, sandy grasslands, and mobile dunes in Maqu alpine regions were investigated and analyzed. The results showed that: 1) 32 species belonging to 13 families appeared in the soil seed bank during the desertification process of alpine meadows, and 24 species from 11 families appeared during both the turning-green period and the withering period; however, the species composition was different. 2) The three grasslands had different degrees of desertification. The density of the seed bank in the 0 – 15 cm soil layer was 3 096.0, 679.4, and 56.6 grains·m−2 in the greening stage, concentrated in the 0 – 5 cm soil layer, and the seed bank density decreased significantly as the degree of desertification increased (P < 0.05). The density during the yellowing period was lower than that during the turning-green period however, the difference was not significant (P > 0.05). 3) For both the greening period and the yellowing period, the degree of species dominance, diversity, uniformity, and abundance in the soil seed bank in the alpine meadow decreased with increasing degree of desertification. Once the typical alpine meadow was desertified, the species diversity of the seed bank noticeably decreased. 4) The similarity between the soil seed banks of the three grasslands with different desertification degrees and their vegetation was low, between 0 and 0.5; however, the similarity during the yellowing period was higher than that during the turning-green period. The results showed that the soil seed bank could be significant for the restoration of alpine desertified grassland. During the rejuvenation period, different types of degraded grasslands can be supplemented with common species or break seed dormancy to achieve vegetation restoration. Land desertification had a clear influence on the destruction of soil seed banks in alpine pastures. The density and diversity of soil seed banks decreased rapidly, zonal vegetation disappeared from the communities, and vegetation restoration became increasingly difficult. Therefore, it was an effective measure for vegetation restoration and reconstruction in alpine meadow areas to establish a scientific artificial soil seed bank.
Validation of MODIS land surface temperature products in grasslands of Qilian Mountain
WANG Wei, WANG Lijuan, SUN Wuhong, DAI Ang, HU Die, GUO Ni
2020, 37(12): 2444-2456. doi: 10.11829/j.issn.1001-0629.2020-0293
[Abstract](1797) [FullText HTML] (732) [PDF 1560KB](26)
Land surface temperature (LST) values measured at automatic weather stations in Qilian Mountain in China, were adopted to perform validation tests and comparative analysis of daily moderate resolution imaging spectroradiometer (MODIS) LST products (MOD/MYD11A1). The aim of the study was to assess the space adaptability of standard MODIS LST products on different underlying surfaces and to correct the error detected in these products due to changes in land surface types. The results indicated that in desert grasslands with low altitudes in the western section of Qilian Mountain, MOD11A1 LST products showed higher space consistency and adaptability, with respect to the measured LST. The average error and root mean square error (RMSE) were 1.62 ℃ and 3.88 ℃, respectively. On the mountain grassland in the eastern section and alpine grassland in the middle section of Qilian Mountain, which had higher altitudes, MYD11A1 LST products showed higher accuracy; average errors were 2.02 ℃ and 3.72 ℃, respectively, while the RMSEs were 5.12 ℃ and 6.92 ℃, respectively. In addition to the effect of land surface types, the accuracy of MODIS LST products is also influenced by vegetation cover and altitude, as seen in the Qilian Mountain. On the mountain grassland in the eastern section and alpine grassland in the middle section of Qilian Mountain, which have higher altitudes, MOD11A1 LST products showed less accuracy due to the slow rate of temperature rise and high vegetation coverage, which resulted in an overestimation of the actual LST in these areas, with an error of over 5.12 ℃. With the help of error correction, the accuracies of MODIS LST products when used on mountain, alpine, and desert grasslands of the Qilian Mountain were effectively improved, as the RMSEs of the products were reduced by 1.29, 2.66, and 0.91 ℃, respectively.
Expression of the cellobiohydrolase gene of Aspergillus fumigatus in Escherichia coli
YANG Haifeng, WEI Yaqin, YANG Yuze, WAN Xuerui, SUN Kangyongjie, CHENG Shuru, WANG Chuan
2020, 37(12): 2457-2462. doi: 10.11829/j.issn.1001-0629.2020-0107
[Abstract](2073) [FullText HTML] (757) [PDF 616KB](22)
In this study, the genomic DNA of Aspergillus fumigatus was used as a template to construct a genetically engineered cellulase strain with high efficiency. The cbh gene was amplified by PCR, ligated into the prokaryotic expression vector pET-28a, and transformed into Escherichia coli BL21(DE3) to induce the expression of cellobiohydrolase (CBH) protein. The enzyme activity of the recombinant strain was determined by Congo red staining and 3,5-Dinitrosalicylic acid (DNS). The results showed that the expression vector pET-28a::cbh was constructed successfully. The final concentration of isopropyl-β-D-1-thiogalactopyranoside (IPTG) was 1 mmol·L−1, the induction temperature was 28 ℃ and induction time was 14 h, and the purified protein of 75 kDa was obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The pET-28a::cbh/E.coli hydrolysis loops were detected by the Congo red plate with carboxymethyl cellulose-Na (CMC-Na). The results showed that the obtained recombinant strain had enzyme activity of 0.0563 U·mL−1. The recombinant cellulase strain constructed in this study can lay a foundation to improve the quality of forage silage and production performance of ruminants.
Applicability of remote sensing inversion models for estimating regional soil moisture in Chinese grasslands
KONG Jie, LI Chunbin, WU Jing
2020, 37(12): 2463-2474. doi: 10.11829/j.issn.1001-0629.2020-0032
[Abstract](2687) [FullText HTML] (893) [PDF 944KB](27)
Using MODIS data, three soil moisture inversion models (ATI, TVDI, and VSWI) of Chinese grasslands were constructed, and the output of the three models was verified using measured soil moisture data and AMSR2 data to assess the models’ applicability. The inversion results of the three models were correlated with measured soil moisture to varying degrees, which may reflect spatial and temporal variation of soil moisture in the entire region. The ATI model was considered suitable for estimating soil moisture inversion in grass ecosystems, meadow ecosystems, and in alpine sparse vegetation and tundra ecosystems in winter; however, it produced high error rates regarding summer soil moisture inversion. Furthermore, this model was considered unsuitable for soil moisture inversion of grassland ecosystems. The TVDI model showed good applicability regarding grass ecosystems, meadow ecosystems, and in alpine sparse vegetation and tundra ecosystems in spring, but it produced considerable deviation in winter. The VSWI model showed low error rates in summer, and it was considered suitable for soil moisture inversion of grassland ecosystems.
Analysis of scientific research funding of turf science in China in the past 20 years
HU Qiannan, CUI Huiting, ZHANG Kun, LI Mingna, SUN Yan
2020, 37(12): 2475-2485. doi: 10.11829/j.issn.1001-0629.2020-0268
[Abstract](1587) [FullText HTML] (633) [PDF 1368KB](19)
The Situation of Scientific Research Funding of Turf Science was reviewed here based on statistical analysis of fata of the national natural science foundation of China, and research content and trends were analyzed. The developments in the past years were respectively summarized from aspects of turf physiology, resource breeding, and phyletic classification, among others. The state of research on some typical genera of turfgrass such as Lolium, Festuca, and Cynodon were selectively analyzed. The results showed that turf science had developed rapidly in the past decade. Research is mainly focused on turf physiology and resource breeding, and molecular biology methods are used most frequently. However, research development is uneven between turfgrass genera, suggesting room for improvement in the future.
Variation in leaf functional traits of different-aged Haloxylon ammodendron communities, and the relationship with soil factors
WANG Fei, GUO Shujiang, FAN Baoli, ZHANG Weixing, WANG Fanglin, HAN Fugui, ZHANG Yunian, SUN Tao
2020, 37(12): 2486-2496. doi: 10.11829/j.issn.1001-0629.2020-0266
[Abstract](1769) [FullText HTML] (644) [PDF 692KB](27)
In this study, we analyzed the variations in leaf functional traits of differently-aged Haloxylon ammodendron in Minqin, and further studied their relationship with soil factors. This analysis allows us to better understand the adaptation strategies of H. ammodendron to the soil environment in arid desert areas. Our results showed that: 1) Except for chlorophyll content, leaf total carbon content and leaf total phosphorus content, the leaf functional traits of different-aged H. ammodendron showed significant differences (P < 0.05). Except for leaf total potassium content and specific leaf area, which showed moderate variation, other leaf functional traits showed only weak variation. 2) The leaf functional traits of H. ammodendron were correlated; the leaf water content, leaf saturated water content and chlorophyll content could be used as the main indices of leaf functional traits of H. ammodendron with the change in time. 3) Soil moisture content, electrical conductivity and pH were the main soil factors affecting the leaf functional traits of different-aged H. ammodendron. The functional traits of H. ammodendron showed different combinations with an increase in age. Corresponding adaptive strategies to the change in soil factors were also found, which indicate that H. ammodendron leaves have strong plasticity, conducive to adaptation to the arid desert ecological environment in Minqin.
Changes in C, N, P content and stoichiometric ratios in response to salt stress in Avena sativa plants
HAN Bo, LI Guang, Zhuomacao, SHAO Qianxiong, HOU Fujiang
2020, 37(12): 2497-2506. doi: 10.11829/j.issn.1001-0629.2020-0193
[Abstract](1619) [FullText HTML] (652) [PDF 647KB](28)
This study investigated the effects of salt stress on C, N, and P distribution, and the stoichiometry of the oat, Avena sativa, providing a theoretical basis for the use of oats as a biological tool for the improvement of saline soil in the Hexi region. The content of C, N, and P, and the stoichiometric ratios of oat plants were studied under 5 kinds of salt concentration stress. Our results showed that: 1) With an increase in salt concentration, the content of C, N, and P in the aboveground and underground parts of oat increased and then decreased, reaching a maximum value at 150 mmol·L−1. 2) Oats adapted to adversity stress primarily by changing the utilization efficiency of N and P. Under salt stress, the C∶N and C∶P ratios were lower in the aboveground regions of oat plants than in the underground parts. Meanwhile, the oat N∶P values (2.5~10.6) were all lower than 14. Compared to P, N showed a higher restriction in the growth of oats in the Hexi area. 3) There was a significant correlation between the conversion and utilization of aboveground and subsurface nutrients under salt stress (P < 0.05), and N was the most sensitive. In summary, 150 mmol·L−1 was the maximum salt tolerance threshold of oats grown in the Hexi region. Reasonable nitrogen fertilizer addition was more conducive to oat growth as a biological tool for the improvement and restoration of saline grassland in the Hexi region.
Advances in research on germplasm resources and genetic breeding of Astragalus sinicus
SHI Haifan, GUO Zhenfei
2020, 37(12): 2507-2519. doi: 10.11829/j.issn.1001-0629.2020-0177
[Abstract](2252) [FullText HTML] (685) [PDF 644KB](36)
Chinese milk vetch (Astragalus sinicus) is a traditional winter green manure crop in the southern rice-growing area of China. It provides important land use and cultivation strategies in agricultural production and can be comprehensively used. Although research on the utilization of A. sinicus germplasm resources and genetic breeding has been conducted, existing A. sinicus germplasm resources are few and uneven due to the long-term stagnation of selection. The existing resources cannot meet production demand, affecting the development of A. sinicus in China. This paper introduces the historical origin and distribution of A. sinicus, clarifies the breeding objectives, and focuses on the utilization of germplasm resources and genetic breeding. Future research on A. sinicus breeding is also discussed in this paper. This paper provides information on germplasm collection and promotes the utilization of existing germplasm resources and development of new varieties of A. sinicus.
A bibliometric review of global research status of Meconopsis
SHI Ning, WANG Jinniu, SONG Yike, HE Jiali, WEI Yanqiang, NIYATI Naudiya, WU Yan
2020, 37(12): 2520-2530. doi: 10.11829/j.issn.1001-0629.2020-0210
[Abstract](3002) [FullText HTML] (757) [PDF 4298KB](50)
Several species of the genus Meconopsis are renowned ornamental and traditional medicinal plants with significant utilization value. This paper presents a comprehensive review of literature on the genus Meconopsis published between 1980 and 2019. A total of 250 studies obtained from CNKI (China National Knowledge Infrastructure) and Web of Science databases were analyzed using CiteSpace V to determine the annual output of publications, main researchers, research institutions, research hotspots, and Meconopsis trends. The results showed an increase in publications related to Meconopsis; however, the citation frequency has varied over the years. The Chinese Academy of Sciences and its affiliated institutions have the largest contribution towards Meconopsis research, which is reflected in the number of publications. This is partly due to the geographical distribution of Meconopsis. Over the years research interest in Meconopsis has shifted from traditional taxonomical work, which was important in the formative years, to chemical and pharmacological studies using sophisticated techniques in molecular biology. Finally, based on the framework of mountain ecosystem structure and composition, functions and services diversity combined with the results of literature metrology, this paper systematically summarized the dominant disciplines, future application value, and the interaction and merging of different fields in the study of Meconopsis. In the future, cooperation and exchanges should be strengthened to better understand the benefits of Meconopsis, and expand multidisciplinary approaches to provide scientific support for sustainable utilization of wild plant resources. There is also a need to reinforce the protection of native species and trade-offs among different ecosystem services.
Effects of barley particle size in diets on growth performance, nutrient digestion, and meat quality of fattening Hu sheep
MA Xiaowen, ZHOU Wenjing, LIU Xin, KOU Yufei, ZHANG Zhian, LI Fadi, LI Fei
2020, 37(12): 2531-2540. doi: 10.11829/j.issn.1001-0629.2020-0136
[Abstract](2044) [FullText HTML] (659) [PDF 654KB](30)
The purpose of this study was to determine the effect of barley particle size in diets on growth performance, nutrient digestion, rumen fluid volatile fatty acids, slaughter performance, and meat quality of fattening Hu sheep. Fifty-four healthy, male (approximately 29.85 ± 0.23 kg) Hu lambs were randomly divided into three treatment groups, each treatment was replicated eighteen times with the sheep being the experimental unit. The three treatments consisted of whole barley that had been ground and passed through a 2 mm sieve [small particle size group (SPS group)], 3 mm sieve [middle particle size group (MPS group)], and a 4 mm sieve [large particle size group (LPS group)]. The trial period included a fourteen-day adaptation period, a seven-day pre-feeding period, and a sixty-three-day formal period. The results showed that: 1) There was no significant difference in the final weight, dry matter intake (DMI), average daily weight gain (ADG), and feed to gain ratio (F/G) among the treatments (P > 0.05). 2) There were no significant differences in dry matter (DM), organic matter (OM), and crude protein (CP) digestibilities among the treatments (P > 0.05), but the apparent digestibilities of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were significantly different (P < 0.05). The apparent digestibility of NDF in the LPS group was 14.3 and 7.8% higher than in the SPS and MPS groups, respectively (P < 0.05). The apparent digestibility of ADF in the LPS group was 22.1% higher than that of the SPS group and comparable to that of the MPS group. 3) The total volatile fatty acid (TVFA), acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid, and valeric acid were not significantly affected by the treatments (P > 0.05). Similarly, the acetic to propionic acid ratio and rumen fluid pH were not significantly affected by the treatments (P > 0.05). 4) There were no significant differences in live weight before slaughter, carcass weight, dressing percentage and brightness, redness, and yellowness of the rumen ventral sac and dorsal sac among treatments (P > 0.05). 5) There were no significant differences in pH, drip loss, water loss rate, muscle brightness, redness, and yellowness at 0 and 24 h post-slaughter among the treatments (P > 0.05); however, the shearing force in the LPS group was significantly higher than that in the SPS and MPS groups (P < 0.05). In summary, barley particle size in diets does not affect the growth performance, slaughter performance, and volatile fatty acids in the rumen fluid of fattening Hu sheep; however, the apparent digestibility of the LPS group was significantly affected, which might indicate improvement in fiber digestibility.
Effects of cellulase treatment of buckwheat straw on production performance of barn feeding Tan sheep and its economic benefit
WU Shuang, ZHOU Yuxiang, JIA Rou, JIN Yadong
2020, 37(12): 2541-2549. doi: 10.11829/j.issn.1001-0629.2020-0299
[Abstract](2070) [FullText HTML] (621) [PDF 535KB](28)
The purpose of this experiment was to study the effects of cellulase treatment of buckwheat straw on growth performance, digestion and metabolism, and slaughter performance of Tan sheep in Yanchi County, Ningxia. Twenty-four healthy three-month-old Ningxia Tan sheep with similar body weights were randomly split into three groups of eight. The ratio of concentration to forage was 30∶70. The control group was fed a basal diet and unprocessed buckwheat straw. Trial group Ⅰ was fed a basal diet and buckwheat straw treated with cellulase Ⅰ (enzyme activity ≥ 10 000 U·g−1). Trial group Ⅱ was fed a basal diet and buckwheat straw treated with cellulase Ⅱ (enzyme activity ≥ 5 000 U·g−1). The preparation period was 15 d, and the formal experiment period was 60 d. Digestion and metabolism tests were carried out in the midway point and near the end of the feeding test feeding test. After the end of the formal experiment period, 5 Tan sheep with approximately equal body weight were selected from each group and slaughtered after fasting for 24 h to determine slaughter performance indexes. The results showed the following: 1) Cellulase treatment of buckwheat straw can improve the average daily weight gain and economic benefit of Tan sheep. Cellulase Ⅰ and cellulase Ⅱ treatment of buckwheat straw increased the average daily weight gain by 31.46% and 10.68%, respectively, compared to that of the control group (P > 0.05). The ratio of feed to gain of trial group Ⅰ was the lowest of the 3 groups at 7.28, which was significantly different from the control group (P < 0.05). 2) The apparent digestibility of dry matter (DM) and neutral detergent fiber (NDF) was significantly increased by 16.96% and 10.45% after treatment of buckwheat straw with cellulase Ⅰ (enzyme activity ≥ 10 000 U·g−1) (P < 0.05). 3) Cellulase treatment of buckwheat straw may reduce fecal and urinary nitrogen (P > 0.05), and significantly improve nitrogen retention, along with the utilization efficiency of nitrogen (P < 0.05). The digested nitrogen and apparent biological value of nitrogen of trial group Ⅰ were significantly increased by 13.09% and 14.28% more than control group (P < 0.05). 4) Cellulase Ⅰ (enzyme activity ≥ 10 000 U·g−1) treatment of buckwheat straw significantly improved the carcass weight, slaughter rate, and net meat weight of Tan sheep (P < 0.05), and the bone weight and loin eye area of trial group Ⅰ were significantly higher than those of the control group (P < 0.05). In summary, cellulase treatment of buckwheat straw can improve the average daily weight gain and carcass weight of sheep, reduce the ratio of feed to gain, increase the deposition of nitrogen, and reduce nitrogen emissions of house-fed Tan sheep to some extent. Under these experimental conditions, cellulase Ⅰ demonstrated the best effects.
Effects of three types of pelleted total mixed rations on production performance and rumen histology in Hu sheep
LIU Ningbo, ZHAO Haishan, GUO Lei, WANG Xia, LI Taotao, MA Youji
2020, 37(12): 2550-2557. doi: 10.11829/j.issn.1001-0629.2020-0044
[Abstract](2230) [FullText HTML] (665) [PDF 619KB](20)
We studied the effects of pelleted total mixed rations containing three different roughage types on the production performance, slaughter performance, meat quality, and rumen tissue morphology of stall-fed Hu sheep. Thirty 80-day-old weaned Hu sheep were selected as the test subjects. The sheep were randomly divided into three groups (10 in each group), and a 60-day fattening test was carried out, during which they were fed pelleted total mixed rations containing one of three types of coarse feed ingredient: corn straw silage (group A), barley grass (group B), or alfalfa hay (group C). The average daily weight gain and final weight of group B were significantly lower than those of group A (P < 0.05), while the average daily weight gain and final weight of group C were not significantly different from those of groups A and B (P > 0.05). In group A, eye muscle area was larger than in groups B and C (P > 0.05), and grade rule value was lower (P > 0.05). In group C, muscle tenderness was significantly greater than in the other groups (P < 0.05), and water loss rate was reduced (P < 0.05). Rumen papilla length was significantly greater in groups A and B than in group C (P < 0.05), while rumen papilla width in group A was significantly greater than in groups B and C (P < 0.05). The muscular and keratinized layers of the rumen were significantly thicker in group B than in groups A and C (P < 0.05). Overall, the total mixed rations containing corn straw silage (group A) provided the most economic benefits. These results can serve as a guide for the use of whole-grain total mixed rations in intensive and large-scale sheep rearing.
Effects of diets with different concentration-roughage ratios on the microbial community structure of Nubian goat rumen
HUO Junhong, FANG Shaopei, WU Pingshan, ZHONG Xiaojun, ZHAN Jinshun
2020, 37(12): 2558-2566. doi: 10.11829/j.issn.1001-0629.2020-0303
[Abstract](1910) [FullText HTML] (769) [PDF 862KB](30)
The purpose of this study was to analyze the effects of diets with different concentration-roughage ratios on the microbial community structure of Nubian goat rumen. Thirty-six healthy Nubian ewes with similar body weights were randomly divided into three groups, with 12 goats per group. Goats in each group were fed total mixed rations with concentration-roughage ratios of 40∶60 (L), 50∶50 (M), or 60∶40 (H). The experimental period was 70 days. The results were as follows: 1) A total of 1901 OTUs were generated, of which 1348 OTUs were shared by the three groups, accounting for 70.91% of the total. The number of OTUs was significantly higher in group L than in group H (P < 0.05). The number of OTUs decreased with the increasing dietary concentration-roughage ratios. 2) The Chao and Ace indexes declined with increasing dietary concentration-roughage ratios. The Ace index was significantly higher in group L than in group H (P < 0.05). The Shannon and Simpson indexes showed no significant differences between the groups. 3) According to cluster analysis, the structure of the rumen microbial community was relatively close in groups L and H. 4) At the phylum level, the relative abundances of Elusimicrobia, Lentisphaerae, TM7, Cyanobacteria, and Spirochaetes were significantly higher in group L than group H (P < 0.05), but the relative abundance of Euryarchaeota had the opposite result. The relative abundances of Proteobacteria and Verrucomicrobia were significantly higher in group L than group M (P < 0.05). 5) At the genus level, the relative abundances of vadinCA11 and Sphaerochaeta were significantly higher in group L than group H (P < 0.05), but the relative abundances of Selenomonas and Methanimicrococcus had the opposite result. 6) At the species level, the relative abundances of Desulfovibrio D168, Ruminococcus albus, Selenomonas ruminantium, and Prevotella ruminicola were significantly higher in group M than group H (P < 0.01 or P < 0.05), but the relative abundances of Ruminococcus flavefaciens and Fibrobacter succinogenes had the opposite result. In conclusion, the diets with different concentration-roughage ratios influenced the microbial community structure of goat rumen, which then affected nutrient digestion and absorption.
Globodera artemisiae, a new cyst nematode record in Gansu, China
HAN Shangming, LI Wenhao, LI Huixia, ZHANG Yiwen, NI Chunhui
2020, 37(12): 2567-2573. doi: 10.11829/j.issn.1001-0629.2020-0163
[Abstract](1540) [FullText HTML] (569) [PDF 816KB](13)
In 2018−2019, a cyst nematode population was isolated from the rhizosphere of Artemisia argyi on an alpine grassland in Tianzhu County, Gansu Province, China. The morphological characteristics of this nematode population were: brown spherical cysts, a prominent neck, generally circumfenestrate, with no vulval cone, underbridge, or bullae. Second-stage juveniles were vermiform, with inconspicuous head constriction, and a strong stylet. The tail was conical and sharply pointed. The ITS-rDNA and 28S-rRNA D2-D3 regions of the population were amplified, from which 948 and 1 015 bp fragments were obtained, respectively. After sequencing, cluster analysis showed that the population was clustered as Globodera artemisiae, with a confidence of over 97%. This population was identified as G. artemisiae based on its morphological and molecular characteristics. This is the first report of the genus Globodera and a new species record in Gansu Province.
Selection of plateau zokor (Eospalax baileyi) DNA barcodes
WANG Chan, PAN Yongtai, WANG Jing, LIU Fayang, YAO Baohui, SU Junhu
2020, 37(12): 2574-2583. doi: 10.11829/j.issn.1001-0629.2020-0054
[Abstract](2069) [FullText HTML] (747) [PDF 762KB](15)
Plateau zokor (Eospalax baileyi) is a unique rodent from the Tibetan Plateau, which has important ecological and economic functions. DNA barcoding is emerging as a useful tool not only for species identification, but also for phylogenetic studies. To screen out DNA barcodes that could be used to identify the plateau zokor, the complete mitochondrial genome sequences of four sibling species of plateau zokor, subfamily Myospalacinae, were determined using PCR direct sequencing. The genetic distance and phylogenetic tree construction were analyzed using bioinformatics software Clustal X 1.83, MEGA 5.0, and Dna SP 5.0. There were 10 gene regions identified as potential DNA barcodes, and the sequence similarity distribution ranged from 30.07% to 98.31%. The results showed that the intraspecific genetic distance of Cyt b, ND4, and COX1 was smaller than the interspecific genetic distance. In addition, the study shows that geographic populations can be determined from Cyt b and ND4 gene sequences, which is consistent with the traditional classification method. Therefore, the comprehensive analysis of Cyt b and ND4 genes is suitable for the DNA barcoding of plateau zokor.
Analysis of factors influencing the degradation rate of neutral detergent fiber in whole-plant corn silage: Taking Zhengda 12 in Ningxia as an example
REN Lijuan, BU Dengpan, WANG Jianping, CHEN Yakun, SHAN Liyan, WANG Kun, WANG Siwei, ZHAO Liansheng
2020, 37(12): 2584-2593. doi: 10.11829/j.issn.1001-0629.2020-0322
[Abstract](1914) [FullText HTML] (610) [PDF 649KB](16)
Taking 23 Zea mays silages from different production areas in Ningxia as the research object, the grey correlation method was used to analyze the correlation degree between the 30-hour neutral detergent fiber degradation rate (NDFD30) and the nutritional components. In addition, a regression model was constructed for predicting the NDFD30 according to the nutrient components. This was done to explore the key factors that affect the NDFD30 of whole corn silage to provide a basis for improving the utilization efficiency of roughage and the production performance of dairy cows. The results showed that the order of the degree of correlation between the nutrient composition and NDFD30 was crude protein > crude fat > crude ash > carbohydrate > neutral detergent fiber > acid detergent fiber > lignin > dry matter > starch. The NDFD30 of corn silage was negatively correlated with the dry matter, crude protein, acid detergent fiber, lignin, and crude ash, and positively correlated with the neutral detergent fiber, carbohydrates, starch, and crude fat. The R2 of the regression model between the NDFD30 and nutrients was 0.912, and the effective influencing factors were lignin, crude fat, crude protein, neutral detergent fiber, and crude ash. In summary, crude protein, crude fat, crude ash, and neutral detergent fiber are the key factors that affect the NDFD30.
Effects of wheat bran supplementation on the quality of mixed silage from feed rape and corn straw
YANG Jie, YANG Yi, DING Yuan, LIU Hui, WANG Jing, XIN Guosheng
2020, 37(12): 2594-2602. doi: 10.11829/j.issn.1001-0629.2020-0347
[Abstract](3069) [FullText HTML] (588) [PDF 609KB](18)
The carbon source is an important factor that affects the fermentation quality of silage. The present study was conducted to investigate the effects of wheat bran addition as a carbon source on the quality of mixed feed rape and corn straw silage. Fresh feed rape and corn straw were evenly mixed at a proportion of 2∶1. Wheat bran, with a humidity 60%, was then added as the carbon source at 0, 2%, 4%, 6%, 8%, and 10%. The pH value of the mixed silage was measured on the 3rd, 7th, 15th, 23rd, 30th, 45th, and 60th days. The evaluations of the sensory characteristics, main nutrient contents, and fermentation index were performed on the 60th day. The results demonstrated that the fermentation quality of feed rape and corn straw silage with wheat bran improved remarkably after 60 days, and the sensory scores were all higher than 13 points. The pH values of each group decreased significantly (P < 0.05), with the fastest reduction before 7 days. The pH value of each group decreased to below 4.25 by the end of the experiment. Nutrient analysis found that the CP, EE, and ash contents in the group with 10% wheat bran addition was significantly higher than those in the other groups (P < 0.05). Meanwhile, the NDF and ADF contents in the group with 10% wheat bran were significantly lower than those in the other groups (P < 0.05). The analysis of the fermentation parameters showed that the ammonia nitrogen content and proportion of ammonia nitrogen in the total nitrogen in the 10% wheat bran group were significantly lower than those in the other groups (P < 0.05). The ammonia nitrogen in the total nitrogen reached the highest ratio of 6.09% in the 0 wheat bran group. Meanwhile, there were also significant intergroup differences concerning the lactic acid content (P < 0.05), with the maximum lactic acid content of 89.83 g·kg−1 being reached in the 10% group. The analysis of the volatile fatty acid composition demonstrated that acetic acid was the most abundant in each group, while no butyric acid was detected. There were significant intergroup differences for both acetic and propionic acids (P < 0.05). The acetic acid content in the 0 addition group reached 19.02 g·kg−1. The propionic acid content in the 10% addition group reached 0.87 g·kg−1. In summary, the addition level of wheat bran significantly influences the quality of mixed rape and corn straw silage. High quality silage can be obtained with the addition of wheat bran at 10%.
Effects of different silage additives on the nutritional quality and fermentation characteristics of mixed alfalfa
LI Xiongxiong, JIAO Ting, LEI Zhaomin, ZHAO Shengguo, LI Fei, RAN Fu, QIN Weina
2020, 37(12): 2603-2614. doi: 10.11829/j.issn.1001-0629.2020-0068
[Abstract](1855) [FullText HTML] (607) [PDF 810KB](20)
In this study, the effects of different silage additives (Sila-MAX, Sila-MIX, Yaxin Bio, Baiaoming, and Taiwan Freshli) on the nutritional quality and fermentation characteristics of mixed alfalfa were explored, without the use of a control additive. The nutritional qualities [dry matter (DM), crude protein (CP), neutral detergent fiber (ADF), acid detergent fiber (ADF), and total digestible nutrients (TDN)] and fermentation characteristics [ammoniacal nitrogen/total nitrogen (NH3-N/TN), pH, lactic acid (LA), and acetic acid (AA)] of the samples placed in aerobic storage for 0, 24, 48, and 72 h after 60 fermentation days were determined. The results showed that the nutritional quality and fermentation characteristics of silage alfalfa changed after 0, 24, 48, and 72 h of aerobic storage. Compared with the control, the DM and TDN contents increased significantly under the Sila-MIX and Yaxin Bio treatments (P < 0.05). The DM content of each treatment increased with the prolongation of aerobic storage, while the TDN content only increased under the Sila-MIX treatment (P < 0.05). The CP content of each treatment was lower than that of the control, especially for 48 and 72 h of Sila-MIX treatment, which decreased by 2.38% and 2.03%, respectively. After 0, 24, 48, and 72 h of aerobic storage, the LA content of silage alfalfa under each treatment increased with the increase in storage time, but no significant differences were found (P > 0.05). There were no significant differences regarding the pH between treatments (P > 0.05). Compared with the control, the NH3-N/TN content decreased after 0, 48, and 72 h of aerobic treatment (P > 0.05), showing an obvious reduction under the Sila-Mix and Yaxin Bio treatments. Grey correlation analysis showed that the quality of alfalfa silage treated with different additives was as follows: Yaxin Bio > Sila-Mix > Baiaoming > Sila-Max > Taiwan Freshli. Therefore, Yaxin Bio and Sila-Mix are suitable additives for alfalfa silage and could be popularized and applied in production practice.
Golfer’s communicative rationality and self-discipline intention on the golf course: Analysis based on an expanded model of the theory of planned behavior
WU Kexiang, YAO Rao
2020, 37(12): 2615-2624. doi: 10.11829/j.issn.1001-0629.2020-0243
[Abstract](2916) [FullText HTML] (600) [PDF 644KB](17)
Based on the extended model of the theory of planned behavior, this study explores the factors influencing golfers' on-course self-discipline behavior and provides a reference for their self-discipline guidance. A total of 358 participants were included through a field survey and online questionnaire. The sample data were analyzed using the structural equation model. The validation results showed that golfers' subjective norms, perceived behavioral control, and self-discipline intention were positively correlated. The results also verified that communicative rationality had a significant effect on golfers' self-discipline intention, and the golf club supervision scenario played a key regulatory role in influencing the golfers' self-discipline intention. This study concludes that the golfers' recognition of golf rules and etiquette and their understanding of golf culture are the basis for establishing normative beliefs and forming self-disciplinary behavior. Golfers' skill levels and opportunities to participate in tournaments serve as the intrinsic motivation that inspires self-discipline and the guarantee of enhancing the concept of and willingness to engage in self-discipline. The rationality of words and deeds is the inner motivation of self-discipline. The club management system is an important means for players with weak self-discipline to promote their self-discipline. This paper presents suggestions from players and clubs to promote the rationality and self-discipline of players on a golf course and jointly create an atmosphere of fair competition on golf courses.