Fresh blood of Tibetan sheep was subjected to protein separation and spray drying, and the effects of drying process on water content, yield and nitrogen soluble index of plasma powder from blood of Tibetan sheep were...Fresh blood of Tibetan sheep was subjected to protein separation and spray drying, and the effects of drying process on water content, yield and nitrogen soluble index of plasma powder from blood of Tibetan sheep were investigated. The results showed that the optimum separation parameters were a centrifugal speed at 6 000 r/min, centrifugal time of 20 min, a mass fraction of dry matter of 20%, an inlet air temperature at 180 ℃ and a feed rate at 400 ml/h, under which the plasma protein was a pale yellow powdery solid, indicating a good separation effect.展开更多
Increased grain yield(GY) and grain protein concentration(GPC) are the two main targets of efforts to improve wheat(Triticum aestivum L.) production in the North China Plain(NCP). We conducted a three-year field exper...Increased grain yield(GY) and grain protein concentration(GPC) are the two main targets of efforts to improve wheat(Triticum aestivum L.) production in the North China Plain(NCP). We conducted a three-year field experiment in the 2014–2017 winter wheat growing seasons to compare the effects of conventional irrigation practice(CI) and micro-sprinkling irrigation combined with nitrogen(N) fertilizer(MSI) on GY, GPC, and protein yield(PY). Across the three years, GY, GPC, and PY increased by 10.5%–16.7%, 5.4%–8.0%, and 18.8%–24.6%, respectively, under MSI relative to CI. The higher GY under MSI was due primarily to increased thousand-kernel weight(TKW). The chlorophyll content of leaves was higher under MSI during the mid–late grain filling period, increasing the contribution of post-anthesis dry matter accumulation to GY, with consequent increases in total dry matter accumulation and harvest index compared to CI. During the mid–late grain filling period, the canopy temperature was markedly lower and the relative humidity was higher under MSI than under CI. The duration and rate of filling during the mid–late grain filling period were also higher under MSI than CI, resulting in higher TKW. MSI increased the contribution of post-anthesis N accumulation to grain N but reduced the pre-anthesis remobilization of N in leaves, the primary site of photosynthetic activity, possibly helping maintain photosynthate production in leaves during grain filling. Total N at maturity was higher under MSI than CI,although there was little difference in N harvest index. The higher GPC under MSI than under CI was due to a larger increase in grain N accumulation than in GY. Overall, MSI simultaneously increased both GY and GPC in winter wheat grown in the NCP.展开更多
Grazing exclusion (GE) is the most effective rangeland restoration technique which facilitates species diversity and forage quality. This study aimed at assessing short-term impact of GE and continuously grazed rangel...Grazing exclusion (GE) is the most effective rangeland restoration technique which facilitates species diversity and forage quality. This study aimed at assessing short-term impact of GE and continuously grazed rangeland on relative frequency, dry matter yield and nutritive value of dominant grasses in an area invaded by Euryops floribundus. A plot of 2.5 ha was measured and the boundaries demarcated using tape measure and steal pins, the plot was further divided into two subplots of 1ha each which were 5 m apart. One subplot was fenced and protected from grazing livestock, while one subplot was grazed continuously and not fenced. Three parallel belt transects of 100 m × 2 m with 3 m apart were laid out in both subplots. Woody plants occurring within the transects were identified and recorded to determine density. In each subplot, a 0.25 m<sup>2</sup> quadrant measuring was thrown randomly to take detailed records on plant species, relative frequency of species and herbage biomass. Four dominant species at the two sites were harvested to determine the nutritive value. Results indicate that grazing exclusion (GE) facilitates grass species diversity, subsequently sixteen and thirteen grasses species were recorded in the GE and uncontrolled grazed (UG) sites, respectively. Eragrostis chloromelas (21.7%), and Themeda triandra (13.2%) had high relative frequencies in the GE site. Highest biomass production was recorded in the GE site (1400 kg·ha<sup>-1</sup>) compared to UG site (1102 kg·ha<sup>-1</sup>). Crude protein content was relatively lower at UG site (5.4% - 5.8%) as compared to GE site (7.2% - 7.8%). It was concluded that, GE showed a positive impact on a relative frequency (%), dry matter yield and crude protein content. UG creates a conducive environment for Euryops recruitment. Further studies are required to examine the impact of GE in long-term trial setup.展开更多
Understanding the relationship between dry matter yield and nutritive value throughout the growing season will help optimize the cutting intervals between harvests in alfalfa (Medicago sativa L.). The Ogallala Aquifer...Understanding the relationship between dry matter yield and nutritive value throughout the growing season will help optimize the cutting intervals between harvests in alfalfa (Medicago sativa L.). The Ogallala Aquifer is a very important water source when growing alfalfa in Southwest Kansas and unfortunately, the water level of the Ogallala Aquifer is shrinking. The objective of this study was to determine the optimum cutting interval that optimizes dry matter yield and nutritive values of alfalfa. Alfalfa was harvested with different cutting intervals, i.e., every 28, 35, 42 and 49 day, which was equivalent of 5, 4, 4, and 3 cuttings per year, respectively in 2013 and 2014. Based on 2-yr total yield, by delaying alfalfa harvest by 21 days, i.e., from every 28th day to 49th day, alfalfa yield increased by 2.25 Mg/ha whereas by 5.58 Mg/ha by delaying cutting intervals from every 28th day to 42nd day. Although harvesting alfalfa every 42nd day had the same cutting frequency as the 35th day treatment (i.e., 4 cuttings per year), the treatment harvesting every 42nd day had significantly higher alfalfa yield than 35th day cutting interval. Alfalfa yield increased by approximately 20% by delaying one week for harvesting alfalfa from 35th to 42nd day interval, based on dry matter yields of 2013 and 2014. As cutting interval increased from every 28th to 49th day, crude protein (CP) content decreased. In contrast to CP, acid detergent fiber and neutral detergent fiber increased as the cutting interval and stage of maturity increased in 2013 and 2014. The results suggest that alfalfa producers in Southwest Kansas possibly could reduce the cutting frequency from 5 to 4 per year. Cutting interval of every 42nd day between harvests appears to be the optimum when considered a dry matter yield and nutritive values in alfalfa.展开更多
[Objective] The paper was to study the effects of different drying methods on moisture content and nutrient composition of alfalfa.[Method] Alfalfa collected from the same piece of land in early flowering period were ...[Objective] The paper was to study the effects of different drying methods on moisture content and nutrient composition of alfalfa.[Method] Alfalfa collected from the same piece of land in early flowering period were dried through three different drying methods, solar drying,outdoor drying in the sun and outdoor drying in the shade, and the effects of different drying methods on contents of moisture, crude protein, crude ash and neutral detergent fiber（NDF） were measured. [Result] The moisture evaporation rate of different drying methods over the same period successively were solar drying 〉 outdoor drying in the sun 〉 outdoor drying in the shade. The crude protein content of alfalfa was the highest through solar drying（P〈0.05）, followed by outdoor drying in the shade, and the crude protein content through outdoor drying in the sun was the lowest. Under the condition of different moisture contents, the crude protein content of dried samples through outdoor drying in the sun decreased by 6.86%-22.43% compared to solar drying, and that through outdoor drying in the shade reduced by 4.92%-17.20%. Under the same moisture content, the crude ash content successively were outdoor drying in the shade 〉 outdoor drying in the sun 〉 solar drying; the crude ash content of alfalfa through solar drying was 3.72%-19.22% lower than outdoor drying in the sun, and 8.12%-29.93% lower than outdoor drying in the shade. The NDF content of alfalfa through outdoor drying in the sun was the highest, significantly higher than the other two drying methods（ P〈0.05）. The NDF content through solar drying was the lowest, 9.08%-27.25% lower than outdoor drying in the sun, and 4.84%-24.84% lower than outdoor drying in the shade. [Conclusion] The paper will provide some references for selection of appropriate alfalfa drying method.展开更多
基金Supported by"123"Science and Technology Support Program from Science and Technology Department of Qinghai Province(2014-GX-136A)~~
文摘Fresh blood of Tibetan sheep was subjected to protein separation and spray drying, and the effects of drying process on water content, yield and nitrogen soluble index of plasma powder from blood of Tibetan sheep were investigated. The results showed that the optimum separation parameters were a centrifugal speed at 6 000 r/min, centrifugal time of 20 min, a mass fraction of dry matter of 20%, an inlet air temperature at 180 ℃ and a feed rate at 400 ml/h, under which the plasma protein was a pale yellow powdery solid, indicating a good separation effect.
基金supported by the National Key Research and Development Program of China (2016YFD0300401)the National Natural Science Foundation of China (32001474, 31871563)the China Agriculture Research System (CARS-3)。
文摘Increased grain yield(GY) and grain protein concentration(GPC) are the two main targets of efforts to improve wheat(Triticum aestivum L.) production in the North China Plain(NCP). We conducted a three-year field experiment in the 2014–2017 winter wheat growing seasons to compare the effects of conventional irrigation practice(CI) and micro-sprinkling irrigation combined with nitrogen(N) fertilizer(MSI) on GY, GPC, and protein yield(PY). Across the three years, GY, GPC, and PY increased by 10.5%–16.7%, 5.4%–8.0%, and 18.8%–24.6%, respectively, under MSI relative to CI. The higher GY under MSI was due primarily to increased thousand-kernel weight(TKW). The chlorophyll content of leaves was higher under MSI during the mid–late grain filling period, increasing the contribution of post-anthesis dry matter accumulation to GY, with consequent increases in total dry matter accumulation and harvest index compared to CI. During the mid–late grain filling period, the canopy temperature was markedly lower and the relative humidity was higher under MSI than under CI. The duration and rate of filling during the mid–late grain filling period were also higher under MSI than CI, resulting in higher TKW. MSI increased the contribution of post-anthesis N accumulation to grain N but reduced the pre-anthesis remobilization of N in leaves, the primary site of photosynthetic activity, possibly helping maintain photosynthate production in leaves during grain filling. Total N at maturity was higher under MSI than CI,although there was little difference in N harvest index. The higher GPC under MSI than under CI was due to a larger increase in grain N accumulation than in GY. Overall, MSI simultaneously increased both GY and GPC in winter wheat grown in the NCP.
文摘Grazing exclusion (GE) is the most effective rangeland restoration technique which facilitates species diversity and forage quality. This study aimed at assessing short-term impact of GE and continuously grazed rangeland on relative frequency, dry matter yield and nutritive value of dominant grasses in an area invaded by Euryops floribundus. A plot of 2.5 ha was measured and the boundaries demarcated using tape measure and steal pins, the plot was further divided into two subplots of 1ha each which were 5 m apart. One subplot was fenced and protected from grazing livestock, while one subplot was grazed continuously and not fenced. Three parallel belt transects of 100 m × 2 m with 3 m apart were laid out in both subplots. Woody plants occurring within the transects were identified and recorded to determine density. In each subplot, a 0.25 m<sup>2</sup> quadrant measuring was thrown randomly to take detailed records on plant species, relative frequency of species and herbage biomass. Four dominant species at the two sites were harvested to determine the nutritive value. Results indicate that grazing exclusion (GE) facilitates grass species diversity, subsequently sixteen and thirteen grasses species were recorded in the GE and uncontrolled grazed (UG) sites, respectively. Eragrostis chloromelas (21.7%), and Themeda triandra (13.2%) had high relative frequencies in the GE site. Highest biomass production was recorded in the GE site (1400 kg·ha<sup>-1</sup>) compared to UG site (1102 kg·ha<sup>-1</sup>). Crude protein content was relatively lower at UG site (5.4% - 5.8%) as compared to GE site (7.2% - 7.8%). It was concluded that, GE showed a positive impact on a relative frequency (%), dry matter yield and crude protein content. UG creates a conducive environment for Euryops recruitment. Further studies are required to examine the impact of GE in long-term trial setup.
文摘Understanding the relationship between dry matter yield and nutritive value throughout the growing season will help optimize the cutting intervals between harvests in alfalfa (Medicago sativa L.). The Ogallala Aquifer is a very important water source when growing alfalfa in Southwest Kansas and unfortunately, the water level of the Ogallala Aquifer is shrinking. The objective of this study was to determine the optimum cutting interval that optimizes dry matter yield and nutritive values of alfalfa. Alfalfa was harvested with different cutting intervals, i.e., every 28, 35, 42 and 49 day, which was equivalent of 5, 4, 4, and 3 cuttings per year, respectively in 2013 and 2014. Based on 2-yr total yield, by delaying alfalfa harvest by 21 days, i.e., from every 28th day to 49th day, alfalfa yield increased by 2.25 Mg/ha whereas by 5.58 Mg/ha by delaying cutting intervals from every 28th day to 42nd day. Although harvesting alfalfa every 42nd day had the same cutting frequency as the 35th day treatment (i.e., 4 cuttings per year), the treatment harvesting every 42nd day had significantly higher alfalfa yield than 35th day cutting interval. Alfalfa yield increased by approximately 20% by delaying one week for harvesting alfalfa from 35th to 42nd day interval, based on dry matter yields of 2013 and 2014. As cutting interval increased from every 28th to 49th day, crude protein (CP) content decreased. In contrast to CP, acid detergent fiber and neutral detergent fiber increased as the cutting interval and stage of maturity increased in 2013 and 2014. The results suggest that alfalfa producers in Southwest Kansas possibly could reduce the cutting frequency from 5 to 4 per year. Cutting interval of every 42nd day between harvests appears to be the optimum when considered a dry matter yield and nutritive values in alfalfa.
基金Supported by National Natural Science Foundation of China(51266009)
文摘[Objective] The paper was to study the effects of different drying methods on moisture content and nutrient composition of alfalfa.[Method] Alfalfa collected from the same piece of land in early flowering period were dried through three different drying methods, solar drying,outdoor drying in the sun and outdoor drying in the shade, and the effects of different drying methods on contents of moisture, crude protein, crude ash and neutral detergent fiber（NDF） were measured. [Result] The moisture evaporation rate of different drying methods over the same period successively were solar drying 〉 outdoor drying in the sun 〉 outdoor drying in the shade. The crude protein content of alfalfa was the highest through solar drying（P〈0.05）, followed by outdoor drying in the shade, and the crude protein content through outdoor drying in the sun was the lowest. Under the condition of different moisture contents, the crude protein content of dried samples through outdoor drying in the sun decreased by 6.86%-22.43% compared to solar drying, and that through outdoor drying in the shade reduced by 4.92%-17.20%. Under the same moisture content, the crude ash content successively were outdoor drying in the shade 〉 outdoor drying in the sun 〉 solar drying; the crude ash content of alfalfa through solar drying was 3.72%-19.22% lower than outdoor drying in the sun, and 8.12%-29.93% lower than outdoor drying in the shade. The NDF content of alfalfa through outdoor drying in the sun was the highest, significantly higher than the other two drying methods（ P〈0.05）. The NDF content through solar drying was the lowest, 9.08%-27.25% lower than outdoor drying in the sun, and 4.84%-24.84% lower than outdoor drying in the shade. [Conclusion] The paper will provide some references for selection of appropriate alfalfa drying method.
