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1.
2.
Sorghum [Sorghum bicolor (L.) Moench] is an ensilable tropical plant known as a good alternative to maize crops in regions with scarce rainfall. The objective of this trial was to obtain prediction models based on nutritional contents and end products of sorghum silage fermentation as related to the dry-matter composition of fresh plants before ensiling. Eleven different sorghum cultivars (including silage, graniferous and sweet types) were used. Twenty-five sorghum plots were harvested between 80 and 120 days of growth. Fifty plastic buckets were used as experimental microsilos and opened between 60 and 90 days of storage. Statistical modelling was used to create a prediction equation that could explain the impact of fresh sorghum composition on the chemical and nutritional composition of its silage. A complex model was detected by stepwise multiple regression to predict the difference of in vitro dry-matter digestibility (IVDMD) before and after ensiling, but a simpler model, which involved only the sum of water-soluble carbohydrate (fWSC) and hemicellulose (fHemi) concentrations in the dry matter of fresh forage, was considered to more usable. It had an acceptable coefficient of determination (0.51). The higher amount of WSC and Hemi in fresh sorghum linearly decreased the difference between IVDMD before and after the ensiling process. A WSC concentration of 125.4 g/kg DM in fresh sorghum is recommended for an ideal silage fermentation when considering pH and lactic acid levels, although ethanol levels continued to increase.  相似文献   

3.
This study attempted to separate the effects of forage source and field microbiota on silage fermentation quality and aerobic stability. Single samples of grass, red clover and maize were used. Field microbiota was obtained by centrifugation of microbial suspensions of the three samples. The intact forages were dried and sterilized by heating at 60°C for 3 h + 103°C for 15 h, inoculated in a 3 (forage) × 3 (inoculum) design and reconstituted to a dry‐matter level of 400 g kg?1 before ensiling. After ensiling for 71 d, subsamples were subjected to an 8‐d aerobic stability test, which included temperature and pH measurements. Bacterial community analysis was performed on samples before and after ensiling by 16S rRNA gene amplicon sequencing. Forage source had a marked effect on the levels of lactic acid, acetic acid, ammonia‐N and 2,3‐butanediol, but microbiota source only affected the acetic acid concentration. The forage and microbiota as well as their interactions affected silage stability variables. The maize microbiota improved silage stability, whereas silages made from the maize forage had the poorest stability. Bacterial community analysis revealed higher abundance of lactic acid bacteria on the maize forage, with Lactococcus and Leuconostoc being the dominant genera. These preliminary results suggested that fermentation quality is mainly affected by forage source, whereas the aerobic stability is affected by both forage and field microbiota.  相似文献   

4.
Re‐ensiling of previously ensiled forage has been a common practice in Brazil, and the use of inoculants may provide a means of reducing dry‐matter (DM) loss. This study aimed to determine the effect of re‐ensiling and the use of microbial inoculants on the quality of sorghum silage. Treatments were presence/absence of an inoculant (Lactobacillus plantarum and Propionibacterium acidipropionici) in the silage, and the re‐ensiling, or not, of the material after 24 h of exposure to air, and these were tested in a factorial 2 × 2 design. Losses due to gas, effluent and total DM were assessed, as were the fermentation characteristics, chemical composition, aerobic stability, and aerobic counts of microorganisms. Effluent loss was higher in re‐ensiled silage, and these silages had lower lactic acid content and higher levels of acetic and propionic acids. The in vitro DM digestibility was lower in the re‐ensiled sorghum silages. The re‐ensiled silage had higher aerobic stability. The inoculant only increased the acetic acid content of the silage. The re‐ensiling of sorghum silage increased effluent loss by 71·2%, and reduced DM digestibility by 5·35%. The use of inoculant did not influence the quality of sorghum silage.  相似文献   

5.
Physical and management factors, such as compaction and sealing, greatly influence the outcome of forage conservation. This study aimed to determine the effects of compaction, delayed sealing and aerobic exposure after ensiling on maize silage quality and on formation of volatile organic compounds. Whole‐crop maize (277 g/kg dry matter [DM]) in 120‐L plastic silos was compacted at either high or low density, and sealed immediately or with delay at 2 days or 4 days post‐filling (six replicates each). After ensiling for at least 175 days, the silages were exposed to air for 6‐day intervals and sampled at 2‐day intervals. A delay in sealing caused an increase in yeast counts and a decline of up to 65% in water‐soluble carbohydrates before ensiling. Sealing the silos after 4 days caused DM losses of up to 11%. Delayed sealing promoted the formation of ethyl esters at silo opening. A 4‐day delay in sealing resulted in the lowest aerobic stability. Aerobic exposure led to considerable changes in silage composition, a loss in feed value and, finally, spoilage. This study indicates that maize silage quality is adversely affected by low compaction, delayed sealing and aerobic exposure.  相似文献   

6.
不同类型青饲青贮玉米的比较研究   总被引:4,自引:0,他引:4       下载免费PDF全文
对7个分蘖、高油和高蛋白型青贮玉米特性和品质的比较。结果表明:独秆晚熟品种中北410、青试01和农大647适宜作为春季播种的青贮玉米,解决冬春季饲料不足;多蘖型的新育01和新育02适宜作为春夏季青饲玉米种植,供给夏秋季青饲料;独秆中熟的高蛋白玉米中原单32品质优,适宜作为在6月底到7月上中旬播种的青饲或青贮玉米种植;同时根据品种的生理特性研究栽培技术,指导各类型青贮玉米种植,满足不同青饲青贮需要。  相似文献   

7.
Two additives (Silo Guard (SG) and propionic acid (PA)) were tested for their effects on the quality and aerobic security of sorghum–sudangrass hybrid silages (JC‐1 and WC‐2). Two sorghum–sudangrass hybrid varieties were harvested for ensiling without additives (CK) or after the following treatments: SG at 0·5% of fresh forage or PA at 0·5% of fresh forage, with three replicates per treatment. The addition of SG and PA both affected the fermentation quality and chemical composition of the silages by lowering pH and NH3‐N/TN and increasing lactic acid, the LA/TA ratio, WSC and CP concentrations compared with the untreated silages. In vitro DM digestibility (IVDMD), in vitro NDF digestibility (IVNDFD) and in vitro CP digestibility (IVCPD) were increased by SG in the JC‐1 silages and WC‐2 silages. Both additives improved the aerobic stability of sorghum–sudangrass hybrid silages. Furthermore, the additives reduced the mould counts and the aflatoxin and zearalenone levels compared with the untreated silages following aerobic exposure. Therefore, ensiling two sorghum–sudangrass hybrid varieties resulted in high‐quality silages. The addition of SG and PA improved silage quality, in vitro digestibility and aerobic security.  相似文献   

8.
The effects of different additives on farm-scale silage quality and beef cattle performance are inconsistent. This study aimed to carry out a systematic review and meta-analysis to evaluate the efficacy of chemical and microbial additives to silage on beef cattle performance. Systematic searches were performed using databases and scientific journals, and 42 articles were selected. Data for all variables were grouped into subgroups according to the additive type. For dry matter intake and average daily gain, the data were also grouped by forage type due to greater comparison numbers. The treatment mean differences and 95% confidence intervals (p < 0.05) were analysed using a random-effects model. The use of homo- and heterofermentative microbial inoculant mixtures and chemical additives (Ch) increased the average daily gain of beef cattle fed maize/sorghum silage. Homofermentative microbial inoculant (Ho), Ch, and a mixture of microbial inoculant and chemical additives also increased the average daily gain of beef cattle fed temperate grasses. Only Ch increased dry matter intake. Ch increased feed efficiency, and Ch and Ho increased carcass weight. The evaluated additives improved the silage fermentation process mainly via pH and ammonia nitrogen reduction. Overall, this meta-analysis demonstrated that silage additives improved the ensiling process and beef cattle performance, with better results with Ch use. Due to the aerobic stability and microbiological profile analyses being carried out more in laboratory-scale silos, more studies are needed to determine these silage parameters after opening the silo at the farm scale.  相似文献   

9.
To reduce losses and improve forage use efficiency in dairy farming systems, mass and nutrient flows during silage production have to be measured from the field to feed bunk. However, data on these losses at the farm scale are scarce. Thus, we examined dry‐matter (DM) losses and changes in nutrient concentrations (proximate constituents, nitrogen [N], phosphorus [P]) and energy values (net energy for lactation [NEL]) of silages on three experimental farms from ensiling to feed‐out. The investigated material included forages from permanent grassland and whole‐crop maize that were stored in 64 side‐walled bunker silos. To determine DM losses, the total‐in versus total‐out method was applied. Additionally, the changes in the nutrient concentrations were measured by comparing the concentrations before and after ensiling. Data analyses were carried out by using ANOVA, and the means across groups were compared via multiple contrast tests. On average, the farms had good silage production management. Average values showed a trend towards higher DM losses during the ensiling process with grass (9%) than maize (7%). The N and P concentrations of the silages remained mainly unchanged during the ensiling process, suggesting that the total losses of N and P were also low (<10%). Regarding the fibre fractions, ensiling resulted in a significant reduction in the concentration of amylase‐treated ash‐excluded neutral detergent fibre (aNDFom) for grass (11%) and maize (15%), while ash‐excluded acid detergent fibre (ADFom) was not affected by the ensiling process. These changes resulted in slightly improved energy values in the silages.  相似文献   

10.
密度及收割高度对复播青贮玉米产量和品质的影响   总被引:3,自引:1,他引:3  
以农大1027组合为材料,在大田条件下分别研究了5种密度及不同收割高度对复播青贮玉米(生长期82 d)产量和饲用品质的影响。结果表明:在密度6万~18万株/hm2范围内随着密度的增加产量先增后降,密度与产量呈二次曲线关系;而饲用营养品质却随密度增加呈现下降趋势。产量最高的密度和品质最优的密度不一致,优质时的密度显著低于高产时的密度。在密度9万~12万株/hm2条件下,可以获得产量高、品质较优的青贮玉米。适当提高收获高度可以明显改善青贮玉米的饲用营养品质。  相似文献   

11.
The hypothesis was that forage species and ensiling conditions have an impact on the formation of biogenic amines and the feed choice of goats in short‐term preference trials. At ensiling, lucerne (Medicago sativa L., first cut), red clover (Trifolium pratense L., first cut) and Italian ryegrass (Lolium multiflorum Lam ., second cut) were treated differently to obtain a range of fermentation qualities. Six treatments of each forage species were prepared and included different dry‐matter concentrations, chemical and biological silage additives, and additions of soil. Silages were sampled for chemical analyses (proximate constituents, fermentation products and other volatile compounds, crude protein fractions and biogenic amines) and stored anaerobically in vacuum‐sealed plastic bags for use in preference trials (one trial for each forage species) with Saanen‐type wethers (= 8 or 6). Each possible two‐way combination of the six silage treatments and a standard hay (= 21 combinations) was offered for ad libitum intake for 3 hr. Data were analysed using multidimensional scaling, analysis of variance and correlation analysis between silage characteristics and dry‐matter intake (DMI). For each forage species, fermentation characteristics and crude protein fractions revealed only small differences among treatments. Although the degree of proteolysis, as measured by non‐protein nitrogen, of all silages was high, biogenic amine and butyric acid concentrations were low. The different treatments apparently had no direct influence on the formation of biogenic amines and feed choice. The preference behaviour within one forage species was strongly divergent, but DMI rankings of the three species were very similar.  相似文献   

12.
Crop composition at harvest affects the ensiling process and the resulting silage quality. The objectives of this study were to determine: (i) the effect of annual N‐fertilizer application (0, 60, 120 and 180 kg N ha?1) and developmental stage (stem elongation, early heading, late heading and early flowering) on the ensiling properties and silage quality of the spring regrowth of timothy (Phleum pratense L.) at two sites for 1 or 2 years, and (ii) the relationship between ensiling properties of the forage and the quality of the resulting silage. Laboratory silos with wilted forage at approximately 350 g dry matter (DM) kg?1 of fresh matter were prepared at each harvest and opened 150 d later for silage analysis. Higher rates of N‐fertilizer application decreased the concentration of water‐soluble carbohydrates (WSC), increased the buffering capacity (BC) and nitrate concentration, and decreased the ratio of WSC:BC, primarily in the early stages of development. The ensiling properties of timothy were, therefore, less favourable when high rates of N fertilizer were applied. Silage pH generally increased with increasing rates of N‐fertilizer application; this increase was particularly evident at the first three developmental stages at one site in 1 year. Non‐protein N (NPN) and soluble N concentrations of the silages increased with increased rates of N‐fertilizer application at the first three developmental stages but decreased at early flowering. Ammonia‐N concentration in the silages increased by 0·85, 0·56 and 0·67 when rates of N‐fertilizer application were 60, 120 and 180 kg ha?1, respectively, compared with that when no N fertilizer was applied. Significant correlations between the composition of the forage ensiled and silage quality variables were found at sites in individual years but, when all data were combined, WSC concentration and BC, and their ratio in the forages, were not correlated with pH, and soluble‐N and ammonia‐N concentrations of the silages, and were weakly correlated with NPN and free amino acid‐N concentrations of the silages. Silage quality was reduced by increased N‐fertilizer application, primarily at the early developmental stages, and this can be attributed to a reduction in WSC concentration and an increase in BC of the forage. Water‐soluble carbohydrate concentration, BC, and their ratio, however, were poor predictors of silage quality.  相似文献   

13.
A non-protein nitrogen additive containing ammonia, molasses and minerals was applied to precision-chopped forage maize to raise the crude protein content of the ensiled crop from approximately 8% to 10, 14 or 16%. The dry matter content, total nitrogen, water-insoluble nitrogen, and water-soluble nitrogen concentrations were measured at ensiling and 2 and 8 weeks later. The pH and lactic, acetic, propionic and butyric acid contents of the resultant silage were determined 2 and 8 weeks after ensiling. The levels of crude protein achieved were 10.8, 11.5 and 14.2%, which are equivalent to recoveries in the silages of 108, 82 and 89% of the applied nitrogen. After 8 weeks the water-insoluble nitrogen content of the treated silages had increased while the water-soluble nitrogen content had decreased. The increase in water-insoluble nitrogen may have been due to either decreased proteolysis or increased levels of microbial protein. There was a significant increase of 0.6 units in the pH of the silage when comparing the control to the highest rate of additive application. The additive increased the levels of lactic and acetic acid in the maize silage.  相似文献   

14.
The biomass production and the nutritive value of three tropical shrub legumes with condensed tannins (CT) ( Calliandra calothyrsus , Flemingia macrophylla , Leucaena leucocephala ) and two without CT ( Cratylia argentea , Desmodium velutinum ) as nitrogen-rich feed supplements for ruminants were assessed in two field experiments in Colombia. In one experiment, conducted on two different typical tropical soils (mollisol vs. oxisol; pH, 7·8 vs. 5·0; P content, 43 vs. 2 mg kg DM−1), the effects of low and high levels of fertilizer application with P, K, Ca, Mg and S were tested in both the dry and rainy seasons. In a second experiment on the oxisol, the effect of a lower level of application of either P or S fertilizer was assessed. On the oxisol, C. calothyrsus and F. macrophylla had the highest biomass production (93 and 100 g DM plant−1 in 9 weeks respectively) but the dry season caused extremely low DM yields in all species tested. Leucaena leucocephala did not grow on the oxisol but had the highest biomass production on the mollisol (454 g DM plant−1 in 9 weeks). On the oxisol, the mineral concentrations of the forage were below the requirements of ruminant livestock. Fertilizer treatment had no clear effects on the nutrient composition of the forage. The non-CT shrub C. argentea had the highest concentrations of most minerals in its forage.  相似文献   

15.
Highlights of progress in the production of silage over the past 50 years include the introduction of improved hybrids of maize (Zea mays L.), the forage harvester, the big baler, polyethylene covering for horizontal silos, stretch‐wrap film for bales and novel additives designed to improve the fermentation and aerobic stability of silage. The key biochemical pathways in the silage fermentation have been described together with the effects of microbial and chemical additives on fermentation and aerobic stability during the feed‐out phase. The significance of oxygen and water in silage fermentation has been quantified and efficacy of covering silos has been established, with recent progress in the development of oxygen barrier film. Future perspectives include improving food safety and animal health by increasing the hygienic quality of silage, reducing the environmental impact of silage by decreasing loss of nitrogen to soil and atmosphere, reducing methanogenesis in the rumen and increasing methane yield from silage as biofuel, and the use of silages as feedstocks for multiple end uses in biorefineries.  相似文献   

16.
A laboratory-scale experiment was conducted with lucerne (Medicago sativa) to determine the effects of acid treatment on proteolysis during ensiling and during subsequent in vitro ruminal protein incubations. Lucerne [300 g dry matter (DM) kg?1 forage] was either untreated (control) or treated with sulphuric, formic or trichloroacetic acid (a protein precipitant that stops enzyme activity) at levels sufficient to adjust immediately forage pH to 4·0, then conserved as either silage or hay. Time-course data indicated that non-protein nitrogen (N) formation was 70–90% complete after 1 d of fermentation in the silo. Non-protein N concentrations (g kg?1 total N) were 177 at ensiling and increased to 567 (control), 426 (sulphuric), 398 (formic) and 263 (trichloroacetic) after 60 d of ensiling. Because non-protein N in silage treated with formic and sulphuric acids was nearly three times greater than that in silage treated with trichloroacetic acid, it is clear that the typical acid treatments only slow proteolysis and do not destroy protease activity during ensiling. The ruminal protein degradation rate of conserved forages was slower than that of fresh-cut forage that was preserved with dry ice immediately after cutting. The degradation rate of all acid-treated forages was similar, indicating a consistent effect on ruminal degradation regardless of method of preservation. There was a clear effect of acid treatment on reducing the rate and extent of ruminal degradation of protein in lucerne hay.  相似文献   

17.
Grazing lands in warm‐temperate and subtropical North America have become less diverse. Pastures are typically grass monocultures, while rangelands are generally managed for the grass components. Overstocking, selective herbicides, fire exclusion and heavy rates of nitrogen fertilizer have contributed to near exclusion of native, warm‐season legumes. The simplicity of managing grass monocultures, pasture production responses to nitrogen fertilizer and profitability of grass‐only systems have limited interest in legume‐based approaches. Changing economics and ecological concerns with ecosystem accumulation of industrial inputs contribute to an increasing interest in legumes. Unlike the development of temperate pasture legumes and recent research in the tropics, legumes tolerant of both freezing temperatures and hot weather have received less attention. Poor establishment, limited persistence and potential invasiveness limit currently available introduced species. Native, herbaceous, warm‐season legume species occur throughout warm‐temperate North America, but little attention has been directed to these plants as potential forage species. Some success with a few native legume species, primarily in the genus Desmanthus, suggests potential for expanded assessment of forage value of the many species available. Current assessments of native legumes, primarily for conservation purposes, provide an opportunity to expand evaluations of these species for pasture and rangeland potential while economics of livestock production and public interest in ecosystem health are supportive. Experiences with legumes of warm‐temperate origin in North America, along with results with temperate and tropical pasture legumes globally, provide a starting point for future efforts at incorporating greater legume diversity in pastures and rangelands of subtropical and warm‐temperate regions around the world.  相似文献   

18.
Neutral detergent fibre (NDF), acid detergent fibre and water-soluble carbohydrates (WSC) were assayed in wet and dry samples of maize silage, either treated with NaOH or untreated (control), before and after ensiling.
Statistically significant effects of drying at 60°C were observed in WSC, NDF and cellulose estimations expressed on the basis of 105°C dry matter.
It could therefore be preferable to analyse wet samples, as these are not altered by the degradations induced by oven-drying and are more representative of the original condition of the forage.  相似文献   

19.
结合近30年来我国优质蛋白玉米(QPM)的发展演变,通过对国外青饲(贮)玉米部分标准的分析与国内优质蛋白玉米(QPM)、青饲(贮)玉米发展现状的研究,提出促进我国优质蛋白玉米种质的经济实用化(商业化)创新利用,加快青饲(贮)玉米、粮饲型玉米育种发展步伐的优先序:青饲(贮)玉米--粮饲型玉米--优质玉米--优质蛋白玉米。  相似文献   

20.
基于知识图谱的我国青贮玉米研究领域可视化分析   总被引:1,自引:0,他引:1  
吴园  易婧 《玉米科学》2021,29(1):184-190
以1992~2019年中国知网(CNKI)数据库收录的721篇青贮玉米研究的核心期刊论文为研究对象,运用文献分析法,并借助CiteSpace软件绘制知识图谱,对我国青贮玉米研究的文献分布、刊物分布、研究机构、研究热点与趋势等进行可视化分析,全面把握我国青贮玉米领域研究的发展进程,为我国青贮玉米理论研究提供有价值的参考....  相似文献   

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