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1.
畜牧产业的快速发展对饲草饲料的需求日益增加,筛选新的饲料作物品种是当务之急。本研究以2个国审牧草甘蔗品种为对照,对15个甘蔗品种的生物产量和10个青饲料常规营养成分指标进行测定分析,探究甘蔗不同刈割期的主成分变化规律,评价甘蔗饲用价值,为甘蔗一年多采和全株饲用提供科学依据。通过因子主成分分析筛选出粗蛋白（CP）、酸性洗涤纤维（ADF）、水溶性碳水化合物（WSC）、粗脂肪（EE）、钙（Ca）5个主要指标,基本包含了所测指标的全部信息。结果显示：15个甘蔗CP含量最高的是‘云蔗12-201’,为8.80%;ADF含量最低的是‘ROC22’,为35.25%;WSC含量最高的是‘云蔗00-290’,为6.16%;EE含量最高的是‘云蔗01-286’,为1.40%。其中‘ROC22’‘云蔗12-201’的CP含量超过CK1、CK2;‘Q27’‘ROC22’‘云蔗01-286’‘云蔗06-160’‘云蔗12-142-1-J’‘滇蔗11-728’的ADF含量均低于CK1、CK2;‘Q27’‘云蔗00-290’‘云蔗12-142-1-J’‘云蔗16-16’‘滇蔗11-726’‘滇蔗11-728’的WS...  相似文献   

2.
The effect of exit temperature of a rotary-drum-drier and of the length of pre-drying storage time on chemical composition and digestibility of dried grass cobs was investigated in two experiments. Increasing exit temperature from 77 to 166°C reduced WSC, NFE and available lysine content and increased CF content of dried grass. In vitro and in vivo DM digestibility was reduced by 16.4 and 24.5 percentage units respectively. Increasing length of pre-drying storage time also reduced WSC and available lysine content and reduced in vitro and in vivo DM digestibility by 2.4 and 5.1 percentage units respectively. The greatest reduction in in vivo digestibility in both experiments occurred in the CP fraction.  相似文献   

3.
The effects of offering a range of grass silages and mixtures of grass and maize silages on the intake of beef cattle were studied. Four grass silages (GS1, GS2, GS3 and GS4) were used. Grass silage 1 was ensiled from a second regrowth in mid‐late September and treated with an inoculant additive. Grass silages 2, 3 and 4 were ensiled, without additive, from a primary regrowth harvested in early July, late May and mid‐June respectively. Wilting periods were 8, 30, 36 and 36 h for GS1, GS2, GS3 and GS4 respectively. Grass silages 1, 2 and 3 were precision chopped and ensiled in bunker silos, while GS4 was ensiled in round bales. The DM content (g kg?1) and starch concentration (g kg?1 DM) of the three maize silages (MS1, MS2 and MS3) used were 256 and 128, 256 and 184, and 402 and 328 for MS1, MS2 and MS3 respectively. Seventy‐two Charolais and Limousin cross‐bred steers were used in a changeover design with two 4‐week periods. The study consisted of sixteen treatments incorporating the four grass silages fed alone and with the three maize silages arranged as a 4 × 4 factorial design. The grass silage and maize silage mixtures were offered in a ratio of 0·60:0·40 (DM basis) once daily using individual Calan gates. All silages were offered ad libitum with 3 kg per head per day of a concentrate supplement. Dry matter and metabolizable energy (ME) intakes were highest with diets based on grass silage GS4 compared with diets containing the other grass silages. Metabolizable energy intakes of diets containing no maize silage, and those based on MS1 and MS2, were similar (P > 0·05) but lower than that of diets containing MS3. Only limited increases were found in DM and ME intakes with the inclusion of maize silage in grass silage‐based diets while offering high‐quality grass silage (assessed in terms of DM content, and fibre and N concentrations) promoted high voluntary intakes.  相似文献   

4.
Kenaf (Hibiscus cannabinus L.) is a potential alternative crop being developed for fiber production. Because planting area varies dramatically from year to year, seed supplies may greatly exceed use so that the excess seed must be stored for one to several years. The objectives of this study were to determine the effect of seed storage duration at 10 °C on germination, vigor, emergence, and yield. Replicated trials were established at Starkville, MS in 1999 and 2000 to evaluate field emergence and biomass yield of kenaf seed from five ‘Everglades 41’ (‘E41’) harvest year seed lots stored at 10 °C in ambient relative humidity for up to 4 years. Germination of these same seed lots under standard (20–30 °C) and cool (20 °C) temperatures, and seed vigor was evaluated over time. Field emergence was the same for the different seed storage durations up to 4 years, but was directly affected by drought conditions for each planted year. Biomass yields ranged from 12.39 to 14.57 Mg ha−1 in 1999 and 16.82 to 18.47 Mg ha−1 in 2000, but were not different between storage durations. Seed germination remained greater than 80% regardless of storage duration. Electrolyte leakage, based on conductivity, was 38–50% less with freshly harvested seed than seed stored for 4 years at 10 °C. However, neither the conductivity nor accelerated aging test were reliable predictors of field emergence. Kenaf seed stored up to 4 years at 10 °C retained germination rates acceptable for commercial use. Neither field emergence nor biomass yield was affected by seed storage duration.  相似文献   

5.
An experiment investigating changes in fermentation variables and microbial composition during storage of small‐bale silage and haylage was performed. Haylage was defined as silage with a dry‐matter (DM) content exceeding 500 g kg?1. Grass was wilted to three different DM contents, and baled into silage (350 g DM kg?1), haylage with a low DM content (550 g kg?1) and haylage with high DM content (700 g kg?1) in small rectangular‐shaped bales (0·80 m × 0·48 m × 0·36 m) that were individually wrapped. Bales were stored for short (2 months) or long (14 months) periods before opening and sampling. Silage had higher concentrations of fermentation products and a lower pH than either of the two haylage types. In general, long‐term storage influenced all fermentation variables except concentrations of butyric acid and succinic acid, and yeast counts were higher after 14 months than 2 months of storage. However, silage changed in more fermentation variables during storage than the two haylage types. Although differences between short‐ and long‐term stored silage were found, linear correlations between short‐ and long‐term stored bales were present for all chemical variables. Pearson's correlation coefficients were highest for lactic acid, followed by pH.  相似文献   

6.
Ice encasement causes major winter damage in grasslands in coastal areas of Northern Scandinavia and may also affect grass performance in a future changing climate. Changes in ice‐encasement tolerance (LD50), frost tolerance (LT50) and water‐soluble carbohydrate (WSC) content were investigated in different cultivars of timothy and perennial ryegrass sampled at three sites with contrasting conditions. Timothy endured ice encasement for 40 d more than ryegrass (maximum LD50 63 vs. 20 d), and a cultivar originating from 69°N tolerated significantly longer periods in ice than a cultivar from 59°N. A similar relationship between cultivar origin and tolerance was observed for ryegrass. The higher LD50 in timothy compared with ryegrass seemed to be associated with a lower rate of change in WSC content during ice encasement, but no apparent relationship was found between WSC content at the start of encasement and plant survival in ice. A significant linear relationship was found between LD50 and LT50 of plants sampled in the field. A differing decline in frost tolerance during ice encasement for the species indicated that timothy is more resistant to dehardening under ice than ryegrass. This study contributes data and functional relationships needed to develop models of grass performance during winter.  相似文献   

7.
A field experiment was undertaken between April 2003 and May 2004 in southern Tasmania, Australia, to quantify and compare changes in the nutritive value of perennial ryegrass (Lolium perenne L.), prairie grass (Bromus willdenowii Kunth.) and cocksfoot (Dactylis glomerata L.) under a defoliation regime based on stage of leaf regrowth. Defoliation interval was based on the time taken for two, three or four leaves per tiller to fully expand. At every defoliation event, samples were collected and analysed for acid‐detergent fibre (ADF), neutral‐detergent fibre (NDF) and total nitrogen (N) concentrations and to estimate metabolizable energy (ME) and digestible dry matter (DDM) concentrations. Amounts of crude protein (CP) and metabolizable energy (MJ) per hectare values were subsequently calculated. There was a significantly lower (P < 0·001) NDF concentration for perennial ryegrass compared with prairie grass and cocksfoot, and a significantly lower (P < 0·001) ADF concentration for cocksfoot compared with prairie grass and perennial ryegrass, regardless of defoliation interval. The CP concentration of cocksfoot was significantly greater (P < 0·001) compared with the CP concentrations of prairie grass and perennial ryegrass. The estimated ME concentrations in cocksfoot were high enough to satisfy the requirements of a lactating dairy cow, with defoliation at or before the four‐leaf stage maintaining ME concentrations between 10·7 and 10·9 MJ kg?1 DM, and minimizing reproductive plant development. The ME concentrations of prairie grass (10·2–10·4 MJ kg?1 DM) were significantly lower (P < 0·001) than for cocksfoot (as above) and perennial ryegrass (11·4–11·6 MJ kg?1 DM) but a higher DM production per hectare resulted in prairie grass providing the greatest amounts of ME ha?1.  相似文献   

8.
An experiment was carried out during 1984 to study the effect of treating grass at ensiling with three commercially available inoculant-type additives (H/M Inoculant, Grass Sile and Siron), formic acid (850 g kg−1; Add-F) or no additive on grass preservation, in-silo loss, intake and animal performance. Primary growth grass ensiled from 28–29 May into concrete-walled covered silos was of high dry matter (DM, 234 g kg−1), water-soluble carbohydrate content (WSC. 212 g kg DM−1) and digestibility (MADF, 250 g kg DM−1).
The untreated silage displayed good preservation and with the exception of the Sirontreated silage which showed significantly lower buffering capacity (Be) and volatile fatty acid (VFA) contents than the untreated silage, the application of inoculant-type additives did not improve silage preservation or decrease in-silo DM losses. The formic acid-treated silage displayed significantly lower Be, water-soluble carbohydrate, ash, ammonia nitrogen (g kg total N−1) and lactate contents than the untreated silage.
After a 133 d storage period, silages were offered to finishing beef cattle for an 84-d period. Cattle offered the silages displayed similar and non-significant daily DM intakes, daily liveweight gains, dressing proportions and daily carcass gains. From this experiment it appears unlikely that any of the additives evaluated will improve animal performance relative to a well-preserved untreated silage.  相似文献   

9.
Gelatinisation and retrogradation of starch in wheat flour systems and whole wheat grains were studied using DSC and the impact of these events on starch digestibility was investigated. Gelatinisation of starch was possible in wheat flours with more than 60% moisture content (dwb) and gelatinised samples had higher digestibility values. Retrogradation of starch was studied with partially and fully cooked (boiled at 100 °C for 12 min and 32 min, respectively) wheat grains that were subjected to storage at 22 °C for 48 h. Stored samples had lower digestibility values when compared to the freshly cooked counterparts. The effect of moisture on retrogradation was studied with fully cooked wheat grains that were dried to a range of moisture contents (14.6–35.9%, wwb) and stored at 20 °C for 24 h. Retrogradation enthalpy increased with increasing moisture content; however, digestibility values did not reflect the changes in retrogradation enthalpy. The possibility of estimating the degree of retrogradation in fully cooked grains (32 min cooking) was investigated using a wheat flour-water system. The retrogradation enthalpy of fully cooked grains was slightly higher than the wheat flour-water system (at a moisture content of 49%, wwb) during the course of storage at 22 °C.  相似文献   

10.
刈割高度对多花黑麦草新品种产量和品质的影响   总被引：1，自引：0，他引：1  
为探讨不同刈割高度对多花黑麦草新品种饲草产量和品质的影响,以2个多花黑麦草新品种为对象,采用5个刈割高度分别测定2个品种的鲜、干草产量、粗蛋白、可溶性碳水化合物(WSC)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和干物质体外可消化率(IVDMD)。结果表明:在65 cm时刈割,所获得的鲜、干草产量最高;随着刈割高度的增加,2个黑麦草品种的粗蛋白和可溶性碳水化合物含量呈抛物线趋势变化,在刈割高度为55 cm时达到最高值;中性和酸性洗涤纤维含量则随着刈割高度的增大逐渐增加;干物质体外消化率亦呈现抛物线的趋势,在刈割高度为65 cm时达到最高。2个品种的表现规律一致。  相似文献   

11.
This study utilized leaf stage‐based defoliation intervals to describe the concentrations and contents of water‐soluble carbohydrate (WSC) and nitrogen (N) in stubble and root reserves and their effect on the regrowth of prairie grass (Bromus willdenowii Kunth.) plants. The priority sequence for allocation of WSC reserves during the regrowth period was also investigated. There were substantially higher concentrations of WSC and N in the stubble compared with the roots following defoliation, confirming the stubble as the primary site for energy storage, with roots playing a lesser role. However, high R2 values for the relationships between WSC concentration in roots and regrowth variables suggested that plants of prairie grass were reliant on WSC reserves from the roots in addition to the stubble to meet the energy requirements of plants until adequate photosynthetic tissue had been produced. The sequence of priority for allocation of WSC reserves followed the order of leaf growth, root growth and tillering during the regrowth period. Although WSC reserves were identified as the primary contributor to plant regrowth following defoliation, there was also a strong relationship between stubble N concentration and regrowth variables.  相似文献   

12.
Synergistic effects and very effective control of citrus postharvest green and blue molds, caused by Penicillium digitatum and Penicillium italicum, respectively, were observed on artificially inoculated ‘Valencia’ oranges and ‘Clemenules’ and ‘Ortanique’ mandarins after a potassium sorbate (PS) treatment was followed by 2 days of storage in atmospheres of elevated CO2 or O2 at a curing temperature. A combined treatment consisting of 60-s dips in aqueous solutions of 3% PS heated to 62 °C was followed by 48-h exposure to air, 15 kPa CO2 or 30 kPa O2 at 33 °C. Control treatment was a 60-s water dip at 20 °C followed by 24-h exposure to air at 20 °C. Synergism was observed on citrus fruit either incubated at 20 °C for up to 22 days, simulating direct commercialization, or stored at 5 °C for up to 45 days, simulating commercial cold storage. This research offers potential new tools to the citrus industry for implementation of nonpolluting integrated postharvest disease management programs, especially devoted to high added value organic markets or export markets with zero residue tolerance.  相似文献   

13.
Silage making practices in respect of 130 samples of autumn made grass silages ensiled in bunkers on commercial farms in South Wales during 1983-1985 were analysed to discern the effect of wilting and/or silage additives on fermentation. Silages were primarily made during late September and early October in fine weather from perennial ryegrass pasture which had not been grazed for 6 weeks. On average 13.9 ha of pasture was cut for silage. Analysis of 120 samples of grass showed it contained 176 g kg?1 dry matter (DM) with (g kg?1 DM) 215 protein, 240 modified acid detergent fibre (MADF), 78 water-soluble carbohydrate (WSC) and 95 ash. Most farmers attempted to pre-wilt grass for 1 day prior to ensilage and one quarter of them made unwilted silage. Silage making was usually completed within 6 days of starting to cut and was generally made with a precision-chop machine. Silage additives applied were (kg t?1) formic acid (4·7), formic acid 4-formalin (5·5), sulphuric acid-+ formalin (5·0) sugars (14) and inoculants (0·65). Formic acid significantly reduced pH, and formic acid with or without formalin significantly reduced ammonia nitrogen (N) content of silages compared with other treatments. Protein contents of acid/formalin treated silages were significantly higher and MADF of acid with or without formalin treated silages were significantly lower than other treatments. Pre-wilting grass prior to ensilage did not significantly increase subsequent silage DM content and significantly increased the pH of non-additive treated silages. Unwilted silages treated with formic acid with or without formalin had a significantly lower ammonia-N content and higher residual WSC than other treatments. It is suggested that only formic acid application either alone or in conjunction with formalin to unwilted silage was successful in producing well preserved silages and that a grass WSC content of 17 g kg?1 would be necessary to achieve this.  相似文献   

14.
Harvest date had no significant influence on weight loss in storage of tubers which were grown under a low fertilizer regime (vines died prematurely). However under a higher fertilizer regime, tubers harvested 21–45 days after vine kill lost significantly less weight than those harvested 2–13 days after vine kill. An average of 4 years’ data indicates that tubers stored continuously at 45 F (7.2 C) lost significantly less weight than those stored at 42 F (5.5 C) or 48 F (8.9 C). This is attributed to lack of suberization and delayed maturation of tubers at 42 F resulting in increased weight loss and to higher respiration at 48 F in comparison to tubers held at 45 F storage. Considerable seasonal differences in weight loss were recorded. The 1971 growing season which was characterized by a prolonged period of extremely high temperatures resulted in tubers which lost significantly more weight during storage than was the case in the other seasons. Air ventilization rates from 20 to 80 cfm/T were used to cool potatoes from 60 F to ambient temperatures of 48 F. No significant differences in weight loss were obtained after 3 week’s continuous cooling with air at 93–95% R. H. regardless of air ventilation rate.  相似文献   

15.
The objective of this study was to examine the effects of predicted milk yields sustained by grazed grass (‘Milk‐from‐Grass’: LOW, MED or HIGH) and Parity (primiparous or multiparous) on the performance and concentrate requirements of grazed Holstein‐Friesian dairy cows offered concentrates on a ‘feed‐to‐yield’ basis during the grazing season. The mean Milk‐from‐Grass values assigned to cows in the LOW, MED and HIGH treatment groups (sixteen multiparous and eight primiparous cows per group) during the experiment (24 May to 2 October; 131 d) were 12·7, 15·4 and 18·1 kg cow?1 d?1, respectively. Concentrate allocations were adjusted every two weeks (approximately) based on individual cows’ milk yields, and concentrate was offered at a rate of 0·45 kg for each kg of milk produced above the assigned Milk‐from‐Grass value at that time. Increasing Milk‐from‐Grass from LOW to MED to HIGH decreased both the mean daily concentrate allocations (4·90, 3·17 and 1·79 kg cow?1 d?1, respectively) and milk yields (23·8, 21·8 and 19·0 kg cow?1 d?1) of the cows. Cows in the LOW treatment group had lower mean and final (i.e. at the end of the study) BCS and LW than those in the MED or HIGH groups. The effects of Milk‐from‐Grass were similar for both primiparous and multiparous cows.  相似文献   

16.
The chemical composition of baled silage frequently differs from that of comparable conventional silage. The extents of wilting, chopping, compaction and air infiltration potentially contribute to these differences in conservation characteristics. An experiment was organized in a 3 (0, 24 or 48‐h wilting to influence herbage dry‐matter content) × 2 (unchopped or chopped) × 2 (with or without compaction) × 2 (with or without air infiltration) factorial arrangement of treatments, to elucidate the relative effects of these factors on the conservation characteristics of ensiled grass. Dry‐matter content of herbage and infiltration of air had a greater effect on silage conservation characteristics than chopping and compaction. The main interactions were between wilting and air infiltration, wilting and compaction, and compaction and air infiltration. Air infiltration stimulated a secondary fermentation in the unwilted herbage, reflected in a large increase (P < 0·001) in clostridial activity. As wilting progressed, air infiltration facilitated yeast respiration of water‐soluble carbohydrates (WSC) and resulted in an increase (P < 0·001) in in‐silo fresh‐weight losses. Compaction reduced (P < 0·05) silage pore space and, as a result, the extent to which air could penetrate the silage mass. Compaction of the wilted herbage restricted respiration and was reflected in increased (P < 0·05) concentrations of WSC and in a reduction (P < 0·001) in fresh‐weight loss. The rapid achievement and maintenance of adequately anaerobic conditions is the primary requirement for baled silage. This study showed that failure to achieve this will lead to progressively greater losses, especially with drier herbage.  相似文献   

17.
The suitability of potatoes for processing into potato chips is dependent on chip color, and internal and external defects. Concentrations of reducing sugars, and more specifically glucose, have been used as a quantitative indicator of acceptability of potato for chipping. The research reported here investigated the correlation between sugar concentrations and chip color, and the variability of sugar concentrations between samples and sample locations. Three potato storage research bins, each with an independent air handling and control system, were located inside of commercial potato storage bins. Snowden potatoes were harvested in the fall of 1992 and stored at different temperatures in the bins through late March, 1993. The potatoes were sampled bi-weekly during the storage period, and the samples were analyzed for sugar concentrations (sucrose and glucose) using a YSI model 2700 sugar analyzer.1 The results indicated that a Snowden potato sample with a glucose concentration less than 0.0075%2 (fresh weight basis) will have a 90% probability of having an acceptable Snack Food Association color score of 1.5 or lower. Lower numbers indicate whiter chips which are generally preferred by chip producers. Similarly, a sample with a glucose concentration of 0.01% will have a 90% probability of having a color of 2 or lower. Based on tubers sampled from four heights within the storage bins, samples from the top of a potato bin will provide a representative sample as long as recommended storage procedures are followed, and potato pulp temperatures are similar throughout the storage.  相似文献   

18.
A total of 2225 samples of herbage, typical of that taken for first-cut silage on commercial farms in England and Wales, was taken between 1988 and 1991. Samples were analysed for dry matter (DM), water soluble carbohydrate (WSC), crude protein (CP) and metabolizable energy calculated from modified acid detergent fibre. The results were used to investigate the effect of weather conditions upon herbage quality for ensilage. In general, in areas of high rainfall, i.e. western areas, herbage DM and WSC were significantly lower than in eastern areas, whilst the reverse situation occurred with CP. Italian ryegrass (IRG) had a significantly higher WSC and lower CP than other grasses, whilst samples from permanent pasture (PP) had significantly lower DM and WSC, and significantly higher CP than other grasses. It was calculated that to produce a WSC concentration in the fresh grass of 37 g kg−1, to produce well-fermented silage without additive use, IRG grown in the east would require a DM of 160 g kg−1, In contrast PP grown in the west would require a DM content of 250 gkg−1.  相似文献   

19.
Mixtures and pure stands of perennial ryegrass, tall fescue, white clover and red clover were grown in a three‐cut and a five‐cut system in southern Norway, at a low fertilization rate (100 kg N ha?1 year?1). The nutritional quality (annual weighted averages) of the dried forage from the two‐first harvesting years was analysed. There was no significant effect of species diversity on crude protein (CP) concentration. In the three‐cut system, we found a significant species diversity effect leading to 10% higher concentrations of acid detergent fibre (ADF), 20–22% lower concentrations of water‐soluble carbohydrate (WSC) and 4% lower net energy for lactation (NEL) concentrations in mixtures compared with pure stands (averaged across the two‐first years). In the five‐cut system, similar effects were seen in the first year only. This diversity effect was associated with a reduction in WSC and NEL concentrations and an increase in ADF, NDF and CP concentrations in the grass species, and not in red clover, when grown in mixtures. This is thought to be a combined result of better N availability and more shading in the mixtures. Species diversity reduced the intra‐annual variability in nutritional quality in both cutting systems.  相似文献   

20.
Windrowed pyrethrum stems were air dried under a range of storage conditions to examine whether the current commercial practice of drying crop material is conducive to pyrethrins’ degradation. Crop material was stored for up to 12 days in a commercial windrow, a shed receiving indirect light or a dark, 5 °C cool-room. Analysis of pyrethrins extracted from flowers of all treatments demonstrated that pyrethrins were not degrading in windrowed crops, plant material stored in the shed or in the 5 °C cool-room. The small differences obtained in pyrethrins content among the treatments can be explained by the natural variation in pyrethrins content of pyrethrum crops. The observation that the achenes were unchanged during this drying period supported the pyrethrins analysis. These results demonstrate that pyrethrins in planta do not degrade as rapidly as extracted pyrethrins.  相似文献   

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