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1.
Toxicogenic fungal moulds have been previously identified in Irish farm silages and are known to be capable of producing mycotoxins. Mycotoxins are detrimental to animal health and performance and can be transferred through feed to animal produce. The objectives of this study were to identify and quantify the challenge posed to livestock from mycotoxins in Irish silages and determine whether conventional chemical characteristics could be used as indicators of mycotoxin occurrence. Over the 2‐year period, 300 silages were sampled on 150 farms and these consisted of round‐baled grass silages (n = 115) and pit silages of either grass (n = 175) or maize (n = 10). There was no significant difference in mycotoxin concentrations across silage types in either year, except for baled silage containing higher concentrations of enniatin B compared with pit silage in Year 1. Conventional chemical characteristics of silages were generally not reliable predictors for mycotoxin incidences; however, dry‐matter digestibility, crude protein, fermentation products and ash did predict the incidence of enniatins and beauvericin. The incidence and concentration of the twenty measured mycotoxins were generally low and individual mycotoxin concentrations recorded were considerably lower than current EU directive or guidance thresholds. Non‐regulated mycotoxins measured were similar to or lower than concentrations reported in the literature. Based on current knowledge and the concentrations of individual mycotoxins detected in this study, the challenge to Irish livestock and livestock products from animal consuming silage is generally low. However, the additive or synergistic effects of multiple mycotoxins in silage are unknown.  相似文献   

2.
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   

3.
Alternatives need to be addressed for reducing losses in elephant grass (EG; Pennisetum purpureum) silages. Furthermore, smallholders lack information on the nutritional aspects of dairy farms. The aim of this study was to evaluate total mixed ration silage (TMR) combining fresh EG and concentrate ingredients, creating the following treatments: (i) EG silage (control); (ii) EG, corn and soya bean meal; (iii) EG, corn, soya bean meal and molasses; (iv) EG, citrus pulp and soya bean meal; and (v) EG, citrus pulp, soya bean meal and molasses. Five replicates of each treatment were ensiled in 15‐L plastic jars. The fermentation profile, chemical composition, microbial counts and aerobic stability were assessed. Three contrasts were tested, as follows: (i) control vs. TMR; (ii) TMR with corn vs. TMR with citrus pulp; and (iii) TMR with molasses vs. TMR without molasses. Variables were analysed through the PROC MIXED procedure of the SAS at the 5% level. The TMR had better fermentation profile, lower effluent production and longer aerobic stability compared to control. When the effect of corn was compared to citrus pulp among the TMR, silages with citrus pulp showed lower fermentation losses, non‐protein nitrogen and effluent production. The aerobic stability also improved with citrus pulp. Molasses did not affect the fermentation profile. Overall, lactic acid was the primary acid in all TMR. Nitrogen source (e.g., soya bean meal) can be used without compromising the fermentation process. TMR with citrus pulp showed better results than corn. TMR may be an alternative to optimize the use of EG on smallholdings.  相似文献   

4.
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   

5.
This study was aimed to perform a screening of Lactobacillus buchneri strains from maize silage and use them as inoculant in maize and sugarcane silages. In all, 151 lactic acid bacteria (LAB) strains were isolated from whole‐plant maize silage, and their identification was based on the sequence analysis of 16S rDNA. In total, 15 strains were categorized to the L. buchneri group and eight of these were selected based on growth rate and fermentation pattern. The selected strains were evaluated on fermentation and aerobic stability of maize and sugarcane silages. For maize, the inoculated silages had lower pH and higher LAB population, but lower acetic acid concentration in comparison with the untreated control silage. For sugarcane silage, the strains 56.1, 56.4 and 40788 resulted in highest dry‐matter (DM) content and lowest DM losses. However, only the strain 40788 showed lowest counts of yeasts and moulds. Sugarcane silages inoculated with the strains 56.9, 56.26 and the untreated control silage showed highest concentrations of lactic acid and ethanol, besides the great DM losses. Even so, for both crops, the aerobic stability was not affected by inoculation. After air exposure, all silages increased temperature and had high population of yeast and moulds. Nevertheless, the strains 56.1 and 56.4 are promising for use as a silage inoculant.  相似文献   

6.
There have been reductions in grazing cattle and corresponding increases in mixed diets across many regions. Mixed diets consist of silage, grains, legumes and other herbaceous plants (termed total mixed ration, TMR). TMR has been associated with increased milk yields but has also been linked to increased enteric methane production. We measured milk yields and methane production from high‐yielding Holstein‐Friesian cattle after substituting 29%–36% of a TMR diet with grass. Two feeding treatments were compared with a diet of TMR: grass grazed at pasture and grass cut in the field and delivered to housed cattle (termed cut‐and‐carry). Each feeding treatment was fed to 15 cattle, and the experiment was conducted in South‐west Scotland. Using a laser methane detector, we measured a twofold and fourfold decline in enteric methane production for the cut‐and‐carry and grazing groups, respectively, when the animals consumed grass. TMR was consumed by both grass‐fed groups overnight, so daily values were adjusted to include elevated methane production during this period. This revealed that methane production for the cut‐and‐carry and grazing groups was 17% and 39% lower than for the TMR‐fed group respectively. Milk yields were maintained for all three groups, and the efficiency of milk production per unit of methane was substantially greater for the two grass‐fed groups. A shift away from exclusively feeding TMR by adding fresh grass to the diets of cattle could contribute to meeting emissions targets and could also represent an economically sustainable climate change mitigation strategy.  相似文献   

7.
A study was conducted on 124 farms in Sweden and Norway where fungal (all farms) and mycotoxin (100 of the 124 farms) presence was examined in wrapped forage bales. Samples were also analysed for chemical composition, and data on the bale production and storage system on each farm were collected. Fungi, analysed by three common sampling methods, were found in bales from 89% of the visited farms (110 farms). The most frequently isolated fungal species from the bale surface was Penicillium roqueforti. Mycotoxins were present in 39% of the 100 samples analysed. The most common mycotoxins present were enniatin B (14 farms) followed by deoxynivalenol (12 farms). The risk of finding fungi in baled forage samples was higher with odds ratio (OR) of 5.1 when less than eight layers of stretch film were applied, low seal integrity of wrapping (OR 172 at <10 s of seal integrity), higher dry‐matter content (OR 1.17–1.56 per % unit DM) and higher concentrations of acetic acid (OR 47.5 per g DM) and ethanol (OR 3.4 per g DM). Mycotoxin presence was not found to be correlated with any of the chemical characteristics of the baled forage, or with any forage production and management factors. A positive correlation was present between total fungal counts and general mycotoxin presence, but not between specific mycotoxins and the toxin‐producing fungal species.  相似文献   

8.
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9.
Silage was made from wilted and unwilted grass in May 1965, 1966 and 1967. The silage was made in sealed silos, but these were not evacuated and additives were not used.
The silages were fed as follows: in 1965 to milking dairy cows and 1-year-old beef steers; in 1966 to steers coming into the experiment at 3, 9 and 15 months of age; in 1967 to weaned steer calves, with or without rolled barley (1 or 2 kg/head per day). In all years the silages were of high in vivo digestibility. The intake of wilted silage was higher than that of unwilted silage. There was no significant difference between the milk yields of cows fed on wilted and unwilted silage only. Liveweight gains were higher with wilted silage in 1965 and 1966, but not in 1967. In 1966 gains increased with age of animal and in 1967 gains were higher at successively higher levels of concentrate feeding.  相似文献   

10.
Grass and maize silages were fed alone and with two levels of a barley supplement to Friesian steers of about 300 kg liveweight. The organic matter (OM) intakes of grass and maize silage were similar although the OM digestibilities of the silages were 0·722 and 0·649 respectively. For both silages, barley supplementation increased total OM intake and total digestible OM intake by 0·46·0·08 and 0·37·0·06 g per g OM of supplement respectively. Liveweight gains on grass and maize silage diets were 1·38 and 1·20 kg d-1 respectively, but the differences were not significant (P> 0·05).  相似文献   

11.
The effects on the production from dairy cows of two annual stocking rates (2.5 and 3.0 cows ha?1) and two systems (grass and maize+rye) were examined. The experiement included three treatments: Treatment A was a grass system with an annual stocking rate of 2.5 cows ha?1 and Treatments B and C were maize+rye systems with a stocking rate of 2.5 and 3.0 cows ha?1 respectively. There were twenty cows per treatment and the total area of the system was 22 ha. Treatment A had 4.05 ha of grass silage area, Treatment B had 0.8 ha of grass silage area and 3.2 ha designated to silage crops (maize+rye), whereas Treatment C had 0.4 ha of grass silage area and 2.7 ha of silage crops. Maize silage had a higher nutritive value that the rye or grass silage. The greter production from the maize+rye crops allowed the silage needs of the cows to be met in systems with a seasonal herbage production when stocking rates are higher than for grass-only systems. Rye plus maize system allowed higher stocking rates (2.7 cows per ha) than grass-only system (2.1 cows per ha) because of more efficident use of land resources. Lower stocking rates and grass-only systems increased milk production per cow but not per hectare in comparison with rye plus maize systems.  相似文献   

12.
A meta‐analysis of feeding trials using grass silages was conducted to predict production responses for dairy cows fed grass silage. They were divided into two subsets: 69 diets from 11 studies were used for comparison of silages made from primary growth and regrowth grass (harvesting subset), and another 157 diets from 24 studies were used for comparison of digestibility influenced by the maturity of grass ensiled (D‐value, digestible organic matter in dry matter) (maturity subset). The minimum prerequisite for an experiment to be included in the data set was that milk production, feed intake, silage characteristics and concentrate ingredients were reported. Both subsets were analysed using the mixed model procedures of SAS. The mean response in dry‐matter intake (DMI) and silage DMI to improved silage D‐value was 0.0175 and 0.0161 kg per unit D‐value (g/kg DM) respectively. The average increase in milk and energy‐corrected milk yield was 0.30 and 0.37 kg per 10‐unit increase in silage D‐value respectively. Milk protein concentration increased, and fat concentration tended to increase with enhanced silage D‐value. Each 10‐unit increase in D‐value reduced milk yield by 0.092 kg at a given dietary metabolizable energy intake (MEI), suggesting that the ME concentration of high D‐value silages was overestimated. Cows fed regrowth silage produced 0.55 kg/day more energy‐corrected milk than those fed primary growth silage at a given dietary MEI. The prediction models can be used to improve ration formulation systems or incorporated into economic models for optimizing milk production in various farming systems.  相似文献   

13.
This study was conducted to evaluate the effects of Lactobacillus plantarum, molasses and/or ethanol on fermentation quality and aerobic stability of total mixed ration (TMR) silage, which is widely used in dairy cow diets at mid‐to‐late lactation in Tibet. TMR was treated with ethanol (E), molasses (M), Lactobacillus plantarum(L), ethanol+molasses (EM), ethanol+Lactobacillus plantarum (EL) plus control. After 45 d of ensiling, inoculant significantly (P < 0·05) increased lactic acid (LA) concentration and decreased pH, ammonia nitrogen (AN) concentration, and aerobic bacterial and yeast counts, compared to control. After the first 3 d of aerobic exposure, LA for silages without ethanol started to decrease, while LA for E silages almost remained unchanged till the end of the aerobic exposure period. The pH in TMR silages without ethanol gradually increased, while that for E and EL remained about 4·60 and 4·00, respectively, and EL showed the lowest pH among six silages over the course of aerobic exposure. Aerobic bacterial counts in control, M and EM silages were significantly higher (P < 0·05) than those in E, L and EL, and yeast counts in E and EL silages were significantly lower (P < 0·05) than those in other silages after 9 d of aerobic exposure. The results suggest that inoculation with L. plantarum was more effective in altering fermentation characteristics than adding molasses, while ethanol showed a potential to protect TMR silages from pH increase and delayed the growth of aerobic bacteria and yeast either alone or in combination with L. plantarum.  相似文献   

14.
Two silages were produced by harvesting grass either unwilted, using a direct cutting flail forage harvester (flail-direct), or wilted following precut-ting and being picked up using a meter-chop harvester (precision-wilted). Formic acid was applied at the rates of 2·45 and 2·9 1 t-1 for the flail-direct and precision-wilted silages, respectively. Weather conditions were difficult, both before and during harvesting with a total of 27 mm rainfall falling on the wilted herbage before ensiling. The in-silo dry matter losses were 199 and 68 g kg-1 for the flail-direct and precision-wilted silages, respectively. The resulting silages had mean particle lengths of 49 and 24 mm, dry matter contents of 186 and 276 g kg--1 and D-values of 068 and 062 for the flail-direct and precision-wilted silages, respectively. During a 141-day feeding period commencing on 19 November, the two silages were offered to 88 British Friesian cows with a mean calving date of 21 January and divided into four groups in a 2×2 factorial design experiment. The silos were divided longitudinally and two groups of cows were self-fed the silages in situ, one for each silage type, while the other two groups were easy-fed the same silages along a feed fence. There were no significant interactions between system of silage harvesting and feeding on any of the measurements of animal performance. Animals on the flail-direct silage consumed 16% less silage dry matter and produced 10% more milk per cow than those on the precision-wilted silage treatment. The overall effect was a 12% greater milk output for each unit of grass dry matter ensiled with the flail-direct than with the precision-wilted harvesting system. System of silage feeding did not significantly influence silage intake or milk output, with the mean milk yields during the final 21 days of the study being 234 and 236 kg d-1 (±0.30) for the self- and easy-feed systems, respectively. The effects of the treatments on milk composition, liveweight change, body condition score and total ration digestibility are also reported.  相似文献   

15.
Two diets were compared: perennial ryegrass ( Lolium perenne L.) silage and perennial ryegrass/white clover ( Trifolium repens L.) silage, in each case fed ad libitum , without supplementation, to lactating dairy cows. The comparison was made with silages cut on each of four dates. The crops were wilted to a dry matter content of at least 256g kg-1 and no additives were used.
The grass/clover silages were well preserved at all four cuts. The grass was well preserved at three cuts, but, at a May cut, the grass silage was less well preserved and less digestible than the grass/clover silage. When the May silages were fed, milk yield was higher with grass/clover than with grass. Taking the experiment as a whole, however, milk yield and composition were similar on the two diets. The grass/clover silages had a lower proportion of cell wall and their intake by dairy cows was consistently higher than that of the grass silages.
It is concluded that perennial ryegrass/white clover crops can be ensiled successfully and fed successfully, with high intake, to lactating dairy cows, but it should not be assumed that cows will give more milk than when fed equivalent all-grass silage.  相似文献   

16.
Wilting grass prior to ensiling generally increases the dry matter (DM) intake but the effect of wilting on animal performance is still poorly understood. There is a need to improve understanding of the effects of wilting on the nutritional components and chemical composition of grass silage. This study focused on the effects of the extent and rate of wilting on N components of grass silage. Meadow grass was wilted to four DM contents (200, 350, 500, 650 g kg?1) at two different rates (fast, slow), creating a total of eight silages. Crude protein (CP) fractions were measured using the Cornell Net Carbohydrate and Protein System. Utilizable CP at the duodenum (uCP), a measure of feed protein value, was estimated using the modified Hohenheim gas test. Ruminally insoluble, undegraded feed CP (RUP) was measured using an in situ technique. Amino acid (AA) composition prior to and after rumen incubation was also investigated. Utilizable CP at the duodenum, RUP and true protein fractions B2 and B3 were increased by rapid wilting and high DM content (DM > 500 g kg?1), although the increase with DM was only mild for uCP, probably due to lower ME content in the DM‐650 silages. Non‐protein‐N decreased with increasing DM and rapid wilting. The higher RUP content from both DM‐650 silages leads to a higher total AA content after rumen incubation. Treatment also influenced the AA composition of the ensiled material, but the AA composition after rumen incubation was similar across treatments. Rapid and extensive wilting (DM > 500 g kg?1) improved protein value and reduced CP degradability. Increased uCP may result in higher milk protein yield, while reduced degradability may reduce N lost from urinary excretion. The primary effect of wilting on post‐ruminal AA supply from RUP appeared to be quantitative, rather than qualitative.  相似文献   

17.
Abstract To counteract a decrease in the availability of grazing for feeding dairy cows in France, a simulation model is proposed in the paper, which combines decision and agronomic submodels to study forage system management strategies compatible with spring grazing use. Nine strategies were tested with the model using a sequence of 16 climatic years. Three of these strategies come from a survey in south‐west France and six others were designed with research scientists or farm advisors. The strategies differ in the duration of maize silage feeding, the area dedicated to maize silage and the area dedicated to grass silage. Results from simulation models show that the consequence of a large and constant maize silage area is a high maize silage overstock if there is an early turnout or a high grass silage overstock if turnout is late. The consequence of a low maize area is a high grazing duration combined in some years with feeding shortages. Strategies that have no feeding shortage and a low level of maize and grass silage overstock have a high grazing duration and have no constant maize or grass silage areas. The solution proposed to avoid climatic risk, and its consequences on feeding, is based on two procedures: use of reserve areas for production and allowing the production programme to be modified to take into account fresh information, especially weather records.  相似文献   

18.
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   

19.
This meta‐analysis based on 19 studies from Finland comprising 43 grass silages was undertaken to evaluate the effect of silage quality on liquid yield, liquid composition and retained compounds in liquid using four different liquid–solid separation methods. Silages were classified according to species (grass, clover or a mixture of them), additive treatment (no, biological or formic acid‐based additive) and harvest (primary growth or regrowth). A mixed model regression analysis with random study effect was used to evaluate the impact of silage characteristics on biorefinery efficiency. There was a large variation in silage quality in the data set. Silage dry‐matter concentration was the characteristic most highly correlated with liquid yield for all separation methods, and when used as an independent variable in the model, it resulted in the best predictions. The liquid–solid separation methods presented a great variation in the liquid yield, ranging from 0.26 to 0.56 when silage dry‐matter concentration was standardized to 250 g/kg. There was no effect of additive treatment and harvest in the estimation of the biorefinery potential, but species was a significant variable in predicting liquid yield for the laboratory‐scale presses with higher liquid yield for mixed grass and legume. The high correlation between silage quality and liquid yield and liquid composition provides potential to predict the biorefinery potential based on equations developed for each separation method. This information can be used to modify the silage production systems so that they best meet the requirements of a green biorefinery process.  相似文献   

20.
The purpose of this study was to evaluate the efficiency of two inoculants of lactic acid bacteria (LAB) on grass silages. The evaluation was made in terms of silage composition, rumen fermentation, digestion and animal production. Over a 2-year period two lots of silage were prepared in two 100-tonne capacity clamps. In each case an untreated silage and an inoculant-treated silage were prepared simultaneously from an identical herbage source using independent sets of silage-making equipment. The inoculant used in the first year was Pioneer Brand 1188 (Pioneer Hi-Bred UK), and in the second year a slightly different inoculant from the same source (Pioneer Hi-Bred) was used. The two inoculants were essentially similar in composition, comprising a mixture of Lactobacillus plantarum and Streptococcus faecalis ; the strains included in the second inoculant were selected for their capacity to tolerate higher temperatures. The fermentation of the inoculant-treated silages appeared to be dominated by homofermentative LAB compared with the untreated silages. The use of either inoculant was associated with a change in the rumen volatile fatty acid (VFA) pattern, with a significantly greater molar proportion of propionate and a corresponding reduction in both acetate and butyrate. There was a trend indicating an enhanced efficiency of microbial protein synthesis within the rumen of the heifers for the inoculant-treated silages, although this was only significant when concentrate was offered with the silage in one experiment. The inoculant-treated silages had significantly greater intake characteristics than did the untreated silages, though this was not reflected in a statistically significant improvement in average daily liveweight gain in either year.  相似文献   

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