Towards improved silage quality – A review

2001 ◽  
Vol 81 (2) ◽  
pp. 157-168 ◽  
Author(s):  
E. Charmley

Silage quality, as with all forages, is governed by the maturity of the crop at harvest. However, fermentation in the silo further influences nutritive value of silage by reducing voluntary intake and utilization of digestible nutrients. Silage research up to the present time has focussed on closing the gap between feeding value of the original crop and that of the resulting silage. This review focuses on the advances made towards closing that gap, and explores the possibility that in the future ensiling can become a tool for actually increasing the feeding value of forages. Following a section defining silage quality, the relationships between silage fermentation quality and voluntary intake and between silage fermentation and protein and energy utilization will be examined, with emphasis placed on measures to minimize the negative effects of fermentation on animal production. Recent literature is reviewed, which suggests that many factors previously thought to reduce silage intake, such as pH, lactic acid and dry matter (DM), have, in fact, only a casual relationship with intake. Concentrations of fermentation acids do not seem closely related to silage intake; however, they are critical in determining the balance of volatile fatty acids (VFA) produced in the rumen. This in turn, affects the non-glucogenic ratio and can influence milk and body composition in productive livestock. While rumen ammonia is often implicated in reducing silage intake, protein solubility may be more the causal agent than ammonia per se. Protein solubility is also a major factor in reducing the efficiency of silage protein utilization. Methods to reduce protein solubility in silages are discussed. Methods shown to improve silage feeding value include effective wilting and rapid acidification, either by direct acidification or the use of inoculants. Their widespread adoption has undoubtedly contributed to improvements in animal production from silages in recent years. Key words: Silage, feeding value, voluntary food intake, fermentation, ruminant

2021 ◽  
Vol 9 (2) ◽  
pp. 225-234
Author(s):  
Liuxing Xu ◽  
Zhaohong Xu ◽  
Mingxia Chen ◽  
Jianguo Zhang

Whole-crop wheat (WCW) is rich in nutrients and is widely used as a forage crop. This study consisted of 2 experiments: Experiment 1 studied the yield, nutritive value and silage quality of WCW at 3 seeding rates (320 kg/ha, S320; 385 kg/ha, S385; and 450 kg/ha, S450) and different fertilizing times, i.e. 60% at seedling stage and the remaining 40% at the jointing stage vs. heading stage; and Experiment 2 examined the yield, nutritive value and silage quality of WCW receiving different fertilizer types, i.e. urea, compound fertilizer (N:P:K) and urea + compound fertilizer (all iso-nitrogenous). With the increased seeding rate, dry matter (DM) and crude protein (CP) yields tended to increase, but relative feed value tended to decrease. Experiment 1: there was no significant interaction between time of applying the second fertilizer dose and seeding rate in terms of concentrations of CP, crude fiber, ether extract, crude ash, nitrogen-free extract, neutral detergent fiber (NDF) and acid detergent fiber (ADF) in wheat (P>0.05). However, a significant interaction between fertilizing time and seeding rate was observed in terms of silage fermentation quality (pH, lactic acid, butyric acid and NH3-N concentrations) (P<0.05). Experiment 2: DM yield, CP yield and concentrations of CP, ADF and water-soluble carbohydrate were not affected by fertilizer type (P>0.05). Fertilizer type had significant effects on pH of silage and concentrations of organic acids (except propionic acid) and NH3-N in WCW silage (P<0.05). Under the present study conditions, considering DM yield, nutrient composition and silage fermentation quality, an optimal seeding rate of wheat for forage appears to be about 385 kg/ha. N fertilizer should be applied at the seedling stage and jointing stage. Although applying a mixture of urea and compound fertilizer had no significant effects on yield and nutritive value of WCW relative to applying urea alone, it did improve silage fermentation quality. Results may differ on different soils.


2015 ◽  
Vol 55 (7) ◽  
pp. 869 ◽  
Author(s):  
D. F. Chapman ◽  
G. R. Edwards ◽  
A. V. Stewart ◽  
M. McEvoy ◽  
M. O'Donovan ◽  
...  

Failure over the past two to three decades to implement industry-led, systematic forage evaluation systems that translate forage performance data to animal production and economics means that the livestock industries are poorly positioned to judge how much economic benefit they are gaining from forage plant improvement and to propose future priorities and targets. The present paper identifies several knowledge gaps that must be filled to enable the value being delivered to pasture-based livestock industries by forage improvement to be determined, demonstrated to farmers and increased in the future. Seasonal yield, total annual yield, nutritive value and feeding value of pasture are all important traits for driving the productivity of pasture-based livestock production systems. From a farm systems perspective, persistence of the yield or quality advantage of new cultivars is also economically important. However, this is the least well defined of the productivity traits considered in the paper. Contrary to anecdotal reports, evidence indicates that the genetic potential of modern ryegrass cultivars to survive in grazed pastures is at least equivalent to that of older cultivars. Plant breeding in Europe and New Zealand has changed the seasonal yield, quality and intake potential of perennial ryegrass. On the basis of dry matter (DM) yield data from small-plot evaluation trials, the New Zealand forage value index indicates that the top-ranked perennial ryegrass cultivars offer between NZ$280 and NZ $650/ha per year potential additional operating profit to dairy businesses (depending on region), compared with a historical genetic base of cultivars that were first entered into yield testing programs between 1991 and 1996. The equivalent figure in Ireland (including nutritive value effects) is about €325/ha per year. These estimates are yet to be confirmed in animal production studies. In intensive dairy systems, current rates of genetic gain in DM yield lag well behind realised rates of gain in animal genetics and associated increases in feed demand per animal. Genetic gains in yield need to double from current rates (estimated at 0.5% per year); but, it is not known whether this is possible in an outcrossing species such as perennial ryegrass, which is normally grown in a mixture with other species, especially white clover. Improvements in DM yield in seasons where extra DM has greatest economic value in grazing systems should dominate breeding objectives, but this must now be augmented by consideration of the environmental impacts of intensive pasture-based livestock production systems and opportunities to mitigate this through germplasm selection. There is less evidence that nutritive or feeding value of ryegrass cultivars significantly limits animal production and profitability and useful improvements have already been made using tetraploids and later heading material.


1970 ◽  
Vol 74 (3) ◽  
pp. 477-485 ◽  
Author(s):  
D. M. Keenan ◽  
W. R. McManus ◽  
M. Freer

SUMMARYNine Merino wethers were used in a cross-over experiment to compare the voluntary intake of three diets after a 4-week period in which the intake of the same diets was restricted, either to a level which maintained the live weight and energy status of the sheep, or to one which resulted in losses of 18% and 26% in their live weight and total energy content respectively. The diets were prepared from lucerne hay; chaffed (L), ground and pelleted (P) and pelleted after mixing with ground wheat (W).The voluntary intake of food increased only slowly during the 4 weeks after restrictions were removed; the total intake of digestible organic matter from diets W, L and P was in the ratio 100:122:146. Differences between diets L and P, but not W, were associated with their rates of disappearance from the rumen. Sheep which had been severely restricted ate less food during the first fortnight and no more during the second fortnight than those which had previously maintained their energy status. The difference in the first fortnight was less for diet P than for diet L. The process of adaptation by the sheep to unrestricted feeding was associated with an increase in the net rate of disappearance of volatile fatty acids from the rumen.Sheep offered food ad lib. after a period of submaintenance feeding gained more weight than sheep which had previously been fed to maintain weight and this increase was greater with diet P than with diet L. However, the differences in live-weight change consisted largely of water in the gut and did not result from a relative increase in the voluntary intake of food or in the efficiency of energy utilization.


1986 ◽  
Vol 42 (3) ◽  
pp. 337-342 ◽  
Author(s):  
B. S. Capper ◽  
E. F. Thomson ◽  
S. Rihawi ◽  
A. Termanini ◽  
R. Macrae

ABSTRACTBarley straw constitutes up to half of the dry-matter intake of Awassi sheep in areas of Syria where the rainfall is 200 to 350 mm. The genotype of barley planted could therefore, through the nutritive value of its straw, significantly affect flock production levels. Selection of suitable barley genotypes may have greater economic potential as a means of improving roughage feeding quality in these areas than chemical or physical processing.The voluntary intake and digestibility of the unsupplemented straw of three genotypes of barley was evaluated with Awassi castrated male sheep. The voluntary organic-matter (OM) intakes of handharvested Beecher, Arabic Abied and ER/Apam straw were 22·2, 34·7 and 27·0 g/kg M0·75 per day and OM digestibility coefficients were 0·39, 0·44 and 0·42. The factors affecting voluntary intake and digestibility appeared to be the proportions of leaf and stem. Beecher straw had less leaf and more stem than the other two genotypes. The chemical composition and in vitro cellulase digestibility of the leaf indicated that it had a higher potential feeding value than stem.ER/Apam appears to be an example of a genotype which under dry environmental conditions combines higher barley grain yields with more acceptable straw feeding value than several other genotypes evaluated.


Author(s):  
W.J.M. Black ◽  
A.R. Henderson ◽  
M. Lewis ◽  
J. Fitzsimons

With increasing flock sizes and the uncertainty of the hay-making process, silage has a part to play as the basal diet of Greyface type ewes during the latter half of pregnancy. Silage also varies considerably in feeding value and there is a demand for advice upon the contribution which grass silage can make to the diet, and also what level of concentrate feeding should be associated with any given silage. Silage is commonly subjected to a number of laboratory analytical procedures to provide estimates of:ME, D value, amonia nitrogen, dry matter, crude protein, pH and MAD fibreThe present series of feeding experiments sets out to provide evidence about the voluntary intake of a range of silages by ewes in late pregnancy and to examine any relationships which would help in predicting intake from laboratory analysis.


2013 ◽  
Vol 22 (1) ◽  
pp. 115-126 ◽  
Author(s):  
Johan De Boever ◽  
Elien Dupon ◽  
Eva Wambacq ◽  
Joos Latré

 The effect of adding an inoculant containing Lactobacillus buchneri, L. plantarum and L. casei to wilted perennial ryegrass, harvested at four growth stages and ensiled for either 60 or 150 d on silage fermentation quality, chemical composition, rumen degradability of neutral detergent fibre (NDF) and organic matter (OM) and in vitro OM digestibility (OMd) was studied. Compared to the control silage, more sugars were fermented to lactic and acetic acid with the inoculant, resulting in a lower pH, less dry matter losses and protein degradation and a better aerobic stability. The effects of the additive on fermentation quality were more pronounced after 150 than after 60 d of ensiling, because the quality of the control silage was worse after long ensiling period. The treatment lowered NDF content of grass harvested at the first two growth stages by degrading cell walls to complex sugars, but had no effect on NDF degradability of the silage. The inoculant had no effect on rumen OM degradability nor on OMd after the short ensiling period, but increased the rumen OM degradability for the first two growth stages and OMd for all growth stages after long ensiling period.


Author(s):  
J.A. Rooke ◽  
N.W. Offer

The voluntary intake of grass silage (VFI) is influenced by the presence of silage fermentation products. Ammonia-N concentration has been used in prediction equations for silage VFI as an indicator of the negative effects of fermentation products upon VFI but accounts for only a small proportion of the variance. The objective of this experiment was to improve understanding of the factors in silage that limit VFI by relating the time-course of the silage fermentation to the development of intake characteristics.Second cut perennial ryegrass was precision chop harvested without wilting. The grass was ensiled untreated (C) or treated (I) with 106Lactobacillus plantarum / g grass (Ecosyl, Zeneca Bio-Products) in 200 l containers (10 / treatment). Two containers / treatment were frozen immediately (0) or after 0.2, 1, 2 or 42 days fermentation to give 10 treatments. Juice was extracted using a cider press from silage immediately on thawing, bulked and then re frozen until required for feeding. For feeding, juice was thawed and maintained at 4° until fed.


1977 ◽  
Vol 25 (1) ◽  
pp. 71-81 ◽  
Author(s):  
Elizabeth Donaldson ◽  
R. A. Edwards

SUMMARYThe nutritive value of four silages was compared using eight rumenfistulated wethers. Wilted ryegrass was ensiled without additive (A); with formic acid (13·9 kg/t dry matter) (B); with formic acid (10·3 kg/t dry matter) plus formalin (formaldehyde at 4·8 kg/t dry matter) (C); with formic acid (4·9 kg/t dry matter) plus formalin (formaldehyde at 2·3 kg/t dry matter) plus propionic acid (5·6 kg/t dry matter) (D).Dry-matter intakes were 13·8, 15·1, 14·3 and 14·3 g/kg live weight for A, B, C and D respectively. Digestibilities of organic matter and dry matter were not affected by the additives. Digestibility of nitrogen and peak ruminal ammonia concentration were significantly (P<0·05) reduced by the addition of formaldehyde.The effect on rumen fermentation characteristics, of chemically restricting in-silo fermentation, is illustrated. Differences in the rumen volatile fatty acids and in the efficiency of utilization of the energy for growth, fattening and lactation are discussed.


1975 ◽  
Vol 15 (73) ◽  
pp. 211 ◽  
Author(s):  
TH Stobbs

Yield and nutritive value of three summer annual forages, hybrid forage sorghum (Sorghum spp. hybrid cv. Zulu), bulrush millet (Pennisetum typhoides cv. Tamworth) and white panicum millet (Echinochloa crusgalli var. edulis) were determined in three experiments. Uninterrupted growth was measured every 2 weeks between 4 and 12 weeks after sowing, and leaf, stem and inflorescence components analysed for nitrogen, phosphorus, calcium, magnesium, sodium and potassium and dry matter digestibility by an in vitro technique. The value of 10-week-old herbage, from crops grown with 50 kg ha-1 N, was determined by grazing with 18 Jersey cows and by feeding chopped material to 12 cows indoors. White panicum was the lowest yielding forage (up to 6,360 kg ha-1 at 10 weeks) but contained the highest concentration of nitrogen, phosphorus, calcium and magnesium in both leaf and stem fractions at all stages of growth. After 10 weeks growth this feed contained a high proportion of seed and was eaten in arger quantities than zulu sorghum or bulrush millet. Cows grazing white panicum produced the highestr lmilk yields (6.5 and 7.1 kg cow-1 day-1 indoors and grazed) and milk from these cows contained a highe solids-not-fat and protein content than milk from cows fed bulrush millet or sorghum. Zulu sorghum was highest yielding (1 1,240 kg ha-1 at 12 weeks in experiment 1 and 81 50 kg ha-1 at 10 weeks in experiment 2). With advancing maturity stem content increased (>80 per cent from 8 weeks onwards) and the nitrogen content of both leaf and stem fractions rapidly declined to sub-optimum levels. Milk production of cows feeding on zulu sorghum was low, averaging 4.7 and 6.0 kg cow-1 day-1 for indoor and grazing experiments. Bulrush millet produced high forage yields with a higher leaf content than zulu sorghum and milk yields were higher. Butterfat content of milk from cows feeding on bulrush millet was lower than when cows were fed the other forages. It was concluded that these three forages are capable of providing a large bulk of feed but their feeding value at a semi-mature stage of growth is similar to perennial tropical pastures.


1973 ◽  
Vol 53 (2) ◽  
pp. 257-263 ◽  
Author(s):  
G. PELLETIER ◽  
E. DONEFER

Three yearling Cheviot × Suffolk ewes and three Columbia wethers were confined in metabolic cages and fed ad libitum fresh and dried marrow-stem kale (Brassica oleracea var. acephala D.C.) harvested in mid- and late October. Chemical analyses of the forages indicated no marked effects on any of the plant constituents due to drying or advancing maturity. Digestibility measurements demonstrated that marrow-stem kale (MSK) was a highly digestible material with an average dry matter digestibility of 78%. The fresh forages had higher (P < 0.05) dry matter and gross energy digestibility values than the dried form. Dry matter digestibility coefficients were higher (P < 0.05) for late October as compared with the earlier harvest. A trend toward higher (P > 0.05) voluntary intake values due to drying maturity was observed with an average relative intake of 80%. The nutritive value index averaged 65, thus indicating a digestible energy intake similar to a high-quality (legume) forage.


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