Zaragoza : CIHEAM Options Méditerranéennes : Série A. Séminaires Méditerranéens; n. 16

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1 Treatment straws Ramalho Ribeiro J.M.C. in Tisserand J.-L. (ed.), Alibés X. (ed.). Fourrages et sous-produits méditerranéens Zaragoza : CIHEAM Options Méditerranéennes : Série A. Séminaires Méditerranéens; n pages Article available on line / Article disponible en ligne à l adresse : To cite this article / Pour citer cet article Ramalho Ribeiro J.M.C. Treatment straws. In : Tisserand J.-L. (ed.), Alibés X. (ed.). Fourrages et sous-produits méditerranéens. Zaragoza : CIHEAM, p (Options Méditerranéennes : Série A. Séminaires Méditerranéens; n. 16)

2 Treatment straws J.M. C. RAMALHO ESTAÇAO ZOOTECNICA NACIONAL FONTE BOA - VALE DE SANTAREM 2000 SANTAREM - PORTUGAL - chemicalmodification in New methods that well as Attention must be paid to due to intake. - Traitement des pailles. Les principaux traitements des pailles sont présentés en précisant leur composition chimique résultant du traitement. De nouvelles techniques microbiennes sont proposées afin d améliorer la valeur nutritive des pailles. convient de discuter des effets des traitements l ingestion et sur la digestibilité des pailles. Introduction To low value and to its limitations in animal methods tested and implemented. to into quality feed it should be to lignin, to cellulose, to solubilize silica to bond hemicelluloses. A so and to obtain this goal a a) digestibility, b) be easily applicable in c) be cheap, d) not toxic compounds, e) not value f) maintain minand vitamins. Chemical modification in straw during different treatments changes that take place when low quality ages with alkali a physical as well as chemical is well known that This may be one intake found (Sundstol, 1988). Ano- that takes alkali ment is a swelling plant cell wall. This is and by et al. (1982). may be sonable, that a amount in is needed to obtain this swelling effect. When cell wall is expanded and. will have access to enhanced. with alkaline in extensively is a chemical taking alkali Saponification linkages between acetic acid and phenolic acids, lignin as wellassuch linkages acids xylans in hemicellulosesand lignin wouldbeexpected 1984). is high enough, in units and As a in linkages to hemicelluloses, an solubility lignin in alkaline solution will n.o : 55-60

3 expected to be solubilized and cellulose to accessible by an alkaline swelling effect. an cellulose is as consequence hemicelluloses and lignin. cleavage linkages between lignin and hemicelluloses sets cellulose That is because cellulose is embedded in hemicellulose-lignin complex which is by action alkali. studies by xylans ment to a position in available et al. (1984) indicate that cell digestion. to is so called peeling by which sugend-unit and aliphatic acids and 1958). As a conclusion one can say that alkali not by phenolic components but by specific linkages. Lignin its association with is solubilised when exposed at cell wall and build up an phenolic is pondingly (Chesson, 1984) Chemical methods Treatment with Sodium Hydroxide (NaOH) Wet Treatment a (until 1920 s) studies on boiling solution, manand method consisting soaking cold solution (1-1. 5% 12 followed by washing out with Almost all cellulose in while about 30 lignin and pentosans solubilized and washed out. digestibility about 46 to 71 (Sundstol 1988a). this is lost with A modified this method was used by beginning 1984). ment was at its height in mid-sixties andhas since declined, mainly because pollution (disposal by a modi- fication method (Sundstol, 1981) is also soaked in a 1.5 solution but lh only, which it is 4-6 days instead digestibility dip is 45-50% to 70-75% (Sundstol, 1988a). With this method is no loss and pollution Dry Treatment with have been developed in many 1984). is that is (chopped milled) a solution containing g is on a mixing a obtaining pellets (10-25 mm in (50 mm in diame- high developed in an almost immediate between and alkali. leaving evapof optimal seems to be 4-6% (Sunstol, 1988). This may be as a combination physical and chemical on have been developed with sodium Systems solution is long oughly chopped in a wagon even bailing have been (Sundstol, 1988). efficient seems to be use a machine especially designed this e.g. JF and machine is chopped into pieces 1-5 cm in length. leaving chop a 20-30% solution is added. and lye well mixed as y pass a mixing being blown into a heap to C in heap and within a week feeding. implies use small amounts it is eyes and skin Ammonia Treatment Amongst chemicals is most suitable because, while ligno-cellulosic linkages, as alkalis do, in addition it to chemical was not used in tice to a extent until Since n a num methods have been developed to conditions each Ammonia is

4 used in ous) and in solid compounds, e.g. solutions (aque- Ammonia low quality was by Sundstol Anhydrous Ammonia stack method ammonia in Stack polythylene and injected with3% ammonia (Sundstol et al. 1978). liquid stack. is used in a This method has become As as is it is not justifiable to exceed 4% basis even if some little beneficial effects, level up to 7%, obtained (Sunstol et al. 1979). in much than that Like all chemical it is time and dependent. At 100 OC is almost immediate; at O "C it is slow. That means that effect is not so if time is long enough (cold climate). content mining effect nia seems to no little effect with less than 3% content (Sundstol et al. 1979). amount optimal level seems to lie between 15 and 20%. Even if a may give effects, a moulding damage. One advantages method is that ammonia has a fungicidal effect, be ammonia is added. effect ammonia on digestibility is less than that dip 10-12% units, digestibility oat to 60-62% is common (Sundstol, 1988a). Ammonia can also be. out in ovens at about 90 "C. in 24h but cost is high. technique 1982) suggests use liquid 5050 with it is made to expand O "C and cell walls - this enhances digestibility. is known as Ammoniation. cost is said to be not too high because liquid can be content (> 5%) ammonia at (> 70%) poisonous component 4-methyl imidasolcan be which may cause in animals and may also be Leng, 1985). With at low should be negligible. a time to to eliminate smell, depends on - cold climates - time high density - - time. weeks. 2-3 days up to As a conclusion one can say that has advantage needing small amounts due to a in bales is it needs a it must be and toxic. Aqueous Ammonia some advantage is that it does not need may be only slightly to 33% has advantage that no be added to Attention must be paid if to be moulding). solution stack which must be and sealed has because and because a lignin is solubilised Urea is decomposed. is 2: 1 (100 g if completely decomposed, yield a little than 50 g is easy to handle and to use with no health and it spontaneously at high 100 "C) - it must be guided by - if not enough enzymes in to be be i.e. soybean not always a significant not in feed as it could lead to

5 an animal. which can cause a in Scotland found no effect at all in with et al. 1981). lack positive in may be due to content (> 50%) and high (60 OC) needed ideal activity (Williams and 1983) which sometimes is difficult to obtain. Protein 'Value Ammoniated Straw added N advantage with digestibility and intake, most this N is in faeces which to et al. (1990) could be due: - to attachment N to indigestible cell utilization this N by to an N,as a consequence an hind but Or Treatments have been attempts to use chemical feedstuffs to enhance digestibility. ley et al. (1986) a new chemical cess using alkaline se showed that digestibility 42.1% sheep fed non to 81.0% sheep fed diets and that digestible intake was when sheep fed to diets. showed that this allowed complete colonization and deg cell wall. Although use ment will be by economics, potential application and (1986) evaluated ability oxidizing agent, ozone, to digestibility high cows with ozone both and lignin imately 35%. digestibility was 36.2 to 65.2% by ozone Ozone in in digestibility than with 5 to 8% dioxide (S02, 62.6 g/kg) was used by O'Shea and (1986) to in digestibility 45 to 80%. This was attained a content 46 to 75% and a 60 to 70 "C. When fed at 40% a complete diet to lambs, invivo digestibility was 11 units. Nolte et al. (1987) suggest that alkaline solution wood ashes effectively utilization by Wheat was soaked in alkaline solu ded in digestibility and when alkali soluble wood With et al. (1987) that dioxide (S02), ozone and alkaline selectively ed phenolic without modifying content was substantially S02 had a effect and with alkaline was ineffective. (1987) studied effect wheat by S02 by S02 and cellulase on in sheep. content cell solubles in by S02 and by combined S02-cellulase in content was associated with a in acetic acid and an ic acid, suggest that it is possible to into a highly by a S02 N metabolism combination is not to was with O, 2, 4 and 6% ethanolamine and days at 40 "C, Flachowsky et al. (1988). Ethanolamine in a in content and an in "in situ" digestibility. se at least tested and some, like digestibility. still to be based At it seems that no effective to Sodium to Ammonia possible. Microbial methods methods quality been tice to date, but it may to be one most in main in biological quality is to find suitable which decompose lignin without using too much hemicellulose and cellulose. (1984), quality into feed, concludes that in digestibility fungal at beginning colonization by white fungi incubation contents soluble substances in digestibility depends on fungal species, cultivation time, in

6 andon bulkdensityand composition digestibility nocellulose bywhite fungi is byaddition Not cellulase and hemicellulase enzymes ineffective in initial such lignified cell a single lignase, is capable causing a high (Tien and 1983). enzyme acts like a and causes a cleavage sten et al, 1985). At levels lignase duced by basidiomycete fungi not sufficient biological to be a use techniques, it is conceivably possible to modify lignase genes and thus to efficiency and stability. With to this objective, have now cloned and sequenced lignin gene chrysosporilrwz (Tien and Tu, 1987; Zhang et al, 1986), a manipulation gene. References SON (1987). J. Sci.Tech.15:47 - vol. 12:31-43 Sciences (1985). J. as and A. by chemical pp C. Sundstol, F and J. Anim. Sci., vol J. Anim. Sci. 63:868 O. J. Sci. have also been quality (Seal and Eggins, 1976), but if cannot be quality cannot anteed and even toxic substances may be may be concluded, that with sufficient knowledge biology fungi and solid-state a low-cost technology lignocelluloses could be developed 1984). tion, Toulouse - C.F. (1987). J. him. Sci, 64:669 G.W. 32:388 J. 15:13. J. Anim. Concluding remarks chemical have also been developed inwhich a combination physical and may also be ensiled with chemicals such as at a moiscontent. No method has been developed yet, but scope such a method may to be in digestibility is used to effectiveness in most cases, this is accompanied by a significant in intake. SEAL, don pp. 58 stol. F. and F. Sundstol F. (1988). 4 - Feed Science - G.G. F. (1981). F. Sund- F. 19: F. F. Sundstol F., E. F., A.N. and J. Scand. Vol. 29:

7 dam p. 45 O. and AMAN (1984). F. Sundstol and E. and (1983). Science F. (1984). In: F. pp. 276 L' and J.N. Chem. Vol. 13: Y.Z., Communications. 137: