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A note on the OECD collaborative experiment on ammonia-treated straw
Animal Feed Science and Technology, 10 (1983/84) 89--91
89
Elsevier Science Publishers B.V., Amsterdam --Printed in The Netherlands
A N O T E O N T H E OECD C O L L A B O R A T I V E E X P E R I M E N T ON AMMONIA-TREATED STRAW
O. THEANDER 1, R.D. HARTLEY2 and C.S. STEWART3 1 The Swedish University o f Agricultural Sciences, 750 07 Uppsala (Sweden) 2 The Grassland Research Institute, Hurley, Maidenhead, Berks, SL6 5LR (Gt. Britain) 3 The R o w e t t Research Institute, Bucksburn, Aberdeen, AB2 9SB (Gt. Britain)
(Accepted for publication 3 August 1983) Theander, O., Hartley, R.D. and Stewart, C.S., 1984. A note On the OECD collaborative experiment on ammonia-treated straw. Anita. Feed Sci. Technol., 10: 89--91. INTRODUCTION In 1979, th e m e m b e r countries o f t he Organisation for E c o n o m i c Coo p e r a t i o n and D e v e l o p m e n t (OECD) began an a t t e m p t to coordi nat e some o f the agricultural research in t he developed countries. Under the cellulose p r o g r a m m e a series of workshops was initiated, the first t w o in 1980 being held at Uppsala, Sweden' (17--19 September) and Amersfoort, The Netherlands (8--10 October). At t he third workshop, held in Braunschweig, W. G e r m a n y , f r o m 30 S e p t e m b e r t o 2 O c t o b e r 1981 (Domsch et al., 1981), it was suggested t h a t the expertise available in the OECD countries should be c o o r d i n a t e d to focus a t t e n t i o n o n a particular ligno-cellulosic substrate f o r r u m i n a n t feeding which was of widespread interest. The aim was to e x a m in e th e feasibility of producing, at a central location, reference substrates f o r studies at di f f e r ent centres, each centre using its own expertise in order to assemble an a c c o u n t of t h e structure and m o d e of b r e a k d o w n o f the material under study which would be m o r e comprehensive t han could be assembled at any one centre. In view of t he general interest in a m mo n ia- tr eated straw and t he reproducibility of t he t r e a t m e n t offered b y this t r e a t m e n t at elevated temperatures, t he collaborative e x p e r i m e n t began with t h e p r o d u c t i o n of barley straw treated with a m m o n i a at 90 ° C, This n o t e describes the m e t h o d of t r e a t m e n t of the straw, gives some preliminary data on its digestibility in vitro and lists the collaborative studies in progress. T h e straw was treated on a large scale in order to provide sufficient material f o r animal feeding experiments (Williams, 1983, this symposium). Samples (up to 5 0 0 g ) are available f or o t h e r investigators interested in small-scale studies. Requests for material should be addressed t o Dr. C.S. Stewart, D e p a r t m e n t o f Microbial Biochemistry, The R o w e t t Research Institute, Bucksburn, Aberdeen, AB2 9SB, U.K. 0377-8401/84/$03.00
© 1984 Elsevier Science Publishers B.V.
90 MATERIALS AND METHODS Barley straw (var. Sonja) was grown on Potters Farm, Ewelme, Oxon, (U.K.), and harvested in 1981. T he bales of straw were randomised and I t (60 bales) was treated with a n h y d r o u s a m m o n i a ( 3 0 k g N H 3 / t straw d r y matter) at 90 ° C for 16 h in a purpose-built oven: the d r y m at t er c o n t e n t o f th e straw was 87.9%. T he straw was treated in t w o batches, each o f 30 bales, on 29 March and 1 April 1982. Eight bales o f u n t r e a t e d straw and 8 bales of treated straw (4 f r o m each batch) were c h o p p e d into 15--25-cm lengths. Small samples ( a p p r o x i m a t e l y 10 g) f r o m each bale were ground t o pass an 0.8-ram screen and analysed f o r their organic m a t t e r digestibility (OMD) by a modification of t he r u m e n liquor--pepsin m e t h o d (Tilley and Terry, 1963). Analysis o f OMD showed large bale-to-bale variation. In order to reduce variation, t he batches of c h o p p e d straw were milled ( 4 0 m m screen) and mixed in a f e e d mixer trailer. RESULTS AND DISCUSSION Th e OMD o f the unt r e a t e d and a m m o n i a t e d straw is shown in Table I. Before milling and mixing, a m m o n i a t i o n markedly increased t he digestibility o f straw, but there was considerable bale-to-bale variation resulting in relatively high standard deviations. Milling and mixing the straw greatly re d u ced this variation, although the mean value o f OMD was n o t significantly altered. T h e milled and m i xed straw has been distributed t o a n u m b e r of centres for f u r t h e r detailed study, as listed in Table II. F o r convenience, t he p r o jects are categorised unde r sub-headings b u t these are n o t mutually exclusive and man y of t he projects involve at least some w ork in each of t h e d i f f e r e n t categories listed. Current recipients o f OECD fellowships are also n o t e d in Table II. Graham and Aman (1983, this symposium) have described the pat t er n of degradation o f this straw u p o n incubation in vitro and in sacco; the o t h e r investigations will be r e p o r t e d separately. TABLE I Organic matter digestibility in vitro of untreated and ammonia-treated barley straw
Range Mean SD
Before milling and mixing
After milling and mixing
Untreated straw
Ammoniated straw
Untreated straw
Ammoniated straw
25.3--37.8 31.8 3.8
42.2--53.2 46.5 3.9
30.8--32.1 31.5 0.6
45.5--46.6 46.1 0.4
91 TABLE II Centres collaborating in the OECD experiments on ammonia-treated straw Chemical composition studies O. Theander, H. Graham 1 and P./kman. Agricultural University Uppsala, Sweden. R.D. Hartley. Grassland Research Institute, Berkshire, U.K. P.J. Van Soest. Cornell University, Ithaca, NY, U.S.A, Studies in sacco, in vitro and in an artificial rumen A.J.H. Van Es and J.M. Van der Meer. Instituut voor Veevoeding-sonderzoek, " H o o r n " , Lelystad, The Netherlands. I.M. Morrison. Hannah Research Institute, Ayr, U.K. H. Meyer and M. Schmidt. Physiologisches Institut, Hannover, F.R.G. (Horse caecum digestion studies). Animal feeding experiments P.E.V. Williams. R o w e t t Research Institute, Aberdeen, U.K. Microbiological studies C.S. Stewart and N. Kolankaya 1 . R o w e t t Research Institute, Aberdeen, U.K. K.-J. Cheng and J.W. Costerton. Agriculture Canada Research Station, Lethbridge and University of Calgary, Alberta, Canada. Rumen metabolism studies D. Demeyer and I. M a n d e l : . University of Gent, Melle, Belgium. Cellulase and xylanase studies J.C. Stewart and J. Heptinstall. Lanchester Polytechnic, Coventry, U.K. 1 Recipients of OECD fellowships.
ACKNOWLEDGEMENTS We thank V.C. Mason these studies.
and Mrs. A. Keene
for their help in initiating
REFERENCES Domsch, K.H., Ferranti, M.P. and Theander, O., 1981. Improved utilisation of lignocellulosic materials for animal feed. Proc. OECD/COST Workshop, 30 September-2 October 1981, Commission of the European Communities, Brussels. Graham, H. and Aman, P., 1983. A comparison between degradation in vitro and in sacco of constituents of untreated and ammonia-treated barley straw. Anita. Feed Sci. Technol., 10: 199--211. Tilley, J.M.A. and Terry, R.A., 1963. A two-stage technique for the in vitro digestion of forage crops. J. Br. Grassl. Soc., 18: 104--111. Williams, P.E.V., 1983. Digestibility studies on ammonia-treated straw. Anim. Feed Sci. Technol., 10: 213--222.
89
Elsevier Science Publishers B.V., Amsterdam --Printed in The Netherlands
A N O T E O N T H E OECD C O L L A B O R A T I V E E X P E R I M E N T ON AMMONIA-TREATED STRAW
O. THEANDER 1, R.D. HARTLEY2 and C.S. STEWART3 1 The Swedish University o f Agricultural Sciences, 750 07 Uppsala (Sweden) 2 The Grassland Research Institute, Hurley, Maidenhead, Berks, SL6 5LR (Gt. Britain) 3 The R o w e t t Research Institute, Bucksburn, Aberdeen, AB2 9SB (Gt. Britain)
(Accepted for publication 3 August 1983) Theander, O., Hartley, R.D. and Stewart, C.S., 1984. A note On the OECD collaborative experiment on ammonia-treated straw. Anita. Feed Sci. Technol., 10: 89--91. INTRODUCTION In 1979, th e m e m b e r countries o f t he Organisation for E c o n o m i c Coo p e r a t i o n and D e v e l o p m e n t (OECD) began an a t t e m p t to coordi nat e some o f the agricultural research in t he developed countries. Under the cellulose p r o g r a m m e a series of workshops was initiated, the first t w o in 1980 being held at Uppsala, Sweden' (17--19 September) and Amersfoort, The Netherlands (8--10 October). At t he third workshop, held in Braunschweig, W. G e r m a n y , f r o m 30 S e p t e m b e r t o 2 O c t o b e r 1981 (Domsch et al., 1981), it was suggested t h a t the expertise available in the OECD countries should be c o o r d i n a t e d to focus a t t e n t i o n o n a particular ligno-cellulosic substrate f o r r u m i n a n t feeding which was of widespread interest. The aim was to e x a m in e th e feasibility of producing, at a central location, reference substrates f o r studies at di f f e r ent centres, each centre using its own expertise in order to assemble an a c c o u n t of t h e structure and m o d e of b r e a k d o w n o f the material under study which would be m o r e comprehensive t han could be assembled at any one centre. In view of t he general interest in a m mo n ia- tr eated straw and t he reproducibility of t he t r e a t m e n t offered b y this t r e a t m e n t at elevated temperatures, t he collaborative e x p e r i m e n t began with t h e p r o d u c t i o n of barley straw treated with a m m o n i a at 90 ° C, This n o t e describes the m e t h o d of t r e a t m e n t of the straw, gives some preliminary data on its digestibility in vitro and lists the collaborative studies in progress. T h e straw was treated on a large scale in order to provide sufficient material f o r animal feeding experiments (Williams, 1983, this symposium). Samples (up to 5 0 0 g ) are available f or o t h e r investigators interested in small-scale studies. Requests for material should be addressed t o Dr. C.S. Stewart, D e p a r t m e n t o f Microbial Biochemistry, The R o w e t t Research Institute, Bucksburn, Aberdeen, AB2 9SB, U.K. 0377-8401/84/$03.00
© 1984 Elsevier Science Publishers B.V.
90 MATERIALS AND METHODS Barley straw (var. Sonja) was grown on Potters Farm, Ewelme, Oxon, (U.K.), and harvested in 1981. T he bales of straw were randomised and I t (60 bales) was treated with a n h y d r o u s a m m o n i a ( 3 0 k g N H 3 / t straw d r y matter) at 90 ° C for 16 h in a purpose-built oven: the d r y m at t er c o n t e n t o f th e straw was 87.9%. T he straw was treated in t w o batches, each o f 30 bales, on 29 March and 1 April 1982. Eight bales o f u n t r e a t e d straw and 8 bales of treated straw (4 f r o m each batch) were c h o p p e d into 15--25-cm lengths. Small samples ( a p p r o x i m a t e l y 10 g) f r o m each bale were ground t o pass an 0.8-ram screen and analysed f o r their organic m a t t e r digestibility (OMD) by a modification of t he r u m e n liquor--pepsin m e t h o d (Tilley and Terry, 1963). Analysis o f OMD showed large bale-to-bale variation. In order to reduce variation, t he batches of c h o p p e d straw were milled ( 4 0 m m screen) and mixed in a f e e d mixer trailer. RESULTS AND DISCUSSION Th e OMD o f the unt r e a t e d and a m m o n i a t e d straw is shown in Table I. Before milling and mixing, a m m o n i a t i o n markedly increased t he digestibility o f straw, but there was considerable bale-to-bale variation resulting in relatively high standard deviations. Milling and mixing the straw greatly re d u ced this variation, although the mean value o f OMD was n o t significantly altered. T h e milled and m i xed straw has been distributed t o a n u m b e r of centres for f u r t h e r detailed study, as listed in Table II. F o r convenience, t he p r o jects are categorised unde r sub-headings b u t these are n o t mutually exclusive and man y of t he projects involve at least some w ork in each of t h e d i f f e r e n t categories listed. Current recipients o f OECD fellowships are also n o t e d in Table II. Graham and Aman (1983, this symposium) have described the pat t er n of degradation o f this straw u p o n incubation in vitro and in sacco; the o t h e r investigations will be r e p o r t e d separately. TABLE I Organic matter digestibility in vitro of untreated and ammonia-treated barley straw
Range Mean SD
Before milling and mixing
After milling and mixing
Untreated straw
Ammoniated straw
Untreated straw
Ammoniated straw
25.3--37.8 31.8 3.8
42.2--53.2 46.5 3.9
30.8--32.1 31.5 0.6
45.5--46.6 46.1 0.4
91 TABLE II Centres collaborating in the OECD experiments on ammonia-treated straw Chemical composition studies O. Theander, H. Graham 1 and P./kman. Agricultural University Uppsala, Sweden. R.D. Hartley. Grassland Research Institute, Berkshire, U.K. P.J. Van Soest. Cornell University, Ithaca, NY, U.S.A, Studies in sacco, in vitro and in an artificial rumen A.J.H. Van Es and J.M. Van der Meer. Instituut voor Veevoeding-sonderzoek, " H o o r n " , Lelystad, The Netherlands. I.M. Morrison. Hannah Research Institute, Ayr, U.K. H. Meyer and M. Schmidt. Physiologisches Institut, Hannover, F.R.G. (Horse caecum digestion studies). Animal feeding experiments P.E.V. Williams. R o w e t t Research Institute, Aberdeen, U.K. Microbiological studies C.S. Stewart and N. Kolankaya 1 . R o w e t t Research Institute, Aberdeen, U.K. K.-J. Cheng and J.W. Costerton. Agriculture Canada Research Station, Lethbridge and University of Calgary, Alberta, Canada. Rumen metabolism studies D. Demeyer and I. M a n d e l : . University of Gent, Melle, Belgium. Cellulase and xylanase studies J.C. Stewart and J. Heptinstall. Lanchester Polytechnic, Coventry, U.K. 1 Recipients of OECD fellowships.
ACKNOWLEDGEMENTS We thank V.C. Mason these studies.
and Mrs. A. Keene
for their help in initiating
REFERENCES Domsch, K.H., Ferranti, M.P. and Theander, O., 1981. Improved utilisation of lignocellulosic materials for animal feed. Proc. OECD/COST Workshop, 30 September-2 October 1981, Commission of the European Communities, Brussels. Graham, H. and Aman, P., 1983. A comparison between degradation in vitro and in sacco of constituents of untreated and ammonia-treated barley straw. Anita. Feed Sci. Technol., 10: 199--211. Tilley, J.M.A. and Terry, R.A., 1963. A two-stage technique for the in vitro digestion of forage crops. J. Br. Grassl. Soc., 18: 104--111. Williams, P.E.V., 1983. Digestibility studies on ammonia-treated straw. Anim. Feed Sci. Technol., 10: 213--222.