Evaluation of Leucaena leucocephala and Ziziphus mauritiana as Sources of Tannins and their Interference with Nitrogen Utilisation in Goats

Transcription

1 159 Evlution of Leucen leucocephl nd Ziziphus muritin s Sources of Tnnins nd their Interference with Nitrogen Utilistion in Gots K.H. Myint 1*, K.S. Mu 3, T.M. Soe 2, N.N. Mw 3, L.T. Ming Gwng 1 & T. Ngwe 3 Abstrct Studies were undertken to identify the roles of tnnins in Leucen leucocephl nd Ziziphus muritin on ruminl degrdbility of sesme mel crude protein (CP) using nylon bgs nd on nutrient digestibility of nitrogen utilistion in gots. Four diets were used in n in situ study using fistulted bull: S (sesme mel), S+L 1 (sesme mel nd Leucen leucocephl [25% of the diet]), S+L 2 (sesme mel nd Leucen leucocephl [50% of the diet]) nd S+Z (sesme mel nd Ziziphus muritin [50% of the diet]). Crude protein disppernce of S+L 1, S+L 2 nd S+Z were significntly lower (P < 0.001) thn tht of S, indicting tht supplementtion with Leucen leucocephl nd Ziziphus muritin lowered degrdtion of sesme mel protein, thereby sving more protein. A digestion tril ws crried out using four indigenous mle gots llocted rndomly to four dietry tretments using 4 4 Ltin Squre design: RS (chopped rice strw nd sesme mel), RSL 1 (chopped rice strw, sesme mel nd Leucen leucocephl t 25% of rtion), RSL 2 (chopped rice strw, sesme mel nd Leucen leucocephl t 50% of rtion) nd RSZ (chopped rice strw, sesme mel nd Ziziphus muritin t 50% of rtion). Dry mtter (DM) nd orgnic mtter (OM) intkes of ll diets were reltively similr, but CP intkes of RSL 2, RSL 1 nd RS were significntly higher (P < 0.01) thn tht of RSZ. Digestibilities of DM, OM, CP, neutrl detergent fibre (NDF) nd cid detergent fibre (ADF) for RSZ were significntly lower (P < 0.01) thn those of other tretments. The proportion of fecl nitrogen:totl nitrogen intke (Nf/NI, percentges) for RSZ ws significntly higher (P < 0.01) thn tht of other diets while the proportion of nitrogen retention:totl nitrogen intke (Nr/NI, percentges) for RSL 1 tended to be higher compred with RS, RSL 2 nd RSZ. Supplementing the rtion with 25% Leucen leucocephl tended to promote nitrogen retention. The results suggest tht tnnins in Leucen leucocephl interfere with protein degrdtion in the rumen nd improve nitrogen retention. 1 Livestock Breeding nd Veterinry Deprtment, Yngon, Mynmr 2 Livestock Breeding nd Veterinry Deprtment, Tmu Township, Mynmr 3 Deprtment of Physiology nd Biochemistry, University of Veterinry Science, Yezin, Mynmr * Corresponding uthor: khinhtymyint2006@gmil.com Introduction Rice strw is mjor feed source for ruminnts in mny tropicl countries including Mynmr (Clrk, 1982), especilly during dry sesons. Like other fibrous residues, it is poor qulity feed but its nutritionl limittions my be overcome by supplementtion with concentrtes, ure or green forge (Preston nd Leng, 1984). Supplementtion of rice strw with concentrte improves its utilistion (Trung et l., 1988). Supplementtion using by-products my increse intke nd/or digestion nd/or utilistion of the bsl diet by improving the microbil ctivity required to optimise rumen digestion when mmoni nitrogen in the rumen is dequte (Tin Ngwe et l., 1993). In Mynmr, sesme mel is one of the common feed supplements for drught cttle nd cross-bred diry cows fed rice strw. However, since sesme mel is highly degrdble (88.7%) in the rumen (Smpth nd Sivrmn, 1987) severl processing tretments (het, tnnins, formldehyde, etc.) hve been used to increse the proportion of dietry protein which is not degrded in the rumen (Chlup, 1975). While protection of highly degrdble feed protein by het nd formldehyde tretment hve lredy been reported, little informtion is vilble bout the effect of including the tnnins in tree foliges on protein protection. Conventionlly, tree foliges hve been fed together with griculturl by-products (minly crop-residues contining low levels of nitrogen) to enhnce rumen microbil fermenttion nd hence niml productivity (Ni Ni Mw et l., 2002). Tnniferous trees nd shrubs re importnt in niml production becuse they cn provide significnt protein supplements (Mkkr, 1999). Forges contining tnnins include Leucen leucocephl, Ziziphus muritin, Albizi chinensis, Mnihot esculent, nd Terminli oblongt (Kumr, 1992), nd tree legume forges offer chep lterntive to concentrte diets in ruminnt nutrition (Abdulrzk nd Ondiek, 1998). Among tnniferous trees nd shrubs, Leucen leucocephl nd Ziziphus muritin re common feedstuffs for gots in Mynmr. Leucen leucocephl is now widespred through most tropicl nd sub-tropicl regions of the world nd provides n importnt source of feed for ruminnt livestock (Norton et l., 1994). It is high qulity fodder tree (Liu nd Wng, 1998) with crude protein content of 28.8% in Mynmr, nd therefore with considerble potentil to replce commercil protein feed resources in rtions or be used s supplementry feed (Abdulrzk nd Ondiek, 1998). Tnnins re generlly regrded s inhibitory to the growth of microorgnisms but the mechnisms involved re poorly understood. Petroleum ether, chloroform, methnol, etc., re used to extrct tn- N.E. Odongo, M. Grci & G.J. Viljoen (eds), Sustinble Improvement of Animl Production nd Helth. Food nd Agriculture Orgniztion of the United Ntions, Rome, 2010: FAO Proc.indb /10/ :10:53

2 160 K.H. Myint et l. nins sequentilly from plnt mterils (Smith et l., 2001). However, detnnifiction methods re very expensive nd re not pplicble in developing countries including Mynmr. Since tnnins re widely distributed in tropicl feedstuffs, if tree forges contining tnnins were used to reduce protein degrdbility, svings on costs of providing dietry protein for ruminnt production systems in developing countries my be expected. Aginst this bckground, n experiment ws undertken to investigte the effect of tnnins in Leucen leucocephl nd Ziziphus muritin on protein degrdtion of sesme mel using the nylon bg method in fistulted bull. Another study exmined the effect of Leucen leucocephl nd Ziziphus muritin on nutrient digestibility nd nitrogen utilistion in gots. Mterils nd Methods Experiment 1 Animls, Feed nd Experimentl Design A fistulted bull (270 kg body weight [BWt]) ws used to investigte the effect of Leucen leucocephl nd Ziziphus muritin, s sources of tnnin on protein degrdtion. Four diets were used: Sesme mel (S) Sesme mel + Leucen leucocephl 25% of the diet (S+L 1 ) Sesme mel + Leucen leucocephl 50% of the diet (S+L 2 ) Sesme mel + Ziziphus muritin 50% of the diet (S+Z) Before the study commenced mintennce rtion contining rice strw (4.75 kg), rice brn (220 g) nd sesme mel (440 g) ws fed 14 d. The experimentl period for ech diet lsted for 2 d. The experimentl period lsted for 8 d. Mesurements Dry mtter, OM nd protein degrdtion of ech diet ws mesured by the nylon bg method (Orskov nd McDonld, 1979). The sesme mel, Leucen leucocephl nd Ziziphus muritin were ground to pss through 2 mm sieve. (Before incubtion, the bgs were dried in hot ir oven t 100 C for 4 h to constnt weight). Bgs (13.5 cm 8.5 cm; pore size 50 µm) were used in this study, with eight incubtion times for ech diet, nd three nylon bgs being introduced into the rumen for ech incubtion time. Thus, twenty four bgs were required to complete incubtion of ech diet. About 5 g of ground smple were weighed into the bg which ws closed with plstic tie nd tied with plstic string. The bgs were then suspended in the rumen by tying the string to bmboo stick plced outside the cnnul. Bgs were incubted in the rumen for 0.5, 1, 3, 6, 12, 18, 24 or 48 h., withdrwn nd wshed immeditely with cold wter for bout 1 h under running tp wter while rubbing gently between the thumb nd fingers until the wter ws cler. They were then dried under sunlight for 5 h., nd finlly to constnt weight t 60 C for 48 h in hot ir oven. After spreding on tble nd llowed to equilibrte with the room temperture for 48 h the bgs were weighed. Suitble mounts of residues were used to nlyse for DM constituents. Chemicl Anlysis Dried residues were nlysed for DM nd OM s described by AOAC (1970). Nitrogen ws determined using the Kjeldhl method (Foss 2020 digestor nd Foss 2100 Kjeltec distilltion unit), nd CP clculted s 6.25 N (AOAC, 1970). All chemicl nlyses were crried out t the lbortory of Deprtment of Physiology nd Biochemistry, University of Veterinry Science, Yezin. Sttisticl Anlysis The experimentl results were subjected to one-wy nlysis of vrince using ANOVA. Experiment 2 Experimentl Animls, their Mngement nd Experimentl Design Four indigenous mle gots ged bout 5 7 months nd BWt rnging from kg were used to evlute the effect of four dietry tretments on nutrient digestibility nd nitrogen utilistion. Before strting the experiment, the gots were dewormed with Ivomec. During the study period, the gots were housed in individul metbolic stlls mde of wood nd n iron sieve nd subjected to similr mngement prctices. The feeding ws done once dily t 09:00 h nd the nimls were given free ccess to wter. The experimentl period for ech dietry regime lsted 17 d. The gots were dpted to the test diet for the first 14 d nd on the lst 3 d of the experimentl period smples of feces nd urine were collected from ech got for determintion of nitrogen retention. The gots were rndomly llocted to four dietry tretments using 4 4 Ltin Squre Design (Tble 1). The dietry tretments were s follows: Chopped rice strw nd sesme mel (RS); Chopped rice strw, sesme mel nd Leucen leucocephl 25% of rtion (RSL 1 ); Chopped rice strw, sesme mel nd Leucen leucocephl 50% of rtion (RSL 2 ); Chopped rice strw, sesme mel nd Ziziphus muritin 50% of rtion (RSZ) All dietry tretments were djusted to be isonitrogenous t the feeding level by clculting the crude protein content of ech feedstuff contined in the diet. Dietry tretments were djusted weekly by the supplement to levels of CP not less thn 18% of the totl diet. Leucen leucocephl nd Ziziphus muritin (leves nd petioles) were hrvested from the mture prts of the plnt, collected, ir dried nd stored. The rice strws were lso sun dried nd chopped. Ech diet ws fed to gots t the level of 3.5% of BWt (s-fed bsis). All feedstuffs used in the experiment were mintined s much s possible t uniform composition throughout the tril period. Amounts of ll feedstuffs fed nd refused were recorded dily for clculting intke levels. At the beginning of ech period, nimls were weighed before the morning feeding. Mesurements Digestion trils were crried out by the conventionl collection method. During collection periods smples of rice strw offered nd refused nd of sesme mel, Leucen leucocephl nd Ziziphus muritin were collected dily for chemicl nlysis. Residues were removed, weighed nd smpled before the morning feeding. Feces voided nd urine excreted were recorded dily during collection periods. The feces from ech got were lso weighed, smpled nd put into plstic bottle. After three consecutive d, 15% of fecl smples were dried under sunlight until constnt weight ws obtined. Urine ws lso mesured, 10% smpled nd stored in refrigertor before chemicl nlysis. Five ml of 15% sulphuric cid ws dded to 200 g fecl smples before drying under sunlight nd lso dded to the urine bucket before collection s preservtive. FAO Proc.indb /10/ :10:53

3 Evlution of Leucen leucocephl nd Ziziphus muritin s Sources of Tnnins nd their Interference Tble 1. Chemicl composition (%) of diets incubted in the rumen of fistulted bull. Description S S+L 1 S+L 2 S+Z DM OM CP S = sesme mel; S+L 1 = sesme mel + Leucen leucocephl t 25% of diet; S+L 2 = sesme mel + Leucen leucocephl t 50% of diet; S+Z = sesme mel + Ziziphus muritin t 50% of diet; 1 All vlues except DM re on DM bsis. Crude protein disppernce (%) S S+L1 S+L2 S+Z b Incubtion time (hour),b:p<0.001 b b Results nd Discussion Experiment 1 Chemicl Composition nd CP Disppernce Tble 1 nd Figure 1 show the chemicl composition of the diets nd disppernce of CP from them. Dry mtter nd OM levels were similr in ll diets, but CP content ws highest in sesme mel nd lowest where sesme mel ws supplemented with Ziziphus muritin t 50% of in the diet. The CP disppernces of ll diets were reltively similr t 3 h incubtion, but CP disppernces of S+L 1, S+L 2 nd S+Z were lower thn tht of S t ll times therefter, significntly so (P < 0.001) fter 12 h, 24 h nd 48 h of incubtion. This would indicte tht supplementtion with Leucen leucocephl nd Ziziphus muritin lowered the degrdtion of the sesme mel protein, nd tht this might be due to the presence of tnnins in these foliges. This is consistent with the observtion of Khin Sn Mu (2002) who reported tht CP disppernce ws reduced by incubting concentrte with tmrind seed husk s source of tnnins to growing femle clves. Also, Smpth nd Sivrmn (1987) showed tht the disppernces of DM nd CP were reduced by incubting het-treted sesme mel in the rumen, nd Chlup (1975) reported tht severl processing tretments (het, tnnin, formldehyde, etc.) incresed the proportion of dietry protein which is not degrded in the rumen. Figure 1. Disppernce of crude protein (%) of sesme mel supplemented with Leucen leucocephl nd Ziziphus muritin in the rumen of fistulted bull Chemicl nlysis Ground smples of feed offered nd of orts nd feces were nlysed for dry mtter (DM) nd orgnic mtter (OM) s described by AOAC (1970), nd for neutrl detergent fibre (NDF), cid detergent fibre (ADF), cid detergent lignin (ADL) nd cid detergent insoluble nitrogen (ADIN) by the methods of Goering nd Vn Soest (1970). Feces nd urine were nlysed for nitrogen using the Kjeldhl method (Foss 2020 digestor nd Foss 2100 Kjeltec distilltion unit) nd crude protein (CP) ws clculted s 6.25 N (AOAC, 1970). Estimtes of tnnin in Leucen leucocephl nd Ziziphus muritin were mde by the sequentil extrction of Leucen leucocephl nd Ziziphus muritin with cid detergent followed by neutrl detergent. Sttisticl nlysis Dt were subjected to sttisticl nlysis of ANOVA using Ltin Squre Design nd the significnce of differences between tretment mens ws compred by Duncn s Multiple Rnge Test (DMRT) (Steel nd Torrie, 1980). Degrdtion Constnts The degrdtion constnts of DM, OM nd CP for S, S+L 1, S+L 2 nd S+ Z re given in Tble 2. Degrdtion rtes (c) of DM, OM nd CP for ll diets were reltively similr but the vlues of b nd +b for S were found to be higher thn those of S+L 1, S+L 2 nd S+Z. The higher degrdtion constnts of S would lso indicte tht tnnins in these tree foliges protect the protein from degrdtion. The lower CP disppernce nd degrdtion constnts of the tretments tht included Leucen leucocephl nd Ziziphus muritin suggest gin tht tnnins contined in these tree foliges interfered with protein degrdtion in the rumen of the fistulted bull. Experiment 2 Chemicl Composition of Feedstuffs The chemicl composition of the feedstuffs re presented in Tble 3 (ll vlues except DM expressed on DM bsis). The CP content of Leucen leucocephl used in this experiment ws 28.8% which ws higher thn reported erlier (Smith, 1992; Wheeler et l., 1994; Ni Ni Mw et l., 2002; Lwin Ning Oo, 2002; Met Aung, 2002; Moe Moe Khing, 2003), but similr to vlues reported by others (Jones, 1979; Abdulrzk nd Ondiek, 1998; Aregheore nd Yhy, 2001). The CP content of Ziziphus muritin ws 13.9% which ws similr to the vlue of 14% reported by Nth et l. (1969) nd lower thn the 18.39% recorded by Ni Ni Mw et l. (2002). The NDF nd ADF vlues of Ziziphus muritin used were 35.8% nd 25% FAO Proc.indb /10/ :10:53

4 162 K.H. Myint et l. Tble 2. Degrdtion constnts of diets in the rumen of fistulted bull. DM 1) Description S S+L 1 S+L 2 S+Z, % b, % c, h b, % OM 1) , % b, % c, h b, % CP 1) , % b, % c, h b, % rpidly degrdble frction; b slowly degrdble frction; +b potentilly degrdble frction; c rte of degrdtion; 1 s described in Tble 1. Exponentil eqution: P=A+B (1-e kdt ). Tble 3. Chemicl composition (%) of feedstuffs. Description Rice strw Sesme mel Leucen leucocephl Ziziphus muritin DM OM CP EE NDF ADF ADL Tnnin Silic EE ether extrct; ADL cid detergent lignin. respectively, higher thn the 30.0% nd 19.78% reported by Ni Ni Mw et l. (2002). The difference of 2.0% between ADF nd NDF in the sequentil nlysis of Leucen leucocephl for tnnins ws in greement with % reported by Wheeler et l. (1994), while the difference of 4.8% between ADF nd NDF in the sequentil nlysis of Ziziphus muritin for tnnins greed closely with the 5.3% reported by Bhti et l. (1987). The differences in chemicl composition between Leucen leucocephl nd Ziziphus muritin used in this experiment nd from other observtions likely reflected differences between prts of the plnts used, their mturity, soil, wether nd environmentl chrcteristics. Digestibility coefficients DM digestibility of RSL 2 ws significntly higher (P < 0.01) thn tht of RS but CP digestibility ws significntly lower (P < 0.01). This might be due to the greter mount of Leucen leucocephl in the rtion which resulted in n incresed mount of the tnnin. The OM digestibilities of RSL 1 nd RSL 2 were not significntly different from tht of RS (Tble 6). Although ll dietry tretments were djusted to be isonitrogenous t the feeding level, significnt decrese ws observed in CP intke of the RSZ diet (Tble 5). This ws due to underestimtion of the CP content of Leucen leucocephl nd overestimtion of CP content of Ziziphus muritin. Therefore, it could be ssumed tht ll nutrient digestibilities were significntly (P < 0.01) reduced (Tble 6) due to decresed CP intke in RSZ diet (Tble 5). It is generlly greed tht intke nd digestion by ruminnts is limited when the roughge contins less thn 7% CP (Doyle, 1987). However, the CP content of RSZ constituted 15.7% of the diet, well bove the CP content tht my hve limited nutrient digestibility. Therefore, the reduced nutrient digestibility might be due to ADIN content in Ziziphus muritin (Tble 4). FAO Proc.indb /10/ :10:54

5 Evlution of Leucen leucocephl nd Ziziphus muritin s Sources of Tnnins nd their Interference Tble 4. Content of cid detergent insoluble nitrogen in Leucen leucocephl nd Ziziphus muritin. Description Leucen leucocephl Ziziphus muritin Totl N % ADIN % ADIN/totl N, % N: = nitrogen; ADIN: = cid detergent insoluble nitrogen. Tble 5. Nutrient intkes (g/kg 0.75 /d). Description 1) RS RSL 1 RSL 2 RSZ DM I OMI CPI DMI dry mtter intke; OMI orgnic mtter intke; CPI crude protein intke. Tble 6. Digestibility of nutrients (%). Description RS RSL 1 RSL 2 RSZ SEM DM digestibility 59.0 B 61.7 A 62.0 A 55.8 C OM digestibility 66.6 A 67.7 A 66.8 A 60.2 B CP digestibility 82.5 A 80.5 AB 75.5 Bb 57.9 C NDF digestibility 59.8 A 55.3 ABb 52.1 Bb 42.3 C ADF digestibility 56.8 A 47.9 ABb 41.9 Bb 26.1 C Significnt differences between mens over the whole experiment re indicted by dissimilr superscripts: A,B,C P < 0.01 nd,b P < Tble 7. Nitrogen utilistion by gots fed different diets. Description RS RSL 1 RSL 2 RSZ SEM Totl NI, g/d 20.1 A 20.5 A 24.5 B 16.6 C Fecl N, g/d 3.5 Bc 4.0 Bc 5.9 Ab 6.9 A Urinry N, g/d 11.8 AB 11.0 AB 13.4 A 6.5 Bb N retention, g/d Nf/NI, % 17.5 A 19.5 AB 24.5 Bb 42.1 C Nu/NI, % Nr/NI, % Nf/DNI, % 21.3 A 24.2 A 32.7 A 73.6 B Nu/DNI, % Nr/DNI, % NI: = nitrogen intke; Nf: = fecl nitrogen; Nu: = urinry nitrogen; Nr: = nitrogen retention; DNI: = digestible nitrogen intke. Significnt differences between tretment mens over the whole experiment indicted by dissimilr superscript: A,B,C P < 0.01;,b,c P < 0.05 The NDF nd ADF digestibilities of RSL 2 nd RSZ were significntly lower (P < 0.01) thn tht of RS. Likewise, NDF nd ADF digestibilities for RSL 1 were significntly lower (P < 0.05) thn for RS, which is in ccord with the report of Reed et l. (1990) tht tnnins hve negtive effect on fibre digestibility (Tble 6). Nitrogen utilistion Totl nitrogen intkes of RS, RSL 1, RSL 2 nd RSZ were 20.1, 20.5, 24.5 nd 16.6 g/d, respectively (Tble 7). Totl nitrogen intke of RSL 2 ws significntly higher (P < 0.01) thn those of other diets while totl nitrogen intke of RSZ ws significntly lower (P <0.01) thn those of other diets. The proportion of fecl nitrogen to totl nitrogen intke (Nf/ NI, %) of RSZ ws significntly higher (P < 0.01) thn RSL 2, RSL 1 nd RS. This might be due to the high content of cid detergent insoluble nitrogen (ADIN) in Ziziphus muritin (68% of totl nitrogen) compred with tht of Leucen leucocephl (37% of totl nitrogen) (Tble 4). This is in greement with the report of Nkmur et l. (1994) who showed tht ADIN nd nitrogen digestibility were correlted (r 2 = 0.66) nd tht ADIN ws completely indigestible leding to underestimtion of nitrogen digestibility. The proportions of urinry nitrogen to totl nitrogen intke (Nu/NI, %) of RS, RSL 1, RSL 2 nd RSZ were not significntly different (P > 0.05). The Nu/NI, % of RSZ (40.3%) ws numericlly lower thn those of RSL 1, RSL 2 nd RS (59.6, 54.5 nd 55.0% respectively), which might be due to the high content of tnnins in the RSZ diet. However, the proportion of nitrogen retention to nitrogen intke (Nr/NI, %) of RSZ tended to decrese compred with other tretments which might be explined by n indequte mmoni nitrogen concentrtion in the rumen for nitrogen utilistion becuse of the higher content of ADIN in Ziziphus muritin (68% totl nitro- FAO Proc.indb /10/ :10:54

6 164 K.H. Myint et l. gen) (Tble 4). This ws confirmed by the higher fecl excretion of nitrogen in RSZ diet (Tble 7). The proportion of nitrogen retention to nitrogen intke (Nr/ NI, %) of RSL 2 ws numericlly lower thn tht of RSL 1, lthough the mount of tnnin included in the RSL 2 ws doubkle tht of RSL 1. This would indicte n excessive mount of Leucen leucocephl in the rtion of RSL 2. Although NDF nd ADF digestibilities of RSL 1 were significntly lower thn for RS (P < 0.05), the proportion of nitrogen retined to totl nitrogen intke (Nr/NI, %) with the RSL 1 diet tended to be higher compred with other diets. Moreover, OM digestibility (Tble 6) nd the nutritive vlue of RSL 1 diet were lso higher (Tble 7). This observtion is in greement Dutt et l. (1999) who reported tht the intkes (g/kgw 0.75 ) of DCP, TDN nd the nitrogen blnces of gots were significntly higher (P < 0.05) when Leucen ws fed. Norton (1994) lso reported tht nitrogen blnce ws pprently improved in nimls tht re fed low levels of tnnins, lthough digestibility of forge fibre my be lowered. No significnt difference ws observed in Nu/DNI, % nd Nr/DNI, % mong tretments suggesting tht post ruminl nitrogen metbolism in gots fed on ll diets ws reltively similr. Bhtt et l. (2000) reported decresed nitrogen excretion in urine with subsequent incresed nitrogen retention in crossbred diry cows fed with tmrind (Tmrindus indic) seed husks. Similr findings hve been reported by Krd et l. (1998) in sheep fed with Leucen leucocephl, by Brry et l. (1986) in sheep fed with Lotus nd Pritchrd et l. (1992) in sheep fed with Acci, by Tin Ngwe (2003) in sheep supplemented with lblb ben (Dlichos lblb) husk, nd by Lwin Ning Oo (2002) in gots supplemented with Leucen leucocephl. In ll these cses, the higher nitrogen retention ws ttributed to the tnnin content of these legumes cusing reduction in protein fermenttion in the rumen nd n improvement in the efficiency of nitrogen utilistion. Although tnnins re regrded s ntinutritionl fctors, certin types of tnnins t low concentrtion re known to lter rumen fermenttion of crbohydrtes nd protein (Brry nd Duncn, 1984) nd microbil protein synthesis (Mkkr et l. 1995) to the benefit of ruminnts. Leucen leucocephl fed t the level of 25% of the rtion used in the present experiment my hve plyed roles fvourble for nitrogen utilistion, while the higher level of ADIN content in Ziziphus muritin might hve been drwbck s ruminnt feed. ConclusionS Compred with other diets, the proportion of nitrogen retined to totl nitrogen intke tended to be higher when the diet ws supplemented with 25% of Leucen leucocephl. The level of 25% of Leucen leucocephl in the rtion ws found to be good supplement to rice strw in terms of promoting nitrogen utilistion without reducing DM nd OM digestibilities nd could therefore be used s source of tnnins for protecting protein provided s concentrte from degrdtion in the rumen. Ziziphus muritin reduced both fibre nd protein digestibility becuse of its higher ADIN content nd might therefore not be so suitble s feed for gots. Acknowledgements Since this pper describes work conducted for MVSc. Thesis (Physiology) by the senior uthor, she would like to tke this opportunity to cknowledge her enormous debt to the Livestock Breeding nd Veterinry Deprtment for its kind permission to enble her to conduct this study nd to the University of Veterinry Science for the hertfelt nd constructive support it provided to enble her to complete the study. The prtil finncil support for ll chemicl nlysis from the IAEA under the MYA/5/011 TC project is lso grtefully cknowledged. References Abdulrzk, S.A. & Ondiek, J.O., The effects of supplementting roughge diets with Leucen leucocephl on intke, digestion nd niml performnce of gots nd cttle in Keny. In: Shelton, H.M., Gutteridge, R.C., Mullen, B.F. & Bry, R.A., eds. Proc. Workshop on Leucen: dpttion, qulity nd frming systems held in Hnoi. Vietnm 9 14 Februry. ACIAR Proceedings No. 86, ACIAR, Austrli. pp Assocition of Officil Anlyticl Chemists Officil Methods of Anlysis. 11th Edn. AOAC. Aregheore, E.M. & Yhy, S.S Nutritive vlues of some browses s supplements for gots. Mlysin J. Anim. Sci. 7: Brry, T.N. & Duncn, S.J The role of condensed tnnins in the nutritionl vlue of Lotus peduncultus for sheep. 1. Voluntry intke. Br. J. Nutr. 54: Brry, T.N., Mnley, T.R. & Duncn, S.J The role of condensed tnnins in the nutritionl vlue of Lotus peduncultus for sheep. 4. Sites of crbohydrte nd protein digestion s influenced by dietry rective tnnin concentrtion. Br. J. Nutr. 55: Bhti, D.R., Kumr, R. & Ptnyk, B.C Annul Report CSWRI, Avikngr, Cited by Kumr, R. & Vithiynthn, S. (1990): Occurrence, nutritionl significnce nd effect on niml productivity of tnnins in tree leves. Anim. Feed Sci. nd Technol. 30: Bhtt, R., Krishnmoorthy, U. & Mohmmed, F Effect of feeding tmrind (Tmrindus indic) seed husk s source of tnnin on dry mtter intke, digestibility of nutrients nd production performnce of crossbred diry cows in mid-lcttion. Anim. Feed Sci. nd Technol. 83: Chlup, W. 1975: Rumen bypss nd protection of protein nd mino cids. J. Diry Sci. 58: Clrke, J.P Roughges nd fodders in Mynmr. Field Document No.23. FAO, Rome. Doyle, P.T Supplements other thn forges. In Hcker, J.B. & J.H., Ternouth, eds. The Nutrition of Herbivores. Acdemic Press, Austrli: Dutt, N., Shrm, K. & Hsn, Q.Z Effect of supplementtion of rice strw with Leucen leucocephl nd Prosopis cinerri leves on nutrient utiliztion by gots. Asin-Aus. J. Anim. Sci. 12: Goering, H.K. & Vn Soest, P.J Forge Fibre Anlysis. Agriculturl Hndbook No ARS USDA, Wshinton, D.C. Jones, R.J The vlue of Leucen leucocephl s feed for ruminnts in the tropics. World Anim. Rev. 31: Krd, I.W., McL, G., Dryden & Gutteridge, R.C The effect of supplementtion with Leucen leucocephl nd ure or sucrose on the voluntry feed intke nd digestibility of Rhodes Grss hy by sheep. In Shelton, H.M., Gutteridge, R.C., Mullen, B.F. & Bry, R.A., eds. Proc. Workshop on Leucen: dpttion, qulity nd frming systems held in Hnoi. Vietnm 9 14 Februry. ACIAR Proceedings No. 86. ACIAR, Austrli: Khin Sn Mu Studies on the Physiologicl Responses of Growing Bulls Fed on Ure-treted Rice Strw Supplemented with Untreted or Het-treted Sesme Mel nd Two Rtes of Chickpe (Cicer rietinum) Husk. MVSc. Thesis submitted to the Deprtment of Physiology nd Biochemistry, University of Veterinry Science, Yezin. FAO Proc.indb /10/ :10:55

7 Evlution of Leucen leucocephl nd Ziziphus muritin s Sources of Tnnins nd their Interference Kumr, R Antinutritionl fctors the potentil risks of toxicity nd methods to llevite them. Animl Production nd Helth Pper 102. FAO, Rome: Liu, G. & Wng, D., Preliminry study of Leucen leucocephl s feed for livestock. In Shelton, H.M., Gutteridge, R.C., Mullen, B.F. & Bry, R.A., eds. Proc. Workshop on Leucen: dpttion, qulity nd frming systems. Hnoi, Vietnm 9 14 Februry. ACIAR Proceedings No. 86. ACIAR, Austrli: Lwin Ning Oo Effect of Feeding Tree Forges s Prtil Replcement of Concentrtes in Rice Strw Bsed Diets of Gots on Voluntry Intke, Digestibility nd Nitrogen Blnce. MVSc. Thesis submitted to the Deprtment of Physiology nd Biochemistry, University of Veterinry Science, Yezin, Mynmr. Mkkr, H.P.S Quntifiction of Tnnins in Tree Folige. IAEA Working Document. IAEA, Vienn. Mkkr, H.P.S., Browy, N.K., Becker, K. & Degen, A Some problems in fibre determintion of tnnin rich forge (Acci slign leves) nd their implictions in vitro. Anim. Feed Sci. Technol. 55: Met Aung The Effect of Feeding Tree Forges s Prtil Replcement of Concentrtes in Rice Strw Bsed Diets in Gots on Feed Intke nd Physiologicl Responses. MVSc. Thesis submitted to the Deprtment of Physiology nd Biochemistry, University of Veterinry Science, Yezin. Moe Moe Khing Study on the Effects of Supplementtion with Leucen Leves nd Ure Molsses Multinutrient Blocks of Rice Strw Bsed Diet in Gots on their Voluntry Intke nd Digestibility. MVSc. Thesis, Deprtment of Physiology nd Biochemistry, University of Veterinry Science, Yezin, Mynmr. Nkmur, T., Klopfenstein, T.J. & Britton, R.A Evlution of cid detergent insoluble nitrogen s n indictor of protein qulity in non-forge proteins. J. Anim. Sci. 72: Nth, K., Mlik, N.S. & Singh, O.N Utiliztion of Ziziphus nummulri leves by three breeds of sheep. Aust. J. Agric. Res. 20: Ni Ni Mw, Khin Sn Mu, Aung Aung & Moe Thid Htun Preliminry report of nutritive vlue of tree foliges vilble in Yezin re. Proceedings of the Annul Reserch Conference, June 28 30, Yngong, Mynmr. Norton, B.W The nutritive vlue of tree legumes. In Gutteridge, R.C. & Shelton, H.M., eds. Forge Tree Legumes in Tropicl Agriculture. CAB Interntionl, Wllingford, Oxford: Norton, B.W., Lowry, B. & McSweeney, C The nutritive vlue of Leucen species. In Shelton, H.M., Piggin, C.M. & Brewbker, J.L., eds. Proc. Workshop held in Jnury, Bogor, Indonesi. ACIAR Proceedings No. 57. ACIAR, Austrli: Orskov, E.R. & McDonld, I The estimtion of protein degrdbility in the rumen from incubtion mesurements weighted ccording to rte of pssge. J. Agric. Sci. Cmb. 92: Preston, T. R. & Leng, R.A Supplementtion of diets bsed on fibrous residues nd by-products. In Sunstol, R.F. & Owen, E., eds. Strw nd Other Fibrous By-products s Feed. Elsevier, Amsterdm: Pritchrd, D.A., Mrtin, P.R. & O Rourke, P.K The role of condensed tnnins in the nutritionl vlue of Mulg (Acci neur) for sheep. Aus. J. Agric. Res. 43: Reed, J.D., Soller, H. & Woodwrd, A Fodder tree nd strw diets for sheep: intke, growth, digestibility nd the effect of phenolics on nitrogen utiliztion. Anim. Feed Sci. Technol. 30: Smpth, K.T. & Sivrmn, E Ruminl degrdbility of het treted nd formldehyde treted groundnut cke, gingelly cke nd rubberseed cke. Indin J. Diry Sci. 40: Smith, O.B Fodder trees nd shrubs in rnge nd frming systems in tropicl humid Afric.Animl Production nd Helth Pper 102. FAO, Rome: Smith, A.H., Odenyo, A.A., Osuji, P.P., Wllig, M.A., Kndil, F.E., Seigler, D.S. & Mckie, R.I Evlution of toxicity of Acci ngustssim in rt biossy. Anim. Feed Sci. Technol. 91: Steel, R.G. & Torrie, J.H Principles nd Procedures of Sttistics. A Biometricl Approch. 2nd Edn. Mc Grw-Hill Book Compny, New York. Tin Ngwe Study on Effects of Chickpe (Cicer rietinum) Husk nd Lblb Ben (Dolichos lblb) Husk s Sources of Esily Digestible Fibre, on Rice Strw Digestion nd Ruminl Chrcteristics in Sheep. Ph.D. Thesis, Grdute School of Agriculture, Hokkido University, Jpn. Tin Ngwe, Mr Mr Kyi, Cho Cho Thein & Zw Win Mung Study on ustiliztion of rice strw by ruminnts supplemented with griculturl by-products vilble in Mynmr. II. Effect of groundnut mel or sesme mel with or without chickpe husk on voluntry intke of rice strw nd digestibility of rice strw diet in growing bulls. Mynmr J. Agric. Sci. 5: Trung, L.T., Plo, L.P., Ateg, T.A. & Lpinid, R.R Ure treted rice strw with copr mel or fish mel in concentrte supplemented t two rtes for diry replcement heifers. Pper presented t the 25th Philippine Society of Animl Science Annul Convention, November 17 18, University of the Philippines Los Bnos, Lgun. Wheeler, R.A., Norton, B.W. & Shelton, H.M Condensed tnnins in Leucen species nd hybrids nd implictions for nutritive vlue. In Shelton, H.M., Piggin, C.M. & Brewbker, J.L., eds. Proc. Workshop on Leucen- Opportunities nd Limittions Jnury, Bogor, Indonesi. ACIAR Proceedings No.57, ACIAR, Austrli. FAO Proc.indb /10/ :10:55