Effect of roastingo n ruminal degradation,in testinald igestibility and absorbable amino acid profile of cottonseeda nd soybeano ilcakem eals

Abstract

The effecto f heatp rocessingo n ruminald egradationi,n testinald igestibility( UDP-D) and absorbablea mino acid (AA) profile of cottonseedo ilcake( CSOC) and soybeano ilcake( SBOC) was calculatedC. SOC and SBOC were roastedi n a drum roastera t six temperatures ettingsa nd five time intervalsr esulting in 30 treatmentsp er feedstuff.P ercentagea cid detergent insolublen itrogen( 7oA DIN) was useda s a screeningte st.R uminal proteind egradationa nd UDP-D were measuredw ith the in sltrzp olyestera nd mobile bag techniques(M BT), respectivelyT. emperaturea nd time altered( P < 0.05) crude protein (CP) disappearancfero m the rumen and total tract,a s well as UDP-D. The VoA DIN and the theoreticaal mounto f AA availablei ncreasedw, herease ffectiver uminal proteind egradabilityd ecreasedw ith temperaturea nd time. The relationship betweent otal N disappearancaen d % ADIN (R2= 0.99) fbr CSOC wasn on-linear( P < 0.0-5)f;o r SBOC it was linear (P < 0.05) (R2 = 0.85). The relationship between UDP-D and Va ADIN (R2 = 0.99) for CSOC was non-linear (P < 0.05); for SBOC it was linear (P < 0.05) (R2= 0.86).H eat processingd ecreased(P < 0.05) Lys in both CSOC and SBOC. The AA Thr, Pro and Gly in CSOC andT hr, Val, Leu, His, Asp, Gly and Ala in SBOC, werem ore (P < 0.05)r esistanto rumend egradation; m ore Thr and Lys (P < 0.05) were absorbablein both CSOC and SBOC, when comparedt o the control. CSOC and SBOC should be treated at 150'C/40 min and 130 "C145 min respectively.

Die invloed van hitteprosesserinogp rumenproteiendegradeerbaarhneied-, degradeerbarper oteienverteerbaarhe(iUd DPV) en absorbeerbaraem inosuurprofie(l AS) van sowel katoensaad(-K SOK) as soja-oliekoek( SOK) is bepaal.K SOK en SOK is in 'n dromroosterg eroosterb y ses temperaturem et vyf tydintervalle.P ersentasies uuronoplosbares tikstof (Vo ADIN) is as 'n siftingstoetsg ebruik.D ie in sitz poli€stere n mobieles akkie-tegniek(eM BT) is gebruik om die effektiewe rumenproteiendegradeerbaarheenid U DP-V respektiewelikt,e bepaal.V erskille( P < 0.05) is verkry in die ru-proteienv erdwyning uit die rumen en totales pysverteringskanaaals, ooki n die UDP-V. Die VoA DIN en die teoretieseh oeveelheidA S beskikbaarh et toegeneemt,e rwyl die effektiewer umen-proteiendegradeerbaarhmeeidt temperatuure n tyd afgeneemh et. Die verwantskapt ussent otale N verdwyninge n 7o ADIN (R2 = 0.99) vir KSOK was nie-liniOr( P < 0.05) en liniOr (P < 0.05) (R2= 0.85) vir SOK. Die verwantskaptu ssenU DP-V en 7oA DIN (R2= 0.99) vir KSOK was nie-lini0r (P < 0.05) en liniOr( P < 0.05)( R2= 0.86)v ir SOK. Hitteprosesserinhge t Lis in sowelK SOK as SOK verlaag( P < 0.05).D ie AA Tre, Pro en Gli in KSOK en Tre, Val, Leu, His, Asp, Gli en Ala in SOK was meer( P < 0.05) weerstandbiedentde enr umendegradering, t eenoorT re en Lis wat meer (P < 0.05)a bsorbeerbaawra s in sowelK SOK as SOK, in vergelykingm et die kontrole. Daar word aanbeveedl at KSOK en SOK teenr espektiewelik1 50" C/40 min en 130'C/45 min behandelw ord.

Keywords: Dairy cows, heat processing amino acid flow, digestion, cotton seed oil cake, soybean oil cake.