Supplemental degradable protein sources for beef cattle consuming low quality roughage
| dc.contributor.advisor | Van der Merwe, H. J. | |
| dc.contributor.advisor | De Brouwer, C. H. M. | |
| dc.contributor.advisor | Spangenberg, H. P. | |
| dc.contributor.author | Jacobs, Henry Lubbe | |
| dc.date.accessioned | 2017-05-31T05:44:00Z | |
| dc.date.available | 2017-05-31T05:44:00Z | |
| dc.date.issued | 2005-05 | |
| dc.description.abstract | English: A study was conducted to determine the best natural source of rumen degradable protein (RDP) not provided by urea to maximize the digestible organic matter intake (DOMI) of a SA natural winter pasture hay (3.51% crude protein (CP) and 74, 23% neutral detergent fibre (NDF). The crude protein degradability of natural winter pasture hay (Cymbopogon- Themeda), cotton oilcake, soybean oilcake and sunflower oilcake was determined by means of the in- sacco- technique. These crude protein degradability values were used to formulate three RDP supplements according to current recommendations (4.01g RDP/kg W 0.75) using the three oilcakes respectively. Urea provided 50% of the supplemental RDP. The other feed ingredients were salt, begasse, molasses, feed grade sulphur and trace minerals. Seven steers (217 SD ± 9.91 kg) per treatment randomly divided were used. The experimental period consist of 14 -day's adaptation, 21- days' intake and 7 days collection period (conventional digestibility study). A significant (P< 0.0001) higher apparent digestibility of NDF occurred when the sunflower oilcake supplement was fed to the steers. The apparent digestibility of dry matter (DM), organic matter (OM), CP and gross energy (GE) was however not influenced significantly (P> 0.05) when different oilcakes supplements were fed. Likewise DOMI/kg W 0.75 , rumen volatile fatty acid concentration and rumen pH did not differ significantly (P> 0.05). The ammonia nitrogen (NH3N) concentration of the rumen fluid of steers that consumed the sunflower oilcake supplements were significantly (P< 0.04) lower than that of cotton oilcake. In a second study the optimum ratio of supplemented urea to the most available oilcake (cotton seed) was investigated. Urea replaced: 0%, 25%, 50%, 75% and 100% of the natural supplemental RDP. The same procedure as described in the first study was used. Steers with an average mass of 200 ± 19.96 kg were used. The replacement of natural supplemental RDP with urea did not significantly (P>0.05) influenced the apparent digestibility of DM, CP, NDF and GE. Accordingly DOMI/kg W 0.75did not differ significantly (P>0.05). The highest (P< 0.05) acetate and propionate concentration in rumen fluid of steers was recorded when urea replaced 75% of the natural RDP in the supplement. The highest (P= 0.008) value for isovalerate concentration in rumen fluid was found when 25% of the supplemental degradable protein was from urea. Increasing levels of urea had no affect on either the rumen NH3N concentration (P=0.3508) or pH (P= 0.0810). According to the results of both studies it seems that urea can supply all the supplemental RDP to steers on low quality roughage. From the results it was concluded that further research is needed on the RDP-requirements of ruminants consuming different types of low quality roughages. | en_ZA |
| dc.description.abstract | Afrikaans: 'n Studie is uitgevoer om te bepaal wat die beste natuurlike bron van rumen degradeerbare proteïen (RDP) is wat nie deur ureum verskaf word nie, wat maksimum verteerbare organiese materiaal inname (VOMI) van 'n tipiese Suid Afrikaanse winterveld ( 3.51% ru-proteïen (RP) en 74.23% neutral bestande vesel (NBV) sal bewerkstellig. Die ruproteien degradeerbaarheid van winterveldhooi ( Cymbopogon-, Themeda), katoensaadoliekoek, soja oliekoek en sonneblomoliekoek is deur middel van die in- sacco- tegniek bepaal. Hierdie proteïen degradeerbaarheid waardes is gebruik om drie RDP aanvullings met die drie oliekoeke onderskeidelik te formuleer wat aan die huidige aanbevelings voldoen (4.01g RDPlkg W 0.75) . Ureum het 50% van die aanvullende RDP verskaf. Die ander bestandele was sout, bagasse, molasses, voergraad swawel en spoorminerale. Sewe osse (217 ± 9.91 kg) per behandeling wat ewekansig verdeel is, is gebruik. Die proeftydperk het bestaan uit 'n; 14 dae aanpassing, 21 dae inname en 7 dae miskolleksie periode (konvensionele verteringstudie). 'n Betekenisvolle (P<0.000I) hoër skynbare verteerbaarheid vir NBV is verkry waar sonneblomoliekoek aan osse gevoer is. Die skynbare verteerbaarheid van droë materiaal (DM), organiese materiaal (OM), RP en bruto energie (BE) is nie betekenisvol (P>0.05) beïnvloed wanneer verskillende oliekoekaanvullings gevoer is nie. VOMI/kg W 0.75 , vlugtige vetsure en pH is ook nie betekenisvol (P>0.05) beïnvloed nie. Die ammonium stikstof (NH3N) konsentrasie van die rumenvloeistof van osse wat die sonneblomoliekoek- III vergelyking met die katoenoliekoekaanvulling ontvang het was betekenisvol (P< 0.05) laer. In 'n tweede studie is die optimum verhouding van aanvullende ureum tot die mees komersieël beskikbare oliekoek (katoensaadoliekoek) ondersoek. Ureum het 0%, 25%, 50%, 75% en 100% van die natuurlike RDP vervang. Dieselfde prosedure soos beskryf in die eerste studie is gevolg. Proefosse met 'n gemiddelde massa van 200 ± 19.26 kg is gebruik. Die skynbare verteerbaarheid van DM, RP, NBV en BE is nie betekenisvol (P>0.05) deur die vervanging van natuurlike aanvullende RDP met ureum beïnvloed nie. Die hoogste (P< 0.05) asynsuur- en propioonsuurkonsentrasies In die rumenvloeistof het voorgekom waar ureum 75% van die RDP In die aanvulling vervang het. Die hoogste (P< 0.008) waarde vir isovaleraatsuurkonsentrasie in rumenvloeistof is gevind waar 25% van die aanvullende RDP vanaf ureum afkomstig is. Toenemende peile van ureum het geen effek op rumen NH3N konsentrasie (P= 0.3508) of pH (P= 0.0810) uitgeoefen nie. Volgens die resultate van beide studies blyk dit dat ureum al die aanvullende RDP aan osse op laegraadse ruvoer kan verskaf. Vanaf die resultate is daar tot die slotsom gekom dat verdere navorsing nodig is rakende die RDP behoeftes van herkouers wat verskillende tipes laegraadse ruvoer benut. | af |
| dc.identifier.uri | http://hdl.handle.net/11660/6317 | |
| dc.language.iso | en | en_ZA |
| dc.publisher | University of the Free State | en_ZA |
| dc.rights.holder | University of the Free State | en_ZA |
| dc.subject | Beef cattle -- Feeding and feeds | en_ZA |
| dc.subject | Nitrogen in animal nutrition | en_ZA |
| dc.subject | Fiber in animal nutrition | en_ZA |
| dc.subject | Dissertation (M.Sc.Agric. (Animal, Wildlife and Grass Sciences))--University of the Free State, 2005 | en_ZA |
| dc.title | Supplemental degradable protein sources for beef cattle consuming low quality roughage | en_ZA |
| dc.type | Dissertation | en_ZA |