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dc.contributor.advisorSnyman, H. A.
dc.contributor.authorBotha, Philippus Rudolf 
dc.date.accessioned2018-11-21T07:20:46Z
dc.date.available2018-11-21T07:20:46Z
dc.date.issued2003-09
dc.identifier.urihttp://hdl.handle.net/11660/9574
dc.description.abstractEnglish: The aim of this investigation was to quantify the spring-, summer-, autumn and annual DMproduction, botanical composition, nutritional value and milk production potential of kikuyu that is over-sown with annual ryegrass, mixtures of perennial white- and red clover or a mixture of perennial ryegrass and white and red clover, within a sustainable management system. Guidelines around the cultivation practices of these over-sowing techniques were determined. The investigation was executed on the Outeniqua Experimental farm near George in the Western- Cape. Three separate pastures under permanent irrigation over nine hectares during three years were compared in a pasture system study. The experimental design was a randomized complete block design with three treatments being repeated in eight blocks. Perennial white clover (Trifolium repens) cultivars (Haifa and Waverley) and perennial red clovers (Trifolium pratense) cultivars (Kenland and Cherokee), annual westerwold ryegrass (Lolium multiflorum: cultivar Energa) and perennial ryegrasses (Lolium perenne: cultivars Yatsyn and Dobson) were over-sown onto existing kikuyu pasture by making use of three implements, namely a Rotovator, Mulcher and a Land roller. The botanical composition (grass-, clover- and herb content), nutritional value (IVOMD-, TDN-, ME-, CP-, NDF-, ADF-, Ca-, P-content) and DM-content of the different pastures were determined on a monthly basis. The Ellinbank rising plate pasture meter was used to determine the DM-production, DM-production rate and the DM-intake of the pastures. A put-and-take system of grazing, using 36 mid-lactation Jersey cows in three groups (12 per group) for each season (90 days), was implemented. The cows received new strips of pasture after each milking. Cows were moved every second day to a new sub-camp and were absent from any sub-camp for a period of 30 days. Concentrate which contained at leat 120 g crude protein kg-1 DM and 12.5 MJ ME kg1 DM was fed at 4 kg cow' day" to all cows. The milk production and the number of cows kept were recorded and milk composition (butterfat-, protein- and milk solids content) was determined monthly. The mass and the condition score of the test cows were determined at the beginning and end of each test period. The DM-production rate (kg DM ha-1 day') of the pure kikuyu pasture was low during spring (33.9 kg DM ha:' day1) and high during the summer (67 kg DM ha' day") and autumn (71.6 kg DM ha' day'). The DM-production potential of kikuyu was not influenced during summer and autumn by over-sowing it with annual ryegrasses during May. When kikuyu was over-sown with clover, the DMproduction potential was reduced by 17% to 46% during the summer and autumn respectively. Kikuyu that was over-sown with ryegrass, reached a higher annual grazing capacity (8.03 to 9.03 cows ha") compared to that of kikuyu which was over-sown with clover (5.27 to 5.78 cows ha"). The clover component of a kikuyu pasture that was over-sown with clover, remained above 40% for longer than two years. In this instance the clover component was also more sustainable than in the perennial ryegrass clover pasture, where .itwas found that the clover component declined below the 30% level during the first production year. In comparison with ryegrass- and clover pasture, the nutritional value of pure kikuyu is less favourable for optimal milk production. The IVOMD, TDN-, ME- and RP-content of the ryegrass dominant kikuyu pasture was higher and the NDF- and ADF-content lower than that of the pure kikuyu pasture. The IVOMD, TDN-, ME- and RP-content of the clover dominant kikuyu pasture was higher and the NDF- and ADF-content lower than both the ryegrass-kikuyu pasture and pure kikuyu pasture. As the kikuyu component of the kikuyu-clover pasture increased, the IVOMD, TDN-, ME-, RP-content decreased and the NDF- and ADF- content increased. Clover pastures during the first production year had a high ME-content (on average 11.09 MJ kg-1 DM) that meets the energy requirements of a dairy cow. The ME-content of the second production year clover pastures (average 9.86 MJ kg-1 DM) was lower than 10 MJ kg-1 DM when the kikuyu content reached a level more than 50%. The Ca-content of the clover dominant pastures (average 1.03%) was higher than that of the grass dominant pastures (average 0.36%). The P-content of the different pastures differed very little (0.40% to 0.54%) and should meet the requirements of ruminants without any seasonal supplementation. A Ca:P-imbalance (average 0.74:1) occurred in grass pastures, which is lower than the ratio that is normally needed for optimal milk production (1.6: 1). In contrast to this the clover pastures maintained a favourable Ca:P-ratio (average 1.98: 1). The annual milk production from kikuyu pasture was 13.8 kg cow-1 day", ryegrass pasture average 15.5 kg cow-1 day", first production year clover pastures average 16.6 kg cow-1 day", second production year clover pastures average 17.0 kg cow-1 day" and first production year perennial ryegrass clover pastures 18.1 kg cow" day", The milk production per cow reduced as the kikuyu component of the pastures increased. The average annual grazing capacity for kikuyu, ryegrass-, first production year clover-, second production year clover pastures and second production year perennial clover pastures was 6.72,8.53,5.57 and 4.80 cows ha" respectively. The total annual milk and milk solids production per hectare from kikuyu were 21 377 and 1 751 kg ha", ryegrass pastures average 32179 and 2 610 kg ha", first production year clover pastures average 30 277 and 2452 kg ha", second production year clover pastures average 23 454 and 1 815 kg na' and first production year perennial ryegrass-clover pastures 29 298 and 2 266 kg ha" respectively. The lower grazing capacity of the clover pasture, combined with the high milk production per cow, resulted in similar milk production per hectare from the clover- and ryegrass pastures. The grazing capacity of the kikuyu-ryegrass pasture during the autumn (10.8 cows ha") was higher than that during the summer (9.05 cows ha'), but the milk production per cow during the autumn (12.3 kg cow' day ') was lower than that during the summer (20.3 kg cow1 daq"). This resulted in a lower milk production per hectare during the autumn (11 294 kg ha") compared to that of the summer (15780 kg ha"), The lower milk production (4486 kg ha") from the kikuyu during autumn in comparison to that of the summer, indicates the inherent nutritional shortages of kikuyu, which prevents that high milk production can be maintained from kikuyu pastures. The milk production from the over-sown clover pastures per hectare was the highest during the summer (9 194 to 13027 kg ha"), followed by that during the spring (7 370 to 10007 kg ha"), autumn (6 156 to 7 359 kg ha") and winter (3 990 to 4 222 kg ha:'). Milk production from the clover pasture was virtually the same as that from the ryegrass pastures during the spring (8 133 to 11 332 kg ha-1) and that from kikuyu pastures during the summer (9 688 kg ha-1). During autumn the milk production from the ryegrass- (9040 to 11 294 kg ha-1) and pure kikuyu pastures (8 930 kg ha-1) was higher than that of the clover pastures (6 156 kg ha-1). Pasture costs can be halved if kikuyu is over-sown with clover. The pasture costs and direct variable costs per kg milk produced from kikuyu was respectively R0.23 and R0.98 and it can be lowered if it is over-sown with ryegrasses (R0.21 and R0.87) or clovers (R0.10 and R0.71). The net cumulative surplus over two years from the ryegrass (R60 984) and clover pastures (R58 240) was similar and somewhat higher than that from the kikuyu pasture (R37 453). It is economically justified to include both ryegrasses and clovers in production systems. The over-sowing of kikuyu with ryegrass increased the grazing capacity and lowered the unit cost of milk produced. The oversowing of kikuyu with clover lowered the unit cost of grazing and the cost of milk produced. This reduces the risk of a dairy cow enterprise. From a fodder flow planning viewpoint it is recommended that ryegrass and clover pasture should be included in a dairy cow production system to lower the cost and the risk of a dairy production system and improve its economic viability. Kikuyu can be successfully over-sown during May with annual ryegrasses or perennial white- and red clovers by respectively making use of the Mulcher and Rotovator planting method.en_US
dc.description.abstractAfrikaans: Die doel van hierdie ondersoek was om die lente-, somer-, herfs- en jaarlikse DM-produksie, botaniese samestelling, voedingswaarde en melkproduksiepotensiaal van kikoejoe wat met eenjarige raaigras, mengsels van meerjarige wit- en rooiklawer of 'n mengsel van meerjarige raaigras, wit- en rooiklawer oorgesaai word, binne 'n volhoubare bestuurstelsel te kwantifiseer. Riglyne rondom die verbouingspraktyke van hierdie oorsaaitegnieke is daargestel. Die ondersoek is op Outeniqua Proefplaas naby George in die Wes-Kaap uitgevoer. Drie verskillende weidings onder permanente besproeiing is deur middel van 'n stelselproef op nege ha oor drie jaar met mekaar vergelyk. Die proefuitleg is 'n ewekansige blokontwerp met drie behandelings wat in agt blokke herhaal is. Twee meerjarige witklawer (Trifolium repens) kultivars (Haifa en Waverley) en twee meerjarige rooiklawers (Trifolium pratense) kultivars (Kenland en Cherokee), is as Trifoilium sp. in dié ondersoek gebruik. Een eenjarige westerwold tipe raaigras (Lolium multiflorum kultivar Energa) en twee meerjarige raaigrasse (Lolium perenne: kultivars Yatsyn en Dobson) was gebruik. Hierdie weidingsgewasse is jaarliks in suiwer of gemengde stande op bestaande kikoejoe oorgesaai. Kombinasies van drie implemente, nl. 'n Kapploeg, Stokkieskapper en LandrolIer was gebruik om raaigras en/of klawer in kikoejoe oor te saai. Die botaniese samestelling (gras-, klawer- en kruidinhoud), voedingswaarde (IVOMV-, TVV-, ME-, RP-, NDF-, ADF-, Ca-, P-inhoud) en DM-inhoud van die verskillende weidings is maandeliks bepaal. Die Elllinbank-skyfmeter was gebruik om die DM-produksie, DM-produksietempo en DM-inname van die weidings te bepaal. Daar is gebruik gemaak van die wisselgetalmetode waar 36 mid-laktasie Jerseykoeie in drie groepe (12 per groep) as proefdiere vir elke seisoen (90 dae) gebruik is. Die koeie het na elke melking 'n vars strook weiding ontvang. Koeie is elke tweede dag na 'n nuwe subkamp verskuif en was afwesig van enige subkamp vir 'n periode van 30 dae. Kragvoer wat ten minste 120 g ru-proteïen kg-1 DM en 12.5 MJ ME kg-1 DM bevat het, was teen 4 kg koel' daq" aan alle koeie voorsien. Die melkproduksie en die aantal koeie op die weidings aangehou is daagliks aangeteken en melksamestelling (bottervet-, proteïen- en melkvastestofinhoud) maandeliks bepaal. Die massa en kondisiepunt van die proefkoeie was aan die begin en einde van elke proefperiode bepaal. Die DM-produksietempo (kg DM ha" daq") van die suiwer kikoejoestand was gedurende die lente (33.9 kg DM ha:' daq") laag en gedurende die somer (67 kg DM ha' daq") en herfs (71.6 kg DM ha" daq") hoog. Indien kikoejoeweiding met meerjarige klawer of eenjarige raaigrasse oorgesaai word, verhoog die DM-produksietempo gedurende die lente na onderskeidelik 59.4 en 57.7 kg DM ha" dag- 1. Die DM-produksiepotensiaal van kikoejoe word nie gedurende die somer of herfs beïnvloed deur dit met eenjarige raaigrasse gedurende Mei oor te saai nie. Indien kikoejoe met klawers oorgesaai word, kan verwag word dat die DM-produksiepotensiaal daarvan gedurende die somer en herfs met onderskeidelik 17% tot 46% kan verlaag. Kikoejoe wat met raaigras oorgesaai is, het jaarliks 'n hoër weidingkapasiteit per eenheidsoppervlakte (8,03 tot 9.03 koeie ha') as dié van kikoejoe wat met klawer oorgesaai word (5.27 tot 5.78 koeie na:'), behaal. Die klawerkomponent van 'n kikoejoeweiding wat met klawers oorgesaai was, het vir langer as twee jaar bo 40% gebly. In hierdie stande was die klawerkomponent ook meer volhoubaar as in dié van 'n meerjarige raaigrasklawerweiding, waar bevind is dat die klawerkomponent gedurende die eerste produksiejaar tot onder die vlak van 30% gedaal het. In vergelyking met dié van raaigras- en klawerweidings, is die voedingswaarde van suiwer kikoejoeweiding minder gunstig vir optimale melkproduksie. Die IVOMV, TVV-, ME- en RP-inhoud van die raaigrasdominante kikoejoeweiding was hoër en die NDF- en ADF-inhoud laer as dié van suiwer kikoejoeweiding. Die IVOMV, TVV-, ME- en RP-inhoud van die klawerdominante kikoejoeweiding was hoër en die NDF- en ADF-inhoud laer as dié van beide die raaigraskikoejoeweiding en suiwer kikoejoeweiding. Soos die kikoejoekomponent van 'n kikoejoeklawerweiding verhoog, neem die IVOMV, TVV-, ME-, RP-inhoud af en die NDF- en ADF-inhoud neem toe. Klawerweidings gedurende die eerste produksiejaar beskik oor 'n hoë ME-inhoud (gemiddeld 11.09 MJ kg-' DM) wat aan die energiebehoeftes van melkkoeie kan voldoen. Die MEinhoud van die tweede produksiejaar klawerweidings (gemiddeld 9.86 MJ kg' DM) daallaer as 10 MJ kg-' DM sodra die kikoejoe-inhoud 'n vlak van hoër as 50% bereik. Die Ca-inhoud van die klawerdominante weidings (gemiddeld 1.03%) was heelwat hoër as dié van die grasdominante weidings (gemiddeld 0.36%). Die P-inhoud van die verskillende weidings het min verskil (0.40% tot 0.54%) en behoort sonder enige aanvulling seisoenaal aan die voedingsbehoefte van herkouers (0.38%) te voldoen. By die grasweidings kom 'n Ca:P-wanbalans (gemiddeld 0.74:1) voor wat laer is as die verhouding wat normaalweg vir optimale melkproduksie (1.6:1) benodig word. In teenstelling hiermee handhaaf die klawerweidings 'n gunstige Ca:P-verhouding (gemiddeld 1.98: 1). Die jaarlikse melkproduksie vanaf kikoejoeweiding was 13.8 kg koei" daq", raaigrasweiding gemiddeld 15.5 kg koei-' daq", eerste produksiejaar klawerweidings gemiddeld 16.6 kg koet' daq", tweede produksiejaar klawerweidings gemiddeld 17.0 kg koei" dag-' en eerste produksiejaar meerjarige raaigras-klawerweidings 18.1 kg koei" daq". Die melkproduksie per koei neem af soos wat die kikoejoekomponent van die weidings toeneem. Die gemiddelde jaarlikse weidingkapasiteit vir kikoejoe, raaigras-, eerste produksiejaar klawer-, tweede produksiejaar klawerweidings en tweede produksiejaar meerjarige-klawerweidings was onderskeidelik 6.72,8.53, 5.53, 5.57 en 4.80 koeie ha" . Die totale jaarlikse melk- en melkvastestofproduksie per eenheidsoppervlakte was onderskeidelik vanaf kikoejoe 21 377 en 1 751 kg ha-1, raaigrasweiding gemiddeld 32 179 en 2 610kg ha", eerste produksiejaar klawerweidings gemiddeld 30 277 en 2 452kg ha-1, tweede produksiejaar klawerweidings gemiddeld 23454 en 1 815kg ha-1 en eerste produksiejaar meerjarige raaigras-klawerweidings 29 298 en 2 266 kg ha-lo Die laer weidingkapasiteit van die klawerweiding, saam met hoë melkproduksie per koei, veroorsaak dat die melkproduksie per eenheidsoppervlakte , tussen die klawer- en raaigrasweidings min verskil. Die weidingkapasiteit vanaf die kikoejoe-raaigrasweiding gedurende die herfs (10.8 koeie ha-1) was hoër as dié gedurende die somer (9.05 koeie ha-1), maar die melkproduksie gedurende die herfs (12.3 kg koer' daq') was weer laer as dié gedurende die somer (20.3 kg koet'). Dit het tot gevolg gehad dat die melkproduksie per eenheidsoppervlakte gedurende die herfs (11 294 kg ha-1) ook laer was as dié wat gedurende die somer (15 780 kg ha-1) geproduseer is. Hierdie afname in die melkproduksie (4 486 kg ha-1) vanaf kikoejoe gedurende die herfs in vergelyking met dié vanaf die somer, dui op die inherente voedingstekorte van kikoejoe wat dus verhoed dat vanaf kikoejoeweiding volhoubaar hoë melkproduksies geproduseer kan word. Die melkproduksie vanaf die oorgesaaide klawerweidings per eenheidsoppervlakte was die hoogste gedurende die somer (9 194 tot 13 027 kg ha-1), gevolg deur dié gedurende die lente (7 370 tot 10 007 kg ha-1), herfs (6 156 tot 7 359 kg ha-1) en winter (3 990 tot 4 222 kg ha-1). Melkproduksie vanaf die klawerweidings was feitlik dieselfde as dié vanaf die raaigrasweidings gedurende die lente (8 133 tot 11 332 kg ha-1) en dié vanaf kikoejoeweidings gedurende die somer (9 688 kg ha-1). Gedurende die herfs was die melkproduksie vanaf die raaigras- (9 040 tot 11 294 kg ha-1) en suiwer kikoejoeweidings (8 930 kg ha") hoër as dié van die klawerweidings. Die melkproduksie van kikoejoe met 'n hoë klawerkomponent (6 156 kg ha-1) was gedurende die herfs laer as dié vanaf 'n suiwer kikoejoestand (8 930 kg ha-1) óf 'n kikoejoestand wat met raaigras oorgesaai (9040 kg ha-1) is. Weidingskoste kan gehalveer word indien kikoejoe met klawers oorgesaai word. Die weidingskoste en direkte veranderlike koste per kg melk geproduseer vanaf kikoejoe, was onderskeidelik R0,23 en R0.98 en dit kan verlaag word indien dit met raaigrasse (R0.21 en R0.87) en klawers (R0.1 0 en R0.71) oorgesaai word. Die netto kumulatiewe surplus van die raaigras- (R60 984) en klawerweidings (R58 240) was oor twee jaar byna soortgelyk en heelwat hoër as dié vanaf kikoejoe (R37 453). Dit is ekonomies geregverdig om beide raaigrasse en klawers in produksiestelsels in te sluit. Die oorsaai van kikoejoe met raaigras verhoog die weidingkapasiteit en verlaag die eenheidskoste van melk geproduseer. Die oorsaai van kikoejoe met klawer verlaag die eenheidskoste van weiding en die koste van melk geproduseer. Hierdeur word die risiko van 'n melkbeesonderneming verlaag. Uit 'n voervloeibeplannings oogpunt word aanbeveel dat raaigrasen klawerweidings saam in 'n melkbeesproduksie-stelsel ingesluit behoort te word. Dit kan 'n lae koste en lae risiko produksie-stelsel, wat ook ekonomies volhoubaar is, verseker. Kikoejoe kan suksesvol gedurende Mei met eenjarige raaigrasse of meerjarige wit- en rooiklawers oorgesaai word deur onderskeidelik van die Stokkieskapper- en Kapploeg-plantmetode gebruik te maak.en_US
dc.language.isoenen_US
dc.publisherUniversity of the Free Stateen_US
dc.subjectKikuyuen_US
dc.subjectOver-sowen_US
dc.subjectCloveren_US
dc.subjectRyegrassen_US
dc.subjectMilk productionen_US
dc.subjectNutritional valueen_US
dc.subjectCarrying capacityen_US
dc.subjectBotanical compositionen_US
dc.subjectDry matter productionen_US
dc.subjectIrrigationen_US
dc.subjectEconomic analysisen_US
dc.subjectKikuyu grass -- South Africa -- Southern Capeen_US
dc.subjectPastures -- South Africa -- Southern Cape -- Managementen_US
dc.subjectThesis (Ph.D. (Animal, Wildlife and Grassland Sciences))--University of the Free State, 2003en_US
dc.titleDie produksiepotensiaal van oorgesaaide kikoejoeweiding in die gematigde kusgebied van die Suid-Kaapen_US
dc.typeThesisen_US
dc.rights.holderUniversity of the Free Stateen_US


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