Thesis (MPhil)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: A farm in Zimbabwe (Farm A) obtains its water for tbe poultry operations from tbe Makavusi River that is heavily contaminated with bacteria and performance results are thereby reduced. Anolyte is a Russian invention that claims to have bactericidal effects that could be beneficial to broilers. The aim of this research is to investigate the effect of Anolyte on production profits of broilers given water of poor quality by carrying out a number of trials. Trials that were conducted are basic in vitro tests on Anolyte within the laboratory, water analysis on water supply to the broiler section (both chemical and bacteriological), and a detailed trial within an experimental trial site comparing broiler performance results with different chemical water treatments and different dilutions of Anolyte. Broiler chicks from different hatcheries (Hatchery A and Hatchery B) were also compared. Performance results were based on growtb rate, mortality, feed conversion ratios (FCR), performance efficiency factors (PEF) and profit margin comparisons. Results showed that in tbe laboratory, Anolyte had an antibacterial activity. In the broiler performance trial on Hatchery B broilers, the live weights at forty two days of age in broilers given 15% Anolyte differed from other treatments (P<0.05) other than 10% Anolyte (P > 0.05). However, the FCR and mortalities did not differ (P > 0.05) between treatments. In the trial on Hatchery A broilers to 42 days of age, growth rates in broilers given 15% Anolyte differed from tbe control, Chematron and 20% Anolyte (P < 0.05). However, the FCR and mortalities did not differ between (P>0.05) treatments. In comparing chicks from different hatcheries, Hatchery B broilers differed (P < 0.05) from Hatchery A broilers in live weights at 42 days on 10% Anolyte, 15% Anolyte and on Chematron treatments. However, tbe cumulative mortalities and FCR did not differ (P > 0.05) between the Hatchery B and Hatchery A on any treatment. When comparing profitability, tbe treatment that had the greatest margin in comparison to tbe control (untreated drinking water) was 15% Anolyte for both tbe Hatchery B and Hatchery A trials. / AFRIKAANSE OPSOMMING: 'n Plaas in Zimbabwe, (Plaas A) verkry water, vir hul pluimvee bedryf vannuit die Makavusi rivier. Die rivier is swaar besmet met bakterië en as gevolg daarvan verhoed dit dat hulle hul volle opbrengs potential bereik. Anolyte is 'n Russiese uitvindsel wat aanspraak maak daarop dat dit bakteriëdodende effekte besit wat tot die bevordering van slaghoenders kan lei. Die doel van die navorsing is om Anolyte op proef te stel aangaande produksie profyt op slaghoenders waaraan swak kwaliteit water verskaf is. Verskeie toetse is uitgevoer n1. 'n basiese 'in vitro' toets in samewerking met die laboratorium, water ontleding op water wat aan die slaghoender seksies verskaf is (beide chemikalies and bakterieologies) asook 'n intensiewe proefnemeing waarin die verskeie obrengs resultate, van chemikaliese behandelde water en verskillende verdunnings van Anolyte, met mekaar vergely is, in 'n experimetele navorsings eenheid. Slaghoender kuikens van twee verskillende broeihuise (n1. Broeihuis A en Broeihuis B) is ook met mekaar vergelyk. Die resultate is gabasseer op groei tempo, sterftes, voer omsettings verhouding, opbrengs geskikthied faktore asook vergelykings op wins. Laboratorium navorsing het bevestig dat Anolyte wel antibakteriese aktiviteit getoon het. Terwyl in die proefneming op Broeihuis B slaghoenders, het die lewende gewig van hoenders, op 42 dae van ouderdom, waaraan 15% Anolyte verskaf is, verskil van ander behandelings (P<0.05) met die uitsondering van 10% Annolyte (P>0.05). Alhoewel die voer omsetting verhoudings en sterftes nie in die verskillende behandelings verskil het nie. In die proefnemeing op Broeihuis A slaghoenders tot 42 dae van ouderdom, het die ontwikkeling van slaghoenders, waaraan 15% Anolyte verskaf is, verskil van die kontiole, Chematron en 20% Anolyte. Die voer omsettings verhoudings en sterftes het egter geen verskil getoon tussen die verskeie behandelings nie. Resultate van die vergelyking tussen die kuikens uit die twee verskillende broeihuise, het getoon dat die Broeihuis A en Broeihuis B lewensgewigte, op 42 dae van ouderdom, wel met mekaar verskil het met 10% Anolyte, 15% Anolyte sowel as die Chematron behandelings. Daar was egter geen verskil, (P>O.05) tussen die twee tipes aangaande elke tipe se saamgestelde sterftes en die voer omsettings verhoudings, in welke behandeling nie. Die vergelykings op wins het getoon dat die behandeling met die grootste brulo marge, die was van 15% Anolyte in vergelyking met die kontiole (onbehandelde drinkwater) vir beide die Broeihuis A en die Broeihuis B proefnemings.

Thesis (MScAgric)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Grinding of feedstuffs prior to in sacco incubation results in fine particles that could escape from dacron bags without being degraded. The objective of this study was to determine the effect of the removal of these fine particles on protein degradation parameters. The feedstuffs that were used were protein feedstuffs that are commonly used in dairy cattle diets in South Africa. Feedstuffs were soybean oilcake, sunflower oilcake, maize gluten 20, maize gluten 60 and fish meal. Treatments were; 1. grinding through a 2 mm screen with no subsequent sieving, 2. grinding through a 2 mm screen followed by sieving through a 106 μm mesh, and 3. grinding through a 2 mm screen followed by sieving through a 150 μm mesh. In the first trial, the material that was lost through sieving and the chemical composition of the different treatments were determined. Protein solubility was also determined. Between 20 and 60% of the material dry matter was lost with the sieving. The chemical composition for the soybean and sunflower oilcake and maize gluten 60 was similar between the three different treatments (or fractions). The CP content of fish meal and maize gluten 20 differed somewhat between the treatments. The 106 μm mesh seemed to be most suitable for fish meal, but a suitable mesh size could not be found for maize gluten 20. In the second trial, the degradability parameters were determined according to the in sacco degradation procedure. Three lactating Holstein cows that were fitted with rumen cannulae were used. The cows received a commercial lactation diet and oat hay that was supplied ad libitum. Samples of all the protein sources were placed in dacron bags and incubated in the rumen. The following removal times were used: 0, 2, 4, 8, 12, 24 or 48 hours. Dry matter and CP disappearances were determined, and the values were used to estimate DM and CP degradability parameters using a non-linear model. Effective CP degradability was also determined. The a-values were affected most of all. On average, the a-values were 39.4 and 40.3% higher for the un-sieved treatments than for the sieved treatments, for DM and CP, respectively. The effective CP degradability was also, on average, 43% higher for the un-sieved treatments. Grinding without the subsequent sieving of samples appears to result in an overestimation of DM and CP degradation in the rumen. It is therefore recommended that after grinding, feedstuffs should be sieved through at least a 106 μm mesh in preparation for in sacco incubations. / AFRIKAANSE OPSOMMING: Die maal van grondstowwe ter voorbereiding van in sacco inkubasies lei tot ‘n potensiële verlies van klein partikels uit die dakronsakkies sonder dat hulle gedegradeer word. Die doel van hierdie studie was om die invloed van die verwydering van fynmateriaal op proteïen-degradeerbaarheidsparameters te bepaal. Die grondstowwe wat in hierdie studie gebruik is, is proteïengrondstowwe wat algemeen in melkbeesdiëte in Suid-Afrika gebruik word. Die grondstowwe was soja-oliekoek, sonneblom-oliekoek, mielie gluten 20, mielie gluten 60 en vismeel. Behandelings was; 1. maal deur ‘n 2 mm sif sonder verdere sifting, 2. maal deur ‘n 2 mm sif gevolg deur sifting deur ‘n 106 μm sif en 3. maal deur ‘n 2 mm sif gevolg deur sifting deur ‘n 150 μm sif. In die eerste proef is die hoeveelheid materiaal wat verlore gaan as gevolg van sifting van die grondstowwe bepaal en die chemiese samestelling van die verskillende behandelings. Proteïenoplosbaarheid is ook bepaal. Tussen 20 en 60% van die materiaal het verlore gegaan as gevolg van sifting. Die chemiese samestelling van die soja- en sonneblom oliekoek, asook dié van die mielie gluten 60 was soortgelyk vir al drie die behandelings. Die ruproteïeninhoud (RP) van die vismeel en mielie gluten 20 het verskil tussen die drie behandelings. Dit wil voorkom asof die 106 μm sif die mees geskikte is vir vismeel, maar ‘n geskikte sif kon nie vir mielie gluten 20 gevind word nie. In die tweede proef is die degradeerbaarheidsparameters bepaal met behulp van die in sacco-metode. Drie lakterende Holsteinkoeie met rumen kannulas is gebruik. Die koeie het ‘n kommersiële melkbeesdieët ontvang en hawerhooi ad libitum. Die monsters is in dakronsakkies in die rumen geïnkubeer. Die sakkies is na die volgende inkubasietye verwyder: 0, 2, 4, 8, 12, 24 of 48 uur. Die DM- en RP-verdwyning is bereken en die waardes is gebruik om die DM- en RP- degradeerbaarheidsparameters te bereken met behulp van ‘n nie-lineêre model. Effektiewe RP- degradeerbaarheid is ook bereken. Die waardes wat die meeste beïnvloed is, is die a-waardes. Die a-waardes was gemiddeld 39.4 en 40.3% hoër vir die ongesifte behandelings as vir die gesifte behandelings, vir DM en RP, onderskeidelik. Die effektiewe RP-degradeerbaarheid was ook gemiddeld 43% hoër vir die ongesifte behandelings. Dit wil voorkom asof DM- en RP-degradeerbaarheid oorskat word wanneer voermonsters slegs gemaal word. Dit word aanbeveel dat grondstowwe ten minste deur ‘n 106 μm sif gesif word ter voorbereiding vir in sacco-studies.

Thesis (MScAgric)--Stellenbosch University, 2012 / ENGLISH ABSTRACT: Ruminal pH is the rumen condition that varies most. Studying the cause and effect of diurnal variation offers a means of improving ruminal conditions for rumen micro-organisms with subsequent improvements in fibre degradation, milk yields and milk composition. A research project was conducted to test the following hypothesis: feeding 6 kg (as is) concentrate per cow/day in different weight ratios, divided in a morning and an afternoon allocation, will result in an improved ruminal pH profile and a concurrent increase in fibre fermentation, milk yield and improved milk composition. The project was conducted at the Outeniqua Research Farm in the Southern Cape of South Africa. A randomized block design was used and two phases, viz. ryegrass phase and a kikuyu phase, were applied. Each phase was conducted during the growing season of the grass specie used as pasture. A rumen study and a production study were done in each phase. The rumen study used six cannulated multiparous cows per treatment, testing rumen pH, volatile fatty acid (VFA) concentration, in sacco degradation of neutral detergent fibre (NDF) and dry matter (DM). The production study used 42 multiparous cows, blocked according to days in milk (DIM), parity and milk yield, and cows were randomly divided into three treatment groups. The study tested milk yield, milk composition and changes in body weight (BW) and body condition score (BCS). Treatments consisted of a maize based concentrate supplement (6 kg per cow/day, as is) being fed to cows on pasture in different weight ratios between morning and afternoon allocation. Treatments used in the production study were: Concentrate fed: 5 kg during morning; 1 kg during afternoon • Concentrate fed: 4 kg during morning; 2 kg during afternoon • Concentrate fed: 3 kg during morning; 3 kg during afternoon The first and the last treatments mentioned above were used in the rumen studies. Results of the rumen study of the ryegrass phase showed no differences in ruminal pH between treatment means. The time (h) spent below the critical ruminal pH, i.e. 5.8, was of short duration (2.92 to 3.42 hours). The concentration of certain VFA’s differed at times, but the differences were not reflected in graphs and data of the ruminal pH. No differences were observed in in sacco NDF and DM degradation between treatment means. Similar results were mostly obtained in the kikuyu phase. No differences were found in either daily maximum, minimum or mean ruminal pH between treatment means. Though time (h) spent below the critical ruminal pH was of a long duration (7.1 hours) it did not differ between treatments. No differences were observed between treatment means for in sacco NDF and DM degradation. Results of the production study of the ryegrass phase showed no differences in milk yield or milk composition between treatment means. The same was observed in the kikuyu phase except that milk fat was higher in the treatment group that received the 3:3 kg ratio treatment. The fact that treatments did not differ in terms of milk yield and milk composition in the production studies can be attributed to no differences between treatments in terms of rumen parameters observed in the rumen studies. Thus, feeding a higher proportion of concentrate in the morning relative to the afternoon for a total of 6 kg per cow/day does not affect ruminal pH, fibre digestion or milk production. Based on the results of both phases it can be concluded that the null hypothesis should be rejected. / AFRIKAANSE OPSOMMING: Die invloed van kragvoer voedingsstrategieë op rumen parameters, melkproduksie en melksamestelling van Jerseykoeie op raaigras- (Lolium multiflorum) of kikoejoe- (Pennisetum clandestinum) weidings. Die invloed van kragvoer voedingsstrategieë op rumen parameters, melkproduksie en melksamestelling van Jerseykoeie op raaigras- (Lolium multiflorum) of kikoejoe- (Pennisetum clandestinum) weidings. Behandelings toegepas in die produksiestudie het bestaan uit ‘n kragvoeraanvulling met ‘n mieliebasis wat aan koeie op weidings gevoer is in verskillende gewigsverhoudings tussen oggend- en middagvoeding, as volg: Behandelings toegepas in die produksiestudie het bestaan uit ‘n kragvoeraanvulling met ‘n mieliebasis wat aan koeie op weidings gevoer is in verskillende gewigsverhoudings tussen oggend- en middagvoeding, as volg:

Thesis (MScAgric)--Stellenbosch University, 2008. / ENGLISH ABSTRACT: Research conducted on beef cattle in Botswana investigated both growth and reproduction. These studies however, did not specifically determine the influence of the different environmental factors on growth in the Tswana and Composite beef cattle breeds. The establishment of a national beef herd recording and performance testing scheme requires knowledge on the appropriate adjustment methods of field data for the fixed effects such as sex of calf and age of dam. A fair comparison of birth and weaning weights between male and female calves, and calves born from young, mature and old dams will be derived from these adjustment factors. There is no information on adjustment factors for the Tswana and Composite cattle breeds in the country. Genetic parameters for growth traits in these breeds are not known and are needed for the implementation of the performance scheme in Botswana. The Composite breed resulted from a controlled crossbreeding programme using the Simmental, Brahman, Tswana, Tuli and the Bonsmara breeds. The Tswana animals are indigenous to the country and were sourced locally at the beginning of the growth evaluation trial in the two breeds. The objectives of the study were to use data collected from Tswana and Composite cattle breeds to estimate the influence of non-genetic factors on growth traits in the two breeds; to develop adjustment factors for the effects of sex of calf and age of dam; and to estimate genetic parameters (heritabilities and genetic correlations) for future genetic evaluations in both breeds. Data were collected over the period 1988 to 2006. A total of 2 257 records for the Composite breed and 5 923 records for the Tswana breed were available for analyses. Growth characteristics of interest in this study were birth weight (BW), weaning weight (WW), pre-weaning average daily gain (ADG1), 18 months weight (18MW) and post-weaning average daily gain (ADG2). Study 1 indicated that non-genetic effects of breed of calf, sex of calf, month and year of birth, previous parous state, weight of cow at parturition, age of dam, and age of calf at weaning significantly affected BW, WW, 18MW, ADG1 and ADG2 in both breeds. The Composite breed had higher BW, ADG1 and WW whereas the Tswana had higher ADG2 and 18MW. Pre-weaning growth rate increased with an increase in the age of the dam, reaching a peak in mature (5-12 years) cows and declined in cows 13 years and older. Conversely, post-weaning growth rates declined as age of dam advanced but increased in old (13 years and older) dams. Male calves were heavier than female calves for all the growth traits. Birth weight increased as calving season progressed whilst a decrease in WW was observed over the same period. Heifers gave birth to lighter calves when compared to mature multiparous dams. The Composite breed can therefore be considered for weaner production under ranch conditions while the Tswana can be reared under extensive systems due to its adaptability to the environment. Additive correction factors for effects of sex of calf and age of dam on BW and WW were studied separately for the Tswana and Composite in study 2. The least squares means procedure was used to derive age groups and the adjustment factors. The three age groups were young (4 years and below) dams, mature (5-12 years) dams and older (13 years and above) dams. Male calves were heavier than their female counterparts. The sex of calf adjustments for BW and WW were 2.75 and 8.21 kg in the Tswana, and corresponding values for the Composite 2.84 and 10.11 kg, respectively. Birth weight and WW increased as age of dam increased, reached maximum in mature dams and declined in older dams. Age of dam adjustment factors for BW in the 3, 4 and 13+ years age groups for the Tswana were 1.74, 0.96 and 1.87 kg, respectively. The corresponding values for the Composite were 2.28, 0.94 and 2.06 kg, respectively. Age of dam adjustment factors for weaning weight in the Tswana were 10.36 and 5.46 kg for age groups 3-4 and 13+ years, respectively. Adjustment factors for WW in the Composite were 13.84, 3.20 and 9.58 kg for age groups 3, 4 and 13+ years. The differences in adjustment factors obtained between the two breeds emphasize the need to compute and apply these factors within breed. Study 3 involved the estimation of genetic parameters for BW, WW, ADG1, 18MW and ADG2. Single-trait and multi-trait analyses were used in the estimation of (co)variance components by fitting an individual animal model (AM) and the animal maternal model (AMM) for the two breeds. Direct heritabilities for BW, WW, ADG1, 18MW and ADG2 in the Tswana were 0.45, 0.32, 0.37, 0.31 and 0.31, respectively from a single-trait AM analysis. Fitting the AMM resulted in direct heritabilities of 0.31, 0.20 and 0.16 for BW, WW and ADG1, respectively, while the maternal heritabilities were 0.11, 0.15 and 0.21, respectively. For the Composite the direct heritabilities for BW, WW and ADG1 were 0.58, 0.32 and 0.30, respectively with single-trait AM. Partitioning using the AMM resulted in the direct heritabilities for BW, WW and ADG1 of 0.55, 0.17 and 0.14, respectively, while corresponding maternal effects were 0.09, 0.15 and 0.15, respectively. The genetic correlations between direct and maternal effects were positive and ranged from 0.20 to 0.89. When using the multi-trait analysis and fitting the AM, the direct heritabilities for the Tswana were 0.45, 0.37, 0.34, 0.39 and 0.31 for BW, WW, ADG1, 18MW and ADG2, respectively. Genetic correlations between the growth traits ranged from 0.16 to 0.97. Direct (and maternal) heritabilities for BW, WW and ADG1 were 0.31(0.11), 0.19(0.15) and 0.14(0.17), respectively, in the Tswana. Correlations between direct heritabilities for BW, WW and ADG1 ranged from 0.45 to 0.95, while maternal effects ranged from 0.12 to 0.99. The magnitude of the heritabilities indicates an existence of the opportunity to make genetic progress through selection in both breeds. Selection based on WW seems to be the ideal procedure to bring genetic improvement in the Tswana without detrimental long term effects. / AFRIKAANSE OPSOMMING: Navorsing wat op die vleisbeesrasse in Botswana gedoen is, het hoofsaaklik op beide groei en reproduksie gehandel. Hierdie studies het egter nie spesifieke gefokus op die bepaling van die invloed wat verskillende omgewingsfaktore op die groei van saamgestelde (d.i. Composite) en die Tswana vleisbeesrasse het nie. Die bepaling van ʼn nasionale vleisbees rekordhouding- en prestasietoetsskema verg kennis van die mees gepaste metode om velddata vir vaste effekte soos geslag van die kalf en ouderdom van die moeder aan te pas. Hierdie aanpassingsmetodes sal lei tot die regverdige vergelyking van geboorte- en speengewigte tussen manlike en vroulike diere, sowel as van kalwers gebore van jong, volwasse of ou moeders. Tans is daar geen inligting oor aanpassingfaktore vir die Tswana en saamgestelde vleisbeesrasse in Botswana bekend nie. Geen genetiese parameters vir groei-eienskappe vir geeneen van die rasse is beskikbaar nie en word benodig vir die implementering van die prestasie skema in Botswana. Die saamgestelde ras is die produk van ʼn beheerde kruisteeltprogram, wat onderskeidelik die Simmental, Brahman, Tswana, Tuli en die Bonsmara beesrasse ingesluit het. Die Tswana ras is inheems aan Botswana en vanaf plaaslike bronne vir die groei evaluasie studie bekom. Die doelwitte van die studie was eerstens die analisering van data wat van beide die Tswana en saamgestelde rasse ingesamel is, om die invloed van nie-genetiese faktore op die groei eienskappe te bepaal om ten einde aanpassingsfaktore vir die effek van geslag van die kalf en ouderdom van die moederdier te ontwikkel. ʼn Tweede doelwit was die bepaling van genetiese parameters (oorerflikhede en genetiese korrelasies) vir die gebruik in toekomstige genetiese evaluering van beide rasse. Data is vanaf 1988 tot 2006 ingesamel. ʼn Totaal van 2 257 waarnemings vir die saamgestelde ras en 5 923 waarnemings vir die Tswana ras is ontleed. Groei eienskappe wat in die studie ondersoek is, het geboortegewig (BW), speengewig (WW), voorspeen gemiddelde daaglikse toename (ADG1), 18-maand gewig (18MW) en naspeense gemiddelde daaglikse toename (ADG2) ingesluit. Studie een het aangedui dat nie-genetiese effekte van die ras van die kalf, die geslag van die kalf, maand en jaar van geboorte, vorige dragtigheidsstatus, koei se gewig met geboorte van kalf, ouderdom van die moederdier en die speenouderdom van die kalf het ʼn betekenisvolle invloed op BW, WW, 18MW, ADG1 en ADG2 van beide rasse gehad. Die saamgestelde ras het hoër waardes vir BW, ADG1 en WW gehad, terwyl die Tswana ras hoër waardes vir ADG2 en 18MW geopenbaar het. Voorspeense groeitempo het toegeneem met ʼn toename in die ouderdom van die moederdier, met ʼn piek in volwasse (d.i. 5-12 jaar ouderdom) moeders en ʼn afname in koeie 13 jaar en ouer. Omgekeerd het naspeen groeitempo afgeneem met ʼn toename in die ouderdom van die moederdier en weer begin toeneem vir ou (d.i. 13 jaar en ouer) koeie. Geboortegewig het toegeneem met die verloop van die kalfseisoen, terwyl ʼn afname in WW vir dieselfde periode aangeteken is. Verse het, wanneer hulle met volwasse koeie vergelyk is, het geboorte aan ligter kalwers gegee. Die saamgestelde ras kan dus oorweeg word vir die produksie van speenkalwers onder kommersiële intensiewe toestande, terwyl die Tswana ras, op grond van sy beter aanpassing by ekstensiewe omstandighede waar die moederlike invloed nie voorkom nie, vir produksie onder ekstensiewe omstandighede gebruik kan word. In studie 2 is die additiewe korreksie faktore vir die invloed van geslag van die kalf en moederouderdom op BW en WW apart vir die twee rasse bestudeer. Die geslag van die kalf x ouderdom van die moederdier interaksie was nie betekenisvol vir enige van die rasse nie. Dus kan geen aanpassing vir die ouderdom van die moeder binne geslagte vir enige van die twee rasse gemaak word nie. Die kleinste kwadraat gemiddeldes metode is gebruik om die ouderdomsgroepe en aanpassingsfaktore te bepaal. Die drie ouderdomsgroepe was jong (d.i. 4 jaar en jonger) koeie, volwasse (d.i. 5-12 jaar ouderdom) en ouer (d.i. 13 jaar en ouer) koeie. Daar is gevind dat manlike kalwers swaarders as hulle vroulike eweknieë is. Die aanpassingswaarde vir die geslag van die kalf vir BW en WW was 2.75 kg en 8.21 kg in die Tswana en 2.84 kg en 10.11kg vir die saamgestelde ras. Geboortegewig en WW het toegeneem met ʼn toename in die ouderdom van die moeder. Dit het ʼn maksimum bereik in volwasse koeie en afgeneem vir koeie ouer as 13 jaar. Die aanpassingsfaktore vir die ouderdom van die moederdier vir BW in die 3, 4 and 13+ jarige ouderdomsgroepe vir die Tswana ras was onderskeidelik 1.74 kg, 0.96 kg en 1.87 kg. Die ooreenstemmende waardes vir die saamgestelde ras was onderskeidelik 2.28 kg, 0.94 kg en 2.06 kg. Aanpassingsfaktore vir WW vir die Tswana ras was 10.36 kg en 5.46 kg vir onderskeidelik die 3-4 jaar en 13+ jaar en ouer ouderdomsgroepe. Aanpassingsfaktore vir WW in die Composite ras was 13.84 kg, 3.20 kg en 9.58 kg vir onderskeidelik die 3 jaar, 4 jaar en 13 jaar en ouer ouderdomsgroepe. Verskille in die onderskeie parameters vir die twee rasse beklemtoon die noodsaaklikheid vir die berekening en toepassing van die onderskeie aanpassingfaktore vir en binne elke ras. Studie 3 het die bepaling van die genetiese parameters vir BW, WW, ADG1, 18MW en ADG2 behels. Enkel- en multivariaat analises is gebruik vir die skatting van die (ko)variansie komponente deur ʼn direkte diermodel (AM) en ʼn dier-maternale model (AMM) vir die twee rasse te pas. Direkte oorerflikhede vir BW, WW, ADG1, 18MW en ADG2 vir die Tswana ras was onderskeidelik 0.45, 0.32, 0.37, 0.31 en 0.31, vir ʼn enkelvariaat AM analise. Die pas van ʼn AMM het direkte oorerflikhede van 0.31, 0.20 en 0.16 vir onderskeidelik BW, WW and ADG1 gegee, terwyl die maternale oorerflikhede onderskeidelik 0.11, 0.15 en 0.21 was. Vir die saamgestelde ras was die direkte oorerflikhede vir BW, WW en ADG1 onderskeidelik 0.58, 0.32 en 0.30 vir die enkelvariaat AM analise. Verdeling (partisie) van die AMM het direkte oorerflikhede vir BW, WW en ADG1 van onderskeidelik 0.55, 0.17 en 0.14 gegee, terwyl die ooreenstemmende maternale effekte onderskeidelik 0.09, 0.15 en 0.15 was. Die genetiese korrelasies tussen die drekte en maternale effekte was positief en tussen 0.20 en 0.89. Met die multivariaat analise en die pas van die AM, is direkte oorerflikhede van 0.45, 0.37, 0.34, 0.39 en 0.31 vir onderskeidelik BW, WW, ADG1, 18MW en ADG2, vir die Tswana ras bereken. Genetiese korrelasies tussen die groei eienskappe het gewissel tussen 0.16 tot 0.97. Direkte (en maternale) oorerflikhede vir BW, WW en ADG1 was onderskeidelik 0.31(0.11), 0.19(0.15) en 0.14(0.17), vir die Tswana ras. Korrelasies tussen die direkte oorerflikhede vir BW, WW en ADG1 het gewissel tussen 0.45 en 0.95, terwyl die maternale effekte tussen 0.12 en 0.99 gewissel het. Die grootte van die oorerflikhede dui op die moontlikheid van genetiese vordering wat deur seleksie in beide rasse gemaak kan word. Seleksie op grond van WW blyk die mees gepaste wyse te wees waarmee genetiese vordering binne die Tswana ras gemaak kan word, sonder enige langtermyn nadelige effekte.

Thesis (MscAgric (Animal Sciences))--University of Stellenbosch, 2005. / The extrusion and dehulling of sweet blue lupins (Lupinus angustifolius, cultivar Wonga) and the expansion of full-fat canola seed were evaluated in terms of their effect on the nitrogen corrected apparent metabolizable energy (AMEn) value and broiler performance.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: The effect of Acid Buf and combinations of Acid Buf and Sodium bicarbonate in dairy cow diets on production response and rumen parameters The objective of this study was to determine the effect of Acid Buf alone, or in combination with sodium bicarbonate, on milk production, milk composition and selected rumen parameters. A high concentrate TMR, formulated to be potentially acidotic, was used to construct four dietary treatments in which Acid Buf (AB), the skeletal remains of the seaweed Lithothamnium calcareum, was used alone or in combination with sodium bicarbonate (BC). The diets contained 3.5 g/kg of AB (Treatment 1) or 1.75 g/kg of AB and 1.75 g/kg of BC (Treatment 2) or 3.5 g/kg of AB and 3.5 g/kg of BC (Treatment 3) or 3.5 g/kg of AB and 5.2 g/kg of BC (Treatment 4). The response to treatment was determined using eight ruminally cannulated lactating Holstein cows randomly allocated to treatments according to a 4 x 4 (n=2) Latin square design, with four treatments and four periods. The total experimental period was 100 days in which every cow received each diet for a period of 18 days prior to a data collection period of 7 days. Rumen pH was monitored continuously over 2 days using a portable data logging system and in-dwelling electrodes. Samples of rumen fluid were collected for volatile fatty acid (VFA) analyses. During each data collection period, milk production was recorded twice daily for 7 days, whereas milk was sampled twice daily for five consecutive days for component analysis. Cows were fed ad libitum and dry matter intake was recorded individually. Treatment had no significant effect on milk production, milk composition or feed intake. Ruminal pH profiles of all the treatments indicated that the diets were well buffered. Average pH over 24 hours was 6.0, 6.1, 6.1 and 6.2 for Treatments 1, 2, 3 and 4, respectively. The pH did not go below 5.8 for any of the treatments and increasing levels of sodium bicarbonate increased the diurnal profile such that at the highest level (Treatment 4), the pH profile ranged from 6.1 to 6.5. Although not significant, Treatment 1 (Acid Buf alone) numerically resulted in the highest milk output without compromising milk quality. It is proposed that high rumen pH may impact negatively on milk output by increasing the acetate:propionate ratio to the detriment of rumen efficiency. Treatment had no significant effect on total VFA concentration, but there seemed to be a tendency for increased total VFA concentration as the level of sodium bicarbonate increased. The acetate:propionate ratio of Treatment 1 (2.91) was significantly lower than Treatment 4 (3.65) (P<0.05). The use of buffers which react to increasing acidity in the rumen may therefore provide an efficient, safe solution to rumen acidosis. This study confirmed previous results indicating that a daily intake of 80 g of Acid Buf by cows receiving high concentrate diets would support high milk production without compromising milk solids contents. / AFRIKAANSE OPSOMMING: Die effek van Acid Buf en kombinasies van Acid Buf en Natriumbikarbonaat in melkkoeidiëte op melkproduksie, melksamestelling en rumenparameters Die doel van die studie was om die invloed van Acid Buf alleen, of in kombinasie met natriumbikarbonaat, in melkbeesdiëte op melkproduksie en melksamestelling, asook op bepaalde rumenparameters, te bepaal. ‘n Volledige dieet met ‘n hoë kragvoerinhoud, wat geformuleer is om potensieel asidoties te wees, is gebruik om vier dieetbehandelings saam te stel waarin Acid Buf (AB), die skeletoorblyfsels van die seegras Lithothamnium calcareum, alleen of in kombinasie met natriumbikarbonaat (BK) gebruik is. Een basale diet is dus geformuleer en die behandelingsdiëte het onderskeidelik 3.5 g/kg AB (Behandeling 1) of 1.75 g/kg AB en 1.75 g/kg BK (Behandeling 2) of 3.5 g/kg AB en 3.5 g/kg BK (Behandeling 3) of 3.5 g/kg AB en 5.2 g/kg BK (Behandeling 4) bevat. Agt rumen-gekannuleerde lakterende Holsteinkoeie is ewekansig aan die behandelings toegeken in ‘n 4 x 4 (n=2) Latynse vierkantontwerp met vier behandelings en vier periodes. Die totale eksperimentele periode was 100 dae, waartydens elke koei elke behandeling vir 18 dae ontvang het voor die datakolleksieperiode van 7 dae. Rumen pH is voortdurend, elke vier minute, oor ‘n twee-dae periode gemeet met behulp van draagbare dataloggers en pH elektrodes wat binne-in die rumen gesetel was. Rumenvloeistof is versamel vir die bepaling van vlugtige vetsuurkonsentrasies. Gedurende elk van die datakolleksieperiodes is die melkproduksie twee maal per dag geneem vir sewe agtereenvolgende dae en melkmonsters is tweemaal per dag versamel vir vyf agtereenvolgende dae vir komponent–analise (samestelling?). Koeie is ad libitum gevoer en voerinnames is individueel bepaal. Die behandelings het geen betekenisvolle invloed op melkproduksie, melksamestelling of voerinnames gehad nie. Rumen pH profiele van al die behandelings het aangedui dat die diëte goed gebuffer was. Die gemiddelde pH oor 24 uur was 6.0, 6.1, 6.1 en 6.2 vir Behandeling 1, 2, 3 en 4, onderskeidelik. Die pH het nie onder 5.8 gedaal vir enige van die behandelings nie en die toenemende vlakke van natriumbikarbonaat het ‘n verhoging in die daaglikse pH-profiele tot gevolg gehad. By die hoogste buffervlakke (Behandeling 4) het die pH-profiel tussen 6.1 en 6.5 gevarieer. Hoewel nie betekenisvol nie, het Behandeling 1 (slegs Acid Buf) numeries die hoogste melkproduksie getoon, sonder dat melkkwaliteit beïnvloed is. Dit is voorgestel dat te hoë rumen pH ‘n nadelige impak op melkproduksie kan hê, as gevolg van ‘n verhoogde asetaat:propionaat verhouding wat rumen doeltreffendheid benadeel. Behandelings het geen betekenisvolle invloed op totale vlugtige vetsuurkonsentrasies gehad nie, maar daar was ‘n neiging vir hoër totale vlugtige vetsuurkonsentrasies namate die vlakke van natriumbikarbonaat verhoog het. Die asetaat:propionaat verhouding van Behandeling 1 (2.91) was betekenisvol laer as dié van Behandeling 4 (3.65). Die gebruik van buffers wat reageer op toenemende suurheidsgraad kan dus aangewend word as ‘n doeltreffende en veilige oplossing vir rumen asidose. Die studie het bevestig dat ‘n daaglikse inname van 80 g Acid Buf deur koeie wat ‘n hoë kragvoerdieet ontvang, hoë melkproduksie ondersteun sonder dat melksamestelling nadelig beïnvloed word.

Thesis (MPhil (Animal Sciences. Aquaculture))--University of Stellenbosch, 2005. / This paper contains literature on tilapia culture, feeding and nutritional factors of prime consideration to survival and growth of Oreochromis mossambicus. Results are presented for a three-phase laboratory experiment on survival of O. mossambicus fry in an attempt to evaluate the use of live Spirulina platensis. The experiment was conducted on fry in a closed system in an effort to maximize the use of live Spirulina and also optimize growth and production. Fry were tested for tolerance levels of salinities, 0-35 g/lt, and showed favourable survival rates up to 15 g /lt salinity without being fed. Manipulation of input in freshwater turned high fry mortalities with increasing rates without difference for physical form of Spirulina. Growth was not significantly affected by types of input. However fry grew well at 0-40% rates with considerable survival performance. It is noted good quality of water that allow improved survival and growth of fry in a closed system may be assured with rates of input up to 5 or 10% of bodyweight. These input rates can guide use of live Spirulina in saline water tilapia culture if Spirulina proves good productivity at the consistency of fry tolerance to the salinity levels established in this paper.

Thesis (MPhil (Animal Sciences. Livestock Management))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: Information from 200 randomly selected egg project beneficiaries was obtain during 2008 to evaluate the impact of managerial factors on the sustainability of poverty alleviation egg laying projects in the Vhembe district, with special reference to the three municipalities (Mutale, Makhado, and Thulamela). A high proportion (80%) of the beneficiaries was poor rural women. The majority of these beneficiaries are old and illiterate. A high proportion of the beneficiary households is composed of extended families and headed by unemployed women. The majority of beneficiaries are sole breadwinners. The majority relies on agriculture and social grants as a source of income. All the beneficiaries indicated that the project increased the household income as a result of the revenue collected from the sale of eggs. From the study, 96% of the projects were initiated by Government, while only 3.52% were initiated by the beneficiaries themselves. A very high proportion of the beneficiaries (88.94%) was not given any opportunity to decide about the type of the project they were interested in. This also included a high proportion (60.61%) of beneficiaries who indicated they were not interested in starting an egg laying project. A high proportion of beneficiaries (60.71%) were not satisfied with the project, and 51.52% indicated is because of lack of funds and the remainder been because of lack of support from the government. A proportion (53.77%) of beneficiaries indicated that they are visited only once a week by extension officers. A high proportion of the beneficiaries (73.23%) rated the support that they get from the extension officers as poor. A high proportion of the beneficiaries received 36 layers, and only 3.02% were having more than 36 layers. About 69.35% of the beneficiaries didn’t know the causes of mortalities of their layers. This also confirmed the high proportion (65.85%) of beneficiaries who indicated that they were not trained to identify and treat diseases. About 73.87% of the beneficiaries rated the performance of the project as good. About 53.27% of the beneficiaries indicated that the project can sustain itself. A proportion of beneficiaries (52.76%) indicated the sustainability indicator as good market of the products. / AFRIKAANSE OPSOMMING: Inligting van 200 lukraak geselekteerde eierprojek begunstigdes is tydens 2008 ingesamel, met die doel om die invloed van bestuursfaktore op die volhoubaarheid van armoede verligtings eierproduksie projekte in die Vhembe distrik, met spesiale verwysing na die drie munisipaliteite Mutale, Makhado en Thulamela. ‘n Groot proporsie (80%) van die begunstigdes was arm landelike vroue. Die meerderheid van hierdie vroue was oud en ook ongeskool. ‘n Groot proporsie van die begunstigde huishoudings bestaan uit direkte en verlangse familielede, met dié huishoudings wat werklose vrouens as familiehoofde het. Die meerderheid van die begunstigdes is ook die alleen broodwinners. Die meerderheid van die huishoudings maak staat op landbou en welsyn toekennings as ‘n bron van inkomste. Al die begunstigdes ht aangedui dat huishoudelike inkomste toegeneem het as gevolg van die verkoop van eiers geproduseer in die projekte. In die studie was 96% van die projekte deur die Regering geïnisieer, terwyl 3.52% van die projekte deur die begunstigdes self geïnisieer is. ‘n Groot proporsie van die begunstigdes (88.94%) was nie die geleentheid gegun om ‘n keuse te kan uitoefen oor die projek wat hulle wil doen nie. Hierdie laasgenoemde proporsie het ook die begunstigdes (60.61%) ingesluit wat aangedui het dat hulle nie in eierlê projekte belanggestel het nie. ‘n Groot proporsie van die begunstigdes (60.71%) was ontevrede met die projek, met 51.52% van hierdie groep wat dit aan ‘n tekort van fondse toegeskryf het. Die oorblywende 9.19% het dit aan ‘n gebrek van ondersteuning vanaf die Regering se kant toegeskryf. ‘n Proporsie van die begunstigdes (53.77%) het aangedui dat hulle een keer per week deur ‘n voorligtingsbeampte besoek word. ‘n Groot proporsie (73.23%) het die kwaliteit van ondersteuning deur die voorligtingsbeamptes as swak beoordeel. ‘n Groot proporsie van die begunstigdes het 36 lêhenne ontvang, met slegs 3.02% wat meer as 36 lêhenne ontvang het.Ongeveer 69.35% van die begunstigdes was onseker oor die redes vir die afsterwe van hulle lêhenne. Dit ondersteun die groot proporsie (65.85%) van die begunstigdes wat aangedui het dat hulle geen opleiding om siektes te kan identifiseer en te behandel, ontvang het nie. Ongeveer 73.87% van die begunstigdes het die projek as goed gereken, met 53.27% wat gevoel het die projek kan ditself onderhou. ‘n Proporsie (52.76%) van die begunstigdes het die bemarkingswaarde van hulle produk as ‘n volhoubaarheidsindikator beskou.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: The production and especially the export of game meat from Southern African are steadily increasing and with this growth, it is inevitable that more emphasis is being placed on the quality of game meat. Research regarding the effect of different cropping methods on ante-mortem stress, and as a result, on meat quality in wild ungulates, is lacking and thus the purpose of this study was to investigate the effect of some of the commonly used cropping methods on the meat quality of red hartebeest, impala, gemsbok and kudu. Antemortem stress was measured using serum cortisol levels (nmol/L), a subjective stress score allocated to each animal as well as the rate and extent of pH decline in the M. longissimus dorsi. Special emphasis was also placed on the meat quality parameters drip loss, cooking loss, colour and Warner-Bratzler shear force (kg/1.27 cm diameter). The effect of day and night cropping on the meat quality of red hartebeest, gemsbok and kudu was investigated. An exponential decay model, y = a + b-ct, was fitted to the pH data of the gemsbok and red hartebeest, and pHu measurements taken at 24 hours post-mortem. Only pHu readings taken at 48 hours post-mortem were analysed in the kudu. Day-cropped kudu had a lower mean pHu (5.40 ± 0.030) than nightcropped kudu (5.48 ± 0.041). No differences in pHu were found for the red hartebeest although night-cropped gemsbok had a higher mean pHu (5.54 ± 0.013) than day-cropped gemsbok (5.49 ± 0.014). None of the constants of the exponential decay model differed for the red hartebeest although day-cropped gemsbok produced a lower constant than night-cropped gemsbok. Mean stress scores and cortisol levels were found to be higher in day-cropped animals for both the gemsbok and kudu while only cortisol levels were higher in die day-cropped red hartebeest. Stress score and cortisol levels were found to be correlated in all three species (red hartebeest: r = 0.51; gemsbok: r = 0.786; kudu: r = 0.823). No treatment differences in drip loss or cooking loss were found for either the red hartebeest or gemsbok, while day-cropped kudu had a higher mean drip loss % (2.76 ± 0.261%) than night-cropped kudu (1.36 ± 0.361%). Night-cropped gemsbok and kudu produced higher mean shear force values (gemsbok = 4.19 ± 0.138; kudu = 4.06 ± 0.237 kg/1.27 cm diameter) than day-cropped animals (gemsbok = 3.57 ± 0.154; kudu = 3.45 ± 0.171 kg/1.27 cm diameter). Colour differences indicated that day-cropped gemsbok and kudu produced lighter meat than night-cropped animals. The results indicate no difference in the effects of day and night cropping in red hartebeest although day-cropped gemsbok and kudu experienced more ante-mortem stress than their night-cropped counterparts. The effect of conventional hunting during the day and night cropping on impala meat was also investigated. No differences were found in pH45 or pHu (taken at 45 minutes and 24 hours post-mortem respectively) although the exponential decay model, y = a + b-ct, fitted to the pH data revealed differences in all the constants (day: a = 5.424 ± 0.039, b = 1.405 ± 0.034, c = -0.385 ± 0.022; night: a = 5.295 ± 0.033, b = 1.556 ± 0.029, c = -0.184 ± 0.019). No differences were found for drip loss, cooking loss or shear force although day-cropped animals produced higher a* and chroma values. The results indicate that, although conventional hunting caused a faster and more severe post-mortem pH decline, both treatments produced meat of similar quality. / AFRIKAANSE OPSOMMING: Die produksie en veral die uitvoer van wildsvleis vanuit Suidelike Afrika is gedurig aan die toeneem en met hierdie groei is dit onvermydelik dat meer klem op die gehalte van wildsvleis gelê word. Daar is ’n tekort aan navorsing oor die uitwerking van verskillende oesmetodes op ante mortem stres en gevolglik ook vleisgehalte van verskillende wildspesies en dus was die doel van dié studie om die uitwerking van sommige van die gewildste oesmetodes op die vleisgehalte van rooihartebees, gemsbok, koedoe en rooibok te ondersoek. Ante mortem stres is gemeet deur die gebruik van serum-kortisolvlakke (nmol/L), ʼn subjektiewe strestelling wat aan elke dier gegee is asook die tempo en vlak van pH-daling in die M. longissimus dorsi. Spesiale klem is gelê op die vleisgehalteparameters drupverlies, kookverlies, kleur en Warner-Bratzlerskeurwaarde (kg/1.27 cm deursnee). Die uitwerking van dag- en nag-oes op die vleisgehalte van rooihartebees, gemsbok en koedoe is ondersoek. ’n Eksponensiële vervalkurwe, y = a + b-ct, is aan die pH-data van die gemsbokke en rooihartebeeste gepas en pHu-metings is op 24 uur ná dood geneem. Net pHu-lesings op 48 uur ná dood in die koedoe is geanaliseer. Koedoes wat in die dag geoes is, het ’n laer pHu (5.40 ± 0.030) gehad as koedoes wat in die nag geoes is (5.48 ± 0.041). Daar was geen verskille in pHu vir die rooihartebeeste nie, alhoewel die gemsbokke wat in die nag geoes is, ’n hoër pHu (5.54 ± 0.013) gehad het as gemsbokke wat in die dag geoes is (5.49 ± 0.014) . Geeneen van die konstantes van die eksponensiële vervalkurwe het verskil in die geval van rooihartebeeste nie terwyl gemsbokke wat in die dag geoes is ʼn hoër konstante a en ʼn laer konstante c getoon het as gemsbokke wat in die nag geoes is. Gemiddelde strestellings en kortisolvlakke was hoër in die geval van gemsbokke en koedoes wat in die dag geoes is terwyl net die kortisolvlakke hoër was in die rooihartebeeste wat in die dag geoes is. Daar is ook bevind dat die strestelling en kortisolvlakke gekorreleer was in al drie spesies (hartebees: r = 0.51; gemsbok: r = 0.786; koedoe: r = 0.823). Geen verskille in drupverlies of kookverlies is aangetref vir die rooihartebeeste of gemsbokke nie, alhoewel koedoes wat in die dag geoes is ʼn hoër gemiddelde drupverlies % (2.76 ± 0.261%) getoon het in vergelyking met koedoes wat in die nag geoes is (1.36 ± 0.361%). Gemsbokke en koedoes wat in die nag geoes is, het ’n hoër gemiddelde skeurwaarde gehad (gemsbokke = 4.19 ± 0.138; koedoes = 4.06 ± 0.237 kg/1.27 cm deursnee) as diere wat in die dag geoes is (gemsbokke = 3.57 ± 0.154; koedoes = 3.45 ± 0.171 kg/1.27 cm deursnee). Kleurverskille het aangedui dat gemsbokke en koedoes wat in die dag geoes is, ligter gekleurde vleis geproduseer het as diere wat in die nag geoes is. Die resultate dui aan dat daar by rooihartebeeste geen verskil is tussen die uitwerking van dag-oes en nag-oes nie, maar dat die dag-oes van gemsbokke en koedoes meer voordoodse stres veroorsaak het as nag-oes. Die uitwerking van konvensionele jag gedurende die dag- en nag-oes op die vleisgehalte van rooibokke is ook ondersoek. Geen verskille is aangetref in pH45 of pHu (geneem op 45 minute en 24 uur ná dood onderskeidelik) nie, alhoewel die eksponensiële vervalkurwe, y = a + b-ct, wat gepas is aan die pH-data verskille getoon het in al die konstantes (dag: a = 5.424 ± 0.039, b = 1.405 ± 0.034, c = -0.385 ± 0.022; nag: a = 5.295 ± 0.033, b = 1.556 ± 0.029, c = -0.184 ± 0.019). Geen verskille is aangetref ten opsigte van drupverlies, kookverlies of skeurkrag nie. Diere volgens die konvensionele maniere geoes het wel hoër a*-en chroma-waardes getoon. Die resultate dui daarop dat, alhoewel konvensionele jag ʼn vinniger en meer ekstreme pH-daling veroorsaak het, albei behandelinge tot dieselfde vleisgehalte gelei het.

Thesis (MPhil (Animal Sciences. Livestock Industry Management: Pig Science))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: This mini-thesis describes the pig industry in South Africa which consists of a commercial intensive sector and an extensive sector that is also known as the small scale sector. Challenges in such as, marketing, feed, housing and genetics of small scale farmers are discussed. The objective of this study is to identify the problems experienced by the emerging/small scale pig farmers and to benchmark the production parameters of these farmers. Data was collected using questionnaires, telephone and site visits to farms/projects. The data collection was grouped into descriptions of small scale piggeries, feeding strategies, management programs, production parameters, regional constraints, marketing, comparisons between stud and commercial piggeries. The results were arranged into the following manner: general, regional constraints, description of small scale piggery facilities, feeding strategies of small scale farmers, management programs in small scale piggeries, production parameters of small scale piggeries in the Limpopo province, production parameters of stud and commercial piggeries, and the management strategy in a commercial piggery. Those piggeries having 5-30 sow units were interviewed. Results indicate that small scale farmers were found not to be sustainable in their production. The small scale farmers have no understanding of the pig industry, genetics and breeding of pigs, feeding strategies, and marketing channels for pigs. Typical problems experienced are: marketing is only done once or twice a year and not regularly as with any commercial piggery – a main problem identified here was access to the formal market. Typical production problems experienced were long farrowing intervals, small litter sizes, late weaning periods and low weaning percentages. This was attributed not only to mismanagement but also to bad infrastructure. Small scale piggeries typically have low cost sty’s that have inadequate floors, walls, roofing and very few of the piggeries has sufficient fresh water. Another problem experienced was poor growth which could be directly linked to the nutrition of the pigs. Most of the feed fed consisted of kitchen waste as balanced diets were perceived to be too expensive whilst access to suppliers, and transport (of both feed and pigs off to market) was generally lacking. Another major problem identified by the producers was insufficient scientific help from Government. Most producers also mentioned that they would welcome a mentorship program and help with the marketing and sourcing of funds. None the less, the pig owners all indicated that they wish to continue farming with pigs and that with the right help, they would be able to be successful. / AFRIKAANSE OPSOMMING: Hierdie werkstuk beskryf die vark industrie in Suid-Afrika wat bestaan uit ‘n kommersiële intensiewe en ekstensiewe sektor wat ook bekend staan as die klein-skaal sektor. Uitdagings soos bemarking, voer, behuising en genetika van klein-skaalse boere word bespreek. Die doel van die studie is om die probleme te identifiseer wat ervaar word deur die opkomende/klein-skaalse boere asook om die produksie-parameters van die boere te bepaal. Data was versamel deur middel van vraelyste, telefoonoproepe asook besoeke aan die boere/projekte. Die dataversameling was op verdeel in beskrywings van klein-skaalse vark eenhede, voerstrategieë, bestuursprogramme, produksie-parameters, distriksbeperkings, bemarking, en vergelykings tussen stoet- en kommersiële-eenhede. Die resultate was gesorteer op die volgende manier: algemeen, distriksbeperkings, beskrywing van klein-skaalse varkeenhede, produksie-parameters van klein-skaalse varkeenhede in die Limpopoprovinsie, produksieparameters van stoet- en kommersiële varkeenhede, en die bestuurstrategie in ’n kommersiële varkeenheid. Ondehoude is gevoer met dié eenhede wat tussen 5-30 soê het. Resultate wys dat klein-skaalse boere nie volhoubaar is in hul produksie nie. Die klein-skaalse boere het geen kennis van die vark bedryf, genetika en teel van varke, voerstrategieë en bemarking van varke nie. Tipiese probleme wat ervaar word is: bemarking word slegs een of twee keer per jaar gedoen en nie gereeld soos met kommersiële eenhede nie – die hoof probleem wat geïdentifiseer is die toegang tot die formele mark. Tipiese produksieprobleme wat hier geïdentifiseer is, was lang kraam intervalle, klein werpsel groottes, laat speenperiodes en lae speenpersentasies. Dit was as gevolg van nie net misbestuur nie, maar ook as gevolg van slegte infrastruktuur. Klein-skaalse vark eenhede het gewoontlik goedkoop varkhokke met onvoldoende bevloering, mure, en dakke en baie min van die eenhede het genoegsame vars water gehad. Nog ’n probleem wat ondervind is, was die slegte groei van die varke wat direk gekoppel kan word aan die voeding van die varke. Meeste van die voer het bestaan uit kombuisvullis omdat gebalanseerde rantsoene beskou was as te duur, terwyl daar oor die algemeen ’n te kort was aan toegang tot verskaffers en vervoer (van beide voer en varke na die mark). Nog ’n groot probleem wat geïdentifiseer is deur die produsente was dat daar ’n tekort is aan wetenskaplike hulp van die Regering. Meeste van die produsente het ook genoem dat hul ’n mentorskapprogram sal verwelkom asook hulp met bemarking en befondsing. Nie te min, die varkeienaars het almal aangetoon dat hul graag met die varkboerdery sou wil aangaan en dat met die regte hulp sou hul suksesvol kan wees.