Ostriches are an important commercial species in South Africa and are becoming increasingly so in other parts of the world. Fertility and hatchability of artificially incubated ostrich eggs, however, is generally regarded as low compared to other poultry species and to ostriches in the wild. Investigation into specific farming practices at present indicated scope for an overall improvement in productivity through a sound breeding strategy. This thesis investigated factors that affect egg production, fertility, and hatchability of artificially incubated eggs in the Little Karoo region of South Africa. Specific breeding pair combinations accounted for the major variations in egg weight, hatchability, chick production and offspring weight at slaughter age. An appreciable proportion of variation in reproductive traits was attributable to the repeatable nature of breeding pair performance from year to year, even from first breeding attempts, suggesting that selection of good breeding stock can be made from an early age. Artificially incubated eggs showed improved hatchability when eggs were collected two to three hours after lay rather than the following morning. Storing position of eggs did not significantly effect hatchability when eggs were stored for a maximum of one week. The critical zero temperature for ostrich eggs, below which no embryonical development takes place, was found to be ± 25°C and cooling eggs to temperatures below 20°C for complete cessation of embryonic development during storage resulted in better hatchabilities compared to eggs stored at 25°C room temperature. Hatchability decreased when incubator temperatures were raised from 36 to 37.3°C. Large temperature fluctuations and gradients, which encompass detrimental temperatures, persist within forced draught wooden incubators of the type most commonly in use in the Little Karoo region. The highest temperatures occurred at the top of these incubators and will consequently have a negative impact on hatchability. The ontogeny of ostrich egg metabolism showed an exponential increase during the first 70% of incubation followed by a decline to 75% of the peak value between days 31 and 38 of incubation. From peak levels of embryonic development it was calculated that single stage incubators needs an airflow of 54.4 1/egg.hour to maintain oxygen levels just below 21% and carbon dioxide levels below 0.5%. Lower embryonic mortalities were observed when eggs were turned twenty-four times/day in an electronic incubator compared to hand turning twice a day. Eggs rotated through increasing angles between 60 and 90° resulted in a linear improvement in hatchability. In incubators where turning angles were fixed at 60°, lower hatchabilities were overcome by incubating eggs for 2 - 3 weeks in a horizontal position before placing them vertically. No specific farming practice could be singled out as the main cause of low fertility or hatchability but rather a combination of certain practices applied wrongly.

Hierdie verhandeling is ‘n samestelling van verskeie studies, elk opgeskryf in die formaat en styl soos vereis deur die Suid-Afrikaanse Vereeniging vir Diereproduksie (South African Society of Animal Science). Hoofstuk 1 is ‘n literatuurstudie bestaande uit ‘n algemene inleiding wat agtergrond oor die studie verskaf en sluit die probleemstelling in, naamlik die swak oorlewing van volstruiskuikens wat onder kunsmatige toestande grootgemaak word. Hoofstukke 2, 3, 4 en 5 bestaan uit die eerste vier studies, waartydens sekere bestuurs-aspekte, wat moontlik oorlewing van volstruiskuikens kan verbeter (nl: populasiedigtheid, tipe vloer-oppervlak, die aanwending van broeipare en die aanwending van peetouers), ondersoek is. Hoofstukke 6, 7, 8 & 9 handel oor studies wat gerig is om voeding meer aanloklik te maak vir volstruiskuikens teneinde voedselinname te stimuleer en sodoende produksie en oorlewing te verbeter (nl: verskaffing van groenvoer, geur van voer, kleur van voer en beligting van voer). Die laaste hoofstuk bestaan uit ‘n algemene gevolgtrekking en aanbevelings. Alhoewel daar gepoog is om herhaling in hoofstukke te beperk, was dit onmoontlik om herhaling van sekere gedeeltes van hoofstukke te voorkom.

Thesis (MScAgric)--University of Stellenbosch, 2001. / ENGLISH ABSTRACR: Approximately 10 years ago South Africa, and specifically the Oudtshoorn region was the only place in the world that supplied ostrich products for the international market. Today, South Africa is only one of several countries with commercial ostrich farming. The largest concentration of ostrich farmers in the world is, however, still in the Oudtshoorn region. Increasing competition, limited possibilities to diversify and the so-called price cost squeeze put the emphasis on aspects such as higher productivity and lower production costs. The profitability of ostrich farming, especially in the Oudtshoorn region, should urgently be determined and evaluated as farmers rely heavily on this venture as an only source of income. Decreases in slaughter realisations and slaughtering numbers have necessarily negative financial implications for the farmers, as well as for the community as a whole. Diversification is often considered strategic to avoiding or minimising risk. However, the possibilities to diversify especially to existing alternatives, have proven limited. One sure solution is to increase productivity of ostrich farming. Production parameters like the number of day-old chicks per female, chick mortality and slaughtering realisations were found to vary considerable providing scope for improvement. It is evident that several factors that determine the generated income lie outside the sphere of influence of the individual ostrich farmer. The large variation in production performances renders the industry risky, especially for farmers with liquidity problems. Two questionnaires as well as group discussion techniques were used to evaluate the economics of ostrich farming. Income and costing budget models were constructed on Microsoft Excel to be able to do calculations to the level of gross margin. A complete representative ostrich-farming unit was constructed to do calculations to the level of net farm income. The budget models were applied to (1) representative ostrich production practices for each of the three phases in the production process of ostrich farming, and (2) the representative ostrich-farming unit. The effect of different critical factors on the gross margin and net farm income of ostrich farming were thereafter evaluated. Different scenarios were also evaluated. The results of these analyses are representative of ostrich farming in the Oudtshoorn region. A computer model was developed whereby ostrich farming can be evaluated economically. This model can also be applied to assist individual farmers with their planning.As no research results exist on the economics of ostrich farming at micro level, several questions regarding the economics of ostrich farming prompted this study. These questions were answered using the above-mentioned computer models. The survival of the ostrich industry in the Oudtshoom region with its limited resources depends on a secure lead in technology which will enable farmers to produce products of higher quality, but also at lower costs than the rest of the world. / AFRIKAANSE OPSOMMING: Sowat 10 jaar gelede was Suid-Afrika, en spesifiek die Oudtshoom-omgewing, die enigste gebied in die wereld wat volstruisprodukte aan die wereldmark verskaf het. Vandag is Suid-Afrika egter een van vele lande waar kommersiele volstruisboerdery voorkom. Die grootste konsentrasie van volstruisboere in die wereld word egter steeds in die Oudtshoom-omgewing aangetref. Toenemende mededinging, beperkte moontlikhede om te diversifiseer en die sogenaamde pryskoste-knyptang impliseer dat aspekte soos hoer produktiwiteit en laer produksiekoste aandag moet geniet. 'n Behoefte bestaan om die winsgewendheid van die volstruisvertakking, spesifiek in die Oudtshoomomgewing, nie net te bepaal nie, maar ook te evalueer. Voistruisboere in die Oudtshoom-omgewing steun swaar op die volstruisvertakking vir die generering van inkomste. 'n Verlaging in slagrealisasies en 'n inkorting van slaggetalle het dus noodwendig negatiewe finansiele implikasies tot gevolg, nie net vir die volstruisboere nie, maar ook vir die hele gemeenskap. 'n Strategie om risiko te vermy, mag wees om te diversifiseer, maar die moontlikhede om te diversifiseer, veral na die bestaande vertakkings wat reeds verbou word, blyk egter beperk te wees. 'n Oplossing kan wees om die produktiwiteit van volstruisboerdery te verhoog, met ander woorde om bestaande dinge beter te doen. Groot variasies kom onder andere voor in die getal dagoudkuikens per wyfie, vrektesyfer onder kuikens en ook slagresultate. Groot ruimte vir verbetering bestaan dus. Dit blyk dan ook dat daar heelwat faktore is wat buite die invloedsfeer van die indiwiduele volstruisboer val wat bepalend is vir die inkomste wat 'n slagvolstruis realiseer. Die groot variasies, soos genoem, impliseer verder dat die risiko van volstruisboerdery hoog kan wees, veral vir volstruisboere met likiditeitsprobleme. Twee vraelysopnames en die groepbesprekingstegniek is gebruik om volstruisboerdery ekonomies te kon evalueer. Inkomste- en kostebegrotingsmodelle is op Microsoft Excel gekonstrueer ten einde berekeninge tot op die vlak van bruto marge te kon doen. 'n Volledige verteenwoordigende volstruisboerdery-eenheid is vervolgens gekonstrueer om berekeninge ook tot op die vlak van netto boerdery-inkomste te kon doen. Die begrotingsmodelle is toegepas op (0 verteenwoordigende volstruisproduksiepraktyke vir elk van die drie fases in die produksieproses van volstruisboerdery en (2) die verteenwoordigende volstruisboerdery-eenheid. Die effek van verskillende kritieke faktore op die bruto marge en netto boerdery-inkomste van volstruisboerdery is vervolgens geevalueer. Verskillende scenarios is ook aan die hand van die verteenwoordigende boerderyeenheid beoordeel. Die resultate van hierdie ontledings is verteenwoordigend van volstruisboerdery in die Oudtshoom-omgewing. 'n Rekenaarmodel is in die proses ontwikkel om volstruisboerdery ekonomies te kan evalueer. Hierdie model kan ook aangewend word om indiwiduele volstruisboere met beplanning te help. Heelwat vrae oor die ekonomie van volstruisboerdery het aanleiding gegee tot die aanvang van hierdie studie. Navorsingsresultate oor die ekonomie van volstruisboerdery op mikrovlak bestaan dan ook nie. Deur gebruik te maak van die genoemde rekenaarmodelle is vrae oor die ekonomie van volstruisboerdery beantwoord. Die enigste behoud van die volstruisbedryf in die Oudtshoom-omgewing, met sy beperkte hulpbronne, is 'n stewige voorsprong in tegnologie om nie net beter nie, maar ook goedkoper as die res van die wereld te produseer.

The South African ostrich industry is presently characterised by a drastic decline in the slaughter price of slaughter birds, due to the drop in the price of meat as well as leather. As a result, the economic viability of ostrich farming is severely hampered by these developments, and many generally accepted industry practices have to be reviewed. Among the practices under review is the possibility of slaughtering ostriches at an earlier age than the traditional slaughter age of 12 - 14 months, in order to minimise feed costs and the incidence of damage to the skin. However, little information is available on the effect of the slaughter age on the yield and quality of the economically important end-products. The effect of slaughter age on production and the economic viability of a commercially intensive ostrich production system was consequently evaluated in a completely randomised experimental design involving two batches (n= 81 and n= 94) of ostriches. The experiments took place at Kromme Rhee experimental farm of the Elsenburg Research Centre near Stellenbosch. The birds were subject to experimental treatment at the age of 4 months (n= 81, from May 2004 to March 2005) and 6 months (n= 94, from August 2004 to August 2005) respectively. The ostriches were randomly divided into 10 groups of between 16 and 20 birds per group. Standard production practices, as applied in an intensive ostrich production unit, were implemented. Clean drinking water and self-mixed grower diet (min 15 percent crude protein, 0.68 percent lysine and 11.4 MJ ME per kg feed) and finisher diet (min 14 percent crude protein, 0.55 percent lysine and 9.8 MJ ME per kg feed) were provided ad libitum to the birds. Birds were slaughtered at the ages of 8.5, 10.5, 12.5, 14.5, and 16.5 months respectively. Data on feed intake and yields of cold carcass, crust skin size, skin grade and total feathers was recorded for birds slaughtered at the respective ages. Data was analysed according to the analysis of variances. Values for meat yield, skin size yield and feed intake were predicted by regression analysis based on experimental values. Industry figures and norms were used as proxy for other production inputs and costs. A gross margin type analysis was performed to evaluate the effect of different slaughter ages on the profitability of each production system. There was a positive correlation between age and feed intake (r2= 0.40), slaughter weight (r2= 0.97), cold carcass yield (r2= 0.48), skin surface area (r2= 0.39), skin grade (r2= 0.19) and total yield of feathers (r2= 0.29). The dry skin grade showed deterioration as slaughter age was prolonged. Highly significant differences (P< 0.01) in slaughter weight, cold carcass yield, skin surface area, dry skin grade and total feathers were detected at the different slaughter ages. There were no significant differences (P> 0.05) with respect to gender for slaughter weight, skin surface area and dry skin grade within the different age groups. Males had significantly higher (P< 0.05) cold carcass yield and total feather yield than their female counterparts. From this study it can be concluded that an increase in slaughter age significantly increases feed intake, slaughter weight, cold carcass yield, and skin surface area. It is also clear that an increase in slaughter age can be detrimental to dry skin grade. The relative income contribution of the three main products (skin: meat: feathers) occurred in a ratio of 47:53:0, 52:47:1, 47:50:3, 44:51:5, 39:56:5 at the respective slaughter ages. Total income revealed an increase of 26 percent from 8.5 to 10.5 months slaughtering, an increase of 4 percent between 10.5 and 12.5 months, and an increase of 11 percent between 12.5 and 14.5 months. The income dropped by 0.3 percent between 14.5 and 16.5 months slaughtering. Total costs increased with slaughter age, particularly feed costs which showed an increase (at a decreasing rate) between the different slaughter ages. The margin above specified cost per bird was the highest for birds slaughtered at the age of 10.5 months. The margin above cost showed a steady decline as birds were slaughtered at higher ages. Slaughtering at 16.5 months revealed a negative margin. To compare the effect of differences in time span on different slaughter age regimes, margin above costs for each system over 5 years were discounted to a present value. In this study, with current feed costs and income from end products, slaughtering at 10.5 months revealed the highest present value for the margin above cost. Furthermore, slaughtering at 16.5 months revealed a negative present value on the margin above cost after 5 years. Financial viability calculations are relevant and valid for data obtained in this case study. Financial viability is however case-specific and may vary between producers, depending on their individual management practices, production systems and cost structures. Results from this study may be of significant value to managerial decision-making in the ostrich industry.

Thesis (MScAgric (Agricultural Economics))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Before the ostrich industry started in the Klein Karoo region of South Africa in 1863, the veld was used mainly for large and small stock production. Returns per hectare (ha) from large and small stock production are low due to the low carrying capacity of the veld in this region. However, when the veld is utilised predominantly to provide space for breeding ostriches sustained mainly by lucerne-based feed supplements, the limited-feed production capacity no longer determines the long-term stocking rate. The returns, per ha, from ostrich production can therefore be much higher than from sheep, goats and cattle. This has resulted in high ostrich stocking rates, which in turn, has caused degradation to most of the veld to a greater or lesser extent. Driven by a personal conviction to manage the veld sustainably, as well as by a fear of environmental damage connotations for ostrich leather products, which could restrict market access, ostrich farmers in the Klein Karoo, represented by the South African Ostrich Business Chamber (SAOBC), increasingly place an emphasis on veld restoration. The various phases of ostrich production are breeding and hatching eggs to produce day-old chicks, rearing chicks, raising birds, and the final phase of weight addition to slaughter. The phase that is considered in this study is the production of day-old chicks. There are two systems that can be used for producing day-old ostrich chicks, namely, the flock breeding system and the small-camp system. Shifting from the flock breeding system to the smallcamp system will enable the farmer to practice genetic selection. This switch from the flock breeding system to the small-camp system requires the farmer to invest in fencing material. The SAOBC requested a study to determine whether the expected private benefits from moving breeding ostriches to small camps in order to free up the large veld camps for veld restoration would justify investing in these small camps. If this investment is not financially justified, the veld restoration will have to be financed via payment for ecosystem services. Both passive and active veld restoration techniques are considered in this study. Passive restoration requires the farmer to invest in fencing material needed for the erection of the small camps. Active restoration requires the farmer to invest not only in fencing material, but also in soil manipulation and seeding. The main aim of this study is to find out if the private (financial) benefits from the switch to small camps can compensate for fencing costs, without the cost of active restoration, or if the switch to small camps can compensate for fencing costs with the cost of active restoration. Typical farm models were developed for this purpose, and the results showed that the private benefits compensate for the investment cost of fencing material used for passive restoration as well as for restoration of 10% of the veld that is heavily degraded. When the full cost of active restoration of the moderately degraded veld (30%) was added, the private benefits could not compensate for the full restoration cost. / AFRIKAANSE OPSOMMING: Voordat die volstruisbedryf in 1863 in die Klein Karoo ontstaan het, is die veld hoofsaaklik gebruik vir groot- en kleinveeproduksie. Die wins per hektaar van groot- en kleinvee produksie in hierdie streek is laag weens die lae drakrag van veld. Wanneer die veld egter primêr aangewend word vir ruimte vir volstruise wat met lusern gebaseerde rantsoene gevoer word, bepaal die natuurlike drakrag nie meer die belading met volstruise oor die langer termyn nie. Die wins per hektaar uit volstruisboerdery kan dus veel hoër wees as wat met skape, bokke of beeste gegenereer kan word. Dit het hoë belading met volstruise tot gevolg gehad wat vernieling van meeste van die veld tot gevolg gehad het. Gedryf deur persoonlike oortuiging om die veld volhoubaar te benut, sowel as deur vrees dat die vernielde veld die beeld van die volstruisbedryf mag skaad en internasionle marktoegang mag belemmer, het volstruisprodusente in die Klein Karoo, verteenwoordig deur die Suid-Afrikaanse Volstruisbesigheidskamer (SAVBK), toenemend klem begin plaas op veldrestorasie. Die verskillende fases van volstruisproduksie sluit in teling en uitbroei van eiers om dagoud kuikens te lewer, kuikens grootmaak, voëls grootmaak en massa toename tot by slag. Die verskillende fases word dikwels deur verskillende produsente behartig. Die fase waarop in hierdie ondersoek gefokus word is die produksie van dagoud kuikens. Daar bestaan twee stelsels vir die produksie van dagoud kuikens, naamlik tropparing en die kleinkamp stelsel. Die oorskakeling van tropparing na die kleinkamp stelsel stel die produsent in staat om genetiese seleksie toe te pas, maar dit verg investering in omheiningsmateriaal. Die SAVBK het ‘n ondersoek aangevra om te bepaal of die verwagte privaat voordele wat verkry kan word uit die oorskakeling na die kleinkamp stelsel om veldrestorasie moontlik te maak, die investering in die kleinkampe sal regverdig. Indien die investering nie finansieel geregverdig kan word nie, sal verder gekyk moet word na finansiering vanuit betaling vir ekostelsel dienste wat moontlik bevorder kan word deur die veldrestorasie. Die koste van beide passiewe en aktiewe veldrestorasie tegnieke word in hierdie ondersoek gedek. Passiewe restorasie vereis alleen van die produsent om te investeer in omheiningsmateriaal vir kleinkampe. Aktiewe restorasie vereis investering in omheiningsmateriaal vir kleinkampe en betaling vir grondmanipulasie en saad vir die hervestiging van plante. Die doel van die ondersoek is om te bepaal of die privaat (finansiële) voordele van die oorskakeling na kleinkampe kan kompenseer vir die investering in omheiningsmateriaal met aktiewe veldrestorasie en sonder aktiewe veldrestorasie (dus passiewe restorasie). Tipiese plaasmodelle is hiervoor ontwikkel. Die resultate toon dat die privaat voordele wel kan kompenseer vir die omheiningskoste van kleinkampe benodig vir passiewe restorasie en vir aktiewe restorasie van 10% van die veld wat die meeste verniel is. Wanneer die koste van restorasie van 30% van die veld wat matig verniel is, bygevoeg word, is die privaat voordele ontoereikend om die totale restorasiekoste te dek.

Ostrich (Struthio camelus) breeding is a well-developed industry in South Africa. However, successful genetic management has yet to be implemented. Parentage in colony breeding ostriches is unknown, where for a given offspring, a number of possible parents exist. Molecular markers have been extensively used in the livestock industry to resolve parentage issues and are only beginning to be utilized to address the issues of the ostrich industry. The aims of this investigation were to test known microsatellite markers developed for other ostrich subspecies in a South African Black ostrich population, and to further test these markers for their use in individual and parentage identification. DNA was extracted from venous blood obtained from two pair bred families and a colony of 97 individuals. Eleven polymorphic microsatellite markers were tested by PCR amplification of DNA samples followed by multiplexing on polyacrylamide gels to generate DNA fingerprints for each individual. Alleles were sized and quantified and used to create genotypes for each individual. Parentage analysis was performed using exclusion and likelihood methods. Pedigrees were constructed for the families by comparison of genotypes. Breeding statistics were calculated for the colony individuals. Three microsatellite markers did not amplify in this population and one marker was found to be monomorphic in this population. Four of the microsatellite markers that successfully amplified produced anonymous amplification products suggesting a second annealing site in the genome sequence of Blacks. All loci displayed low observed heterozygosities indicative of little genetic variation in this population. For the colony sample, four individuals were not assigned either parent and one female did not contribute any offspring. On average females produced 4.86 ± 2.71 fertile eggs during the sampling period with a coefficient of variation of 55.86%. A total of 79.2% of individuals were assigned paternity and 88.3% were assigned maternity. A greater number of loci are required to improve the power of parentage analysis within breeding flocks incorporating all eggs laid. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.