The evaluation of locally produced full-fat canola seed (Brassica napus) as an alternative protein source in the diets of slaughter ostriches (Struthio camelus var. domesticus)

Date
2018-03
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: Ostriches are multi-purpose animals, producing feathers, leather and meat that contribute to the income generated from slaughter ostrich production. Compared to other domesticated farm animals, knowledge of the nutritional requirements of ostriches has been very limited, until recently. Together with simulation models this knowledge gained is being used to formulate least cost, nutrient specific rations for ostriches in different production phases. In an effort to reduce feeding costs, which make up the largest expense (ca. 75%) in an intensive ostrich production unit, the use of alternative protein sources are being explored to replace the more expensive protein sources that make up a large portion of the diet. Full-fat canola seed (FFCS) is one such locally produced protein source that has the potential to replace current protein sources such as soybean oilcake meal. However, it is unclear whether ostriches will readily consume canola, due to its anti-nutritional factors, and what effect its consumption may have on animal performance. The feeding preference (Chapter 3) of ostriches towards canola was established by placing 60 South African Black ostriches (82.2 ± 1.06 kg in live weight, 233 days of age) in ten camps of six birds per camp. Each camp had five identical feed troughs, each containing diets, where FFCS incrementally (0, 25, 50%, 75 and 100% of protein source) replaced the soybean oilcake meal (9.8% of the total diet composition in control diet) as protein source. Feed and water were made available ad libitum. Dry matter intake (DMI) was measured on a daily basis and feed colour characteristics were measured based on CIE L*, a* and b* colour attributes. Only the 25%FFCS (25% soybean oilcake meal replacement diet) showed a higher DMI (817.4 ± 81.98 g/bird/day) than the other diets (average of 488.8 ± 81.98 g/bird/day). While there were slight differences between some of the colour attributes, it is believed to have had no effect on DMI. Based on the results of this study, FFCS can be used to replace 25% soybean oilcake meal without any negative effect on DMI; resulting in an inclusion level of 6.8% FFCS in ostrich diets. To evaluate to what extent FFCS can be utilised in the diets of slaughter ostriches, 187 day old South African Black ostrich chicks were randomly divided into 15 groups (9 - 12 animals per group). The growth trial (Chapter 4)commenced at the onset of the starter phase when the chicks were 84 days of age weighing 24.7 ± 0.36kg. Five iso-nutritional treatment diets with varying levels of FFCS were randomly allocated to the groups with three replications per treatment diet. Birds were reared according to standard practises and slaughtered at 309 days of age (93.2 ± 1.82 kg). Within each feeding phase, FFCS incrementally (0%, 25%, 50%, 75% and 100% of protein source) replaced the soybean oilcake meal as protein source. Feed and water were supplied ad libitum. Dry matter intake, average daily gain (ADG), feed conversion ratio (FCR) and end weights were recorded with in each phase and over the entire trial period, as well as slaughter traits. No differences were observed regarding production traits during the starter and finisher phases. Dry matter intake during the grower phase was lowest (P =0.01) for the 100% replacement of soybean oilcake meal (100%FFCS) (1.52 kg/bird/day). The rest of the diets with an average DMI of 1.80 kg /bird/day did not differ. The 100%FFCS also showed the slowest growth (P =0.01) (152.0 g/bird/day) during the grower phase, and did not differ from 25%FFCS (208.9 g/bird/day) and 75%FFCS (209.5 g/bird/day) diets. With the 0%FFCS (236.2 g/bird/day) and 50%FFCS (267.8 g/bird/day) diets resulting in higher ADG. End weights during the grower phase for the 0%FFCS, 25%FFCS, 50%FFCS and 75%FFCS (74.8, 72.2, 76.8 and 72.5 kg respectively) did not differ from each other. The 100%FFCS resulted in lower end weights (67.4 kg), although not differing from the 25%FFCS and 75%FFCS. For the overall trial period the only differences observed, were within ADG, with the 0%FFCS, 50%FFCS and 75%FFCS replacement diets showing the fastest growth and the 100%FFCS, although not differing from the 25%FFCS and 75%FFCS diets, resulted in the slowest growth. Fat pad weight was the only slaughter trait that revealed differences between diets, with the 50%FFCS resulting in the heaviest fat pad weights. Based on these results, it is recommended that a maximum of 20.6% inclusion (75%FFCS) of FFCS be used in diets during the grower phase as it may lead to reduced performance when exceeded. Although in the other phases, FFCS can be included up to the maximum levels evaluated (100% replacement of soybean oilcake meal) without any detrimental effects. The aim of the study in Chapter 5 was to evaluate the effect of different dietary FFCS inclusion levels on the feathers, leather and meat composition of slaughter ostriches. The end products of the South African Black ostriches slaughtered in Chapter 4 were used during this trial. The only differences between diets regarding feather yields were within chick body short (P =0.021) and unmarketable feathers (P =0.011). The 50%FFCS resulted in the heavier yields of chick body short feathers (283.2 ± 14.84 g), however, it did not differ from the 0%FFCS, 25%FFCS and 75%FFCS. The 100%FFCS resulted in lighter yields (202.3 ± 14.84 g) of chick body short feathers, although not differing from the 75%FFCS. The 50%FFCS had the lightest yield (97.1 ± 13.18 g)of unmarketable feathers, differing from all the other diets. The rest of the diets did not differ and yielded anaverage of 161.2 ± 13.18 g unmarketable feathers. Skin thickness was the only leather trait showing differences (P =0.038) between diets. With the 0%FFCS resulting in thicker skins (0.65 ± 0.027 mm), not differing from the 25%FFCS and 50%FFCS diets. The 100%FFCS resulted in thinner skins (0.53 ± 0.027 mm), not differing from the 50%FFCS or 75%FFCS diets. Moisture and protein concentration of the meat were the only chemical components showing differences (P =0.008 and P =0.004, respectively) between diets. Meat from the 100%FFCS was found to have higher moisture concentrations (77.0 ± 0.29%). The 25%FFCS meat resulted in the lowest mean moisture concentration (75.2 ± 0.24%), not differing from the 0% and 50%FFCS meat. The inverse of moisture concentration could be seen with regards to protein concentration where the 25%FFCS diet resulted in the highest meat protein concentration (22.6 ± 0.19%), not differing from the 0%FFCS and 50%FFCS diets’ meat. The 100%FFCS diet resulted in the lowest (20.9 ± 0.23%) meat protein concentration. Dietary FFCS inclusion had beneficial effects on the fatty acid profile of the abdominal fat tissue. Total saturated fatty acids concentrations decreased from 37.8% (0%FFCS) to 20.3% (100%FFCS) of total identified fatty acids. Total MUFA concentrations increased from 39.7% for the 0%FFCS fed birds to 51.0% for the 100%FFCS fed birds. The total PUFA concentrations also increased from 22.1% for the 0%FFCS fed birds to 28.7% for the 100%FFCS fed birds. These changes resulted in the PUFA:SFA ratios to increase from 0.60 (0%FFCS) to 1.43 (100%FFCS). Both n-6 and n-3 fatty acids increased with an increase in FFCS inclusion, however the n-6:n-3 ratio showed a beneficial decrease from 3.20 for the 0%FFCS fed birds to 2.28 for the 100%FFCS birds. Overall it is recommended that full-fat canola seed can be used to replace up to 75% (not exceeding inclusion levels used within each growth phase in this trial) of the soybean oilcake meal in slaughter ostrich diets. Prescribed replacement of soybean oilcake meal with FFCS can be done without affecting growth of ostriches or the quality of end products, and achieve similar results as current standard commercial diets.
AFRKAANSE OPSOMMING: Volstruise is veeldoelige diere, met vere, leer en vleis wat bydra tot die inkomste van slagvolstruisproduksie. In vergelyking met ander kommersiële plaasdiere was kennis ten opsigte van die voedingsbehoeftes van volstruise tot onlangs nog baie beperk. Simulasiemodelle word, saam met die huidige inligting beskikbaar, gebruik om die laagste koste, nutriëntspesifieke rantsoene vir volstruise in verskillende produksiefases te formuleer. Die voerkoste in ʼn intensiewe volstruisproduksie-eenheid is verantwoordelik vir ongeveer 75% van die uitgawes, en om sodoende die koste daarvan te verminder, word die benutting van alternatiewe proteïenbronne ondersoek om die duurder proteïenbronne soos sojabone-oliekoekmeel, wat 'n groot deel van die dieet uitmaak, te vervang. Volvet kanolasaad (VVKS) is 'n plaaslike verboude proteïenbron wat die potensiaal het om huidige proteïenbronne soos ingevoerde sojabone-oliekoekmeel te vervang. Dit is egter onduidelik wat die reaksie van volstruise sal wees teenoor VVKS in hul dieet, omdat antinutriënte die vrywillige inname van voer kan beïnvloed en sodoende die diere se produksie vermoë verlaag. Die voedingsvoorkeure (Hoofstuk 3) van volstruise teenoor kanola in hul dieet was ondersoek deur 60 Suid-Afrikaanse Swart volstruise (82.2 ± 1.06 kg in lewende massa) in tien kampe van ses voëls per kamp te plaas. Elke kamp het vyf identiese voerbakke gehad wat elk 'n dieet bevat het waar VVKS inkrementeel (0, 25, 50, 75 en 100% van die proteïenbron) die sojabone-oliekoekmeel (9.8% van die totale dieetsamestelling in kontrole dieet) as proteïen bron vervang het. Voer en water is ad libitum (vrylik en onbeperk) beskikbaar gestel. Droë materiaal inname (DMI) is daagliks gemeet en voerkleur eienskappe is gemeet, wat gebaseer is op L*, a* en b* kleur eienskappe. Slegs die 25% sojabone-oliekoekmeel vervangingsdieet het 'n hoër DMI (817.4 ± 81.98 g/voël/dag) getoon in vergelyking met die ander diëte (gemiddeld 488.8 ± 81.98 g/voël/dag). Alhoewel daar klein verskille was tussen diëte vir sommige kleurkenmerke, word dit nie as die rede vir die verskil in DMI geag nie. Gebaseer op die resultate van hierdie studie, kan VVKS gebruik word om 25% sojabone-oliekoekmeel te vervang sonder enige negatiewe effek op DMI; dit dui op 'n insluiting vlak van 6.8% VVKS in volstruise dieet. Vir die evaluasie om vas te stel tot watter mate VVKS in die dieet van volstruise ingesluit kan word, was 187, dagoud Suid-Afrikaanse Swart volstruiskuikens ewekansig verdeel in 15 groepe (9-12 voëls per groep). Die groeiproef (Hoofstuk 4) het begin met die aanvangsfase toe die kuikens 84 dae oud was en 24.7 ± 0.36 kg geweeg het. Vyf diëte met dieselfde nutriëntwaardes maar met verskillende vlakke van VVKS was ewekansig toegeken aan elk van die groepe, wat dan drie herhalings per behandelingsdieet tot gevolg gehad het. Voëls is volgens standaardpraktyke gevoer waarna hul geslag was op die ouderdom van 309 dae (93.2 ± 1.82 kg). Binne elke voedingsfase het VVKS inkrementeel (0%, 25%, 50%, 75% en 100% van die proteïenbron) die sojabone-oliekoekmeel as proteïenbron vervang, die voer en water was ad libitum beskikbaar gestel. Droë materiaal inname, gemiddelde daaglikse toename (GDT), voeromsetverhouding (VOV) en eindmassa is aangeteken binne elke fase asook oor die hele proefperiode, waarna slagopbrengste ook aangeteken was. Geen verskille is waargeneem ten opsigte van produksie eienskappe gedurende die aanvangs- en afrondingsfase nie. Droë materiaal inname tydens die groeifase was die laagste vir die 100% vervanging (100%VVKS) (1.52 kg/voël/dag) van sojabone-oliekoekmeel (27.5% totale VVKS-insluiting), verder het die res van die diëte met 'n gemiddelde DMI van 1.80 kg/voël/dag geen verskille tussen mekaar getoon nie. Die 100%VVKS het ook tydens die groeifase die stadigste groei getoon (152.0 g/voël/dag), maar het egter nie verskil van die 25%VVKS (6.9% totale insluiting) (208.9 g/voël/dag) en 75%VVKS (20.6% totale VVKS insluiting) (209.5 g/voël/dag) nie. Die 0%VVKS (0% totale FFCS insluiting) (236.2 g/voël/dag) en 50%VVKS (13.8% totale FFCS insluiting) (267.8 g/voël/dag) diëte het gelei tot ʼn hoër GDT in die groeifase. Eindmassas gedurende die groeifase vir onderskeidelik die 25%VVKS, 75%VVKS en 100%VVKS (onderskeidelik 72.2, 72.5 en 67.4 kg) het nie verskil van mekaar nie, die 0%VVKS (74.8 kg), 25%VVKS, 50%VVKS (76.8 kg) en 75%VVKS het ook nie van mekaar verskil nie. Gemiddelde daaglikse toename was die enigste eienskap wat verskille getoon het tussen diëte, met die 0%VVKS, 50%VVKS en 75%VVKS wat die vinnigste groei getoon het en die 100%VVKS die stadigste groei, alhoewel die 100%VVKS nie verskil het van die 25%VVKS en 75%VVKS nie. Die abdominale vetmassas was die enigste slagopbrengs wat verskille tussen diëte getoon het, die 50%VVKS het die swaarste vetgewigte tot gevolg gehad. Op grond van die resultate wat verkry is in die huidige studie, word aanbeveel om nie meer as 20.6% VVKS (75%VVKS) in diëte in te sluit tydens die groeifase nie, aangesien dit tot swakker produksie kan lei. Verder, in die aanvangs- en afrondfase kan VVKS tot die maksimum insluitings vlakke (100%VVKS diëte) wat in die studie geëvalueer was in volstruis diëte ingesluit word, sonder enige nadelige effekte. Die doel van die studie in Hoofstuk 5 was om te evalueer wat die effek van verskillende VVKS insluiting vlakke op die vere, leer en vleissamestelling van slagvolstruise is. Eindprodukte van die voëls wat in Hoofstuk 4 gebruik was, is tydens hierdie proef gebruik. Die enigste verskille tussen diëte ten opsigte van veeropbrengste was binne kuikenliggaam-kort (Chick body short) en onbemarkbare veerklasse. Die 50%VVKS wat die hoër opbrengste (283.2 ± 14.84 g) tot gevolg gehad het, het nie verskil van die 0%VVKS, 25%VVKS en 75%VVKS nie. Verder was bevind, dat die 100%VVKS gelei het tot laer opbrengste (202.3 ± 14.84 g) van kuikenliggaam-kort vere, alhoewel dit nie van die 75%VVKS verskil het nie. Die 50%VVKS het die laagste opbrengs (97.1 ± 13.18 g) onbemarkbare vere getoon. Die res van die diëte wat nie verskil het van mekaar nie en ʼn gemiddeld van 161.2 ± 13.18 g onbemarkbare vere gelewer. Vel dikte was die enigste leer eienskap wat verskille tussen diëte getoon het. Die 0%VVKS het dikker velle (0.65 ± 0.027 mm) opgelewer, maar het nie verskil van die 25%VVKS en 50%VVKS diëte nie. Die 100%VVKS wat dunner velle tot gevolg gehad het (0.53 ± 0.027 mm) het nie verskil van die 50%VVKS of 75%VVKS diëte nie. Vog en proteïen konsentrasie van die vleis was die enigste chemiese komponente wat verskille tussen diëte getoon het. Die 100%VVKS het die hoogste gemiddelde vog konsentrasie getoon (77.0 ± 0.29%) en 25%VVKS die laagste (75.2 ± 0.24%), met geen verskille tussen 0%VVKS 25%VVKS en 50%VVKS vleis nie. Die invers van die vog konsentrasie kan gesien word met betrekking tot proteïen konsentrasie. Die 25%VVKS het die hoogste proteïen konsentrasie (22.6 ± 0.19%) tot gevolg gehad, maar nie verskil van die 0%VVKS en 50%VVKS vleis nie. Die 100%VVKS dieet het die laagste proteïen konsentrasie (20.9 ± 0.23%) opgelewer. Insluiting van VVKS het voordelige veranderinge op die vetsuurprofiel van die abdominale vetweefsel gehad. Totale versadigde vetsure konsentrasies het van 37.8% (0%VVKS) tot 20.3% (100%VVKS) van totale geïdentifiseerde vetsure afgeneem. Totale mono-onversadigde vetsure (MUFA) konsentrasies het toegeneem van 39.7% vir die 0%VVKS gevoerde voëls tot 51.0% vir die 100%VVKS gevoerde voëls. Die totale poli-onversadigde vetsure (PUFA) konsentrasies het ook toegeneem van 22.1% vir die 0%VVKS gevoerde voëls tot 28.7% vir die 100%VVKS gevoerde voëls. Hierdie veranderinge het gelei tot die PUFA:SFA verhoudings se verhoging van 0.60 (0%VVKS) tot 1.43 (100%VVKS). Beide n-6 en n-3-vetsure het toegeneem met 'n toename in VVKS-insluiting in die dieet, maar die n-6:n-3 verhouding het 'n voordelige afname van 3.20 vir die 0%VVKS gevoerde voëls tot 2.28 vir die 100%VVKS gevoerde voëls getoon. Die bevindinge afgelei uit die huidige studie is dus dat, volvet kanolasaad gebruik kan word om 75% (nie die insluiting vlakke wat in elke fase in hierdie proef gebruik word nie) van die sojabone-oliekoekmeel in die diëte van slagvolstruis te vervang. Dieselfde resultate as wat verkry word van die huidige standaard kommersiële diëte kan dus opgelewer word met insluiting van VVKS, sonder om die eindprodukte wat deur volstruise geproduseer word negatief te beïnvloed.
Description
Thesis (MScAgric)--Stellenbosch University, 2018.
Keywords
Ostriches, Ostriches -- Feeding and feeds, Ostrich products industry -- South Africa, UCTD
Citation