Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Antibiotic growth promoters (AGP’s) have been used in feed of production animals to improve
their growth performance and disease resistance. However, there has been an increase in the
presence of antibiotic residue in animal products, as well as an increase in untreatable illnesses
due to antibiotic resistant bacteria. This led to the European Union banning the use of antibiotic
growth promoters, in production animals, in 2006. An alternative to AGP’s is therefore needed in
animal feed in order to maintain performance. Plant extracts and essential oils have gained
much attention, due to their natural antimicrobial, antibacterial, anticoccidial and antioxidant
properties. This study tested the efficiency of Ateli plus®, an oregano plant extract based
product, as a replacement to AGP’s on production parameters, carcass characteristics and
organ and gut health of broilers.
This study consisted of five treatments fed to broilers from hatch till 33 days of age, fed in three
phases; starter, grower and finisher. The treatment diets consisted of a negative control (no
AGP), positive control (AGP), Ateli plus® at 1kg/ton (Ateli plus® min), Ateli plus® at 2kg/ton for
week one followed by 1kg/ton for the remainder of the period (Ateli plus® max), and AGP plus
Ateli plus® max (AGP plus Ateli plus® max). Results from this study show that there was no difference in performance parameters between
treatments. The performance parameters tested included liveability, average daily gain (ADG),
average weekly feed intake, average cumulative feed intake, average weekly live weight,
average cumulative weight gains, feed conversion ratio (FCR), cumulative FCR and the
European production efficiency factor (EPEF). Broiler breast and thigh muscle pH and colour
(L*, a* and b*) reading values were measured, showing a trend for improved L* colour reading
value and ultimate pH, in broilers supplemented with Ateli plus®. This leads to an increase in
water binding capacity and tenderness, therefore resulting in an improvement in meat quality.
No differences were shown for dressing percentage and portion percentages relative to carcass
weight. No significant differences were seen for tibia bone Ca and P content, or tibia bone fat,
moisture or ash percentages. However a significant decrease in tibia bone strength was found
in all broilers supplemented with Ateli plus® diets and the negative control diet, compared to
AGP supplemented broilers. Gut morphology showed no consistent effect of treatment on villi
height or crypt depth of the duodenum, jejunum and ileum. No significant differences between
treatments were found for organ pH or organ weights, except the gizzard, which was heavier for
Ateli plus® max supplemented broilers.
Ateli plus® shows promise on improving meat quality characteristics of broilers, however the
significant decrease in tibia bone strength in Ateli plus® supplemented broilers is a major
concern and needs to be researched further. Ateli plus® acts as a good AGP replacement, as
broiler performance for the Ateli plus® supplemented broilers was maintained, and not decreased, when compared to the AGP supplemented broilers. However, the broilers fed the
negative control diet had performance parameters statistically equal to both the Ateli plus® and
AGP supplemented broilers, as well as no significant differences between organ weights were
found. It can therefore be said that the broilers were raised under good management, and their
optimal environmental conditions. Therefore conclusive effectiveness of Ateli plus® as a
replacement for AGP on broiler performance cannot be reported from this study. / AFRIKAANSE OPSOMMING: Antibiotiese groeistimulante (AGP’s) word gereeld as voerbymiddels vir diere gebruik om groei
en siekte weerstandbiedenheid te verbeter. Die verbod op die gebruik van antibiotika as 'n
groeipromotor in die Europese Unie (sedert 2006) kan toegeskryf word aan die toename in
onbehandelbare siektes as gevolg van weerstandbiedende bakterieë, asook die
teenwoordigheid van residue in die dierlike produkte. Alternatiewe vir AGP’s in dierevoeding
word dus benodig om produksie te handhaaf. Plant ekstrakte en essensiële olies het baie
aandag gekry as gevolg van hul natuurlike antimikrobiese, antibakteriële, antikoksidiese en
antioksidatiewe eienskappe.
'n Studie is gedoen om die doeltreffendheid van Ateli plus® ('n origanum plant ekstrak
gebaseerde produk) op groei produksie parameters, karkaseienskappe, orgaan- en
dermgesondheid te bepaal wanneer Ateli plus® as 'n AGP plaasvervanger in die dieëte van
braaikuikens gebruik word. Gedurende die proef was vyf verskillende diëte/behandelings vir 33
dae vir braaikuikens gevoer. Die behandelings het bestaan uit 'n negatiewe kontrole (geen
AGP), positiewe kontrole (AGP), Ateli plus® teen 1kg/ton (Ateli plus min), Ateli plus® teen
2kg/ton vir die eerste week gevolg deur 1kg/ton vir die res van die tydperk (Ateli plus® max), en
AGP plus Ateli plus® max (AGP plus Ateli plus® max). Resultate van hierdie studie toon dat behandelings nie 'n effek op produksie parameters gehad
het nie. Die groei produksie parameters wat getoets is sluit in oorlewing, gemiddelde daaglikse
toename (GDT), die gemiddelde weeklikse voer-inname, gemiddelde kumulatiewe voerinname,
gemiddelde weeklikse lewendige massa, gemiddelde kumulatiewe gewig toename,
voeromsetverhouding (VOV) en die Europese produksie doeltreffendheid faktor (EPEF). Die
pH en kleur (L*,a* en b* waardes) van die dy- en borsspier is gemeet. Ateli plus® aanvulling in
braaikuiken diëte het 'n tendens getoon vir verbeterde L * en finale pH waardes in die spiere,
wat lei tot 'n toename in waterhouvermoë en sagtheid en dus verbeterde vleiskwaliteit. Geen
verskille tussen behandelings is gevind vir uitslagpersentasie en die massa van porsies
(uitgedruk as persentasie relatief tot karkasgewig) nie. Behandelings het nie 'n effek op die vet,
vog, as persentasies of Ca- en P-inhoud van die tibia gehad nie.
In vergelyking met AGP aangevulde braaikuikens, is 'n beduidende afname in die tibia
breeksterkte van kuikens in die negatiwe kontrole groep en kuikens wat met Ateli plus®
aangevul is, gevind. Spysverteringskanaal morfologie het getoon dat behandeling geen
konsekwente effek op villi hoogte of krip diepte van die duodenum, jejunum en ileum gehad het
nie. Slegs die krop massas van kuikens wat met Ateli plus® max aangevul is, was swaarder in
vergelyking met hoenders in die ander behandelings; verder is geen beduidende verskille
tussen behandelings gevind vir orgaan pH of orgaan gewigte nie.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/86448 |
| Date | 04 1900 |
| Creators | Teuchert, Nicole |
| Contributors | Pieterse, E., Hoffman, L. C., Stellenbosch University. Faculty of AgriSciences. Dept. of Animal Sciences. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | xi, 102 p. : ill. |
| Rights | Stellenbosch University |
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