Comparison of production parameters, gut histology, organ weights, and portion yields of broilers supplemented with Ateli plus

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.

Masters