Influence of limestone particle size in layer diets on shell characteristics at peak production
| dc.contributor.advisor | Van Der Merwe, H. J. | |
| dc.contributor.advisor | Du Toit, J. E. J. | |
| dc.contributor.advisor | Hayes, J. P. | |
| dc.contributor.author | Phirinyane, Boitumelo Tobin | |
| dc.date.accessioned | 2015-11-12T12:47:27Z | |
| dc.date.available | 2015-11-12T12:47:27Z | |
| dc.date.copyright | 2004-12 | |
| dc.date.issued | 2004-12 | |
| dc.date.submitted | 2004-12 | |
| dc.description.abstract | English: A study was conducted to investigate the influence of different particle sizes of a specific amorphous limestone source (calcium carbonate) in a layer diet on egg production and egg quality at peak production (week 24). Ninety nine layer pullets, 17 weeks old, were obtained from a commercial layer breeder. The pullets were randomly allocated to three groups. All the pullets received the same layer diet. The only differences among the treatment groups were that the pullets in each group received one of the three different particle sizes in the diet namely:- (a) Less than 1.0 millimetre (b) 1.0 and 2.0 millimetre (c) 2.0 and 3.8 millimetre The influence of the three particle sizes on the feed intake, body weight and egg production as well as egg characteristics was recorded. The average weekly feed intake, body weight and egg production of layers from week 18 up to 28 were not (P> 0.05) different among the layer diets with the different particle sizes. The particle size of limestone in the layer diets did not influence egg weight (P= 0.2159) and egg output (P=0.2388) significantly at peak production. Average egg weight tended (P= 0.2159) to be heavier when coarse particles were fed. No statistic al significant (P> 0.05) differences in egg volume, egg contents, egg surface area, shell weight per unit surface area, shell percentage and shell thickness occurred. According to these results limestone particle size in layer diets has no influence on eggshell quality. In the second study the effect of particle size distribution of a specific limestone source in layer diet on egg production and egg quality at peak production (week 24) was investigated. One hundred and sixty seven layer pullets , 17 weeks old, were obtained from a commercial layer breeder. The pullets were randomly allocated to five groups. All the pullets received the same layer diet. The only differences among the treatment groups were that the pullets in each group received one of five different ratios of fine (less than 1.0 mm) and coarse (between 2.0 and 3.8 mm) limestone particle size namely 100, 75, 50, 25 and 0 % fine or coarse. The influence of the five dietary limestone particle size distributions on the feed intake, body weight, and egg production of layers as well as egg characteristics mentioned in the first study were investigated. No significant (P> 0.05) influence of dietary limestone particle size distribution was found on feed intake, body weight and egg production of layers. Accordingly no significant differences occurred in egg volume, (P= 0.1310) and egg surface area (P= 0.1393). The highest (P< 0.001) egg contents were recorded where 100 and 75% fine limestone particles were included in the diet. Although significant differences for shell weight (P<0.0017) and shell percentage (P<0.0001) occurred, no clear influence of particle size distribution on these characteristics could be detected. In accordance wit h shell weight per unit surface area no significant differences (P> 0.05) in eggshell thickness occurred. It was concluded that different dietary limestone particle sizes and distributions have no influence on eggshell quality at peak production (week 24). The influence of dietary limestone particle size and distribution during the later stages of the laying period on bone formation and egg quality needs further investigation. | en_ZA |
| dc.description.abstract | Afrikaans: ’n Studie is uitgevoer om die invloed van verskillende partikelgroottes van ’n spesifieke amo rfe kalksteenbron (kalsiumkarbonaat) in lêhendiëte op eierproduksie en eierkwaliteit by piekproduksie (24 weke) na te gaan. Nege - en negentig, 17 weke oud lêhenne is van ’n kommersiële teler verkry. Die henne is ewekansig in drie groepe ingedeel. Al die lêhenne het dieselfde lêhendieet ontvang. Die enigste verskille tussen die behandelings was dat die lêhenne in elke groep een van drie verskillende partikelgroottes in die diet ontvang het naamlik: - a) kleiner as 1.0 millimeter b) tussen 1.0 en 2.0 millimeter c) tussen 2.0 en 3.8 millimeter Die invloed van die drie partikelgroottes op voerinname, liggaamsgewig en eierproduksie asook eiereienskappe is ondersoek. Die gemiddelde weeklikse voerinname, liggaamsgewig en eierproduksie van lêhenne vanaf 1 8 tot 28 weke h et nie betekenisvol (P>0.05) tussen die lêhendiete met verskillende kalksteen partikelgroottes verskil nie. Die partikelgroottes van voerkalk in die lêhendiete het nie eiergewig betekenisvol (P=0.2159) by piekproduksie beïnvloed nie. Gemiddelde eiergewig (P = 0.2159) en eiermassa (g eier/hen/dag) (P= 0.2388) het geneig om swaarder te wees indien growwe kalksteen verskaf is. Geen statisties betekenisvolle (P>0.05) verskille in eiervolume, eierinhoud, eieroppervlakte, dopgewig per eenheid oppervlakte, dop persentasie en dopdikte het voorgekom nie. Volgens hierdie resultate het kalksteen, partikelgrootte in lêhendiete geen invloed op eierdopkwaliteit nie. In ’n tweede studie is die invloed van partikelgrootte verspreiding van ’n spesifieke kalksteenbron in ’n lêhendieet op eierproduksie en eierkwaliteit by piekproduksie (24 weke) ondersoek. Eenhonderd sewe - en sestig 17 weke oud lêhenne is van ’n kommersiële teler verkry. Die lêhenne is ewekansig aan vyf groepe toegeken. Al die lêhenne het dieselfde lêhe ndieet ontvang. Die enigste verskille tussen die behandelings was dat die lêhenne in elke groep onderskeidelik een van vyf verskillende verhoudings van fyn (minder as 1.0 mm) en growwe (tussen 2.0 en 3.0 mm) kalksteenpartikels ontvang het naamlik 100, 75, 50, 25 en 0% fyn of grof. Die invloed van die vyf dieetkalksteen partikelgrootte verspreidings op voerinname, liggaamsgewig en eierproduksie van lêhenne asook die eiereienskappe genoem in die eerste studie, is ondersoek. Geen betekenisvolle (P>0.05) inv loed van dieetkalksteen partikelgrootte verspreiding op voerinname, liggaamsgewig en die eierproduksie van die lêhenne is gevind nie. Dienooreenkomstig is geen betekenisvolle verskille in eiervolume (P = 0.1310) en eieroppervlakte (P = 0.1393) gevind nie. Die hoogste (P<0.001) eierinhoud is gevind waar die 100% en 75% fyn kalksteen partikels in die dieet ingesluit is. Alhoewel betekenisvolle verskille vir dopgewig (P<0 . 0017) en doppersentasie (P<0.0001) voorgekom het, kon geen duidelike invloed van partikelgrootte verspreiding op hierdie eienskappe waargeneem word nie. In ooreenstemming met dopgewig per eenheidsoppervlakte het geen betekenisvolle (P>0.05) verskille in e ierdopdikte voorgekom nie. Daar is tot die gevolgtrekking gekom dat verskillende dieetkalksteen partikelgroottes en verspreidings, geen invloed op eierdopkwaliteit by piekproduksie (24 weke) tot gevolg het nie. Die invloed van beide dieetkalksteen part ikelgrootte en verspreiding gedurende die latere stadiums van die lêperiode op beenvorming en eierkwaliteit vereis verdere ondersoek. | af |
| dc.description.sponsorship | Botswana Defence Force | |
| dc.identifier.uri | http://hdl.handle.net/11660/1623 | |
| dc.language.iso | en | en_ZA |
| dc.publisher | University of the Free State | en_ZA |
| dc.rights.holder | University of the Free State | en_ZA |
| dc.subject | Dissertation (M.Sc.Agric. (Animal Science))--University of the Free State, 2004 | en_ZA |
| dc.subject | Eggshells | en_ZA |
| dc.subject | Minerals in nutrition | en_ZA |
| dc.subject | Chickens -- Feeding and feeds | en_ZA |
| dc.title | Influence of limestone particle size in layer diets on shell characteristics at peak production | en_ZA |
| dc.type | Dissertation | en_ZA |