Year: 2007
Type: dissertation
Abstract: Over the last few decades various authors have reported the influence of day old chick quality on integrated broiler industries.Although various methods of determining chick quality have been reported, defining a good or a first grade day old chick can be problematic as it involves many subjective measurements.Incubation temperature (embryo temperature) is probably the biggest, most influential factor during incubation on chick quality.High temperatures cause the most damage.It leads to poor growth, stress, black buttons, threads, weak chicks, chicks with poorly erupted down that are bleached in appearance, low hatchability, late embryonic death and early broiler mortality.This trial was designed to test whether 37.2, 37.4 or 37.5ºC was the optimum incubation temperature for hatching Hybro G+ chicks with superior quality.The parameters that were measured were the chick length, bodyweight, and the yolk residue of the day old chicks of the flocks set at different setter temperatures.After hatching, 1440 chicks (480 chicks per temperature treatment) were placed at a broiler facility where the daily mortalities, weekly bodyweight gain and feed conversion were recorded and calculated.The age of the breeder flock had a significant effect on all three parameters measured in the incubation trial with p values of <0.001, <0.001 and 0.005 respectively.There were no significant differences in chick quality parameters due to different incubation temperatures.The age x temperature interaction could be attributed to the large influence of the age of the breeder on egg size and consequently chick parameters.The results could be related to the fact that bigger eggs from older breeder flocks have higher initial egg mass, which will result in heavier embryos and thus converted to a larger day old chick.The performance trial performed after the incubation trial showed no significant effect of the incubation temperature on 7-day and daily mortalities, weekly bodyweight gain and feed conversion efficiency to 42 days of life.The lack of effects observed in these trials could be attributed to the small range of temperatures used in addition to the difficulties brought about the use of multi-stage incubators.III UITTREKSEL Die afgelope paar dekades het verskeie skrywers die invloed van dagoud kuikenkwaliteit op geintegreerde braaikuiken produsente in diepte bespreek.Alhoewel daar verskeie maniere is om kuikenkwaliteit te bepaal bly dit moeilik om 'n eerstegraad kuiken te definieer aangesien dit baie subjektief is.Inkubasie temperatuur of liewers embrio temperatuur is waarskynlik die grootste enkele faktor op kuikenkwaliteit.Hoë temperature veroorsaak die meeste skade.Dit lei tot swak groei, swart knoppe of dun stringe in die naaltjie area, swak en lam kuikens, kuikens met swak ontwikkelde dons wat wit en vaal in voorkoms is, lae uitbroeibaarheid, laat embrioniese sterftes en hoë eerste week braaikuiken mortaliteite.Die proef was ontwikkel om vas te stel of 37.2, 37.4 of 37.5ºC die optimum inkubasie temperatuur is om Hybro G + kuikens uit te broei met hoe kwaliteit.Die parameters wat gebruik was, was kuikenlengte, kuikengewig en residuele eiergeel van die kuikens by die verskillende inkubasie temperature.1440 Dagoud kuikens (480 per temperatuur behandeling) was in 'n braaikuiken fasiliteit geplaas waartydens die daaglikse mortaliteite, weeklikse gewigstoename en voeromset genotuleer en uitgewerk was.Die ouderdom van die teeltrop het 'n betekenisvolle invloed gehad op die parameters wat gemeet was tydens die inkubasie proef.Die verskillende inkubasie temperature, naamlik 37.2, 37.4 en 37.5ºC, het geen betekenisvolle verskil getoon op die parameters wat gemeet was tydens die inkubasie proef nie.Die ouderdom x temperatuur interaksie kan hoofsaaklik toegeskryf word aan die feit dat 'n ouer teeltrop groter eiers produseer en met die omskakeling van eiergeel na kuiken 'n groter kuiken geproduseer word.Soortgelyk uit die braaikuiken resultate is dit duidelik dat die verskillende inkubasie temperature geen betekenisvolle effek gehad het op 7 dae en daaglikse mortaliteite, weeklikse gewigstoename en voeromset tot en met 42 dae in ouderdom nie.Die rede vir bogenoemde resultate kan hoofsaaklik toegeskryf word aan die feit dat die temperatuur verskille naamlik 37.2, 37.4 en 37.5ºC waarteen die eiers geinkubeer was te klein was, en dat die proef uitgevoer was met die gebruik van veelvuldige ouderdom inkubators wat opsigself sy eie probleme teweeg bring.
Author: Du Preez
Language: English
Subfield: Animal Science and Zoology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W1941511637