Effect of different amounts of pansy and nettle in feed mixtures for chickens on physical, chemical and strength parameters of their bones

摘要

The aim of the present study was lo determine the effect of an herbal supplement used in feed mixtures on the selected physical features and the chemical composition of broiler chickens' bones in reference lo antibiotic growth promoter. The experimental material was provided by 180 KOSS broiler chickens. One-day-old nestlings were divided randomly into 2 control groups and 4 experimental groups, in three replications, 10 birds each. The feed mixtures (Starter and (Grower/Finisher types) were made ofcorn and extracted soy meal and they also contained fodder yeast, soy oil, mineral additives, premixes (with an addition of growth promoters or without) and an addition of dried green forage or dried herbs. The mechanical properties of the bones were determined on the basis of the three-point bend test performed with the use of an Instron 4302 apparatus coupled with a computer. The test registers as a graph the dependence between the force acting perpendicularly to the long axis of the bone and its deformation. An examination was performed to determine maximum force, and the maximum elasticity force. The studies revealed that both the type and the amount of the herbs determined chickens' growth and the physical and strength properties of their bones. The most beneficial effects were observed in feeding birds mixtures containing 1% of pansy, since the vallies noted for all traits and indices were not worse than the effects obtained in the control group receiving antibiotic growth promoter, and in somecases they were even higher. The least positive results occurred in supplementing feed mixtures with 3% of nettle.