Medycyna Wet. 64 (4), 480-483, 2008
Kwiecień M., Winiarska-Mieczan A.
Changes of bone parameters of chickens fed a decreased energy value feed mixture
The objective of the study was to determine the effect of a feed mixture of decreased nutritive value in the broiler chickens’ diets on bone resistance parameters and bone mineral composition for Ca, P and Mg. The experiment was conducted on 144 broiler chickens of the cobb line. The chickens were allocated to two feeding groups: control and experimental. Starter mixture, administered till 21-days-of-life was similar for each group. Growth mixture was supplied from the 22nd day. The nutritional value of 1 kg of growth mixtures was 19.5% crude protein and 13.38 MJ EM in the control group, and 19% crude protein and 12.12 MJ EM in the experimental (ecological) group. In the prepared bones, the physical, mechanical and geometrical parameters were estimated, as well as the mineral composition. The lowest bone weight and length was reported for the experimental group as compared to the chickens from the control group. The ecological mixture influenced the bone resistance parameters, which were higher by 12.3% for Wf, 11.9% for Wy, 24.7% for dy and 8.7% for Wf/A in comparison to the control group. The geometrical parameters and cortical bone proved to be higher at the experimental mixture application. The Ca and Mg content in the bones was slightly higher, whereas P content was lower in the bones, yet not confirmed statistically. The introduction of a reduced nutritive value mixture had a positive influence on the studied physical properties, most resistance and geometrical parameters and the mineral composition of broiler chicken tibia bones. It is vital not only for the chicken performance but animal welfare as well. Reduction of the nutritional value in the diets had a beneficial effect on the studied physical and geometrical parameters, as well as on resistance parameters and mineral composition of broiler chicken tibia bones. This fact is of primary importance not only for the production performance but also for the birds’ welfare.
Keywords: chicken, tibia bone, resistance parameters