The influence of dietary zinc content on mechanical properties of chicken tibiotarsal bone

Abstract

The authors evaluated the effect of diets with different Zn levels on mechanical properties of bones in 60 Ross 308 hybrid broilers, from 2 to 35 days of age, which were randomly divided in 2 groups, with 30 chickens each. The first group (Zn50) was fed a commercial basal diet with no Zn additives (zinc content - 50 mg/kg feed). The second group (Zn100) was fed the basal diet + 50 mg of Zn/kg feed. In this group the dietary Zn level was increased by adding 62.23 mg of zinc oxide (ZnO)/kg feed to starter and grower feeds. In group Zn100 compared to Zn50 the values of blood zinc level were significantly higher on days 7 and 35 (p<0.01 and p<0.05). Significant differences in bone zinc content were not detected. On days 7, 21, and 35 the selected mechanical properties of the tibiotarsus were evaluated. The results obtained in the experiment showed differences in biomechanical competence of broiler bones from group Zn50 compared to Zn100. In broilers from group Zn100, there were significantly higher values in the limit of elasticity (Re), bending strength (Rm) and fracture stress (Rl) (p<0.05 to p<0.01) of chicken bones on day 35. The mean levels (117.80 ± 19.66, 126.70 ± 32.56, 114.10 ± 19.92, respectively) were determined in broiler bones from group Zn100 compared to Zn50 (95.27 ±18.71, 100.2 ± 20.56, 80.93 ± 35.22, respectively). In group Zn100 were observed significantly increased values of the bone crosssection area (Ar) on day 35 and moment of inertia (I) on days 21 and 35 (p<0.05). The clinical examination of the locomotory system showed bone deformities of the intertarsal joint in 10% of broilers from group Zn50. Present results suggest that the determination of the weight bearing of the tibial bone evaluated by assessing of mechanical properties of bones is an indicator of the locomotory system disorders and the Zn content in feed has a direct and statistically significant effect on bone strength in broiler chickens

Subsequent somatic axis and bone tissue metabolism responses to a low-zinc diet with or without phytase inclusion in broiler chickens

“…However, the increase of the ultimate strength was the same in both groups of chickens fed low-Zn diet irrespective of phytase inclusion. Our results agree with others, who report an influence of dietary Zn on the mechanical properties of bones [ 49 – 51 ]. On the other hand, there are studies showing that low-Zn diets do not increase bone breaking strength when compared to the Zn-deprived control [ 8 , 21 , 52 ] or group supplemented with ZnO at recommended dose [ 48 ].…”

“…These additionally available minerals could play a significant role in the synthesis of hormones of somatotropic axis which also could be responsible for a faster growth observed in broilers from the Zn25%+phyt group. It agrees with other studies showing a better growth and bone development in poultry after added phytase to the diet, irrespective of analyzed mineral elements [ 26 , 51 , 53 ].…”

The Effect of High-Level Dietary Supplementation with Different Zinc Sources on Performance, Eggshell Quality and Bone Characteristics in Layer Quails

“…The present study shows that dietary supplementation of 200 mg/kg Zn significantly increased the shear force of bone compared with the 300 mg/kg group. This result was similar to that of Stofanikova et al (2011) and Olgun and Yildiz (2017), who showed that bone biomechanical properties were affected by Zn supplementation in poultry. However, Swiatkiewicz and Koreleski (2008) indicated that supplementation of different levels of Zn had no effect on the mechanical characteristics of bone in laying hens.…”

Optimization of Dietary Zinc Requirement for Broiler Breeder Hens of Chinese Yellow-Feathered Chicken

“…It is considered to be a coenzyme of more than 240 enzymes in birds’ bodies, and plays a major role in activating some antioxidant enzymes which sustain the defense system of avian body against reactive oxygen species [1,2,3]. The results of previous studies have indicated that Zn supplementation is important for enhancing the antioxidant capacity and improving the productive and reproductive performance [4,5,6,7], egg quality [8,9,10], and tibial quality [11,12,13] in laying hens and laying breeders. Reproductive performance, egg quality, tibial quality, antioxidant status, and tissue deposition are common variables employed in estimating the optimal dietary nutrient requirements for laying hens and breeders, following nonlinear regression models [6,14].…”