Influence of age, sex and cross on body concentrations of trace elements (zinc, iron, copper and manganese) in chickens

Abstract

1. Environmental problems in areas of intensive animal production necessitate new constraints in food formulation concerning nitrogen and phosphorus and also concerning trace minerals, especially zinc and copper, which are found in excess in poultry manure in relation to nitrogen and might cause phytotoxicity in soil. 2. Whole body concentrations of zinc, iron, manganese and copper were measured in chickens in order to estimate the percentage of deposition and excretion. Body concentrations were determined on 390 chicks of both sexes at different ages in 2 commercial crosses. 3. Age affected the trace element body concentration. Higher concentrations were observed at earlier ages (4 to 11 d). Sex and cross had little influence on body Zn, Fe, Cu and Mn concentration and interactions were observed between these factors. 4. Body retention percentage (% of intake) was very low when birds were fed on commercial diets and decreased with age. For the period 0 to 40 d, the percentages of retention were 6%, 10%, 0.2% and 6% for Zn, Fe, Mn and Cu, respectively, and therefore 90% to 99% was excreted. 5. These findings make it possible to calculate trace mineral excretion for various feeding systems and confirm the excess of zinc and copper in poultry manure in relation to nitrogen. A nutritional approach such as reduction in dietary trace mineral supplementation may alleviate the risks of phytotoxicity in the soil resulting from Zn and Cu excesses.

Effect of age upon utilisation of iron in chickens

“…The difference between hybrids was insignificant (P > 0.05). The content of Fe in body tissues was much higher than the values published by Mohanna and Nys (1998). In accordance with observations described by Cao et al (1996) it could be caused by the fact that the content of dietary Fe was higher than in the experiment of the authors mentioned above.…”

“…(Figure 2). In broiler chickens, the dependence of body Fe concentration on age (Mohanna and Nys, 1998) Correlation indexes were highly significant (P < 0.01).…”

“…Similarly like in the experiment conducted by Age (day) Coefficient of retention of Fe Mohanna and Nys (1998), a rapid decrease in coefficients of Fe retention gradually slowed down and the minimum values were recorded on Days 64 and 68 in laying and meat type chickens, resp. ; therea�er, an only slight increase in measured values was observed.…”

“…Mohanna and Nys (1998) estimated percentages of Fe retention and concentrations of body iron in chicks of the age of 0, 4, 11, 21, 29, 40 and 50 days. The highest retention of Fe was recorded during the first days of life.…”

Zinc availability and digestive zinc solubility in piglets and broilers fed diets varying in their phytate contents, phytase activity and supplemented zinc source

“…and so on), Zn supplementation is generally supplied with high safety margins for Zn; even when not supplied for pharmacological purposes in piglets. High safety margins in Zn lead to unbalanced manure composition relative to nitrogen (Mohanna and Nys, 1998) and to environmental concerns in areas with concentrated livestock production (Dourmad and Jondreville, 2008;Rö mkens et al, 2008). Along with new legal limitations on dietary Zn supply (e.g.…”