Allometric growth of copper, zinc, manganese and iron in slow- and fast-growing young chickens

Abstract

Allometric growth of body microminerals was examined in slow-growing laying-type cockerels (SG) and in fast-growing male broiler hybrids (FG) during the growing period from hatch to Day 22. Allometric coefficients for dry matter, copper, zinc, manganese and iron in relation to body weight were 1.0914, 1.0429, 1.2743, 1.0299 and 1.0730 for SG chickens and 1.0752, 0.9450, 1.0459, 1.0779 and 1.0059 for FG chickens, respectively. Allometric coefficients describing the relationships of Cu, Zn, Mn and Fe with dry matter weight were 0.9495, 1.1654, 0.9390 and 0.9772 for SG chickens and 0.8754, 0.9698, 0.9981 and 0.9336 for FG chickens, respectively. High allometric coefficient for Zn in SG genotype likely indicate a rapid growth of skeletal tissues which requires an adequate mineral nutrition during this period of growth. The deposition of Zn relative to live body and dry matter weights was higher (P < 0.01) in SG chickens thus suggesting that the relative growth of this trace element may be affected by genotype.

Keywords

• age
• growth rate
• chemical allometry
• Cu
• Zn
• Mn