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

ZELENKA JIŘI: Allometric growth of copper, zinc, manganese and iron in slowand fast-growing young chickens. Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 2013, LXI, No. 1, pp. 237–241 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 coeffi cients 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 coeffi cients 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 coeffi cient 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 aff ected by genotype. age, growth rate, chemical allometry, Cu, Zn, Mn, Fe Requirement for concentration of an available mineral in the diet for growing poultry depends on the inevitable mineral losses, the growth rate, the mineral concentration in gained body weight, and the feed conversion ratio. Mineral concentration in body weight is quantitatively the most important (Rodehutscord, 2006), but it can be studied with reasonable eff ort by a whole body analysis. We have studied retention of calcium, phosphorus, magnesium, sodium and potassium in laying and meat type chickens (Zelenka, 2012) recently, and we want to pay attention to some microminerals now. Copper is essential for haemoglobin formation and also plays a role in many enzyme systems, such as cytochrome oxidase, which is important in oxidative phosphorylation (Leeson, 2009). The reduced elasticity of the vessels in copper-defi cient chickens is responsible for ruptures of the aorta (Hill et al., 1967). Copper also has a role in the crosslinking of collagen and elastin, which gives bone its tensile strength and elasticity (Dibner et al., 2007). Zinc is required constituent of several hundred metalloenzymes and therefore impacts a wide array of basic cellular functions. In the form of zinc fi nger proteins is involved in the regulation of DNA transcription (Dibner and Richards, 2006). The element participates in regulation of hydroxyapatite crystallization, collagen synthesis, and the cellular invasion of the cartilage matrix by the osteoblasts (Dibner et al., 2007). Manganese plays both structural and catalytic roles in metalloproteins (Scrutton et al., 1966). It is necessary for the normal development of bone. The ground substance of tissue, particularly the proteoglycan matrix in which collagen and elastin are embedded, requires manganese for glycosylation of its protein core molecule (Dibner and Richards, 2006). The manganese requirements of poultry are appreciably higher than those of other domestic livestock and manganese defi ciency as a practical production problem is largely confi ned to these species (Suttle, 2010).