Abstract
Meat is an important source of minerals to meet human requirements. There is scarce information about mineral content in meat of lambs raised in pasture based system that are predominant in South America. The aim of this study was to elucidate the effect of different feeding system in the concentration of Fe, Zn, Cu, Mg, P and K in the loin muscle of lambs. Eighteen castrated male lambs Corriedale x Ile de France (BW = 29.5 ± 2.1 kg) were assigned by stratified randomization to 3 dietary treatments. Mix...A: alfalfa grazing (8h/d) and TMR composed by an amylaceous energy source (ground corn and wheat grain); Mix_F: alfalfa grazing (8h/d) and a TMR composed by a fibrous energy source (defattened corn germ), the TMR of both mixed diet was offered at 75% of the potential intake, and C: TMR (mixture of both TMR in a 1:1 ratio) offered ad libitum. Both TMR were formulated according to the NRC (2007) for an average daily grain of 300 g and were isoenergetic and isoproteic. After 44 days lambs were slaughtered and the longisimus dorsi muscle of each one was collected and immediately stored at -20º C until mineral content analysis by a flame atomic absorption spectrophotometer. Data were analysed using a mixed model with dietary treatment as fixed effect. There were no significant differences between treatments in the mineral concentrations of lamb meat. All studied minerals were detected in concentrations that would allow supplying, in one serving of cooked meat (defined as 100 g which equates to 143 g of fresh meat, assuming a 30% moisture loss during cooking), more than 25% of the recommended daily intakes (according main international health institutions guidelines) for a wide range of population groups. These concentrations allow declaring lamb meat as a good source of minerals.
Keywords: minerals concentration, lamb meat, pasture