MINERAL CONCENTRATION IN BONE TISSUE OF SHEEP GRAZING IN THE STATE OF YUCATAN, MEXICO

摘要

Studies on the mineral profile of fodder consumed by grazing ruminants must be completed with information on its effect on the tissues since deficiencies and mineral imbalances are reflected in the body composition and consequently in the productivityof animals. The aim of this study was to quantify four minerals on the twelfth rib of hair sheep grazing in the state of Yucatán during the rainy season (June-October). Fifty farms of sheep breeders were sampled in 47 municipalities and 139 rib sampleswere collected through biopsies. The contents of Ca, K, Cu and Fe were determined by using atomic absorption spectrophotometry. Results were statistically analyzed using a completely randomized experimental design with a trifactorial arrangement, including the effect of the geographical area (Centre, East, West and South), the physiological status of sheep (Weaning, Yearling and Adult), soil type (Luvisol, Vertisol, Cambisol, Rendzina, Litosol), double and triple interactions. The geographical locationshowed no effect (p>0.05) on the Ca content; the average was 42.7 %, above 36 % (considered normal). In the eastern and central zones, 33 % and 27 % of the samples recorded a Ca content below normal. In addition, the average concentrations of K (0.017 %), Cu (0.68 ppm) and Fe (4.6 ppm) were lower than normal levels. Weaning showed the lowest Ca content (p<=0.05) and the highest of K (p<=0.05) on the rib. There was no effect (p>0.05) of the soil type on the content of Ca, K, Cu and Fe. It was concludedthat there are Ca deficiencies in the central zone which affect the lambs mostly at weaning. Deficiencies of K, Cu and Fe were also detected in bone.