Influence of minerals on the aetiology of geophagia in periurban dairy cattle in the derived savannah of Nigeria

The aetiology of geophagia in periurban dairy cattle in Nigeria was assesse d in relation to the mineral status of the serum, the herbage consumed, and the soil from where the herbage was consumed. The study was carried out us ing nine herds in the derived savannah zone during both the wet and dry sea sons. Generally, the Na, Ca, Fe, Zn and Cu levels in the samples were adequ ate. However, the forages were low in Ca and the serum was deficient in P. Forage, soil and termite hill samples were also deficient in P. The low lev els of P in the soil and termite hill samples showed that the consumption o f sand by the cattle did not have any positive impact on their P intake. A seasonal effect was apparent (p < 0.05) on the serum Na+, PO43-, Cu2+ and F e2+ concentrations but not on Ca2+ and Zn2+ concentrations. A seasonal effe ct was also significant (p < 0.05) on the minerals in the forage. There wer e also seasonal differences in most of the soil and termite hill minerals. Most samples had higher (p < 0.05) mineral levels in the dry season. Herd s ize and farming activity had no apparent influence on the aetiology of geop hagia as they did not affect (p > 0.05) the concentration of P in the serum , the reported cause of geophagia. Geophagia is probably caused by a margin al level of P in the serum and low levels in the forage and soil. Experimen tal trials will be required to confirm these observations.