A NOTE ON THE CHEMICAL-COMPOSITION OF FECES AND URINE OF GRAZING COWS

The main results on the chemical composition of the faeces and urine o f daily cows under three grazing systems are shown: I) star grass (Cyn odon nlemfuensis) with 72 paddocks (PR-72); II) idem to I but with 12 paddocks (P.R-12) and III) guinea grass (Panicum maximum) grazing with 72 paddocks and protein bank(PR + PB). Grazing intensity was 280, 110 and 280 cows for PR-72, PR-12 and PR + BP, respectively. Average valu es of N, P, Ca, Na and Kin urine (mg/100 ml) were 1.91, 3.58, 5.01, 42 7 and 589, respectively and they did not differ between grazing system s although the nitrogen was slightly higher in the treatment with less grazing intensity. There was no marked effect of the treatment in the chemical composition of the faeces, but an increase in phosphorus exc retion was observed in the system with the protein bank. The chemical composition of the faeces showed average values of 15.48, 12.59, 1.91, 87.41, 1.21, 0.41, 0.29 and 0.53% for DM, ash, N, OM, Ca, P, Na and K , respectively. Data show the potentiality of the use of faeces and ur ine and nutrient carriers for the soils in grazing areas, although oth er aspects as grassland area, volatilization, nutrient drainage, etc. must be taken into account.