Seasonal phosphorus supplementation to steers in fertilized pasture

Abstract

A study to verify the effect of P supplementation in the dry and wet season was conducted on fertilized guineagrass (Panicum maximum Jacq.) pasture. The experiment was carried out at 20°14’30” south latitude and 56°22’42” west longitude, in the municipality of Miranda, MS, Brazil, and lasted for 719 days. A total of 176 Nelore cross-bred steers were used in the following treatments: 1. NaCl + P + micro-elements during all year; 2. NaCl + P + micro-elements in the wet season and NaCl + micro-elements in the dry season; 3. NaCl + micro-elements in the wet season and NaCl + P + micro-elements in the dry season; and 4. NaCl + micro-elements during all the year. The experiment did not show significant difference (P > 0,05) among treatments. The average final weights per animal were 436,4 kg for treatment 1, 421.7kg for 2,428.0kg for 3, and 422.5kg for treatment 4. Biopsy of rib-bone showed low Ca and P for all treatments. The forage was deficient in P, Na, Zn and Cu and the soil in Zn and Cu.