| Autor: |
Schild CO; National Institute for Agricultural Research, Animal Health Group, Tacuarembó, Uruguay., Boabaid FM; Department of Pathology, School of Veterinary Medicine, University of the Republic, Tacuarembó, Uruguay., Olivera LGS; National Institute for Agricultural Research, Animal Health Group, Tacuarembó, Uruguay., Machado M; National Institute for Agricultural Research, Animal Health Group, Tacuarembó, Uruguay., Vildoza A; National Institute for Agricultural Research, Animal Health Group, Tacuarembó, Uruguay., Saravia A; National Institute for Agricultural Research, Animal Health Group, Tacuarembó, Uruguay., Custodio A; National Institute for Agricultural Research, Animal Health Group, Tacuarembó, Uruguay., Command C; Laboratory Clinical Analysis CEB, Paysandú, Uruguay., Martinez A; Independent Veterinarian, Tacuarembó, Uruguay., Jaurena M; National Institute for Agricultural Research, Animal Health Group, Tacuarembó, Uruguay., Dixon R; Queensland Alliance for Agricultural and Food Innovation, The University of Queensland, Rockhampton, Australia., Riet-Correa F; Escola de Medicina Veterinária e Zootecnia, Universidade Federal da Bahia, Salvador, Brazil. |
| Abstrakt: |
We investigated 2 outbreaks of osteomalacia as a result of phosphorus (P) deficiency in herds of lactating beef cows grazing subtropical native pastures in Uruguay. Cows exhibited pica, difficulty to stand and walk, rib fractures, and body weight loss even with adequate forage availability. Osteopenia and severe osteomalacia were observed on gross and histologic examination. The concentrations of bicarbonate-extractable P in soil (4.0, 4.1 mg P/kg), total P in pasture (0.9, 1.1 g P/kg), inorganic P in serum (1.0, 0.71 mmol P/L), and P in bone (73 mg P/mL) were all low. Although injectable and mineral salt supplements provided additional P in both outbreaks, these supplementary amounts were insufficient to prevent P deficiency. The P ingested by the cows from the pasture and supplements would have provided 20-55% of their daily P requirements of ~21 g P/d. Osteomalacia occurred in cattle at the 2 ranches as a result of severe P deficiency in the soil and forage, and inadequate P supplementation. Following diagnosis, control of P deficiency in beef cattle requires estimation of the amount of pasture P ingested and provision of sufficient additional supplementary P to meet the animals' requirements. |
