Effect of Calcium/Phosphorus Imbalance in the Ration on Flock Performance in Two Broiler Flocks in North Georgia

SUMMARY. Five- and six-day-old broilers from two flocks experiencing excessive mortality were submitted for necropsy. Rickets was diagnosed based on clinical signs of lameness and on gross and histopathologic lesions. Because of a confirmed feed mill error, these flocks had been fed a starter ration with a high calcium/phosphorus ratio (either 7.7:1 or 3.5:1). After debate concerning the profitability of salvaging the remaining birds in the affected flocks, the starter feed was replaced at 7 days of age. At processing, the affected flocks had weighted averages of body weight and feed conversion of 1.71 kg and 1.88, respectively; these averages compared favorably with the company averages of 1.72 kg and 1.87. The majority of the mortality in the affected flocks occurred during the first week. This case report demonstrates that it may be advantageous for a producer to salvage chicks that have been affected severely with rickets at less than 1 week of age.