Pigs experiencing a moderate and a high level of antigen exposure were self-fed one of six dietary concentrations (.30, .40, .50, .60, .70, .80%) of available phosphorus (AP) from 14 to 60 pounds body weight. Pigs reared via a management scheme that resulted in a moderate level of antigen exposure consumed more feed daily, gained body weight faster, required less feed per unit of gain, and accrued more body protein daily than pigs reared in a high antigen exposure environment. Over the duration of the study, dietary AP concentrations of .6 to .7% and .4 to .5% in the moderate and high antigen exposure pigs, respectively, were needed to maximize daily body weight gains, gain:feed ratios, and body protein deposition.
Based on these data, the dietary available phosphorus needs expressed as a percentage of the diet for 14 to 60 pound pigs experiencing a moderate or high level of antigen exposure are about 2.4 and 1.7 times greater, respectively, than current NRC (1988) estimates.
Iowa State University
Zimmerman, Dean R. and Cook, D. R., "Dietary Available Phosphorus Needs of Pigs Experiencing a Moderate and High Level of Antigen Exposure" (1997). Swine Research Report, 1996. 4.