PSVI-15 - Effects of Phosphorus Level and Increasing Phytase Dose on Basal Endogenous Loss of Calcium and Balance of Phosphorus in Pigs Fed Diets Containing Phytate P at Commercial Levels

Tuesday, March 15, 2022

5:00 PM – 5:45 PM CST

Location: Grand Ballroom Foyer

Presenting Author(s)

MN

Megan E. Nelson

University of Illinois at Urbana-Champaign
Urbana, Illinois, United States

Author(s)

Su A Lee, PhD

Postdoctoral Research Associate
University of Illinois at Urbana-Champaign
Urbana, Illinois, United States
YD

Yueming Dersjant-Li

Innovation Senior Scientist
Danisco Animal Nutirtion (IFF)
Oegstgeest, Zuid-Holland, Netherlands
DV

Deepak Velayudhan

Innovation Scientist
Danisco Animal Nutirtion (IFF)
Oegstgeest, Zuid-Holland, Netherlands
JR

Janet C. Remus, PhD

Technical Services Director
IFF Danisco Animal Nutrition
Spicer, Minnesota, United States
HS

Hans H. Stein

Professor
University of Illinois at Urbana-Champaign
Urbana, Illinois, United States

Abstract: The objective was to test the hypothesis that dietary P concentration and level of phytase influences basal endogenous loss of Ca in pigs. Seventy barrows (body weight: 17.66 kg) were housed in metabolism crates and allotted to 7 Ca-free diets containing corn, potato protein concentrate, and full-fat rice bran (0.27% phytate P). A positive control (PC) diet contained P at the requirement for digestible P for 11 to 25 kg pigs. Negative control (NC) diets were formulated by reducing concentration of digestible P by 0.15% and adding a novel consensus bacterial 6-phytase variant at 0, 250, 500, 1,000, 2,000, or 4,000 phytase units/kg diet. Feces and urine samples were collected separately for 4 d after 5 d of adaptation. Dried and ground fecal samples were analyzed for dry matter, Ca, and P and urine was analyzed for P. Data were analyzed using a model that included diet as fixed effect. Positive control and NC were compared using a contrast statement and linear and exponential effects of dietary phytase were tested. Results indicated that apparent total tract digestibility of dry matter was not affected by dietary P or phytase (Table 1). The basal endogenous loss of Ca was not affected by dietary P, but exponentially (P = 0.030) decreased as dietary phytase increased. Phosphorus retention (g/d) was greater (P < 0.001) in pigs fed PC compared with NC without phytase. The standardized total tract digestibility (STTD) of P exponentially (P < 0.001) increased as phytase increased, however, retention of P as % of absorbed P decreased (linear, P = 0.006) as phytase increased because the extra P absorbed as a result of phytase could not be retained due to the lack of Ca. In conclusion, increasing the phytase dose decreased basal endogenous loss of Ca and increased STTD of P.