PSVI-8 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

Autor: Megan E Nelson, Su A Lee, Yueming Dersjant-Li, Deepak Velayudhan, Janet C Remus, Hans H Stein
Rok vydání: 2022
Předmět:
Zdroj: Journal of Animal Science. 100:165-166
ISSN: 1525-3163
0021-8812
DOI: 10.1093/jas/skac064.282
Popis: 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.
Databáze: OpenAIRE
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