Basal endogenous loss of calcium and phosphorus and use of phytase in diets for pigs

Nelson, Megan Elizabeth

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https://hdl.handle.net/2142/120182 Copy

Description

Title

Basal endogenous loss of calcium and phosphorus and use of phytase in diets for pigs

Author(s)

Nelson, Megan Elizabeth

Issue Date

2023-05-05

Director of Research (if dissertation) or Advisor (if thesis)

Stein, Hans H

Committee Member(s)

• Swanson, Kelly
• Ellis, Michael

Department of Study

Nutritional Sciences

Discipline

Nutritional Sciences

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

basal endogenous loss, calcium, digestibility, phosphorus, phytase, pigs

Abstract

Three experiments were conducted to test a series of hypotheses regarding basal endogenous loss (BEL) of Ca and P and the use of microbial phytase in diets for pigs. In experiment 1, the hypothesis was that BEL of P from pigs fed a diet containing spray dried plasma, casein, or potato protein concentrate is not different from that of pigs fed a diet containing gelatin. Forty growing pigs (body weight: 19.34 kg; SD = 0.80) were allotted to four low-P diets using a completely randomized block design with two blocks of 20 pigs and five pigs per diet in each block. The diets were based on cornstarch and sucrose and were formulated to contain 20% gelatin, 20% spray dried plasma, 18.5% casein, or 20% potato protein concentrate as the only source of P in the diets. Results indicated that the BEL of P was greater (P < 0.001) in pigs fed diets containing spray dried plasma or potato protein concentrate compared with pigs fed diets containing gelatin or casein, but no differences in BEL of P were observed between pigs fed diets containing casein or gelatin. It was concluded that casein may be used as an alternative to gelatin to estimate BEL of P. In experiment 2, the hypothesis was that increasing dietary phytase reduces BEL of Ca and increases P balance in pigs. Seventy growing pigs (body weight: 17.66 kg; SD = 1.69) were allotted to seven Ca-free diets using a completely randomized block design with two blocks and five pigs per diet in each block. Experimental diets based on corn, potato protein concentrate, and full-fat rice bran were formulated. A positive control diet was formulated to contain P at the requirement for standardized total tract digestible (STTD) P and six negative control diets were formulated by reducing the provision of digestible P by 0.15% and adding 0, 250, 500, 1,000, 2,000, or 4,000 phytase units/kg of diet (FYT). Results indicated that BEL of Ca was not affected by dietary P, but exponentially decreased (P = 0.030) as phytase concentration increased in diets. The STTD of P exponentially increased (P < 0.001) as phytase level increased in diets, but because of the lack of Ca, P retention linearly decreased (P < 0.001) as phytase increased in diets. It was concluded that BEL of Ca decreased as dietary phytase increased demonstrating that endogenous Ca can be bound by phytate in the intestinal tract of pigs, but STTD of P increased as phytase level increased in the diets. In experiment 3, the hypothesis was that there are differences in the apparent total tract digestibility (ATTD) of Ca and in the response to microbial phytase among sources of Ca carbonate obtained from different parts of the world. Three hundred and twenty growing pigs (body weight: 17.47 kg; SD = 1.28) were allotted to 40 diets using a completely randomized block design with eight blocks of 40 pigs for a total of eight replicate pigs per diet. All experimental diets were based on corn and potato protein concentrate. Twenty sources of Ca carbonate were obtained from different regions of the world (i.e., Europe, United States, Asia, and South Africa), and each source was used in two diets, one diet without microbial phytase and one diet that contained 1,000 FYT. Results indicated that there were no interactions between source of Ca carbonate and phytase, or region and phytase. Differences in ATTD and STTD of Ca were observed among pigs fed diets containing different sources of Ca carbonate (P < 0.001) and pigs fed diets containing 1,000 FYT had greater (P < 0.001) ATTD and STTD of Ca compared with pigs fed diets containing no phytase. There was a tendency (P = 0.050) for pigs fed diets containing different sources of Ca carbonate to have different ATTD of P, but pigs fed diets containing 1,000 FYT had greater (P < 0.001) ATTD of P compared with pigs fed diets containing no phytase. The ATTD and STTD of Ca in Ca carbonate from the United States was less (P < 0.001) than in Ca carbonate from Europe, Asia, or South Africa. In conclusion, differences in ATTD and STTD of Ca were observed among Ca carbonate sources obtained from different regions of the word, and inclusion of microbial phytase increased the ATTD and STTD of Ca in the sources of Ca carbonate.

Graduation Semester

2023-05

Type of Resource

Thesis

Copyright and License Information

Copyright 2023 Megan Elizabeth Nelson

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