Date of Award

1991

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Animal Science (Animal, Dairy, and Poultry Sciences)

First Advisor

L. Lee Southern

Abstract

Six experiments were conducted to evaluate the effects of supplemental dietary tryptophan (TRP), picolinate (Pic), CrCl$\sb3\cdot$6H$\sb2$O, chromium picolinate (CrPic), or a combination of Pic and CrCl$\sb3\cdot$6H$\sb2$O on growth performance, liver mineral concentrations, insulin, growth hormone, organ weights, and serum and carcass traits of pigs. One experiment was conducted to evaluate the effect of chromium picolinate (CrPic) on serum cholesterol (CH), egg CH, egg quality, and egg production of laying hens. Dietary TRP, Pic, CrCl$\sb3\cdot$6H$\sb2$O, and a combination of Pic and CrCl$\sb3\cdot$6H$\sb2$O did not affect growth performance, liver mineral concentrations, insulin, growth hormone, and serum and carcass traits of pigs. The effects of CrPic on pig growth performance, growth hormone, and insulin were not consistent. Organ weights were not affected (P $>$.10) by CrPic. However, CrPic, when provided at the 100 or 200 ppb level of Cr, increased (P $<$.01) loin eye area and percentage of muscling, reduced (P $<$.01) 10th rib fat thickness, and reduced (P $<$.05) serum CH in growing-finishing pigs. Chromium was equally effective in pigs from the Louisiana State University Agricultural Center Swine Unit as well as pigs from a different ancestral source. The effects of graded levels of CrPic also were evaluated in laying hens. Egg CH, Haugh units, and specific gravity of eggs were not affected (P $>$.10) by CrPic supplementation. Egg crude protein and percentage of egg fat were inconsistently reduced (P $<$.10) by CrPic. However, egg production was increased (P $<$.04) and serum CH was reduced (P $<$.08) by CrPic, especially at 100 and 200 ppb Cr. Supplemental dietary CrPic increases muscling and decreases fat and serum CH in growing-finishing pigs. Laying hen egg production also is increased and serum CH is reduced by CrPic supplementation.

Pages

103

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