Purdue University Graduate School
Tobi Ogunribido dissertation (FINAL).pdf (3.41 MB)

Regulation of growth and nutrient digestibility by supplemental myo-inositol and luteolin in pigs and chickens

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posted on 2024-05-07, 18:34 authored by Tobi Zachariah OgunribidoTobi Zachariah Ogunribido

Newborn animals undergo a lot of early-life stress that heavily impact on their long-term growth, performance, and welfare. Typically, the stress would indirectly interfere with the capacity of these neonates to utilize dietary nutrients and consequently impact tissue growth and development. In piglets, weaning is a stressful situation characterized by disruption of intestinal epithelial cell development which causes poor digestion of solid feed and a negative impact on absorption of nutrients especially in the post-gastric region. In addition, weaning in piglets could cause an increase in cellular assault by reactive oxygen species thereby potentially causing gut leakiness and paracellular loss of nutrients along the intestinal tract. In broiler chickens, access to feed may take up to 72 h following hatching which may affect their gut development as well as their gut microbiota. After the first feed ingestion, there is a sharp increase in the gut microbiota which triggers an increase in the development of the immune system as well as the gut. There is continuous attention on the strategies and nutritional interventions to mitigate or ameliorate the adverse effects of early life stressors in these food animals, especially in broiler chickens and piglets. In the studies described in this dissertation, myo-inositol (purely supplemented or phytase-induced) and luteolin were tested as nutritional strategies to mitigate the effects of early-life stressors on growth and the potential mechanisms by which myo-inositol and luteolin regulate growth were investigated.

In study I, the effect of myo-inositol on growth in 128 postweaning piglets fed protein-deficient corn-soy diets was tested. There were 4 dietary treatments in a randomized complete block design with body weight as the blocking factor. The treatments consisted of 1 positive control (PC) diet formulated to meet all the nutrient requirements of the piglets with a 20% crude protein (CP); the remaining 3 diets were the negative control (NC) diets with a 3% reduction in CP, a 2 g/kg myo-inositol supplemented negative control diet (NC+INO), and phytase (3,000 FTU/kg) supplemented negative control (NC+PHY) diet. The results showed that phytase enhanced the apparent total tract digestibility (ATTD) of P in the weanling pigs. Myo-inositol supplementation in a protein-deficient diet improved (P < 0.05) porcine plasma myo-inositol concentration while an in vitro myo-inositol incubation with intestinal epithelial cells increased the expression of genes that encode for Claudin-1, Claudin-3, Claudin-4, ZO-1, NaPiIIb, GLUT2, and SLC7A2. The in vitro analysis of tight junction integrity in the IPEC-J2 cells indicated by the transepithelial electrical resistance and FITC-Dextran permeability showed an enhancement in response to myo-inositol treatment. Although the in vivo study found that myo-inositol did not improve growth performance or ATTD, the in vitro myo-inositol enhanced markers of gut health and function.

In study II, the effect of myo-inositol on the growth of broiler chickens was tested. In this study, there were 6 experimental treatments based on two dietary protein levels (PC and NC) and three supplement types (BASAL, INO, and PHY) resulting in a 2 x 3 factorial arrangement in a completely randomized design. A total of 384 broiler chickens comprising 6 treatments with eight replicates per treatment and 8 birds per replicate were used. The birds were fed a common starter diet for the initial 7 days after they arrived at the poultry unit followed by a 14-day trial. The protein-deficient diet decreased the feed efficiency of the birds. Phytase addition increased (P < 0.05) the apparent ileal digestibility (AID) and ATTD of P and Ca in both PC and NC groups. The jejunal gut morphology was enhanced by supplemental phytase as indicated by an increase in villus height and the ratio of the villus height-to-crypt depth, coupled with an increase in serum myo-inositol concentration caused by both myo-inositol and phytase. In conclusion, myo-inositol showed a differential influence on growth performance, nutrient digestibility, and gut morphology.

In study III, the effects of luteolin on weanling pigs and IPEC-J2 cells were examined. A total of 48 piglets were randomly allotted to two dietary treatments consisting of a control group and a luteolin (LUT)-supplemented dietary group for a 4-week trial. A weekly assessment of the growth performance and expression of specific proteins in the jejunal mucosa was performed. In each dietary group, 8 piglets were slaughtered at weeks 1, 2, and 4 postweaning to collect blood, jejunal and ileal mucosa, and tissues. Luteolin supplementation numerically improved the ADG and G:F of the pigs. Luteolin feeding altered the jejunal and ileal gut morphology with increased villi height (P < 0.05) and villus height-to-crypt depth ratio (VCR, P < 0.05) in the jejunum and decreased crypt depth in the ileum. The effect of luteolin on IPEC-J2 global proteome and phosphor-proteome showed that luteolin could potentially improve intestinal barrier integrity by enhancing the abundance of proteins important in cell growth and survival.

In summary, dietary supplementation with myo-inositol and luteolin could regulate growth and nutrient digestibility in broiler chickens and weanling pigs by enhancing the integrity of intestinal cells and facilitating the expression of nutrient transporters that are significant in the uptake of nutrients across the lining of the gastrointestinal tract. Phytase supplementation improves the P release from phytate in the diets thereby alleviating its loss.


Degree Type

  • Doctor of Philosophy


  • Animal Sciences

Campus location

  • West Lafayette

Advisor/Supervisor/Committee Chair

Dr. Kolapo M. Ajuwon

Additional Committee Member 2

Dr. Olayiwola Adeola

Additional Committee Member 3

Dr. Theresa M. Casey

Additional Committee Member 4

Dr. Kimberly K. Buhman

Additional Committee Member 5

Dr. John S. Radcliffe