Theses and Dissertations
Advisor
Liao, Shengfa
Committee Member
Rude, Brian
Committee Member
Jean, Feugang
Committee Member
Musser, Madhurima
Committee Member
Fan, Peixin
Date of Degree
8-7-2025
Original embargo terms
Embargo 2 years
Document Type
Dissertation - Open Access
Major
Agricultural Sciences
Degree Name
Doctor of Philosophy (Ph.D.)
College
College of Agriculture and Life Sciences
Department
Department of Animal and Dairy Sciences
Abstract
The main objectives were to compare the effects of dietary supplementation of DL-methionine (DL-Met) and DL-methionine hydroxyl analogue (MHA-Ca) on the growth performance, blood and liver redox status, intestinal morphology, integrity, and immunity, and the intestinal luminal microbiota profile in growing pigs challenged with diquat injection. Forty barrows (average BW 21.5 ± 2.50 kg) were used in two feeding trials. In each trial, 20 pigs were randomly assigned to four treatment groups: Groups 1 and 2 received a basal diet, Group 3 received a DL-Met supplemented diet, while Group 4 received an MHA-Ca supplemented diet. Both DL-Met and MHA-Ca were supplemented at an equivalent level. After three weeks of feeding (Phase 1), pigs in Groups 2, 3 and 4 were injected with diquat (10 mg/kg BW), while those in Group 1 received only saline. All pigs continued their assigned diets for one more week (Phase 2). The growth performance parameters (BW, ADG, ADFI, and G: F) were measured for Phases 1 and 2 alongside the blood collection. After Phase 2, pigs were euthanized, and liver, intestinal tissues and digesta samples were collected for laboratory analyses. Results showed that DL-Met and MHA-Ca produced similar (P > 0.10) growth performance and antioxidant status in blood and liver. Pigs fed MHA-Ca exhibited shorter (P = 0.01) ileal villus width and greater (P < 0.05) ileal expression of pro-inflammatory cytokines IL-6 and TNF-α compared to those fed DL-Met. Luminal microbial analyses revealed lower alpha diversity (1.34 ± 0.12 vs. 1.91 ± 0.12; P = 0.006) and reduced abundance of Clostridium bornimense and Clostridium butyricum in the ileum of pigs fed MHA-Ca. Conversely, both forms of the Met supplements promoted enrichment of beneficial bacterial species in the colon. In conclusion: (1) DL-Met and MHA-Ca had comparable effects on growth performance and blood and liver antioxidant status; (2) MHA-Ca showed lower efficacy in supporting small intestinal morphology and modulating intestinal immune responses; (3) DL-Met increased the relative abundance of certain beneficial bacterial species in the ileum relative to MHA-Ca supplement; and (4) both supplements contributed similarly to the enrichment of beneficial bacterial species in the colon. Key words: methionine, redox status, intestinal morphology, intestinal integrity, intestinal immunity, intestinal microbiota, growth performance, growing pigs
Recommended Citation
Oladejo, Emmanuel Oluwaramipada, "Evaluation of the effects of dietary DL-methionine and DL-methionine hydroxyl analogue supplementation on growing pigs challenged with diquat injection" (2025). Theses and Dissertations. 6684.
https://scholarsjunction.msstate.edu/td/6684
