154 Evaluating the effects of prophylactic antibiotics on intestinal health in pigs given a corticotropin-releasing factor antagonist during weaning and transport

Abstract Prophylactic antibiotics improve intestinal health in pigs; however, it is unknown whether their efficacy interacts with a pig’s stress response following weaning and transport. The study objective was to determine whether a corticotropin-releasing factor (CRF) antagonist would impact the efficacy of prophylactic antibiotics on improving intestinal health in transported weaned pigs. Mixed-sex pigs (n = 56; 5.70 ± 1.05 kg BW) were weaned (20.49 ± 0.64 d), a blood sample was taken, pigs were given an i.p. injection of saline (SAL) or a CRF antagonist (CRFA; 30 µg/kg BW; Astressin B), and then were transported for 12 h. Pigs were given a second and third i.p. injection at 6 and 12 h of transport, respectively. Following transport, 4 SAL and 4 CRFA pigs were blood sampled and euthanized. The remaining 48 pigs were individually housed and assigned to an antibiotic [A; chlortetracycline (441 ppm) + tiamulin (38.6 ppm)] or no antibiotic (NA) diet treatment balanced by injection treatment (n = 12 pigs/treatment combination). Blood was collected at 12 h and on d 3, 7, and 14 and pigs were euthanized on d 7 (n = 24) and d 14 (n = 24) post-weaning and transport. Plasma adrenocorticotropic hormone was reduced overall (P = 0.05; 9.1%) in CRFA versus SAL pigs. On d 7, jejunal villus height was greater (P = 0.04; 33%) in A versus NA pigs. Jejunal zonula occludens-1 (58.8%) and ileal claudin-1 (100.5%) mRNA abundance tended to be increased (P = 0.09) in CRFA+NA versus SAL+NA pigs on d 7. On d 14, jejunal tumor necrosis factor-alpha mRNA abundance was reduced (P = 0.02; 29.9%) in A versus NA pigs and jejunal glucagon-like peptide-2 mRNA abundance was increased (P = 0.03) in CRFA+NA versus SAL+NA (48.4%) and SAL+A versus SAL+NA (55.8%) pigs. No intestinal health parameter differences were detected (P > 0.05) between CRFA+NA and SAL+A pigs. In conclusion, CRFA and A impacted weaned pig intestinal health measures at similar levels.

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Inhibition of central actions of cytokines on fever and thermogenesis by lipocortin-1 involves CRF

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1992.263.4.e632 ◽

1992 ◽

Vol 263 (4) ◽

pp. E632-E636 ◽

Cited By ~ 7

Author(s):

P. J. Strijbos ◽

A. J. Hardwick ◽

J. K. Relton ◽

F. Carey ◽

N. J. Rothwell

Keyword(s):

Tumor Necrosis ◽

Corticotropin Releasing Factor ◽

Tnf Alpha ◽

Eicosanoid Synthesis ◽

Necrosis Factor Alpha ◽

Recombinant Fragment ◽

Factor Alpha ◽

Central Actions ◽

Colonic Temperature ◽

Necrosis Factor

In the present studies, the mechanisms underlying the inhibitory actions of lipocortin-1 on the pyrogenic and thermogenic properties of cytokines were investigated. Central (icv) injection of corticotropin-releasing factor (CRF, 4.7 micrograms) or the recombinant cytokines interleukin (IL)-1 alpha (50 ng), IL-1 beta (5 ng), IL-6 (20 ng), IL-8 (20 ng), or tumor necrosis factor-alpha (TNF-alpha, 1 microgram) in conscious rats produced significant increases in resting oxygen consumption (VO2, 13-26%) and colonic temperature (0.7-1.6 degrees C) within 2 h postinjection. Administration (icv) of a recombinant fragment (NH2-terminus, 1-188 amino acids) of human lipocortin-1 (1.2 micrograms) produced small increases in VO2 (< 5%) and body temperature (< 0.3 degrees C). Pretreatment (-5 min) with lipocortin-1 significantly attenuated the thermogenic and pyrogenic effects of centrally injected IL-1 beta (80% inhibition), IL-6 (60%), IL-8 (80%), or CRF (60%). However, pretreatment with lipocortin-1 failed to modify the actions of IL-1 alpha or TNF-alpha. We have previously demonstrated that the pyrogenic and thermogenic effects of IL-1 beta, IL-6, and IL-8 are dependent on the central actions of CRF, whereas IL-1 alpha and TNF-alpha act independently of CRF. Fever and thermogenesis induced by all of these cytokines (with the exception of IL-8) can also be prevented by administration of a cyclooxygenase inhibitor. The data presented here suggest that the potent antipyretic effects of lipocortin-1 may result from inhibition of the release or actions of CRF rather than modulation of eicosanoid synthesis.

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Replacing dietary antibiotics with 0.20% L-glutamine in swine nursery diets: impact on intestinal physiology and the microbiome following weaning and transport

Journal of Animal Science ◽

10.1093/jas/skab091 ◽

2021 ◽

Author(s):

Alan W Duttlinger ◽

Ruth E Centeno Martinez ◽

Betty R McConn ◽

Kouassi R Kpodo ◽

Donald C Lay ◽

...

Keyword(s):

Dietary Treatment ◽

Mrna Abundance ◽

Production Environment ◽

Necrosis Factor Alpha ◽

Study Objective ◽

Microbiome Composition ◽

Intestinal Physiology ◽

Factor Alpha ◽

Two Phases ◽

Dietary Treatments

Abstract Previous research demonstrates that supplementing 0.20% L-glutamine (GLN) in the diets of newly weaned and transported pigs improves growth rate to a similar extent as providing dietary antibiotics (AB). However, research comparing the effects of GLN versus AB on intestinal physiology and the microbiome is limited. Therefore, the study objective was to compare the effects of supplementing nursery diets with GLN, AB, or no dietary antibiotics (NA) on intestinal physiology and the microbiome of pigs in a production environment following weaning and transport. Mixed sex piglets (N=480; 5.62 ± 0.06 kg BW) were weaned (18.4 ± 0.2 d of age) and transported for 12 hr in central Indiana, for two replicates, during the summer of 2016 and the spring of 2017. Pens were blocked by BW and allotted to 1 of 3 dietary treatments [n = 10 pens/dietary treatment/replicate (8 pigs/pen)]; AB [chlortetracycline (441 ppm) + tiamulin (38.6 ppm)], GLN (0.20% as-fed) or NA fed for 14 d. From d 14 to 34, pigs were fed common AB free diets in two phases. On d 33, villus height:crypt depth tended to be increased (P = 0.07; 7.0%) in GLN and AB pigs vs. NA pigs. On d 33, glucagon-like peptide 2 (GLP-2) mRNA abundance was decreased (P = 0.01; 50.3%) in GLN and NA pigs vs. AB pigs. Crypt depth was increased overall on d 33 (P = 0.01; 16.2%) during the spring replicate compared to the summer replicate. Villus height:crypt depth was reduced (P = 0.01; 9.6%) during the spring replicate compared to the summer replicate on d 33. On d 13, tumor necrosis factor alpha and occludin mRNA abundance was increased (P ≤ 0.04; 45.9% and 106.5%, respectively) and zonula occludens 1 mRNA abundance tended to be greater (P = 0.10; 19.2%) in the spring replicate compared to the summer replicate. In addition, AB pigs had increased (P = 0.01; 101.3%) GLP-2 gene expression compared to GLN and NA pigs. Microbiome analysis indicated that on d 13, dietary treatment altered the microbiota community structure (P = 0.03). Specifically, the AB pigs tended to be distinct from both the NA and GLN pigs (P = 0.08), and Lactobacillus was increased nearly 2-fold in AB compared to NA pigs (q = 0.04) and GLN pigs (q = 0.22). In conclusion, GLN supplementation tended to improve some morphological markers of intestinal health similarly to AB pigs while the microbiome composition in GLN pigs was more similar to NA pigs than AB pigs.

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