Exploring Gut Development, Function & Nutrition in Pigs

Sheila Jacobi, PhD

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Outline • Growth & Factors Affecting Productivity

• Gut Development • Why it is important

• Factors impacting development

• Postnatal digestive development

• Impact of weaning • Gut health

• Nutritional interventions

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Factors affecting growth/productivity • Genetics/performance capabilities

• Reproduction

• Housing/Environment

• Management

• Mortality/Health

• Nutrition • Feed efficiency → the amount of feed necessary to produce a pound of live weight

gain

Growth “The progressive net accretion of nutrients and their metabolites, which begins at conception and continues as long as nutrient supply exceeds requirements for the oxidative metabolism and regeneration of existing tissues” – Bell et al. 1987 JAS(Supl. 2):186-212.

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The Organ That Controls Nutrient Supply & Why Gut Health is Important The Gut – A Major Metabolic Organ

Gut is 5-7% of body mass but accounts for: • 20-35% of whole body energy expenditure • 20-60% utilization of dietary amino acids

• Gut health is a requirement to ensure feed digestibility,

achieve the optimal intake and realize optimal growth during all phase of pork production

• Optimal digestion and absorption of feed • Absence of gastrointestinal tract illness • ‘Homeostatic’ GI microbiome • Ideal immune status (The gut is largest immune organ) • A state of animal well-being

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GI Tract Transition at Birth

Sangild et al., 2012

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Mother’s Milk Orchestrate GI Development

Bioactive components in mother’s milk

Donovan and Comstock, Ann Nutr Metab 2016;69(suppl 2):42–51

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Factors affecting nutrient “availability” • Digestibility • Absorption of end product of digestion • Metabolism of absorbed products

• Digestibility – probably the most important factor in the

efficiency of feed utilization • Inherent feature of feedstuffs to a large extent

• Absorption and utilization – usually not a major problem but is influenced by the pig (e.g. age, sex, physiological state/health of the gut)

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The post-weaning reality

Weaning-related stressors

Post-weaning starvation

Intestinal integrity Nutrient absorption

Pathogen proliferation Diarrhea

• Dietary changes • Environment • Social interactions

• 45% of weaned pigs no contact with feed in first 15 h • 10% remain with the problem for over 40 h

• Growth depression • Morbidity • Mortality

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Postnatal Digestive Development • Rapid transition in digestive function

• Qualitative and quantitative alterations in digestive enzyme secretion occur

• Dietary intake of substrate influences enzyme expression • Alteration in intestinal architecture

Pluske JASB 2013. 4:1

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Post-weaning Changes in the Small Intestine of pigs Weaned at 21 days

Lalles et al. Anim. Res. 53 (2004) 301–316

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Gut Carbohydrase Development

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1 7 14 30

Enzy

me

Activ

ity

(um

ol/m

in/g

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tein

)

Age (d)

Lactase Maltase

Egorova et al. 2001; Ch 13 in Digestive Physiology Of Pigs

Sucrase follows similar development as maltase

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Ontogeny of Lipases

Jensen et al. JAS 1997. 75:437

Pre-weaning Post-weaning

Decrease at weaning

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Ontogeny of Pancreatic Enzymes in the Piglet

Jensen et al. JAS 1997. 75:437

Weaning

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Bacterial Diversity in the GI tract • Approximately 800 species found in the swine gut (Looft et

al 2012). • In humans, bacterial cells are estimated to outnumber the host cells

by a factor of ten, and bacterial genes outnumber host genes by a factor of 100 (Savage 1977).

Frese et al. Microbiome (2015) 3:28

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Why Gut Health is Important

The Gut – A Major Metabolic Organ Gut is 5-7% of body mass but accounts for:

• 20-35% of whole body energy expenditure • 20-60% utilization of dietary amino acids

• Gut health is a requirement to ensure feed digestibility,

achieve the optimal intake and realize optimal growth during all phase of pork production

• Optimal digestion and absorption of feed • Absence of gastrointestinal tract illness • ‘Homeostatic’ GI microbiome • Ideal immune status (The gut is largest immune organ) • A state of animal well-being

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Gut Barrier Function

Groschwitz et al. J Allergy Clin Immunol 2009;124:3-20.

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Factors Impacting Gut Barrier

Moeser and Blikslager, JAVMA, Vol 231, No. 1, July 1, 2007

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Weaning Negatively Impacts GI Health • Weaning presents simultaneous stressors on

young pigs • Nutritional • Environmental • Psychological

• Post-weaning “growth check” is correlated with changes in gut health.

• The goal at weaning is to reduce the negative impact weaning has on production, disease, morbidity and mortality.

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Feed intake is one of main factors affecting gut barrier function

Adapted from Wijtten et al., 2011

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Minimal Feed Intake After Weaning Compromises Gut Barrier Function • Period of temporary starvation after weaning

• Reduce intestinal surface area • Increases intestinal inflammation

4 days post weaning

Moeser et al. Res. Vet Sci 2012. 93:975

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Weaning Compromises Barrier Function

Moeser et al. Res. Vet Sci 2012. 93:975

High TER; intact epithelial barrier Low TER; more permeable epithelial barrier

High Flux Rate; more permeable epithelial barrier Low Flux Rate; intact epithelial barrier

22 Pluske, JASB 2013, 4:1

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Prebiotics* Yeast cell wall derivatives • Oligosaccharide derive from yeast cell wall • Increases pig ADG & ADFI of weanling pigs (Miguel et al., 2004) • Mechanism of action: modification microbiota, anti-adhesive function and inhibition of immune system activation

How does it help with production cost? • Animals remain on feed so they continue to grow • Microbes extract energy from the prebiotic function that can be used in energy maintenance of GI tract in SCFA • Reduces activation of mucosal immune system

*Prebiotics are selectively fermented nondigestible ingredients that allow specific changes in both the luminal microbial population and their activity to promote intestinal health by being fermented to SCFA

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Formula PDX Supplementation Linearly Increases Colon Lactic Acid and Reduces pH

Herfel et al.,2011 J. Nutr. 141: 2139

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.6

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6.0

6.1

6.2

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0 1.7 4.3 8.5 17

Col

on la

ctic

aci

d,

umol

/g w

et d

iges

ta

Col

on p

H

Formula PDX, g/L

lactic acid

pH

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Prebiotics Modulate Microbiome (Jacobi et al. unpublished data)

Control

Prebiotic 1 Prebiotic 2 Combined

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Probiotic Summary

Pate

l et a

l. L

ive.

Res

. Int

er.,

2015

. 3(2

):31

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Probiotics Cont.

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Bioactive Amino Acids & Gut Health

Lalles et al. Animal 2009. 3(12):1625

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Role of Nutrients on Gut Health

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Trace minerals

Essential oils

Organic acids Probiotics

Peptides

Bacteriophages

Enzymes Immunoglobulins

31 Trust the gut, beat stressful weaning lags. National Hog Farmer, Feb. 2016

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Questions

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Antibiotics Shifts GI Populations