Performing Department
Veterinary Physiology & Pharmacology
Non Technical Summary
In the swine industry, antibiotic supplementation of feed for post-weanling piglets has been used to ensure piglet health and growth. However, such supplementation may be linked to the development of antibiotic resistant bacterial strains. Therefore, there has been much interest in the development of animal feed supplements designed to maintain immune function and growth in the absence of antibiotic feed additives. Although probiotics have been explored as an alternative to antibiotic supplementation in pigs due to their modulation of the immune system, they have not been found to help maintain good growth gains in young pigs.This research aims to examine the suitability of coconut oil supplementation of post-weanling piglet diets as a substitute for antibiotic supplementation in these diets. Coconut oil is comprised of 91% saturated fatty acids and has been explored as a potential dietary component to modulate cholesterol and high density lipoprotein in humans. Coconut oil also may improve insulin sensitivity. In addition to modulation of metabolism, fatty acids are key to membrane structure and function. Current human parenteral nutrition guidelines favor the inclusion of medium chain fatty acids, like coconut oil, for the ease with which they are broken down and their anti-inflammatory properties.We propose that coconut oil may provide a safe, effective alternative method to antibiotic feed supplementation that will maintain, and perhaps, improve post-weanling piglet health and growth without dramatically changing carcass quality. This research is of benefit to piglet health, because if coconut oil is found to be a suitable or superior replacement for swine feed antibiotics, the health, productivity, and immune function of post-weanling piglets will be enhanced, thereby improving the welfare of the Nation's food supply. Furthermore, if coconut oil supplementation significantly alters the fatty acid composition and adipose tissue metabolism in swine, it may improve the health of humans who consume this meat.
Animal Health Component
100%
Research Effort Categories
Basic
20%
Applied
80%
Developmental
0%
Goals / Objectives
The long-term goal of this research program is to determine the performance of alternatives to antibiotic feed supplementation for support of the health and growth of post-weanling pigs. The short-term goal of this research project is to determine the efficacy of virgin coconut oil feed supplementation as compared with antibiotic feed supplementation for the support of health and growth of post-weanling pigs. The specific objective of this application is to determine whether virgin coconut oil feed supplementation will yield similar or improved growth performance, immune function, and metabolism compared with antibiotic feed supplementation in post-weanling pigs. We have formulated these goals and objectives based on increasing pressures in the production animal industry to find alternative growth and health promoters to antibiotics and based on our preliminary data in the Ossabaw mini-pig.
Project Methods
To test our central hypothesis that supplementation of post-weanling piglet diets with virgin coconut oil will yield growth performance and immune function parameters in piglets as good as or better than those found in piglets fed an antibiotic-containing diet, will favor the production of "good" cholesterol, and will improve glucose homeostasis, we propose the following Specific Aim: SPECIFIC AIM 1. IDENTIFY THE EFFECTS OF VIRGIN COCONUT OIL FEED SUPPLEMENTATION ON GROWTH PERFORMANCE, IMMUNE FUNCTION, AND METABOLISM IN POST-WEANLING PIGS. Our working hypothesis is that a diet containing virgin coconut oil, and no antibiotics, will improve growth performance and immune function, will favor production of cholesterol and HDL, and will yield tighter glucose regulation. Specifically, we will test how the replacement of antibiotics with virgin coconut oil in post-weanling piglet diets will effect: 1) fecal bacterial diversity, serum cytokine profile, and Th17/Treg populations in the periphery and GALT (gastrointestinal associated lymphoid tissue); 2) incidence of scours and overall health; 3) weight gain, feed intake, and feed conversion; 4) glucose, insulin, low density lipoprotein (LDL), HDL, triglycerides, and cholesterol; free fatty acids in circulation, adipose tissue and skeletal muscle; and NAPDH enzyme function in adipose tissue.Specific Aim 1.1: Do post-weanling piglets fed a diet containing virgin coconut oil and no antibiotics have increased fecal bacterial diversity, an anti-inflammatory cytokine profile, and altered peripheral and GALT populations of Th17/Tregs? Experimental Design: These experiments will determine, in comparison with antibiotics, the effects of virgin coconut oil on immune function in post-weanling piglets. At the beginning of the study, piglets will be weaned on ~ D 21 of age, placed in nursery pens of 10 pigs (5 females, 5 males) per treatment group, and immediately placed on diet trial (Fig. 3). We will run the entire 50 day study will run in duplicate to achieve n=20 piglets per diet treatment group and two technical replicates (pen, n=2). Diet treatments will consist of: 1) (+) control: soybean meal, cornmeal, 2% soybean oil, antibiotics; 2) (-) control: soybean meal, cornmeal, 2% soybean oil; 3) coconut oil: soybean meal, cornmeal, 2% coconut oil, 0.25% flax oil. The flax oil will be added to the experimental coconut oil diet, because coconut oil is extremely low in a-linoleic acid (18:3n-3), which is essential for adequate growth. We will complete a dietary analysis for each diet treatment. Pigs will be fed 2 lb/head/day of feed during the nursery phase and 3.5 lb/head/day of feed during grower phase. Piglets will have fasting blood and fecal samples collected prior to beginning the diet treatments (ie, on D 25), at D 40 of age, and at D 70 of age (euthanasia; Fig. 3). At euthanasia, intestine, skeletal muscle (longissimus muscle), visceral adipose tissue, and subcutaneous adipose tissue (back fat) will be collected. Animal experimental procedures are pending approval by the Texas A&M University Institutional Animal Care and Use Committee (IACUC Number 2015-0385).Specific Aim 1.2: Do post-weanling piglets fed a diet containing virgin coconut oil and no antibiotics have a decreased rate of scours and better overall health?Experimental Design & Assessments: We will collect twice daily assessments for signs of illness (lethargy, anorexia, fever). Piglets that are lethargic or anorexic will have their rectal temperatures taken. A piglet will be defined as "ill" if it has had a decreased feed intake or lethargy for 2 or more days. A piglet will be classified as febrile if it has had a rectal temperature above 103.0 °F for 2 or more days. Daily diarrhea scores will be taken on each pen using the following rubric: 0=none; 1=semi-solid feces, no blood, 2= watery, no blood, 3=profuse diarrhea +/- blood. All health parameters and scours records will be collected in a treatment-blinded manner. Plasma samples collected at D 25, D 40, and D 70 will be run for a complete blood count at the Texas Veterinary Medical Diagnostic Lab. We expect piglets fed the coconut oil diet will have similar or improved rate of scours and overall health compared to piglets fed the (+) control diet and a lower rate of scours and better overall health compared to piglets fed the (-) control diet.Specific Aim 1.3: Do post-weanling piglets fed a diet containing virgin coconut oil and no antibiotics have increased weight gain, feed intake, and feed conversion? Experimental Design & Assessments: We will collect daily feed intake per pen on an as-fed basis as the difference in the weight of the feed in the troughs before and after feeding for each pen. We will divide this weight by the number of piglets per pen to get the daily feed intake per piglet per day. Piglets will be weighed weekly throughout the trial. We will utilize these parameters to calculate average daily gain (ADG), average daily feed intake (ADFI), and the feed conversion ratio (G:F). We expect piglets fed the coconut oil diet will have similar or greater ADG, ADFI, and G:F compared to piglets fed the (+) control diet and a greater ADG, ADFI, and G:F compared to piglets fed the (-) control diet.Specific Aim 1.4: Do post-weanling piglets fed a diet containing virgin coconut oil and no antibiotics have altered circulating fatty acids and lipids, altered adipose tissue fatty acid and lipid metabolism, and improved systemic glucose control?Experimental Design: We will collect fasting blood samples (serum and EDTA plasma) on D 25, D 40, and D 70 for analysis of fatty acids, lipids, insulin, and glucose. At euthanasia on D 70, we will collect skeletal muscle (longissimus muscle), visceral fat, and subcutaneous fat (back fat) for assessment of lipid and fatty acid content and NADPH enzyme activities. All tissues will be snap frozen upon collection and stored at -80 °C until analysis.Statistical Analyses: A power analysis with α=0.05, effect size (δ)=1.0 for 3 treatments indicates a sample size of 20 piglets is sufficient for a power of 0.79. Data will be assessed for normality, non-normal data will be transformed, and data will be analyzed by ANOVA with ad-hoc contrasts (SAS, Inc). The level of significance will be α=0.05.