The impact of specialty protein ingredients on the growth performance and health of nursery pigs

Abstract

The pork industry is interested in feed additives, such as specialty protein ingredients, that can be fed to pigs in order to help mitigate the effects of weaning on pig performance and gastrointestinal tract (GIT) health and function. Functional specialty proteins, such as spray-dried plasma protein (SDPP) and hyperimmunized dried egg protein (DEP), have been identified as potential alternatives to dietary antibiotics due to their biologically active components (such as immunoglobulins) that can aid in pathogen inhibition in the GIT. However, the industry’s understanding of these protein’s mode of action and their impact in commercial environments is lacking. Reducing the inclusion of soybean meal (SBM), which contains anti-nutritional factors, in early nursery diets has been identified as a way to mitigate the effect of weaning stress in pigs. Enzymatically-treated SBM (ESBM) has reduced anti-nutritional factor concentrations and improved nutrient digestibility compared to SBM, but this ingredient has yielded inconsistent results in performance studies. Further, there is a lack of research investigating this ingredient’s mode of action, so its true value to producers is unknown. Therefore, the primary objective of the research reported in this thesis was to investigate the impact of specialty protein ingredients on nursery pig performance and specific markers of GIT health and function. In order to achieve these objectives, two experiments were conducted with the specific objectives to 1) compare under commercial conditions the effects of including SDPP or DEP in the diet, with or without subtherapeutic levels of antibiotics in the phase 1 and 2 nursery diets, on growth performance and markers of intestinal physiology and function (experiment 1), and 2) determine the impact of diets in which ESBM replaced increasing amounts of SBM on growth performance, intestinal structure and barrier integrity, inflammation, and oxidative status in newly weaned pigs (experiment 2). In experiment 1, (Chapter 2) the inclusion of either SDPP or DEP in the diet improved the growth rate and feed intake of weaned pigs when antibiotic-free diets were fed during phases 1 and 2. However, when antibiotic-positive diets were fed, the inclusion of SDPP or DEP failed to alter the growth performance of the pigs compared to that of the SBM control. Due to the low dietary inclusion of DEP versus SDPP (0.2% or 3% in phase 1; 0.1% or 2% in phase 2), feeding DEP was a cost-effective method to improve performance in the antibiotic-free diets. The pigs fed the SDPP and