Use of Microorganisms as Nutritional and Functional Feedstuffs for Nursery Pigs and Broilers

Abstract

The objectives of this review paper are to introduce the structures and composition of various microorganisms, to show some applications of single cells as alternative protein supplements or energy feeds in swine and poultry diets, and to discuss the functional effects of microorganisms as feed additives on the growth performance and intestinal health of nursery pigs and broilers. Microorganisms, including bacteria, yeasts, and microalgae, have been commonly supplemented in animal diets because they are cost-effective, stable, and have quantitative production that provides nutritional and functional benefits to pigs and broilers. Microorganisms could be alternative antibiotics to enhance intestinal health due to bioactive components from cell wall components, which interact with receptors on epithelial and immune cells. In addition, bioactive components could be digested by intestinal microbiota to produce short-chain fatty acids and enhance energy utilization. Otherwise, microorganisms such as single-cell protein (SCP) and single-cell oils (SCOs) are sustainable and economic choices to replace conventional protein supplements and energy feeds. Supplementing microorganisms as feedstuffs and feed additives improved the average daily gain by 1.83%, the daily feed intake by 0.24%, and the feed efficiency by 1.46% in pigs and broilers. Based on the properties of each microorganism, traditional protein supplements, energy feeds, and functional feed additives could be replaced by microorganisms, which have shown benefits to animal’s growth and health. Therefore, specific microorganisms could be promising alternatives as nutritional and functional feedstuffs in animal diets.

Saccharomyces yeast postbiotics supplemented in feeds for sows and growing pigs for its impact on growth performance of offspring and growing pigs in commercial farm environments

“…Yeast cell wall components have also been used in nursery diets for their prebiotic effects, antibacterial properties, and toxin binding property [ 18 – 20 , 51 ]. A thorough review of bioactive compounds in microbial cell wall [ 52 ] characterized the composition of typical yeast cell wall including mannoprotein (35% to 40%), 1,3-β-glucan (50% to 55%), 1,6-β-glucan (5% to 10%), chitin (up to 3%) with immunomodulatory properties, antibacterial properties potentially beneficial to maintain healthy intestine and to reduce the occurrence of diarrhea as observed in this study. Yeast cell contents, however, are shown to be a good source of protein and also rich in nucleotides improving intestinal health when fed to nursery pigs reducing pathogenic invasion [ 21 , 53 , 54 ].…”

Intestinal Damages by F18+ Escherichia coli and Its Amelioration with an Antibacterial Bacitracin Fed to Nursery Pigs

“…Gram-positive bacteria are the main target for bacitracin due to the thicker peptidoglycan layer [35,36]. However, Gram-negative bacteria also contain peptidoglycan on the cell wall [37]. Xu et al [7] demonstrated that bacitracin can mitigate the effects of PWD caused by F18 + E. coli in nursery pigs.…”

Amino Acid Digestibility of Different Formulations of Torula Yeast in an In Vitro Porcine Gastrointestinal Digestion Model and Their Protective Effects on Barrier Function and Inflammation in a Caco-2/THP1Co-Culture Model

“…Active dry yeast is the most common form of yeast supply in feed, but it can also be provided inactivated or fractionated, though at increased production costs. When administered live, yeast can act as a probiotic, improving gut health and growth performance [ 23 ]. Moreover, yeast biomass is a good source of macroelements such as calcium, phosphorus, and zinc, micronutrients such as selenium, and chromium or B-complex vitamins [ 24 ].…”