Chlorhexidine Nanoparticles: A New Molecule for Improving Microbiological Quality of Feed and Performance of Piglets in the Nursery Phase

• Grant number: 24/22402-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2025
• End date: February 28, 2026
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Cesar Augusto Pospissil Garbossa
• Grantee: Flávia Stievano de Souza Tavares
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

In response to the growing concern about antimicrobial resistance, alternatives are being sought, suchas new technological additives, to replace the use of antibiotics as growth promoters. Chlorhexidinenanoparticles have antimicrobial actions and effects, making them promising in animal production.However, there are no studies demonstrating the effects of chlorhexidine nanoparticles on themicrobiological quality of feed and the performance of pigs during challenging and stressful periods,such as post-weaning. Therefore, this study aims to evaluate the effects of adding chlorhexidinenanoparticles on the microbiological quality of feed and on productive performance, incidence ofdiarrhea and nutrient digestibility in piglets during the nursery phase. The experiment will beconducted at the Swine Research Laboratory at the University of São Paulo (LPS - USP), located inPirassununga, São Paulo. One hundred and twenty (120) piglets (barrows and gilts), weaned at anaverage age of 21 days, will be randomly allocated to one of five experimental treatments: T1 -negative control diet; T2 - positive control diet (with 120 ppm of halquinol); T3 - control diet withthe addition of 25 ppm of chlorhexidine nanoparticles; T4 - control diet with the addition of 50 ppmof chlorhexidine nanoparticles; and T5 - control diet with the addition of 75 ppm of chlorhexidinenanoparticles. The experimental design will be randomized blocks (initial weight and sex). Theexperimental unit will be the average of the animals in each pen (composed of three animals), totalingeight repetitions per treatment. Through individual weighing, control of the amount of feed providedand wasted, parameters related to the animal's performance (live weight, average daily weight gain,average daily feed intake, and average feed conversion) will be analyzed. Daily fecal scoring will beconducted in the pens to calculate the incidence of diarrhea. At the end of the experiment, fecalsamples will be collected to assess the digestibility of dry matter, mineral matter, crude protein, etherextract, calcium, and phosphorus. Samples of all feeds will be collected on the day of manufacturingand analyzed for the count of mesophilic aerobic bacteria, fungi and yeasts, Salmonella spp.,Escherichia coli and Enterobacteriaceae. It is expected that the inclusion of the new chlorhexidine nanoparticle molecule will improve the microbiological quality of the feeds (lower microbial growthin cultures) and result in better or equivalent productive performance to the positive control treatment (with antibiotics), without compromising intestinal health or the apparent digestibility of nutrients.