Evaluation of leukogram and immunological parameters of piglets in the nursery phase challenged with Escherichia coli lipopolysaccharide (LPS)

• Grant number: 24/07912-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2024
• End date: March 31, 2025
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal Investigator: Marcos Livio Panhoza Tse
• Grantee: Gabriela Lorenzini
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Escherichia coli (E. coli) is one of the main bacteria that causes diarrhea after weaning in piglets. To simulate sanitary challenged conditions in the field and its consequences for the immunologic system of the animals, Lipopolysaccharide (LPS) from E. coli is used in experimental conditions. However, the doses used and the responses in animals vary greatly. Thus, the present study aims to evaluate the effects of intramuscular LPS from E.coli in increasing levels to identify the best (effective) dose able to provoke effects on rectal temperature, blood leukometric and immunological parameters. Thirty-two weaned piglets (21 days) distributed in a randomized block design (weight), with four treatments, eight replications and one animal per pen (experimental unit), with the following treatments: 0LPS = intramuscular application of 0µg/ kg body weight (saline solution); 33LPS = intramuscular application of 33µg/kg of body weight; 66LPS = intramuscular application of 66µg/kg of body weight; 99LPS = intramuscular application of 99µg/kg of body weight. The animals during the whole experimental period (14 days) will receive only one isonutritive diet (ad libitum). The first six days of the experiment will be used to adapt the animals to the facilities and diet. On the seventh day of the experiment, the animals will receive an intramuscular injection of LPS from E.coli serotype 055:B5 for measurement (before and three hours after LPS application) of rectal temperature (ºC) and determination of glucose, leukocytes, lymphocytes, neutrophils, eosinophils, monocytes, Tumor Necrosis Factor TNF-± and acute phase proteins (total protein and albumin) in the blood.