Banca de DEFESA: MARCO AURÉLIO GALLINA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MARCO AURÉLIO GALLINA
DATE: 17/07/2023
TIME: 08:30
LOCAL: Web Conferência - Google Meet: https://meet.google.com/psm-hmcc-mdc?hs=224
TITLE:

Reduction of antimicrobial use in the control of swine proliferative enteritis through an intramuscular vaccine against Lawsonia intracellularis

KEY WORDS:

Antibiotic; Ileitis; Bacterial resistance; One health; Vaccine

PAGES: 45
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUMMARY:

Enteric diseases in swine production, such as proliferative enteritis, are prophylactically treated through the addition of subtherapeutic dosages of antimicrobials in animal feed. The use of antimicrobials on a large scale, however, contributes to the emergence of multiresistant bacteria. In this sense, the vaccination procedure can be an important measure to prevent proliferative enteritis in pigs, potentially contributing to reducing the use of antimicrobials in animal production and, consequently, promoting the one health principle. The aim of this study was, therefore, to evaluate the intramuscular vaccination for Lawsonia intracellularis as a strategy to abolish the use of antimicrobials against this agent in the feed throughout the nursery, growth, and finishing phases. A total of 900 male piglets, weaned at ~28 d-old, were selected and individually weighed. According to their weight, animals were assigned to three different treatments: T1: Medicated and non-vaccinated (piglets non-vaccinated for L. intracellularis receiving feed with antimicrobials anti-L. intracellularis); T2: Medicated and vaccinated (piglets vaccinated for L. intracellularis receiving feed with antimicrobials anti-L. intracellularis); T3: Vaccinated and non-medicated (piglets vaccinated for L. intracellularis receiving feed free of antimicrobials anti-L. intracellularis). The intramuscular vaccination was carried out on the second day of nursery housing using the Porcilis ileitis® (MSD Saúde Animal). The piglets were monitored throughout the nursery (n=900) and growth and finishing (n=792) phases, and subgroups of each treatment (n=30) were evaluated concerning the serum concentration of IgG anti-L. intracellularis (at 29, 49, 65, 98, 128, and 175 d-old) and the fecal excretion of L. intracellularis (qPCR; at 49, 65, 98, 128, and 175 d-old). Moreover, variables such as average daily weight gain (ADG), feed conversion (FC), drug intervention occurrence, antimicrobials consumption and cost, and mortality, were assessed. At slaughter, the pneumonia and pleurisy index (PPI) was registered. No difference in the fecal excretion of L. intracellularis was observed and, as expected, groups T2 and T3 had a higher percentage of seroconversion. The ADG value from group T3 over the nursery phase was lower (350.1 g) compared to the other groups (T1: 387.5 g and T2: 385.0 g; P<0.01), but no differences were found in the growth and finishing phase (P=0.37). The FC did not differ among the treatments during the nursery (P=0,56) or growth and finishing phases (P=0.23). The percentage of piglets medicated as well as the mortality in both phases did not differ among treatments (P≥0.13). In group T3, the consumption and cost of antimicrobials anti-L. intracellularis over the nursery, growth and finishing phases were 70% lower compared to groups T1 and T2. Regarding the PPI, all the groups showed pneumonia, however, with no significant risk to the herd (index from 0.56 to 0.89). Therefore, it is possible to conclude that intramuscular vaccination for L. intracellularis can be considered an effective and potential strategy to replace the prophylactic use of antimicrobials in swine production, with no impairment to animal health or performance.

COMMITTEE MEMBERS:
Externo à Instituição - RAFAEL FRANDOLOSO - UPF
Presidente - ***.081.370-** - JALUSA DEON KICH - EMBRAPA
Externo à Instituição - JOSÉ PAULO HIROJI SATO