INTERACTION OF ZINC OXIDE NANOPARTICLE SUPPLEMENTATION AND HAEMONCHUS CONTORTUS INFECTION ON THE RUMEN AND ABOMASUM MICROBIOTA IN SANTA INÊS LAMBS.

• Grant number: 24/18029-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: April 01, 2025
• End date: November 30, 2028
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Helder Louvandini
• Grantee: Brenda Luciana Alves da Silva
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 19/26042-8 - Nanoparticle of zinc oxide as a functional feed, AP.TEM

Abstract

The gastrointestinal microbiota plays an essential role in the health and development of ruminants, and changes in its composition can significantly impact the performance and well-being of these animals. Recent studies have shown that parasitic infections, such as those caused by Haemonchus contortus, are not only one of the main health challenges in sheep farming but can also alter the microbiota of ruminants. Supplementation with zinc oxide nanoparticles (ZnO-NP) has emerged as a promising strategy to modulate animal microbiota and mitigate the adverse effects of H. contortus infection, promoting gut health. This study aimed to evaluate the interaction between ZnO-NP supplementation and H. contortus infection on the rumen and abomasum microbiota of Santa Inês lambs, investigating how these interventions may alter the taxonomic and functional diversity of the rumen and abomasum microbiota. For this purpose, an experiment was conducted with 30 Santa Inês lambs, distributed in a 3x2 factorial design. The treatments consisted of three forms of supplementation (control, micrometric zinc oxide, and ZnO-NP) and two health conditions (animals infected and not artificially infected with H. contortus). The experiment lasted six months, with supplementation beginning at 60 days of age and infection starting at 90 days, when the lambs received 360 third-stage larvae (L3) of H. contortus weekly until the end of the experiment. Body weight was monitored, and blood and fecal samples were collected every 15 days until 8 months of age. Forty-five days after the first infection, 30 lambs (5 from each treatment) were placed in open-circuit chambers for 5 days for individual measurements of intake, apparent dry matter digestibility of the diet, short-chain fatty acid (SCFA) production, enteric methane (CH¿) emissions, and nitrogen use efficiency. At the end of the experiment, the animals were slaughtered, and rumen and abomasum content samples were collected immediately post-mortem, frozen in liquid nitrogen, and stored at -80ºC for future analyses. Rumen and abomasum DNA will be extracted using the QIAamp DNA Stool Mini Kit (Qiagen), and sequencing will be performed on the Illumina HiSeq 2500 platform (2x150). Subsequent bioinformatics analyses will identify the composition and functionality of the microbiota. Microbial taxonomic diversity will be evaluated using statistical and bioinformatics methods, allowing us to determine the impact of ZnO-NP and its interaction with H. contortus infection on microbiota modulation