Influence of genotype and maturity on microbiological diversity, chemical-fermentative characteristics and protein matrix of corn kernels for silage

• Grant number: 17/15934-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: September 01, 2017
• End date: April 30, 2019
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Pastures and Forage Crops
• Principal Investigator: Luiz Gustavo Nussio
• Grantee: Dannylo Oliveira de Sousa
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 14/06819-4 - Nutritive value and hygienic quality of corn silage and corn kernels under ensiling strategies, AP.TEM
• Associated scholarship(s): 18/07268-2 - Nutritional characteristics of grasses and legumes: effects of crop, variety and maturity stage at harvest, BE.EP.PD

Abstract

Ensiling of corn gain can be a worth and also economically viable strategy, once the starch digestibility is increased, resulting in greater animal performance and lower nutrient losses. Knowledge of the ensiling process can improve the efficiency of production, once the interactions of inter and intra microbial species can alter the fermentation end-products significantly, as well as mycotoxins that may be present in this process. The experimental design will be randomized block, with 2×3×5 factorial arrangement of treatments, two genotypes, three maturation stages, and five storage times, with four replications. The harvesting shall be defined according to the dry matter (DM) content of the whole plant or grain. Sealed mini bags will be used as experimental silos. Data will be submitted to analysis of variance and their means compared by orthogonal contrasts, using the GLM procedure of SAS. The variables measured more than once will be analyzed as repeated measures by the MIXED procedure of SAS. The mycotoxins quantification in the silages will be performed by high-performance liquid chromatography at the Laboratory of Mycotoxins Analysis (LAMIC). The microbiological diversity will be evaluated independently of culture by the technique of Denaturing Gradient Gel Electrophoresis (DGGE) and the PCR products from samples that exhibit changes in the community according to the studied variables will be submitted to the Illumina MiSeqTM system. The data obtained will be submitted to analysis of variance and the means compared by the Bonferroni-t test (P <0.01). For the profiles analysis of microbial communities, the programs Primer (PRIMER-E Ltd, Ivybridge, UK) and Canoco will be used. The effects of ensiling time and stage of maturity at harvest and interaction with the microbial community will be evaluated.