Effect of chromium propionate for pregnant ewes fed at different nutritional levels on the proteomic characterization of offspring meat

• Grant number: 24/16360-0
• Support Opportunities: Scholarships in Brazil - Support Program for Fixating Young Doctors
• Start date: November 01, 2024
• End date: October 31, 2025
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Sarita Bonagurio Gallo
• Grantee: Helena Viel Alves Bezerra
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Associated research grant: 24/02249-0 - Effect of chromium propionate for pregnant ewes fed at different nutritional levels on the proteomic characterization of offspring meat, AP.R

Abstract

Chromium is a mineral that has been studied as a nutritional supplement in animal production. Its ability to amplify intracellular insulin signaling increases the efficiency of energy distribution in the body, and it can have antioxidant action, especially in phases of high nutritional demand and situations of metabolic stress, such as the final phase of gestation. The objective of the project is to evaluate the supplementation of chromium propionate in diets with different levels of nutrients, at the end of the gestation of sheep, and to evaluate the effect on the mother and offspring. To evaluate the efficiency of chromium supplementation, both the ewe and the offspring will be measured in relation to performance, milk production, colostrum quality, blood parameters, gene expression and metabolomics. The experiment will take place in the Sheep Farming Sector of the School of Animal Science and Food Engineering of the University of São Paulo. A flock of 108 ewes will be used and divided into randomized blocks, according to the type of delivery, in a 3 x 2 factorial, with three levels of nutrition and (2) with or without chromium. Chromium supplementation will be 0.5 mg of chromium propionate/kg/DM. CTL, fed with 100% of the nutritional recommendation, but without chromium supplementation; CTLCR, similar to CTL, but with chromium supplementation. LOW, fed with 80% of the nutritional recommendation and without chromium; LOWCR, similar to LOW plus chromium. PLUS, fed with 120% of the recommendation and without chromium, PLUSCR, with a diet identical to PLUS and chromium. The animals will be divided and treated from 100 days of gestation (DG) and ending supplementation at delivery. Blood samples will be collected at 135 DG and at 15 and 60 days of lactation in the matrices for analysis of serum concentrations of glucose, insulin, NEFA, BHB, calcium and phosphorus. Colostrum collection will occur 72 to 48 hours before delivery, and the nutritional composition, IgG, IgM and antioxidant profile will be analyzed. Milk collection will occur at 15 days of lactation, and the chemical composition and fatty acid profile will be analyzed. In the offspring, blood samples will be collected at 24, 15 and 60 hours, and the concentrations of IGF-1 (only at 24 hours), glucose and insulin will be analyzed. Male lambs will be confined from 60 to 120 days of age, where IMS will be measured daily and live weight, monthly. After slaughter, parameters of carcass, meat, viscera and adipose tissue will be evaluated. Material (tissue and blood) will be collected from the sheep and lamb for analysis of specific genes and metabolites. Statistical analysis will be performed using PROC MIXED and comparison of means using the Tukey test at 5% probability. The hypothesis is that chromium will alleviate the consequences of energy deficit in the case of low-nutrition diets and will increase the efficiency of the use of excess energy in the case of diets with more energy.