Supplementation with chromium propionate for pregnant ewes fed different nutritional levels and its effects on the sheep and offspring

• Grant number: 23/08188-0
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2024
• End date: January 31, 2026
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Sarita Bonagurio Gallo
• Grantee: Sarita Bonagurio Gallo
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Associated researchers: João Alberto Negrão ; Luis Orlindo Tedeschi ; Miguel Henrique de Almeida Santana ; Nara Regina Brandão Cônsolo ; Paulo Roberto Leme
• Associated research grant(s): 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 may have an antioxidant action, especially in phases of high nutritional demand and situations of metabolic stress, such as late pregnancy. The aim of the project is to evaluate the supplementation of chromium propionate in diets with different levels of nutrients, at the end of ewe pregnancy, and to assess the effect on the dam and offspring. In order to evaluate the efficiency of chromium supplementation, both ewes and their offspring will be measured in terms of 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 at the University of São Paulo. A flock of 108 ewes will be divided into randomized blocks, by type of birth, 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/MS. CTL, fed 100% of the nutritional recommendation, but without chromium supplementation; CTLCR, similar to CTL, but with chromium supplementation. LOW, fed 80% of the nutritional recommendation and no chromium; LOWCR, similar to LOW plus chromium. PLUS, fed 120% of the recommendation and without chromium; PLUSCR, with the same diet as PLUS and chromium. The animals will be divided and treated from 100 days of gestation (GD) and supplementation will end at calving. Blood samples will be taken at 135 GD and at 15 and 60 days of lactation from the sows to analyze serum concentrations of glucose, insulin, NEFA, BHB, calcium and phosphorus. Colostrum will be collected between 72 and 48 hours before calving, and its nutritional composition, IgG, IgM and antioxidant profile will be analyzed. Milk will be collected at 15 days of lactation and its chemical composition and fatty acid profile will be analyzed. In the offspring, blood samples will be taken at 24h, 15 and 60, and concentrations of IGF-1 (only at 24h), 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, carcass, meat, viscera and adipose tissue parameters will be evaluated. Material (tissue and blood) will be collected from ewes and lambs for analysis of specific genes and metabolites. For statistical analysis, PROC MIXED will be used and the means will be compared using the Tukey test at 5% probability. The hypothesis is that chromium will mitigate the consequences of energy deficit in the case of low-nutrition diets and increase the efficiency of use of surplus energy in the case of higher-energy diets. (AU)