Evaluation of gene expression profile in cattle supplemented with selenium, vitamin E and canola oil: the interaction diet-gene-meat quality

Author(s)

Gisele Fernanda Greghi

• Document type: Master's Dissertation
• Press: Pirassununga.
• Institution: Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT)
• Defense date: 2014-08-15

Examining board members

Arlindo Saran Netto; Heidge Fukumasu

• Advisor: Arlindo Saran Netto

Abstract

World beef production corresponds to 58.856 million tons, of which 9.92 million tons of meat are produced by Brazil. With the largest commercial cattle herd (approximately 209 million animals), our country occupies a prominent position in the beef market: 1st in exports (2.03 million tons) and 2nd in production and consumption (40 kg / capita /year). Over the years, beef production increased, as critical in the field of human health due to its high content of saturated fatty acids and a possible but still questionable relationship with cardiovascular disease, diabetes and cancer. For these reasons a lot of research has been conducted in an attempt to change the composition of the meat fatty acids, which consequently affects the oxidative stability of the meat. To evaluate the influence of specific dietary components on the responses of the body and its effects on the production and quality of meat, has evaluated the expression of individual genes, or has used transcriptomics. From the use of this tool, the present study evaluated the interaction between supplementation with selenium, vitamin E and/or canola oil and the expression of key genes in the regulation of antioxidant, lipogenic and cholesterolemic pathways in cattle. Nelore (n= 48) uncastrated, initial weight ± 350kg, allocated in calan gate in the Department of Animal Science, FZEA Pirassununga-USP, SP were divided into 4 groups: Control (C): basic diet; (Se + Vit E): 2.5 mg Se and 500 IU vitamin E/kg DM; (Canola): addition of 3% canola/kg of DM oil; (Se + Vit E + Canola): adding 2.5 mg Se, 500 IU vitamin E and 3% canola/kg of DM oil. After 12 weeks, they were slaughtered (final weight ± 456 kg) and samples of liver, L. dorsi muscle and subcutaneous adipose tissue collected for analysis of gene expression of NFE2L2, GPX1, GPX4, GSR, GCLG, GSS, SREBF1, PPARA, SCD, HMGCR, ACAT1, ACAT2 and LCAT. Data were analyzed using PROC MIXED (SAS 2005), the means were compared by contrasts evaluated by Student\'s t test and the correlation between hepatic gene expression were estimated using the Pearson correlation coefficient. The liver tissue was more sensitive to changes in the rate of transcription of mRNA. Animals that received supplementation with Vitamin E and Se had higher expression of cytoprotective genes (NFE2L2, P≤0.05; GPX1, P≤0.08; GPX4, P≤0.03; GSS, P≤0.06), lipogenic (SCD, P≤0.06) and cholesterolemic (HMGCR, P≤0.06) compared to those receiving canola oil. These, in turn, showed a higher amount of mRNA for LCAT (P≤0.05) than those who received supplementation with antioxidants. The gene expressions of SREBF1 (lipogenic, P≤0.03) and ACAT1 (cholesterolemic, P≤0.08) were higher for animals receiving these antioxidants associated with canola oil compared to those which received these nutrients isolated. These results stimulate more studies about antioxidants and polyunsaturated fatty acids such as canola oil because of their potential either for the quality of the meat, either for therapeutic use in animal or human health. However, caution is needed because these antioxidants can both induce cytoprotective genes, as well as lipogenic and cholesterolemic genes, and the way this activation occurs suggests the involvement of NFE2L2. (AU)

• FAPESP's process: 12/13666-4 - Supplementation of feedlot cattle with selenium, vitamin E and canola oil on feed efficiency, meat quality and gene expression
• Grantee: Gisele Fernanda Greghi
• Support Opportunities: Scholarships in Brazil - Master