Well, meat carbohydrate content is very low. Even so you can perform the proximate analysis and calculate the carbohydrates by difference as with most of foods. Usually, the energy is calculated on the base of the kcal apported by each component., i.e., 9 kcal per g of lipids and 4 kcal per g of proteins and carbohydrates. So, if you have the percentages of each component in the meat you can easily calculate the energy. I hope this serves to you. Regards