[Music] so how to evaluate net energy of ingredients and diets we have seen in the previous videos that measuring net energy is rather complex i mean it needs specific equipments it is also time consuming it can be very expensive according to the equipment and the time and so i consider that measuring net energy or feeds is more research activity but in practice feed industry or formulators or people from the field require rapid very simple and cheap methods for development of the net energy concept the solution for solving that problem is using the prediction equations that have been produced in the literature so several equations have been proposed and developed from studies where the net energy of a large number of diets was measured i would say 20 diets or even more and what is important as well is that one equation and i mean one equation obtained from a set of diet data is equivalent to a net energy system so that means that one difficulty or one source of confusion for the net energy concept is that several equations have been proposed or have been produced per for the peaks for instance and these equations are not exactly comparable but nowadays the most used set of equations implemented is in most countries and also implemented in the most important feeding tables such as those of the nrc of inra and brazilian tables is based on a large-scale study that was conducted in france in the 80s 90s one example of these equations is provided here where the net energy of the feed is a function of the d content of the feed plus or minus some factors related to the crew nutrients you can notice that eater extract or starch have a positive effect on that equation while crude protein and crude fiber have a negative effect on this energy value so as for pigs a few studies have considered net energy in poultry and they have attempted to establish net energy prediction equations also in the 60s and the 70s but i must say that up to now none of these equations have been really implemented in the field industry but new studies have been conducted over the last 10 or 15 years and the most important and recently published equations originating from the university of new england in australia so in practice we should say that net energy value of diets of ingredients is calculated from an equation the question now is to decide on one equation i should stress that also there is no need to measure the net energy of ingredients but as you have seen from the previous equations net energy is calculated from d e or me that means that d e or m e values or dietable nutrients should be very reliable i have also shown that net energy equation and also net energy value is very much dependent on the methodologies and the protocol of the studies which means that net energy values originating from different labs of different studies shouldn't be combined so coming back to the first point i think it's important to decide on one equation and one system for moving to net energy i have tried to show you that net energy system is a nice concept but establishing this the network system is rather complex and is devoted to research activities but according to the equations that are available this concept is very easy to implement at the industry level i would i would simplify by saying that you need only a spreadsheet for calculating the net energy value from the your de or your me this has been done i would say in the peak sector and to a very large extent in the main areas of peak production in the world but it's not yet available and not available and not used in poetry