you so the second aspect of the net energy measurements is to get estimates of values for fasting reproduction a very popular technique that was used in the past was consisted in measuring heat production at variable M intakes and extrapolating the hip adduction for zero M intake so you get a so-called recreation hip adduction which corresponds to the fasting reproduction that is illustrated on that figure for cars which were fed different energy levels but for these cars if we also measure they are fasting in production during the trial you can see that the fasting a production that is directly measured on the animal first is much higher than the fasting reproduction obtained by the regression method and is also variable it is as high as the feeling level is high which means that overall the heat increment which we are looking for is dependent on the technology of the middle we use for evaluating fasting production clearly the best estimate is obtained according to actually measured fasting reproduction and the so called regulation fasting reproduction is producing an estimate of the freighting fasting production which is about almost meaningless and which means that the each increment obtained according to that mythology is also meaningless so that technology is used the with variable aiming intakes but I think I am pretty sure that it shouldn't be used any more in the future since it provides very strange data meaningless data the second method for fasting a production is to measure directly the annual reproduction on animals we not detail all this aspect but that should be done very carefully by taking you talk into account the duration to fast at the physical activity of the animals and the different calculation method and so on but some data are available now and there is no problem for that but one further question when we talk about fasting in production is the way of its expression usually in the past fasting in production was considered as relatively constant per unit of metabolic body weight the metabolic body weight being historically considered as body weight with a point 75 exponent which means that the fasting production was proportional to body weight point 75 but clearly all literature data from over obtained over the last thirty years or 20 years at least indicate that the so called metabolic body weight point 75 is no more applicable to growing animals it is okay for others but not for growing and for instance that figure shows that it could should be something like point 70 embroiders we have shown us well that it is something equivalent point seventy for turkeys but it should be something equivalent to point sixty for pigs and it is even much higher point 85 for veal calves so fasting a production in growing animals is not any more proportional to body weight point seventy five and I think there is some there is a lot of information now providing fasting production values for growing animals and these values could be used in the future you