Do you have to pay attention to protein-energy ratio and lysine-energy ratio when making chicken feed?

In the past, when I was at school, the teacher stressed that livestock and poultry should eat for energy, and the formula must be designed according to the recommended protein-energy ratio and amino acid-energy ratio. In actual production, it is found that many people do not follow this method, and the protein-energy ratio and amino acid-energy ratio are quite different from the standard. For example, in the stage of fast big yellow chicken, some eggs can achieve 63g/Kcal, and some people can achieve 60g Kcal. How can there be such a difference? does it affect production? -the formula has to be tailored to local conditions.-not necessarily, it's changed a lot! -look at the balance of amino acids.-Yes, according to the needs of the market.-protein-energy ratio is very important in chicken feed, because energy generally determines chicken feed intake. Is the egg energy ratio positively or negatively related to the growth and weight gain of chickens? Can the egg be a little lower? is the fatness of the chicken better? (that is, if the energy is slightly higher and the protein is lower, the fatness of the chicken will be better? There is no way to do a comparative feeding experiment, ask experienced people to give advice!