EFFECT OF HAY SEPARATION PRINCIPLE ON THE ENERGY-METABOLISM

A cross-over experiment was conducted with 8 adult, nonpregnant sows i n order to test whether feeding according to the principle of May's se paration diet exerts a stimulant effect on thermogenesis. The protein part of the daily ration was offered at the morning feeding, the other ration components in equal amounts at two further feedings. The contr ol group received the daily ration in three equal portions. The levels of all nutrients in the rations matched the maintenance requirement b ased on the initial weight of the sows and remained unchanged througho ut the experiment, In both 3-week metabolism periods a complete balanc e was undertaken for each animal using the collection technique (feed, feces, urine) and 45hour measurement of the gas exchange in a respira tion chamber, The body weight of the sows fed the separation diet was 178.3 kg and that of the control 178.6 kg, Oxygen and carbon dioxide w ere reduced by 1.5% with separation. The respiratory quotient remained unchanged, The experimental treatment had no effect on energy digesti bility and metabolizability. Heat production of the animals on the sep aration diet was 20.6 versus 20.1 MJ/day on the control diet, The resu lt was reversed for energy retention, namely 0.6 versus 0.0 MJ/day. Th e daily energy exchange profile, represented by thermogenesis plotted at 5-min intervals, showed slightly lower values than the control afte r the protein meal and only random differences between the two treatme nts fur the remainder of the day. It can be concluded from the results that separation of the protein and carbohydrates in the diet within 1 day, father than stimulating thermogenesis, is more likely to reduce it.