Effect of specific structured triglycerides on energy metabolism in broiler chickens

摘要

Structured triglycerides (STG) are a chemical mixture of fatty acids incorporated in the same glycerol moiety by hydrolysis and esterifications. STG have been found to have a positive effect on body weight gain, nitrogen balance in rats, and in humanstudies to show an increase in body fat oxidation. A study was designed to investigate the effects on nitrogen and energy metabolism of dietary inclusion of specific STG containing medium chain fatty acids in 1- and 3-positions and a long chain fatty acid in 2-position , which was prepared from rapeseed oil and capric acid (C 10:0) in broiler chickens. A total of 40 female broiler chickens (Ross 208) were kept at 37 °C in the first day and then temperature was decreased by 1 °C each day until 25 °C,after which the room temperature was kept constant. Relative humidity was 60-65 %. Light was on for 24 h during the first 12 days and 20 h (0300 to 2300) thereafter. The animals were at random allocated into five dietary treatments: A basal diet in mealform based on wheat, pea and soybean meal with graded level of STG of 0, 2, 4, 6 and 8% at the expense of rapeseed oil. At 12 day of age the chickens were placed pair-wise in metabolism cages. The grower period was divided into four consecutive balance periods of six days. Two 24 h measurements of gas exchange in two open-air circuit respiration chambers were performed during the second and third day of each balance period. The chickens were slaughtered at 36 d of age. Weight of the total empty digestive tract was relatively smaller when the chickens were fed STG compared with rapeseed oil. Furthermore feed efficiency, metabolizability and the relative protein retention were slightly improved when feeding STG. Also energy from oxidized fat increased with increasing level of STG in diets.