Effects Of Oil Types, Dietary Energy Levels And Interaction On Fat Metabolism Of Broilers

The aim of this study was to understand more about the effect of oil types,dietary energy levels and interaction on fat metabolism of broilers.We chose three common oils in China (tallow rich in saturated fatty acids,fish oil rich in n-3 polyunsaturated acids and soybean oil rich in n-6 polyunsaturated acids) at three dietary energy levels (3100kcal/kg,3200kcal/kg,3300kcal/kg),determined fat deposition in different tissues, LPL activity and LPL mRNA expression in abdominal fat tissue,inspected dynamically fat intake and excretion.Trying to achieve added oil not only decreased fat deposition but also decreased fat waste, so we could provid the basis about regulating fat depositon and exploring new technology of fat metabolism of broilers.Exp.one The effect of oil types,dietary energy levels and interaction on growth performance of broilersA total of 900 1-d-old AA male broilers were randomly divided into ten groups(six pen replicates of fifteen chicks each) in a completely randomized design involving a 3×3 factorial arrangements of groups. Diets with three types of fat (tallow,fish oil and soybean oil),at three levels of energy inclusion(3100kcal/kg,3200kcal/kg and 3300kcal/kg) and the group without oil was the control group.We calculated growth performance on 21d and 42d.The results showed the broilers fed fish oil and soybean oil had better ADG,ADFI and FCR than broilers fed tallow.Added oil(L,M,H) also improved growth performance of broilers. 3200kcal/kg is the best dietary energy level because broilers had best growth performance at this level.ADFI of broilers in 22-42d showed a significant interaction,on the energy level of 3200kcal/kg,broilers fed tallow had best ADFI and on the energy level of 3100kcal/kg,broilers fed fish oil had lowest ADFI.Exp.two The effect of oil types,dietary energy levels and interaction on fat contents in different tissues of broilersExperiment diet and treatments were same to Exp.one.The results showed abdominal fat content was not affected by oil types and the groups added oil had higher abdominal fat content than control group.During the whole feeding phrase ,abdominal fat content was the highest on the fifth week.The results of fat content in different tissue showed fish oil caused higher TG in serum on 21d and lower fat content in thigh on 42d.Liver fat content,TC content in serum and fat content in breast were not affected by oil type.L,M and H group had higher fat content in different tissues than control group except TG content in serum on 21d and 42d and fat content in thigh on 42d.Abdominal fat content,breast fat content on 21d and TC content in serum on 42d showed no significant interaction, on the energy level of 3100kcal/kg,abdominal fat content of broilers fed tallow was highest,and which broilers fed fish oil was lowest.Exp.three The effect of oil types,dietary energy levels and interaction on LPL activity and LPL mRNA expression in abdominal adipose tissue of broilersExperiment diet and treatments were same to Exp.one.The results showed effect of added oil on LPL activity and LPL mRNA was not consistent.Added oil inhibited LPL activity on 21d and 42d,but only inhibited LPL mRNA on 42d in abdominal adipose tissue.The effect of oil type on LPL activity and LPL mRNA expression was different.LPL activity of abdominal adipose tissue showed a significant interaction,on the energy level of 3300kcal/kg,broilers fed soybean oil had highest LPL activity, on the energy level of 3200kcal/kg,broilers fed tallow had lowest LPL activity.Exp.four The effect of oil types,dietary energy levels and interaction on fat absorption and utilization of broilersExperiment diet and treatment were same to Exp.one.The results showed fat intake and fat absorption and utilization of broilers in part of weeks showed a significant interaction, the interaction mainly affected fat excretion.Percentage of ether extract in excretion increased with energy levels and the value of broilers fed tallow was higher than those fed soybean oil and fish oil. fat excretion and fat absorption and utilization of broilers were increased with dietary energy levels.The higher fat intake and excretion in broilers fed tallow than in those fed soybean oil and fish oil.Fat absorption and utilization of broilers fed soybean oil was the best.