Effects Of Emulsifier On Broilers Fed Diets With Different Soybean Oil Levels

The objective of this experiment was to study the effect of emulsifier on fat metabolis-m of Arbor Acres (AA) broilers fed diets with different soybean oil levels. The study inclu-des three trials and the general results are presented as follows:Trial1:The objective of this experiment was to study the effect of emulsifier on the growth performance, digestibility of feed nutrients,carcass characteristics of Arbor Acres (AA) broilers fed diets with different soybean oil levels. A2×2factorial arrangement of treatments was used in trial.320one-day-old AA broilers were randomly allocated to four groups, and each group had10replicates with8broilers in each replicate. The broilers were given one of four diets:(1) control with normal soybean oil level(CN);(2) CN supplemen-ted with0.05%emulsifiers(SN);(3) control with0.5%less soybean oil level than CN(CL);(4)CL supplemented with0.05%emulsifiers (SL).The results showed that emulsifier supplementation decreased feed/gain ratio (F/G) and increased average daily gain (ADG) of broilers in the starter (P<0.05) and whole (P<0.05) phase. Emulsifier supplementation increased average daily gain (ADG)(P<0.05),and decreased feed/gain ratio (F/G)(P<0.01) of broilers in the finisher phase. Also, there was an interaction between soybean oil levels of diets and emulsifier supplementation for decreased feed/gain ratio (F/G) of broilers in the whole phase. However, soybean oil levels of diets had no significant influence on the growth performance on broilers in the each phase. Emulsifier supplementation improv-ed availability of crude fat (P<0.05), dry matter (P<0.05), organic matter (P<0.05) and energy (P=0.01) during36-38d. Furthermore, there was an interaction between soybean oil levels of diets and emulsifier supplementation for improved crude fat (P=0.05) of broilers during36-38d. But emulsifier supplementation or soybean oil levels of diets did not affect availability of nutrients during12-14d. Emulsifier addition to diets with different soybean oil levels reduced significantly thickness of intramuscular fat (P<0.05) and subcutaneous fat (P<0.05) as well as abdominal fat yield (P<0.05) in broilers at42d, and emulsifier supplementation increased leg muscle yield (P=0.10) of broilers at42d respectirely. Furthermore, there seem to be an interaction between emulsifier supplementation and soybean oil levels of diets for reduced thickness of intramuscular fat (P=0.06) of broilers at42d. However, emulsifier supplementation or soybean oil levels of diets did not affect carcass characteristics on broilers at21d. In conclusion, emulsifier supplementation to diets with different soybean oil levels increased the growth performance and availability of feed nutrients as well as carcass characteristics of Arbor Acres (AA) broilers.Trial2:The objective of this experiment was to study the effect of emulsifier on plasma lipid level and activity of lipid metabolic enzymes (lipoprotein lipase, hepatic lipase, total lipase) of Arbor Acres (AA) broilers fed diets with different soybean oil levels. The materials and methods used were the same as those in trial1. Parameters related to lipid metabolism were determined at the end of trial. The results showed that emulsifier supplementation obviously reduced LDL level in serum (P<0.05), and increased the ratio of HDL and LDL level in serum (P<0.05) of broilers at21d. Emulsifier supplementation obviously reduced LDL level in serum (P<0.05), and increased the ratio between HDL and LDL level in serum (P<0.05) on broilers at42d. Emulsifier supplementation had no significant effects on activity of lipid metabolic enzymes(lipoprotein lipase, hepar lipase, total lipids) on broilers at21d (P>0.05).But there was interaction between emulsifier supplementation and soybean oil levels of diets for increased activity of lipoprotein lipase in serum of broilers at21d (P＜0.05). Meanwhile, emulsifier supplementation increased activity of lipoprotein lipase on broilers at42d (P<0.05), as well as activity of total lipids on broilers at42d (P<0.05). But activity of hepatic lipase was not affected at42d (P>0.05).Trial3:The objective of this experiment was to study the effect of emulsifier on the expression of hepatic apolipoprotein B (apoB) and fatty acid synthetase(FAS) mRNA of Arbor Acres (AA) broilers fed diets with different soybean oil levels. The materials and methods used were the same as those in trial1. The results showed that emulsifier supplementation obviously increased the expression of hepatic apoB mRNA with exception of hepatic FAS mRNA of broilers at21d (P<0.05). And there was not interaction between emulsifier supplementation and soybean oil levels of diets for influence of the expression of hepatic apoB and FAS mRNA of broilers at21d (P<0.05).