Studies On Development Changes Of Key Enzymes Involved In Lipid Metabolism In Rongchang And DLY Pigs Feed Different Dietary Nutrient Levels

The fat deposition is a fundamental mode of energy storing. The deposition quantity of animals body fat is a homeostasis ,which includes fat intussuscept, the fatty acid synthesizes, the trigalloyl glycerol (TG) synthesizes and break down. the fat biosynthesis and decomposition are complete through certain enzyme catalyses.The factors of affects enzyme-catalyzed reactions as enzyme activeness and the enzyme content and so on ,all of that can affect the fat synthesis. So this paper studies on development changes of key enzymes involved in lipid metabolism in Rongchang and DLY pigs fed different part of different dietary nutrient levels. It has practical significance that fully esert the excellent production performance, and improve IMF deposition of commodity pig.Selected 84 healthy Rongchang and DLY barrows(10kg BW) were differently allocated to two treatments(high and low nutrition level), each group having 6 replicates comprising 7 pigs each. low nutrition level of this two species was according to recommendations of GB 7223-1987(Nutrient Requirements of Rongchang Pig, 1987),and high nutrition levels were in line with revised nutrient requirements of Chinese lean-meat pig(Rongchang pigs) and Nutrient requirements of swine by NRC(1998)(DLY) differently.One animal from every replicate was slaughtered when their body weight(BW) were10, 20,35,50,80 and 110kg to determine the biochemical parameters (TG,TC,HDL- CHO,LDL-CHO,VLDL-CHO and NEFA) and the enzymes activity(FAS,G-6-PDH,MDH,HSLå’ŒLPL) of different part (liver,backfat and intramuscular) and the correlation of the enzymes with production performance (IMF,BFT).The results showed as follows:With the level of dietary nutrient increaseed, FAS activity of the Rongchang pigs and DLY pigs longissimus Dorsi were enhanced and dropped in back fat after the 20kg stage (P<0.05). But for the DLY pigs , the MDH activity of the longissimus Dorsi at the 80kg and 110kg stages were enhanced when the level of dietary nutrient was increased, whereby 110kg stage have a remarkable differance(P<0.01); With the level of dietary nutrient increaseed, HSL activity of longissimus Dors of Rongchang pigs and DLY pigs at the 50kg stage were reduced, whereby 50kg stage of DLY pigs have a remarkable difference (P<0.01). For the Rongchang pigs, the LPL activity of the back fat at the 80kg and 110kg stages were remarkable reduced(P<0.05) when the level of dietary nutrient was increased, but the LPL activity were enhanced at the 80kg and 110kg stages of the DLY pigs back fat; With the level of dietary nutrient increaseed, LPL activity of the Rongchang pigs at the 80kg stages longissimus Dorsi were remarkable enhanced (P<0.05), and extremely remarkable enhanced in liver at the 35kg, 50kg, 80kg stages (P<0.01). But for the DLY pigs, the LPL activity at the 35kg and 50kg stages were reduced when the level of dietary nutrient was increased, whereby 35kg stage have a remarkable differance(P<0.05). From the factor of heredity type, the key enzymes of fat synthesis at Rongchang pigs are higher than DLY pigs,and the key enzymes of fat decomposition at Rongchang pigs are lower than DLY pigs,but the remarkableness is difference at various stages.From correlational analysis, It was concluded as follows: In the case of high level of dietary nutrient, negative correlation rank for between FAS or MDH activity to longissimus Dorsi have a difference which is from remarkable to extremely remarkably (P<0.01); the HSL activity from remarkable to unremarkable;the LPL activity from remarkable to extre mely remarkable(P<0.01). Therefore, it can reduce the FAS and LPL activity in the back fat when the level of dietary nutrient was increased. Increase the level of dietary nutrient,can reduce the FAS and LPL activity in the back fat.