Effects Of Lysine And De Levels On Fat Accumulation And Gene Expression Of UCP2 And UCP3 In Rongchang Pigs

One hundred and twelve Rongchang pigs(20±2kg)were used to determine the effect of different level of DE and lysine:DE ratio on the Adipose Growth and the mRNA level of UCP2 and UCP3. The experiment was a 2×2 factors(two DE×two Lysine: DE ratio)and randomized complete block design, initial BW served as the blocking factor, with three feeding phases: 20～35kg,35～60kg,60～90kg. Four dietary treatments were included for every phase, the DE levels in every phase were: 13.11 MJ kg-1 and 14.22 MJ kg-1, and the Lysine: DE ratio was: 0.49,0.67gLys MJ-1DE;0.38,0.53gLys MJ-1DE;0.30,0.42gLys MJ-1DE. Pigs were housed in pens of four, with seven replicate pens per treatment. When the means weight for pigs in a pen reached 60kg and 90kg, one pig per pen whose weight was close to the aim of slaughter weight was selected and slaughtered for Adipose Growth and genes expression measurements. The results shown that: Increased Lysine: DE ratio resulted in markedly decreased carcass skew length of pigs slaughtered at 60kg (P<0.05) and the DE and lys:DE ratio interaction was obversed (P<0.05). Increased Lysine: DE ratio resulted in markedly decreased intramuscular of pigs slaughtered at 60kg (P<0.05). Increased the DE level increased backfat(P<0.05)of pigs slaughtered at 90kg,and the DE and lys:DE ratio interaction was obversed(P<0.05).Carcass length was decreased significantly (P<0.05)by increasing Lys:DE ratio. Higher DE level diet decreased the carcass yield(P<0.001).Higher Lys:DE ratio also decreased the carcass yield(P=0.05)and the DE and lys:DE ratio interaction was obversed(P<0.05).Increased the DE level and Lys:DE ratio decreased lean yield (P<0.05,P<0.001).The intramuscular was markedly decreased(P<0.05)by higher Lys:DE ratio. Increased the DE lys:DE ratio decreased the UCP2 mRNA level in liver of pigs slaughtered at 60kg (P<0.05). Increased DE level resulted in markedly decreased UCP2 mRNA level in fat of pigs slaughtered at 90kg (P<0.05). Increased Lysine: DE ratio resulted in markedly increased UCP3 in muscle and UCP2 in fat mRNA level of pigs slaughtered at 90kg (P<0.05).