Effect Of Lysine And DE On The Performance And Meat Quality In Rongchang Pigs

One hundred and twelve Rongchang pigs(19.9± 1.1kg BW) were used to determine the effect of different level of DE and Lysine: DE ratio on the performance, carcass merits and meat quality. The experiment was a 2×2 factors (two DExtwo 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 carcass and pork measurements with the left side of each carcass. The results show that: The first for performance: Increased DE resulted in improved ADG from 60 to 90kg (P < 0. 05), F:G from 20 to 35kg (P < 0. 001) and from 20 to 90kg (P < 0. 05). Meanwhile, energy and Lysine: energy ratio interaction influenced ADG from 35 to 60kg (P < 0. 05), and from 60 to 90kg (P < 0. 05), ADFI from 35 to 60kg (P < 0. 05) .The second for carcass merit: Increasing the DE concentration in diet or decreasing Lysine: DE ratio increased backfat depth (or including skin), and the DE and Lysine: DE ratio interaction was observed. Carcass length was decreased significantly (P < 0.05) by increasing Lysine:DE ratio. Different level of lysine and DE only influenced the carcass yield and lean yield of pigs slaughtered at 90kg. Higher DE concentration diet increased carcass yield (P< 0. 001) and decreased lean yield (P=0. 001), higher lysine: DE ratio resulted in lower carcass yield (P< 0. 05) but higher lean yield (P < 0. 01) .The third for pork quality: pHl was larger as Lysine: DE ratio increased. The effect of DE on water holding capacity was only found in pigs slaughtered at 90kg (P < 0.05). Different level of lysine and DE influenced shear force without any regular patterns, but significantly affected meat color of L^* (P < 0. 05),a^* (P < 0. 01) and b^* (P < 0.001) in pigs at 90kg. The intramuscular fat contents of pigs slaughtered at 60kg and 90kg were both decreased (P < 0. 05) as increasing Lysine: DE ratio in diet.