Effects Of Dietary Lys/DE Ratio On Meat Quality And Gene Expression And Activation Of Some Transcription Regulators Invovled In Adipocyte Differentiation Of Rongchang Growing-finishing Pigs

One hundred and twenty Rongchang pigs(20±3kg) were used to study the effect of different dietary levels of DE and Lys/DE ratio on the meat quality and the mRNA level of PPARγ, C/EBPβand the activation of PPARγ, C/EBPα, C/EBPβin 2×2 factors(two DE×two Lys/DE ratio) and randomized complete block design. The feeding phases for the animals were 20~35kg, 35~60kg and 60~90kg. The dietary DE levels in every phase were: 13.11 MJ/kg and 14.22 MJ/kg, and the dietary Lys/DE ratios were: 0.49, 0.67g/MJ; 0.38, 0.53g/ MJ; 0.30, 0.42g/MJ. The pigs were housed in four treatment groups, with six replicates per treatment group and every replicate had five pigs. One pig from each replicate was slaughtered when their body weight (BW) arrived at 35kg, 60kg and 90kg to measure meat quality, genes expression and activation of PPARγ, C/EBPα, C/EBPβ. The results shown that: (1) Decreased Lys/DE ratio resulted in increased intramuscular fat content and increased the DE level resulted in decreased water loss rate. (2) With the increasing of the DE level, fat deposition had a rising tendency in the whole period. (3) PPARγmRNA level in Longissimus Dorsi had a peak when BW was at 60 kg and showed extremely significant difference among three feeding phases (P<0.01). (4) With the increasing of the body weight, PPARγmRNA level in backfat tissue tissue had a rising tendency in the whole period and showed extremely significant difference among three feeding phases (P<0.01). (5) Increased the DE level resulted in increased the PPARγmRNA level both in Longissimus Dorsi and backfat tissue tissue of the pigs slaughtered at 60kg and 90kg (P<0.05). (6) C/EBPβmRNA level in Longissimus Dorsi had a peak when BW was at 60 kg, same as in backfat tissue tissue. (7) Higher dietary Lys/DE ratio increased C/EBPβmRNA level in Longissimus Dorsi at 35kg and 90 kg BW , the difference was very significant (P<0.01). (8) Higher dietary DE level markedly increased C/EBPβmRNA level in backfat tissue tissue when BW were at 35 kg and 60kg (P<0.05). (9) The activation of PPARγhad a downward trend in the whole period. Increased the DE level resulted in increased the activation of PPARγin backfat tissue tissue of the pigs slaughtered at 60kg and 90kg. (10) Lower dietary DE level could increase the activation of C/EBPαin Longissimus Dorsi when BW were at 35kg and 60 kg. (11) Increased dietary DE level resulted in increased the activation of C/EBPβin Longissimus Dorsi when BW was at 90 kg. (12) Higher dietary Lys/DE ratio markedly increased the activation of C/EBPβin backfat tissue tissue at 90kg BW (P<0.05).