Genotype And Nutrition Interaction And Its Effect On Pig Meat Quality

The interaction effects of Duroc (D), Duroc×(Landrace×Large White) (D.LL), LargeWhite×DaWeiZi (L·DWZ), and DaWeiZi (DWZ) and three nutrition levels (high—H, medium—M and low—L) on performance and carcass and meat quality traits were studied in this paper.During performance test, pigs from 15 to 90 kg were fed on ad-libitum feeding regimes, averagedaily gain (ADG), feed conversion ratio and average daily feed intakes were measured. Carcasstraits, meat quality traits and the contents of amino acid of 80 pigs at 90kg were also tested. Theinteraction effects were examined with general linear model. At the same time, fourmicro-satellites markers on chromosome 6 and polymorphisms of CAST gene on HinfⅠ, MspⅠand RsaⅠsites were studied using RCR-RFLP in four swine breeds. The interaction effects ofmicro-satellites markers and CAST gene and nutrition on meat quality traits were also studied inthis paper. This study will provide scientific basis for advanced pig breeding.The results were as follows.1. 1 Significant interaction effects on some carcass traits, meat quality traits and thecontents of amino acids were found between genotypes and nutrition (P＜0.05). Meat from D. LLx H pigs decreased average back-fat thickness(ABF), presented higher lean meat percentage(LMP) than others (P＜0.01), and had lower moisture percentage(MP) and muscle intramuscularfat (MIF) (P＜0.05), while meat from D.LL×M pigs increased dressing percentage (DP)significantly (P＜0.05),and decreased cooked meat percentage (CMP) and MIF. Meat from D x Lincreased MP and dehydrating rate(DR) (P＜0.05 ; Meat from L.DWZ×H and L·DWZ×M hadhigher DR, and had lower CMP and the contents of amino acids(CAA) (P＜0.05); Meat fromL·DWZ×M increased carcass length (CL) and MP (P＜0.05).Meat from L·DWZ×H had significant effect values in 10 amino acids, and meat fromL.DWZ x M also had significant effect values in 11 amino acids (P＜0.05 or P＜0.01), while meatfrom D·LL×H had significant effect values only in 3 amino acids, and no significant differencewas found in other combinations (P＞0.05). 1.2 The polymorphism was found only on SW1067 among four micro-satellites onchromosome 6, and five alleles (A, B, C, D and E) were also tested. The results showed that thecombination of AC×H decreased DR significantly (P＜0.05); AC×M could increase DP, ABF,CMP and CAA (P＜0.05), while decreased DL and LMP (P＜0.05).1.3 Polymorphisms of CAST gene on HinfⅠ, MspⅠand RsaⅠsites were used to study theinteraction effects of CAST gene and nutrition on meat quality traits. The results showed thatthere were polymorphisms on HinfⅠ, MspⅠand RsaⅠsites in four pig populations, and therewere one allele A and B on HinfⅠsite, one allele C and D on MspⅠsite, and one allele E and Fon RsaⅠsite.The interaction of AA×H decreased MCP, DL and CAA, but AA×M decreased DR, andincreased DL significantly(P＜0.05). AB×H decreased CL, CAA and loin eye area(LEA), andincreased DL significantly(P＜0.05). AB×M decrease DP, ABF and CMP, and increasedLMP, CAA and percentage of ham in carcass significantly(P＜0.05). CD×H had significantinteraction effect values in all traits. CC×M decreased DR and CAA, and increased DL(P＜0.05).EF×H had significant interaction effect values in most of the traits (P＜0.05). EE×M increasedBF significantly(P＜0.05). There was no significant interaction between other combinations.1.4 As for ADG, significant difference were found within genotypes or nutrition levels(P＜0.01),there were a little interaction effect of genotype and nutrition on ADG, somesignificance was found (P＜0.05).