Effect Of Maternal Or Post-Weaning Methyl Donor Supplementation On Growth Performance,Carcass Traits,Meat Quality In Pig Offspring

The annual meat production of sows is a key factor affecting the production efficiency of pig industry.Previous studies in our laboratory indicated that methyl donors?MET?supplementation during gestation significantly improved the growth performance and meat quality of offspring.In addition,some studies also pointed out that the growing-finishing diet with methyl donors would also significantly shorten the time of listing and improve the meat quality.It seen not difficult to find that either maternal or offspring diet with MET is beneficial to the growth performance and meat quality of the finishing pig.Which stage is the best period to supplementation?While it is still unclear whether MET supplementation throughout gestation and lactation or post-weaning period can change the growth performance,meat quality of the adult pigs,and,if so,whether muscle fiber characteristics or antioxidative capacity can be changed during this process.A total of 24 multiparous crossbred sows?Landrace×Yorkshire?were assigned into 2 groups matched for parity(parity 5 to 7 and body weight,receiving basal diet?C?or basal diet with MET supplementation?MET?from mating to weaning.At weaning,24 female piglets from each maternal diet group were randomized to receive either the control or the MET-supplementation diet until d 180.This resulted in 4 groups?n=12,6 litters per group?based on dam diet-offspring diet matches:control-control?C/C?,control-MET supplementation?C/MET?,MET supplementation-control?MET/C?,MET supplementation-MET supplementation?MET/MET?.The results were presented as following.?1?No significant difference in the reproduction performance of sows and growth performance of suckling piglets was observed between the two groups,excepting for the higher litter weight?P=0.08?and the lower?P=0.047?piglet mortality in the MET supplementation groups during the gestation and lactation.The BW of finishing pigs at d 180 and ADG from d 28 to 180 was significantly higher?P<0.05?by maternal MET supplementation.?2?The main carcass characteristics were not significantly different in all groups.However,the fattening pig with maternal MET supplementation during gestation and lactation period had a significantly increased LD index?P=0.01?and LDA?P<0.01?,had a tendency numerically increased mean myofiber CSA?P=0.077?,significantly improved the muscle pH_24h values?P=0.022?and reduced the L^*_45min value?P=0.013?compared with their counter parts.Furthermore,L^*_24h values had a tendency to be lower in post-weaning MET supplementation groups?P=0.053?.?3?Dietary MET supplementation had no effect?P>0.10?on the IMF and lactate content,but resulted in greater?P<0.05?crude protein content.Meanwhile,the glycolytic potential content was lower?P<0.05?in the fattening pigs with maternal MET supplementation.There was an M×PW interaction?P=0.032?on glucose+glucose-6-P content showing that the value in the MET/C groups was lower than the C/C group.?4?The plasma Hcy concentration of the finishing pigs was significantly affected by maternal and post-weaning MET supplementation,and interaction between M×PW with highest concentration being found in CC group compared with other three groups?P<0.05?.Dietary MET supplementation had no effect?P>0.10?on plasma MDA content,CAT enzyme activity but resulted in a greater plasma T-AOC activity was significantly higher.The plasma SOD enzyme activity tended to increase in maternal MET supplementation groups.Furthermore,the LD muscle MDA content was significantly lower in the finishing pigs with maternal exposure to MET?P=0.04?.The T-AOC?P<0.01?and CAT?P=0.041?activity in the LD muscle were significantly lower in the post-weaning MET-supplemented pigs.The SOD enzyme activity of the LD was significantly higher in the finishing pigs with maternal exposure to MET during gestation and lactation period?P<0.05?.The G-PX was significantly upregulated in the LD muscle of the finishing pig with maternal MET dietary supplementation?P<0.01?.the CuZn-SOD was significantly downregulated in post-weaning MET supplementation groups?P=0.019?.?5?Dietary MET supplementation had no effect?P>0.10?on muscle MyHCI and MyHCIIb mRNA levels or mtDNA copy number but resulted in greater?P<0.05?MyHCIIa mRNA levels,IGF-1R mRNA levels and the mRNA expression of genes responsible for mitochondrial biogenesis and function in longissimus dorsi of the d180 finishing pigs.Meanwhile,MyHCIIx?P<0.01?,MyoD?P=0.032?and MRF4?P=0.019?mRNA levels were greater in both the maternal MET supplementation groups.The finishing pig with maternal MET supplementation during gestation and lactation period exhibit a significantly upregulated NRF1 expression?P=0.048?and tended to increase IGF-1?P=0.08?and Sirt1 expression?P=0.072?.There was an M×PW interaction?P=0.008?on PGC1-?showing that the expression in the MET/C groups was higher than the C/C and MET/MET group.Meanwhile,both TFAM and ATP5B had M×PW interaction?P=0.012,P=0.021?,which the former was more significant in the C/MET than in MET/MET,and the later higher in MET/C group compared with the MET/MET group.In summary,the maternal methyl donor supplementation significantly improved litter weight and lower piglet mortality increased the market weight of the finishing offspring 180 days and improved LD pH_24h.The leading causes may be related to the greater MyHC II and tendency numerically increased mean myofiber CSA,the upregulation of the myogenic regulatory factors,and the mitochondrial biosynthesis.Meanwhile,these changes may derive from the decrease of plasma Hcy and the advance of antioxidant capacity.