Effects Of Different Feeding Patterns During Pregnancy On Growth And Development Of Piglets Of Guangdong Small-ear Sow’s Piglets

The effect of feed intake on the reproductive performance of sows at different stages of pregnancy is essential.The birth weight of piglets is an important indicator of the reproductive performance of sows,and the birth weight is closed related to pre-weaning mortality of piglets and feed conversion efficiency,fat rate and meat quality postnatal growth.The aim of this study was to investigate the effects of different feeding patterns on the backfat thickness,body weight,reproductive performance of the sows and the slaughter performance of the newborn piglets,and to explore the effects of their feeding patterns on muscle weight,skeletal muscle fiber number and cross-sectional area and the mechanism may occur.On the breeding day,80 primiparous Guangdong small ears sows with the same weight and backfat thickness were selected and randomly divided into two groups,a repeat for each group,and a sow for each repeat.The stepwise and concave feeding patterns were used throughout the entire pregnancy.The average daily feed intake of sows in early and mid-term pregnancy between the two groups was significant difference,but there was no significant difference in total feed intake and average daily feed intake during the entire pregnancy.The results showed that: 1)The two feeding patterns had no significant effect on the weight and backfat thickness of the sow during the whole pregnancy;2)the birth weight of the stepwise group was higher than the concave group(P = 0.06),the stillbirth rate and the invalid rate(stillbirth rate + mummy rate)was significantly lower than the concave group(P < 0.05).3)the duodenum unit length weight of the Low birth weight piglets(LBW)in the stepwise group was significantly higher than the concave group(P < 0.05),The liver viscera index of the normal birth weight piglets(NBW)in the stepwise group was also significantly higher than the concave group(P<0.05).4)The two feeding patterns had no significant effect on the change of insulin,insulin-like growth factor(IGF-1),growth hormone,progesterone during the different sow gestation.5)The weight of the supraspinatus,infraspinatus and psoas major of the NBW in the stepwise group was significantly higher than the concave group(P < 0.05),and the number of muscle fibers in the LBW(P < 0.05)and the relative cross-sectional area of the longissimus dorsi of the NBW in the stepwise group(P < 0.05)was significantly higher than the concave group.What more,relative gene expression of MEF2 and Myo G in the longissimus dorsi of NBW(P < 0.05)and the relative genes expression of My CH-IIA and My CH-IIX in the psoas major of LBW(P < 0.05)in the stepwise group was significantly higher than that the concave group.6)The contents of Glu and TAA in the longissimus dorsi muscle of LWB(P < 0.05),and the contents of Asp and TAA in the longissimus dorsi of NWB(P < 0.05)in the stepwise group were significantly higher than those in the concave group.The content of Glu in the psoas muscle of LBW piglets(P < 0.05)and the contents of Thr,His,Glu and Asp of NBW piglets(P < 0.05)in the stepwise group was significantly higher than those in the concave group.Correspondingly,the relative gene expression of ASCT2 in the longissimus dorsi muscle of LBW in the stepwise group was significantly higher than that of the concave group(P < 0.05),and the relative gene expression of GLAST in the stepwise group was higher than the concave group(P = 0.07).The relative gene expression of ASCT2 in the longissimus muscle of NBW in the stepwise group was higher than the concave group(P = 0.08).The relative gene expression of GLAST and ASCT2 in the psoas muscle of LBW in the stepwise group was significantly higher than the concave group(P < 0.05),and the relative gene expression of CAT1 in the psoas muscle of LBW in the stepwise group was higher than that of the concave group(P = 0.06),and the relative gene expression of the CAT1 in the psoas muscle of NBW was significantly higher than the concave group(P < 0.05).In summary,the stepwise feeding pattern of primiparous Guangdong Small-ear Spotted sow during pregnancy can improve the birth weight,muscle weight,liver viscera index and muscle-related gene expression of piglets,which is conducive to the growth and development of their offspring.