31 Effect of gestation dietary Methionine/Lysine ratio on placental angiogenesis and reproductive performance of sows.

摘要

The research was conducted to study the different gestation dietary Met/Lys (Methionine/Lysine) ratio on reproductive performance, placental vascular density and mRNA levels of genes related to vascular development. A total of 325 parity 3 multiparous sows were randomly allocated to 5 dietary treatments (n=65) with 5 dietary ratios of Met/Lys (0.27, 0.32, 0.37, 0.42, 0.47). The number of live birth and birth weight were recorded. Placenta samples were collected for analysis of placental vascular density by using HE staining and mRNA levels of genes related to vascular development. Reproductive performance was analyzed according to different range of total litter size (≤ 12 Vs > 13). One way ANOVA, Chi-squared test and quadratic repression analysis methods was adopted to compare effects of different dietary Met/Lys ratio on reproductive performance, placental vascular density and mRNA levels. Dietary Met/Lys ratio had no significant effect on reproductive performance when litter size was lower than 12 piglets. Result from table shown that 0.37 dietary Met/Lys ratio is most appropriate for obtaining maximum birth weight, birth litter weight, placental vascular density and mRNA expression of gene related to placental angiogenesis. The weak piggies rate (y,%) depending on dietary Met/Lys ratio (x) were described by y=242x -174.02x+35.288 R = 0.98 ＜0.01. According to this model, the most appropriate Met/Lys ratio for obtaining the lowest weak piggies rate was 0.36. The weak piggies rate changes with gestation dietary Met/Lys ratio quadratically, and 0.37 dietary Met/Lys ratio shows the best reproductive performance and vascular density by improving the expression of