Effects Of Embryonic Exogenous Nutrients Intervention On Developing Rules Of Breast Muscle And Intestinal Track In Goslings

This research was conducted to study laws of breast muscle and intestinal development of Jilin white geese in late-term goose embryos and goslings, and reveal physiological characteristics of breast muscle and small intestine of goslings. Furthermore, it was designed to explore effects of exogenous nutrient manipulation on breast muscle and small intestinal development of goslings. The main results are listed as follows:1. Research on the breast muscle and small intestine development of late-term goose embryos and goslingsOn the 23rd(E23) and 27 th days(E27) of incubation, the hatching day, and the 1st, 4th and 7th days post-hatch respectively, six geese were selected for breast muscle, liver and small intestine(n = 6) at each time point, and weight of the breast and small intestine was measured. Pectoral and liver glycogen content was determined, and sucrase and maltase activity of duodenum, jejunum and ileum was analyzed, breast muscle fiber diameter, villus height, villus width, crypt depth, muscle layer thickness of duodenum, jejunum and ileum were measured by paraffin section HE staining method; pectoral myogenic factor 5(Myf5) gene and sucrose-isomaltase(SI), sodium-glucose cotransporter 1(SGLT1), glucose transporter 2(GLUT2) gene of jejunum were cloned and sequenced, and breast muscle Myf5, myostatin(MSTN) and changing rules of m RNA relative expression of SI, SGLT1, GLUT2 genes of each small intestine segment were detected by using reverse transcription PCR method. The results of present experiment demonstrated that breast muscle catabolized because of lack of energy and nutrients in pre- and post-hatch periods leading to the diminishing of breast muscle fiber diameter and tardiness of breast muscle development. By increasing Myf5 and reducing MSTN m RNA relative expression, breast muscle growth was promoted. The small intestine developed rapidly during late-term embryos and goslings, owing to the following reasons: villus area was increased, the mucosal disaccharidase activity was enhanced, and the SI, SGLT1 and GLUT2 m RNA relative expression was improved. The development of the duodenum and jejunum was better than ileum, and the jejunum was the main part of carbohydrate absorption.2. The effect of in ovo feeding disaccharide and methionine on breast muscle and small intestinal development in goslingsThe experiment selected 600 goose eggs containing viable embryos and divided them into 4 groups. 1.5 ml solution was injected into each egg on the 24 th days of incubation(E24). Nothing was injected into the control group. The followings were injected into the three treatment groups: 25 g·L-1maltose + 25 g·L-1sucrose(DS), 5 g·L-1methionine(Met), 25 g·L-1maltose + 25 g·L-1sucrose + 5 g·L-1methionine(DS+Met), which were dissolved in 7.5 g L-1 Na Cl. Goslings in each treatment were randomly divided into 3 replicates with 30 goslings for each replicate and the feeding period was 28 d. On the E23 and E27, the hatching day(0 d), the 1st, 4th, 7th, 14 th, 21 st and 28 th day post-hatch respectively, blood, breast muscle, liver and jejunum within each group were sampled(n=6) for morphological analysis, and the content of glycogen, glucose-6-phosphatase activity, mucosa enzyme activities, antioxidant ability and Myf5, MSTN SI, SGLT1 and GLUT2 m RNA relative expression were determined. The results of this experiment demonstrated that: In ovo feeding DS can improve glycogen status and reduce breast muscle protein mobilization of embryos by increasing pectoral and hepatic glycogen content. In ovo feeding DS can also promote intestinal development and improve the ability of the digestion and absorption in small intestine due to the increase of villus area of small intestinal, the promotion of intestinal epithelial cells of mature, the enhancement of disaccharidase activity and the improvement of SGLT1, GLUT2 and SI m RNA relative expression. In ovo feeding Met improved Myf5 and reduced MSTN m RNA relative expression to promote the development of breast muscle. In ovo feeding Met reduced cell apoptosis by improving the GSH content and GSH-Px activity to enhance antioxidant ability of small intestine. There were significant interactive effects of DS and Met on development of breast muscle and small intestine.3 The effect of in ovo feeding disaccharide and methionine on hatchability and growth performance of goslingsAt post-hatch, hatching time, hatchability and assist hatched rate were measured. On the hatching day(0 d), 7th and 28 th day post-hatch respectively, blood and yolk sac within each group were sampled(n = 6). The growth performance, blood biochemical indexes and antioxidant ability were measured. The experiment results showed that in ovo feeding DS and Met shortened hatching time, increased glycogen reserves, enhanced protein deposition and improved antioxidant capacity, and thereby improved the absorption of yolk sac and weight gain of goslings.