| The trial adopted one–factor completely random design.In order to investigate the growth and development of body mass index and digestive system of Guanzhong dairy goats from farmer individuals, the anatomical and tectology observation was used for the systematic study.A total of 28 healthy Guanzhong dairy goats from farmer individuals with similar body weights were slaughtered at the age of 0d, 7d, 15d, 30d, 60d, 90d and 365d, respectively, and each with 4 replicates. Weighted, measured the main body mass index, measured the weight and the length of the digestive organ and alimentary canal, and the pH of alimentary canal were detected also. In order to determine the effects of age on morphology growth and histology structure of the digestive organ and alimentary canal, 3 lambs from each group were selected to make paraffin section. The results showed that:1) The body weights and the body mass index grown fast after birth. Relative daily growth rate was obviously higher from 0d to 7d, achieve 5.51%; the daily weight gain increased significantly before 60d(P<0.05),average daily gain reached the maximum (190.19g/d )from the 7d to 15d.The body length and body height strongly correlated with the body weight,and the correlation coefficients were 0.975 and 0.973, respectively.The regression equation was ?y=-22.572+0.383x1+0.366x2,x1:body height,x2:body length.2) The absolute weights of digestive organs increased gradually, and the relative organ weights of digestive organs and digestive glands peaked at different time points, the liver, pancreas, stomach and small intestine peaked at 15d, 15d, 60~90d and 90d, respectively. They had different allometric growth rate, most of them grown faster than the body weights, while the length of alimentary canal increased more than the body length.3) The rumen pH value maintained 5.9～6.7, the pH value of abomasum was acidic of neutral at first and then decreasing to pH2.75 at 60 d.The pH value of duodenum ranged from 5.1~5.9; jejunum's and ileum's was about 5.8 at newborth, raising to neutral at 60d. Comparing the pH value of different parts of intestine at the same age, ileum was highest, and duodenum was lower than jejunum.4) The structure of liver developed completely at 0d; connective tissues of liver were undeveloped, so the edge of the hepatic lobule was not clear. The volum and the quantity of hepatocyte increased gradually, the proportion of hepatic sinusoid decreased with age increasing.The structure of pancreas developed completely at newborn, the edge of the pancreas lobule was clear. Acinar cells were enlarged and the spaces between acinar cells were decreased with age increasing. The amounts of islets multiplied gradually after 30 days.5) The color of mucosa membrane in forestomach was pink at newborn, and then the color was brown, gradually. The papillae in rumen was not developed at 0d and then developed fast. Mucosa membrane in omasum has four stages leaflets, the height of leaflets increased with age increasing.6) The villus height, villus width, crypt depth and muscular thickness in every segment of small intestine increased with age increasing. The villus height in small intestine decreased in order of duodenum, proximal jejunum, distal jejunum and ileum, respectively, after 15d. The C/V value at newborn was higher, and then decreased gradually. Muscular thickness decreased in order of duodenum, ileum and jejunum respectively. The C/V value of proximal jejunum and distal jejunum was higher than duodenum and ileum(P<0.05). The C/V values in each section of small intestine were similar and fluctuate between 1.9 and 2.6 after 90d.
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