Research Of The Difference Of Gastrointestinal Development And Apparent Digestibility Of Diets In Pigs Of Different Breeds During Their Earlier Period

This study was carried out to research the regular patterns and differences of the development of landrace's ,large white×taihu crossbred's and taihu's gastrointestinal tract. 24 heads of healthy newborns of landrace, large white× taihu crossbred and taihu respectively were used. When the pig at the age of 0,30,60,and 90 days, selected 4 pigs respectively from each breed and weighed their body weight with an empty stomach ,then drew blood in order to mensurate the concentration of somatotropin and gastrin.To butcher the piglet after drawing blood then took the pancreas and chymus of stomach out in order to mensurate the activity of the digestive enzyme.Weighed the stomach and small intestine and measured the length of the small intestine then calculated the proportion between them and the body weight. 1 cm length of ileum was cut off to measure the height of the villus and the depth of the crypt.Two digestion experiments were carried out when the pig at the age of 42 to 45 days and 72 to 75days ,then measured the nutrients digestibilities of every breed.The results showed: From the new born to 90 days old, the relative weight of stomach of landrace(4.51→6.05g/kgBW) was lower than large whitextaihu crossbred(5.85→6.25g/kgBW) and taihu(4.26→8.52g/kgBW); the relative length of small intestive of landrace(3.24→0.56m/kgBW) was shorter than large whitextaihu crossbred(4.94→0.65m/kgBW) and taihu(4.74→0.79m/kgBW).The relative length of small intestive of landrace was always shorter than taihu during 90 days period(p<0.01).The villus height of every breed of pig was decreased with the daily age increasing, but the villus height of landrace(445→307μm) and large whitextaihu crossbred(426→297μm) were always higher than taihu(355→230μm) from 0 to 90 days...