Study On The Body Development,Meat Quality And Meat Tissue Dynamic Changes Of Jiangquhai Meat-type Pigs At Early Stage

The experiment was conducted to study the early stage development law of Jiang Quhai meat-type line. Analyses of the growth of innards and vitals, limb bone and chine bone were carried out. A piece of longissimus muscle from every gilt were taken to make slide and ultra-slide and to analyze dynamic growth of muscle fiber and myofibril diameter, sarcomere length, A length, I length, and H length, respectively. The content of mitochondria, glycogenosome and fat granule were also tested. The results showed:1. Jiang Quhai meat type line gilts grow very fast from birth to 75d. The Logistic curve (R2=0.9984) is the best model to describe the growth-development law of Jiang Quhai meat-type line in early stage. The growth standard of Jiang Quhai meat-type line can be set up according to the Logistic model, which will provide theoretical base for further breeding. The growth-intension sequence of body- measurement is ham circle> circumference> body-height> body-length>forelegs-circle. The forelegs-circle maturates earlier than others. Body-height and body-length grow moderately, ham circle and circumference maturate later than others. Ham circle and circumference are fast-growing within 75d.2. Every innards change regularly in early stage and liver and spleen grow fastest. The growth-intension sequence is of the order: liver>spleen>renal>lung>heart. Liver and spleen grow very fast after birth, while heart and lung grow very fast at embryonic stage.3. The growth-intension sequence of foreleg-bone is scapula>radius>humerus >phalanx, and the ham-bone is hipbone>phalange>thigh >tibia, and the vertebra is loin vertebra>neck vertebra>tail-vertebra>thoracic vertebra>sacrum. Scapula, hipbone and loin vertebra grow fastest after birth, but phalanx, tibia and tail vertebra grow slowly from birth to 75 days age, which shows that hipbone and loin vertebra can grow larger at later stage and this will ensure the healthiness of the body.4. The content of protein, Ca and P in muscle change slightly, but the content of fat in muscle increases significantly from birth to 75d. The content of ash increases slowly. The level of water in muscle decreases slowly from birth to 75d. PH24 decreases, butwater loss rate has no significant change. The value of OD changes and shear force of muscle changes increasingly from birth to 75d. The composition of fatty acid in longissimus muscle are C16:0 and C 18:1.The levels of C18:3 and C20:0 are small. And the content of USFA is higher than SFA. The trend of IMP content is low-high-low, which is affected by weaning (45d) significantly. The results showed that Jina Quhai meat-type line kept high level of IMP in muscle and fine flavour.5. The longissimus muscle fiber grows very fast at early stage. The fiber grows fastest from 45d to 60d. To exert the gilts' growing potency, it is important to intensify feeding and management at this stage. The myofibril diameter at 15d is almost 1.5 times that of the birth. The following days, the myofibril diameter grow slowly and it almost maturate at the time of 75d. The length of sarcomere is 1649 nm and maturate at 45day.The growth of A length gets longer slowly from birth to 60 day. At 60 day, the length of A is 1346nm, but I length and H length do not grow with it's age, which shows that I length and H length was maturate and remain stable at the embryonic period. The results also show that the content of mitochondria, glycogensome and fat granule were high at of birth, 15d, low at 30d and 45d,(but glycogensome at 45d), high at 60d and 75d .