Study On Dynamic Changes Of Conventional Ingredients, Enzymes And Hormones In Sows Colostrum And Their Comparisons With Milk

In this paper ,we used the dominant swine species- Landrace XYorkshire as a research model. The dynamic changes of conventional ingredients, enzymes and hormones in colostrum during 5 days and milk on 20 day of 8 sows in their 4-5 parturitions were studied. The results of the experiments can serve as the basic data and theoretic foundation for confecting artificial colostrums and milk replacer.Colostrum on Oh(started from the first piglet bom), 2h, 4h,6h,8h,10h,12h,16h,20h,24h,2d,3d,4d and 5d and milk on 20d postpartum were collected from 8 sows similar in parturition .The concentrations of conventional ingredients were determined. Skim milk was obtained by precipitating with 3500rpm for 20 minutes. The concentrations of enzymes and hormones in skim milk were measured. The dynamic changes of ingredients in colostrums were studied and compared with milk. The results were showed as follows:(l)The dynamic changes of conventioanl ingredients in colostrum and milk.Dry matter, fat, protein, lactose, calcium, phosphorus and pH value changed significantly during the 24 hours after parturition. Their changes is not significant after d 3 and proximate to d20. Dry matter, protein and energy concentrations were the highest on 0 hour after parturition and decreased with time went by. Lactose, calcium, phosphorus and pH value were the lowest on 0 hour and increased with time went by.(2)The dynamic changes of enzymes in colostrum and milk.The activities of AP , Y -GT and AM were the highest in the first day and decreased gradually. The activities of AP in the first day were significantly higher than those on d 20 (PO.01), d 2 to d 5 were significantly higher than d 20 (P<0.05).The activities of Y -GT and AM on d 1 to d 4 wererespectively significantly higher than those on d 20 (P<0.05 and P<0.01),and no significant difference between d 5 and d 20 (P>0.05).The activities of LP were lower after parturition and increased sharply and reached their peaks on d 4.Afterward it decreased gradually. There were no significant difference between the activities of LP on d 2 to d 5 and on d 20 (P>0.05).There was positive correlation between Y -GT activities and total protein concentrations(r=0.983,P<0.01),which showed that Y -GT had close relationship with the synthesis of protein. While the activities of AM was negatively correlated with those of LP (r=-0.924,P<0.01), which maybe indicate that they act compensatory effect in the milk defense system. (3 )The dynamic changes of hormones in colostrum and milk.The contents of GH, INS, PRL, Cort, TS and T4 were measured by radioimmnoassay. The concentrations of GH, INS, PRL, Cort, T4 were higher on 0 hour(the first piglet born) and decreased with time went by. There were no significant difference between their contents on d 5 and on d 20(P>0.05). The concentrations of Ta were lower on 0 hour and increased with time went by .The content of TS reached a peak on d 3 and declined remarkably. The contents of Tj between d 4 and d 20 were not significantly different(P<0.05).There were no significant difference between the contents of T3 on d 5 and on d 20(P>0.05).The contents of INS maintained high levels during the 16 hours postpartum,which may be related to Gut Close. (4) According to the nutritional ,immune and communicable function of colostrum ,we defined the terminative day of colostrum period in Landrace X Yorkshire sows was 4 day postpartum.