Dynamics of the Biosynthesis of Niacin During Development to Maturity of Soybean Seed

Dynamics of the biosynthesis of niacin was followed in developing seed of four soybean genotypes under the defined climatic conditions in the course of three years. Tests were carried out at weekly intervals from the moment the seed was suitable for analysis up to its full maturity with the moisture content of about 14 %. Observation of the content of niacin determined more intensive synthesis of this vitamin in the third and fourth development stages, at the time of the highest cumulation of dry matter and metabolic activity. Maximal concentrations of niacin were noticed in the year in which along moderate temperatures considerably ampler precipitation was recorded. A comparison of the fluctuation of proteins and fatty acids with the fluctuation of niacin content confirm its role in the biosynthesis of these most important components of soybean seed.     

肉仔鸡卵黄囊烟酸的利用

ＡＡ肉仔鸡９２只，其中８０只于出壳１２时龄内每只鸡卵黄囊注射［３］－Ｈ－烟酸２ｃｉ；于注射后的２，４，６，８，１０，１２．１６，２０，２４，３２，４８，７２，９６，１２０，１４４和１６８小时屠宰，共１６次，每次５只鸡，测定卵黄囊、肝脏发血液中［３］Ｈ－烟酸的含量。另外１２只于出壳当日屠宰，测定卵黄囊、肝脏及血液中烟酰胺初始含量。雏鸡卵黄囊注射［３］Ｈ－烟酸后，卵黄囊、肝脏及血液中［３］Ｈ－烟酸含量下降到最大值的１／２时间分别为１１、２５和７５小时，下降到最大值的１／５时间分别为４０、１０１和１６３小时。卵黄囊烟酸含量的８０％在出壳后２天内被动用。     

豆粕型日粮条件下绵羊瘤胃内烟酸的产生、消失及流通规律

选用3只体重为35-43kg、安装永久性瘤胃瘘管、十二指肠近端瘘管的内蒙古半细毛羯羊，在饲喂豆粕型日粮条件下，通过非同位素标记烟酸的启动-连续灌注方法，测定绵羊瘤胃烟酸的基本产生、消失、外流速率及十二指肠的流通速率。试验结果表明，饲喂豆粕型日粮的绵羊瘤胃烟酸的基本产生速率为2．50mg／h。通过灌注的方法提高烟酸产量后，烟酸在瘤胃内的产生速率为5．06mg／h；消失速率则为1．90mg／h；瘤胃内烟酸的外流速率为3．16mg／h；同时得出烟酸在十二指肠的流通速率为1．73mg／h。     

烟酸和烟酸铬对断奶犊牛应激的影响

选用三月龄断奶荷斯坦犊牛30头,将其等分为三组,对照组为基础日粮,烟酸组和烟酸铬组分别在基础日粮中添加400 mg/kg的烟酸和6.4 mg/kg的烟酸铬.结果表明:烟酸和烟酸铬在前10 d对犊牛的增重影响不明显(P>0.05);20～30 d,烟酸组和烟酸铬组的平均日增重比对照组分别提高5%和27.6%;30～40 d,烟酸组和烟酸铬组的平均日增重比对照组分别提高12.8%和18.11%;而最后一个阶段,烟酸组和烟酸铬组的平均日增重比对照组分别提高8.9%和7.45%.试验期间,烟酸铬组与对照组相比提高T3、T4、生长激素、胰高血糖素水平分别为25.68%(P<0.05)、17.31%、6.73%、9.03%;烟酸组与对照组相比提高T3、T4水平分别为11.5%、12.7%.