Studies On Effects Of Diet AA Profiles On Lactating Performances Of Goats

This paper mainly studied on effects of different AA profiles on lactating performances of goats by nutrients infusion technique and arterio-venous technique.Firstly,it was analyzed and evaluated that effects of different AA profiles of intestinal absorption AA on the arterial concentrations of AA and mammary uptake rates of AA by infusion casein and EAA. Secondly, casein and bean was infused to observe the effects of different CP levels and AA profiles on lactating performances.The results showed that the casein couldn't be regards as the ideal protein for the lactating ruminants;and the AA profiles of casein was superior to the bean.It was suggested that milk protein synthesis could be improved by regulating mammary blood supply of the profiles of amino acids and increasing mammary uptake of amino acids.Trial one Effects of abomasal infusions of sodium caseinate and AA on lactating performances of goatsIn 3×3 complete Latin Square design,three Shaneng goats(35±5kg) with the same milk yield,fitted with permanent abomasal cannulas,and embeded carotid artery under the skin were used to estimate of casein as the ideal AA profile of lactating ruminants. Which wasⅠ:casein35g/d ;Ⅱ:casein 35g/d +lys (2g/d) met(1.5g/d) his (1g/d)arg (2g/d) thr(1.5g/d)Ⅲ:casein35g/d+phe(2g/d)leu(2g/d)ile(1.5g/d)val(1.5g/d)trp (1g/d) . The results showed CP%(P=0.0009) was affected byⅢ.The milk yield increased 11.4%, CP% increased 32% compared withⅠ.It suggested that the 5 kinds of AA include the first limit AA of lactating ruminants,as to which one or ones shoud be check out further .Ⅱdid not affect the milk yield or CP%. It suggested that the mammary gland did not need these AA after infused casein .Trial two Effect of different CP levels of casein and bean on lactating of late dairy goatsIn 4×4 crossover desige,four Shaneng goats(40±5kg) with the same milk yield,fitted with permanent cannulas,and embeded carotid artery under the skin were used to investigate the effect of different CP levels of casein and bean on lactating of late dairy goats .Ⅰ: casein 50g/d ,CP =130% of lactating requirement casein ;Ⅱ: casein25 g/d ,CP =100%;Ⅲ:bean72 g/d , ,CP =130%;Ⅳ: bean 36 g/d,CP =100%. The results showed that the AA profiles of casein was superior to the bean.The fat percentage and yield had different change tendency.The PUN of two 130% groups were larger than the 100% groups(P=0.1593).The AA profiles had significant effect on the same CP level(.P=0.0003).And the casein had the lower PUN .It suggested that we can decrease the AA of diet that has larger oxidation rate to reduce PUN to get the greater utilization rate. Key words: lactating goats; Mammary gland;Mammary plasma flow; Sodium caseinate;Bean;Amino acids;Lactating performantion...