The Investigation Of Intestinal Absorbable EAA And The Conversion Efficiency Of Lactation In Lactating Goats

Lactation processes employ the priority to utilize the plasma AA, we use this theory toprovide limited AA of lactation. In this way, AA extraction by the mammary gland from bloodmay be maximized. Four nonpregnant, multiparous lactating British SAAnen goats (40±6kgof BW) were used. Under general anesthesia, a catheter was placed into the abomasum,thecarotid artery was elevated to a subcutaneous position, the common collateral vessels betweenthe udder halves were ligated, and an ultrasound flow probe was positioned around theexternal pudic artery (EPA). In four successive4×4and one3×3complete Latin Squaredesignes. Between the5Latin square design a repeat. Lactating goats were fed a low proteinration that provided only100%of metabolizable protein and energy requirements formaintain. The protein and energy of milk production was alleviated by infusion into theabomasum of an AA mixture (full AA or excluding one AA) and glucose. Treatments wereabomasal infusion of TAA (EAA and NEAA), Lys deleted, Met deleted,Leu deleted,Phedeleted,Ile deleted,Arg deleted (-A),Trp deleted, Thr deleted, His deleted or Val deletedamino acid mixture. Goats were assigned to treatments (8to10d) according to the design.On the three days of the sampling period, arterial and mammary vein blood were withdrawnto determine blood AA concentration(10ml/30min). Flow probes monitored mammary bloodflow. The results showed that low levels of blood EAA （-Lys、-Met、-Leu、-Phe、-Ile、-Arg、-Trp、-Thr、-His or-Val）were yields of milk, and CP (milk N×6.25) content have the tendencyto reduce or significantly reduced,CP content has the (2)mammary blood flows increasedby20.55%、26.03%、34.23%、3.6%、30.99%、63.19%、32.22%、4.79%、23.26and10.09%whenmoved-Lys、-Met、-Leu、-Phe、-Ile、-Arg、-Trp、-Thr、-His or-Val respectively.(3)abomasalinfusion of deletion of individual EAA from the complete AA mixture changed arterial andvenous blood concentration of EAA,the deleted individual EAA significantly decreased inarterial (P <0.05） except Val and Trp;Except forLeu、 Ile、 Trp and Val,the venousconcentrations of the deleted EAA decreased significantly.Mammary extraction efficienciesof all the deleted EAA were not significangtly changed except Arg decreased(P<0.1).(4)Theconversion efficiency of AA have no significant change besides Arg,Val and Phe numerically increased.In conclusion,the ideal rate of EAA secreted into milk is lys:Met:Leu:Phe:Ile:Arg:Trp:Thr:His:Val=6.5：4.3：6：3.6：2.7：1.8：8.3：1.2：1：8.6.