Effects Of Dietary Threonine On Production Performance, Nitrogen Metabolism And Blood Biochemical Indices Of Rabbits

The experiment was conducted to study the effects of dietary threonine levels ongrowth performance, nitrogen metabolism, biochemical indices, serum hormoneconcentration of weaner to3months old and3～5months old growing rex rabbits andreproductive performance, blood biochemical parameters and serum hormones of the females.The test is divided into two parts, part of the object of study for the growth Rabbit, anotherpart of the breeding females. The first part of the test includes sub-weaning to3months oldand3months old to5months of age in two stages. The first part selects two hundred weanlingrex rabbits with an average body weight of (864±40) g were randomly assigned to5groupswith40replicates in each group and each replicate contained1rabbit. Rabbits in5groupswere fed with experimental diet with the following threonine levels:0.49%,0.59%,0.69%,0.79%and0.89%. The second part selet eighty does with similar weight were randomlyassigned to4groups with20replicates in each group and each replicate contained1rabbit.Does in4groups were fed with experimental diet with the following threonine levels:0.49%,0.69%,0.79%and0.89%. The results were as follows..Dietary threonine levels did not affected significantly average daily intake (ADI),average daily gain (ADG) and feed/gain (F/G)(P>0.05) of weaned to3months old RexRabbits. Dietary threonine significantly increased serum alkaline phosphatase activity (P=0.0226),0.2%add a group reaches its maximum value; dietary threonine levels of serum totalprotein, albumin, alanine aminotransferase, and blood urea nitrogen significantly (P>0.05).Dietary threonine can not significantly improve the quality of hair (p>0.05), but a gradualupward trend with increasing dietary threonine, coat weight and coat area. Comprehensiveobtained by this test indicators weaning to3months of age appropriate growth Rex dietarythreonine adds a level of0.10~0.20%, the appropriate dietary threonine0.59~0.69%.Dietary threonine levels had very significant differences on cholesterin (P<0.05) andglutamic-pyruvic transaminase (P<0.05) of3～5month old rex rabbits, expect for averagedaily intake (ADI) etc.(P>0.05). Meanwhile, Dietary threonine levels had no extremesignificantly influence on Serum total protein and blood urea nitrogen (P<0.05), and had nosignificantly influence on fur quality (P>0.05). In conclusion, the appropria-te threonine concentration in the diet of3～5months old growing rex rabbit was0.69～0.79%. Theoverall situation observed, the the dietary threonine INS not significant (P>0.05), butcompared to the control group, insulin with higher threonine are on the rise. Dietary threoninefecal nitrogen, urinary nitrogen, digestible nitrogen deposition of nitrogen, nitrogen apparentdigestibility, nitrogen utilization and biological potency had no significant effect (P>0.05).The dietary threonine significant effects on ingestion of nitrogen (P <0.01). From this studymeasured indicators, the optimum dietary threonine level of0.69%.Pregnant Rabbit: The test results showed that with increasing levels of dietary threonine,pregnant rabbit ’s litter weight at birth and lactation is not significant, but for weaning weightwas significantly affected (P>0.05); addition, dietary threonine levels can significantly affectpregnancy rabbit serum urea nitrogen and triglyceride levels, and its IgG levels increasedwith increasing levels of threonine, just proves threonine can promote immune function andsignificantly improve the anti-fatty liver effects. Different dietary threonine levels cansignificantly affect serum prolactin and follicle-stimulating hormone content of0.30%dosereached the peak, and weaning weight effects consistent with the results. Integrated indicators,optimum dietary threonine level of0.69~0.79%.