Need suggestions for mating my female spitz

Question
Dear mam, my name is Sujatha and I had mailed you 2 months back that my female miniature spitz did not conceive during the last 2 matings .... You had advised me to put her on a high beef or lamb diet ... Accordingly, I am feeding her with a dog food named "SCience Plan ( Lamb and Rice )" and even fed her twice with beef ... She has come into heat now ( day before yesterday - On 20th November  2012 ) ... As, it did not click the last 2 times, could you please suggest me any tips that I should follow this time ... ??? & Is there any special food that I need to  feed her during this period ???
Will beef be too heavy for her during this estrous time ??

I am planning to mate her with 2 males this time ( 1 with the male which I mated last time and the 2nd with my own male dog ) .... The first male is smaller than my female ( only half her size ), while my male is bigger than her ( he looks like a wolf and she looks like a fox )... Will it be ok to mate her with 2 male dogs ???


NOTE :
My male is a proven dog and has sired pups with another female ..

Regards,
Sujatha

Answer
Hello Sujatha,
If it were me, I would mate her with the proven stud only for this time.  That way you will know if the problem is with the female or the male.   Mate her on Dec 1 and Dec 3.  Only those two days.  This will keep her wanting, and will give the male sperm time to renew itself.
Let me know how you make out.
The lamb and rice is fine.  Beef is fine anytime.  I hope you are not giving her supplements at this time.  Take her off all of them for the next 14 weeks.  When you are certain she is pregnant, start her on a half a cup of cottage cheese each day to help her with calcium.
Nancy