In this study, considering the normal ingredients in guinea pig's milk, by using cow milk, mixture of
vitamins and minerals, a milk substitute was prepared and sterilized by autoclaving and filtration methods.
In food analysis of produced milk, the important substances values, such as protein, fat and ash, were
suitable. Milk substitute was fed to four groups of newborn's guinea pigs that were obtained by
hysterectomy from out bred color Pirbright conventional parents, and maintained in the sterile environment
inside laminar flow. The health, growth and reproductive parameters were evaluated during 6 months in
four treated groups at the suckling age (milk substitute) and solid pellets feeding stage and these values
were compared with four coequal's control groups. The results show, all young fed with substitute milk,
reached to puberty at normal age (3-4 months old ), The males, had the normal fecundity and the duration of
pregnancy in all females were in the normal range (22-25 weeks), litter size (4-5) and birth weight (70-100g)
were in the normal ranges. In this study the preparation of suitable substitute milk and also a part of the
method and protocol for production of the specific pathogen free (SPF) animals were introduced and put
into the practice.