Semi-synthetic diet versus diet using natural ingredients-Comparative study in female Golden Syrian hamsters

Semi-synthetic diets (SSD) are recommended and are widely used to carry out experiments in rodents. However, in our experiments planned to carry out generation studies in female Golden Syrian hamsters using semi-synthetic diets, it was observed that the hamsters did not conceive as a result of decreased food intake. In this paper, we present the effects of both semi-synthetic diets and natural source diets (NSD) on food intake, body weight and reproductive performance of this species. Four-week-old female hamsters were equally divided into 3 groups and initially acclimatized for 2 weeks on natural chow diet (NCD). Thereafter, they were fed either control diet, high fat diet (HFD) or low protein diet (LPD) based on semi-synthetic/natural source ingredients until 12 weeks. Daily food intake and weekly body weights were monitored. Hamsters were kept for mating for about 2 weeks from 10th week onwards, during which the pregnancy confirmation test was done using standard vaginal smear examination. In all the groups fed SSD, the food intake was very poor, hamsters lost body weight and did not conceive, thus preventing us from carrying out further experiments. Hamsters fed NCD/NSD ingested more than twice as much as hamsters fed SSD (7-8 g/day/hamster against 3 g/day/hamster on average respectively). Based on the results of the current research, we conclude that the routinely used semi-synthetic diet is not suitable for carrying out studies in female hamsters. We suggest that scientists must also consider the unusual biological characteristics of a given species besides other biological factors. It is therefore critical to select appropriate biological models and diets that provide optimal sensitivity and specificity to accomplish the research objectives.