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

Abstract

| INTRODUC TI ONLaboratory animals invariably serve as the basis for all scientific discoveries and technological advancements in the medical field including almost all medical knowledge, treatment regimes and medical device development. Proper selection of animal model for research is the key factor for extrapolation of animal research findings to humans, thus helping to improve the lives of people and other animals (Rand, 2008). Of the several factors that influence reproducibility of results, diet is an important environmental factor besides microbiological and genetic factors that affect reproduction, growth, disease and responses of laboratory animals to scientific manipulation. AbstractSemi-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-weekold 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. K E Y W O R D Sbody weights, female hamsters, food intake, natural source diet, reproductive performance, semi-synthetic diet

Grain versus AIN: Common rodent diets differentially affect breeding and metabolic health outcomes in adult C57BL/6j mice

“…More research is needed to confirm this hypothesis; only a limited number of studies have systematically compared breeding outcomes of rodents kept on semi-synthetic diet types to those of rodents kept on grain-based chow, and effects vary between studies. A recent study with Syrian hamsters showed that semi-synthetic diets can strongly reduce reproductive performance (36) whilst a different study, using rats, showed that birth weight was reduced as a result of semi-synthetic diet compared to grain-based diet (37), however, to our knowledge, impaired offspring survival has not been reported. Diet type did not appear to affect fertility, fetal implantation sites and litter size in CD-1 mice that were mated for 10 days (22).…”

Grain versus AIN: Common rodent diets differentially affect health outcomes in adult C57BL/6j mice

“…More research is needed to confirm this hypothesis; only a limited number of studies have systematically compared breeding outcomes of rodents kept on semi-synthetic diet types to those of rodents kept on grain-based chow, and effects vary between studies. A recent study with Syrian hamsters showed that semi-synthetic diets can strongly reduce reproductive performance [ 36 ] whilst a different study, using rats, showed that birth weight was reduced as a result of semi-synthetic diet compared to grain-based diet [ 37 ], however, to our knowledge, impaired offspring survival has not been reported. Diet type did not appear to affect fertility, fetal implantation sites and litter size in CD-1 mice that were mated for 10 days [ 22 ].…”