Effect of dietary inclusion of Spirulina on nutrient apparent digestibility in chinchillas

Spirulina (Arthrospira platensis) is a blue-green microalgae characterized by a high level of protein as well as potential antiobesity, antioxidant and hypolipidemic effects. The objective of the study was to evaluate the nutrient apparent digestibility of two isoprotein (15.7% crude protein), isoenergy (16.8 MJ/kg) and isofiber (17.8% crude fiber) pelleted diets for chinchillas, with or without Spirulina supplementation. With this aim, 20 growing chichillas (Chinchilla lanigera) of both sexes, with an average body weight (BW) of 268 g, were fed either a control diet (diet C) or an experimental diet with Spirulina at 2% inclusion level (diet S). The animals were individually allocated indigestibility cages for an adaptation period of 7 days followed by a 5 day-digestibility trial. During the digestibility trial, for each subject feed intake was calculated and faeces were collected and weighed. Diets and faeces were analysed for dry matter, organic matter, crude protein, ether extract, ash, starch, crude fiber, and fiber fractions content. The effect of the diet was tested by ANOVA using the results from the animals that completed the trial: 5 on diet C and 8 on diet S. The treatment showed no difference on feed intake (0.10 g DM/kg BW for C and S diets). The energy digestibility of the experimental diets (C: 41.3 vs. S: 49.1%), as well as the digestibility of dry matter (C: 38.0 vs. S: 44.9%) and organic matter (C: 40.7 vs. S: 47.3%) were similar although generally low. Contrarily to what was observed in rabbits and guinea pigs, enriching the diet of chichillas with Spirulina resulted in higher crude protein (C: 50.0 vs. S: 59.8%; P<0.05) and ether extract (C: 70.2 vs. S: 80.3%; P<0.05) digestibility as well as in a higher starch (C: 98.7 vs. S: 99.0%; P=0.05) digestibility. In chinchillas, the dietary inclusion of Spirulina has the potential of improving the nutritional value of the diet.