Method of feed presentation affects the growth of Mongolian gerbils (Meriones unguiculatus)

The Animal Welfare Regulations, which define legal requirements for the care and use of gerbils in research and testing, and the Guide for the Care and Use of Laboratory Animals describe feeding practices for several species of rodents but not Mongolian gerbils (Meriones unguiculatus). To investigate whether the method of feed presentation affected reproduction and growth of gerbils, we compared the reproductive performance and rate of growth of gerbils fed on the cage floor, by hopper (J-feeder), or by wire-bar cage lid. Reproductive parameters of 10 breeding pairs for each method of feeding were followed for 63 d and did not differ between methods. To investigate the effect of feeding method on weight gain in juvenile gerbils, groups of 80 male and 80 female weanling gerbils per feeding method were fed for 5 consecutive weeks after weaning and weighed weekly. Gerbils fed on the cage floor and by means of J-feeders were significantly heavier than were those fed by using a wire-bar top. Our findings indicate that feeding gerbils by using J-feeders or on the cage floor are both acceptable practices.