Effect of feed restriction on organs and intestinal mucosa of growing rabbits

This experiment was carried out to evaluate the effect of feed restriction on internal organs with respect to their weight and size, and the development of the intestinal mucosa of growing rabbits. Sixty 33-day-old New Zealand White rabbits were used in a randomized block with four treatments and five blocks. The treatments consisted of ad libitum feeding; feed restriction from 33 to 40 days of age; feed restriction from 54 to 61 days of age; and feed restriction from 33 to 40 and from 54 to 61 days of age. There was no effect of feed restriction on weight, length and width of internal organs, except for heart weight, which decreased when feeding was restricted from 54-61 days and from 33-40 and 54-61 days of age. There was no effect of feed restriction at the different ages on duodenal morphometry. In jejunum, the villi of rabbits fed ad libitum or restricted from 33 to 40 days were higher, and rabbits restricted from 33-40 days had wider villi and higher absorption surface. In the ileum, only rabbits fed ad libitum had higher villi. Feeding restriction reduced heart weight, but not its size, and negatively affected jejunum morphometry when performed in later stages.