Effect of maternal feed restriction on muscular characteristics of rabbit offspring

Thirty hybrid female rabbits of 15 weeks of age were at random divided into three groups and fed with one of the 3 following diets: "C diet" for young females (DE = 11.71 MJ/kg DM) fed ad libitum; "R diet" was the C diet fed at 80% of ad libitum , "F diet" rich in fiber (24.6% vs 18.7% for C diet; DE = 9.77 MJ/kg DM) fed ad libitum. The does were inseminated at the 19th weeks of age. The 3 diets were administered until the first parturition, afterwards all the does received the C diet ad libitum. Three pups per litter were slaughtered at birth, at 35d of age (weaning) and at 81d of age, respectively. At the second parturition, another pup per litter was slaughtered at birth. Ten minutes post mortem the Longissimus lumborum (LL) muscle of each slaughtered rabbit was sampled and then underwent the histochemical treatment: mean cross-sectional area (CSA), compactness index (CI) and sphericity (SPH) of the fibers of the new-born rabbits; percentage of the fiber types (bR, aR or aW) and CSA for rabbits of 35 and 81d of age. At birth all the fibers of LL muscle were typed as aR. The maternal feed restriction, applied as qualitative restriction (diet F) or quantitative restriction (diet R) significantly increased the CI of LL fibers of newborn rabbits of the first kindling, while maternal feed restriction effect was not evident on young of second kindling. At weaning, the young rabbits belonging to the first kindling exhibited an effect of maternal feed rationing on fiber type distribution. R diet, compared with F and C diets, significantly increased the percentage of fR fibers, while F diet significantly reduced the percentage of aR fibers. The greatest effect of maternal feed restriction on weaning rabbit was observed on the percentage of aW fibers (P