Influence of maternal feed rationing on metabolic and contractile properties of Longissimus lumborum muscle fibres in the rabbit offspring

Thirty hybrid female rabbits of 15 weeks of age were divided into three groups and fed for 8 weeks (until the first parturition) on one of the three following diets: "C diet" (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 fibre (24.6% vs 18.7% for C diet; DE = 9.77 MJ/kg DM) fed ad libitum. Afterwards, all the does received the C diet ad libitum. One pup per litter was slaughtered at birth, one at 35 d (weaning) and one at 81 d of age. At the second parturition, another pup per litter was slaughtered at birth. Ten minutes post mortem the Longissinius lumborum (LL) muscle was sampled and the mean cross-sectional area, compactness index (CI) and sphericity of the fibres of the new-born rabbits were determined; oil rabbits of 35 and 81 d of age the fibre type distribution (beta R, alpha R or alpha W) was also measured. The two maternal rationed-diets significantly increased the Cl of LL fibres of new-born rabbits of the first kindling, compared to the C diet. On weaning rabbits the greatest effect of maternal feed rationing was observed on the percentage of alpha W fibres (P < 0.01), which was the highest for the F diet (85.2%), intermediate for the C diet (78.0%) and the lowest for the R diet (71.8%). At 81 d of age, no effect of maternal dietary treatment was found on offspring.