Feed restriction during pregnancy: effects on body condition and productive performance of primiparous rabbit does

Abstract

This study examined the effects of feed restriction at different stages of rabbit pregnancy on body condition and productive performance. Just after insemination, pregnant primiparous New Zealand White does were assigned to 4 groups (10/group): the control group (C) was fed with 130  g/d of commercial feed while the others received 90 g/d from day 0 to 9 (R1), from day 9 to 18 (R2) or from day 19 to 28 (R3) of pregnancy and 130 g/d the remaining periods. A 3-point scale for loin and rump was used to calculate the aggregate body condition score (BCS), while perirenal fat weight (PFW) was estimated by ultrasound measurement of its thickness. The C does showed a positive balance of the pregnancy (0-26 d) for both body weight (P<0.001) and PFW (P<0.01). In particular, these increases occurred in the first 18 d of pregnancy (BW: P<0.001; PFW: P<0.05). The R1 does showed compensatory body growth after feed restriction (10-18 d: P<0.01), but lower BCS (P<0.05) at 26 d compared to control group. Feed restriction in mid and late pregnancy determined negative PFW balance (0-26  d: P<0.05), lower BCS at 26  d (R2: P<0.05) or lower BW gain compared to control (R3: P<0.05). The effects of feed restriction on productive performance depended on the restriction period: while R1 does did not show any differences compared to C, restriction during the last third of pregnancy increased perinatal (9.9 vs. 16.1%; P<0.05) and pre-weaning mortality (10.6 vs. 36.7%; P<0.01). However, milk production was lower in all restricted groups (C: 156, R1: 132, R2: 133; R3: 124  g/d; P<0.001, respectively). Thus, the energy deficit due to concurrent undernutrition and metabolic demands during pregnancy has short- and long-term consequences on both mother and offspring.