Effects of lactation, energetic deficit and remating interval on reproductive performance of primiparous rabbit does.

Female rabbits (n = 151) were assigned at their first parturition (day 0) to one of three treatment groups (A: non-lactating does and ad libitum feeding, R: non-lactating does and restricted feeding, L: lactating does and ad libitum feeding). Additional females (n = 18) were slaughtered at parturition. Experimental females were presented to the male on days 3 (A3, L3 and R3 groups, n = 25, 26 and 26, respectively) or 10 (A10, L10 and R10 groups, n = 25, 25 and 24, respectively) and were slaughtered on day 28 after parturition. Compared to does slaughtered on day 0, adipose tissues were lighter in L (-66%) and R (-32%) females while they were heavier in A females (+40%; P < 0.01). These results suggest that both L and R females were in energy deficit. Receptivity (80% vs. 98%) and conception rate (51% vs. 83%) were lower in L compared to A females (P < 0.01) regardless the day of male presentation. Ovulation rate (-14%) and conception rate (-26%) were lower in R3 than in A3 does (P < 0.05). Ovulation rate was 24% lower in the L10 than in the A10 group (P < 0.01). The uterine contents were lighter (-25%) in L and R than in A does (P < 0.001) regardless the day of male presentation. These results suggest that the energy deficit associated with milk production can partly explain the negative influence of lactation on reproductive performance.