The study focused on the estimation of genetic trends for behavior and performances of does and kits during lactation in parallel to 22 generations of selective breeding for litter size and kit growth. The direct effects from the kit (kit line) were separated from the maternal effects of the doe (doe line) with use of a crossfostering design between the old-type (L0) and the modern-type (L22) lines. Does were studied over the two first parities. They raised rabbits from a single kit line. None kit was raised by its biological mother. At d21, L22 females produced more milk than L0 females (250 g vs 206 g, p=0.0003) which resulted in a higher weight of the kits at d21 (378 g vs 340 g, p<0.0001). L22 does had better maternal abilities than L0 does as refered to nest quality (p=0.06), fur puckling (p<0.0001), milk production (p=0.0003) and willingness to nurse (p=0.007). At most dates, more L22 kits were observed out of the nest than L0 kits, whether they were raised by L0 or L22 does. L22 kits exited the nest earlier during lactation and where bolder in an emergence test than L0 kits. Trends in doe behaviour were positive and favorable to litter performance. In advanced lactation, genetics of the kit influenced kit behaviour more than genetics of the nursing dam.