In this experiment the effects of the colour of light and reproductive rhythm on rabbit does' production was examined. The does (n=122) were first inseminated at the age of 16.5 wk and housed in 2 rooms. White coloured light was applied (W), in the first room, and blue lighting (B) was used in the second room. In both rooms, the does were randomly divided into 2 subgroups and inseminated using a theoretical reproductive rhythm (interval between parturitions) of 42 (42D) and 56 d (56D), respectively. Kits were weaned at 35 and 23 d of age in 42D and 56D subgroups, respectively. The rabbit does' performance was examined over 336 d (8 and 6 reproduction cycles in groups 42D and 56D, respectively). During the first gestation, the W rabbits had higher feed consumption (162 vs. 145 g/d, P<0.05) and during the whole period a larger body weight than the B does. The colour of the light did not influence the kindling rate and litter size (P>0.10). In contrast, individual kit and litter weights measured at 23 d of age was higher in the B group (451 vs. 435 g and 3611 vs. 3498 g, respectively; P<0.05). No significant differences were found for productivity index between the W and B groups. The kindling rate was more favourable in the 56D than in the 42D group (89.3 vs. 82.0%, P<0.05). The 56D does'body weight at kindling was larger than that of the 42D group (4474 vs. 4188 g, P<0.001). No significant effect of reproductive rhythm were found for litter size. Individual kit weight and litter weight at 23 d of age were slightly higher for the 42D group than the 56D (447 vs. 439 g, P=0.057 and 3598 vs. 3513 g, P=0.055). Kindling intervals of the 42D and 56D groups were 46.6 and 59.5 d, respectively (P<0.001). Body condition of does (measured by the TOBEC method) was higher in the 56D group at 4-5 th parturition. Survival rate at the age of 336 d was slightly higher for 56D than 42D female (26 and 13% respectively, P=0.07). Based on the results, the blue colour could have a favourable effect on the litter weight as well as the individual weight of kits at 23 d (+3.2 and +3.7% respectively), it may be concluded that the effect of the colour of light merits further research. Comparing the two reproduction rhythms, extend reproductive rhythm and early weaning (group 56D) could be more favourable (condition, survival) from the animal welfare viewpoint but the productivity index (number of kits/doe/yr and kits' weight at 23 d/doe/yr) of the 42D group exceeded that of the 56D group by 19-23%, which has a high economical impact.
ASJC Scopus subject areas
- Animal Science and Zoology