EFFECT OF DIFFERENT LIGHTING SCHEDULES (16L:8D OR 12L:6D) ON REPRODUCTIVE PERFORMANCE OF RABBIT DOES

The objective of the experiment was to compare the reproductive performance of rabbit does in a routine (16L:8D) and in proportionally shorter (18 hours) 12L:6D lighting regime. The experiment was conducted at the experimental rabbit farm of the Kaposvár University. Crossbred rabbit does were randomly housed in two identical rooms. Drinking water (from nipple drinkers) and commercial pellet were available ad libitum. The temperature varied between 14-28 C, depending on the season. The two rooms only differed in the lighting regime: 24h group = 16 hours light and 8 hours dark (n=54 does); 18h group = 12 hours light and 6 hours dark (n=54 does). Rabbit does were first inseminated at 16.5 weeks of age. AI was applied 11 d post partum (42 d reproductive rhythm, single batch system). Cross-fostering was applied within groups with max. 8 kits/litter at first kindling and max. 10 kits/litter at subsequent parities. Rabbit does could nurse their kits freely. Data of the first 5 consecutive reproductive cycles were evaluated. Body weight of the does at kindling, kindling rate, litter size at birth, at day 21 and 35 showed no significant differences among the groups. Mortality of the kits for the periods of 0-21 and 0-35 days were independent of the lighting schedule. Litter weight at day 21 and 35 was 4% lower in 18h group compared to the 24h group (P<0.05). Calculating the productivity index, the number of kits born alive and number of kits at day 35, per 100 AI, were 7.5% (813 vs. 757 kits) and 5.2% (714 vs. 679) higher in the 18h group compared to the 24h group. Considering the opposite tendencies of the kits’ body weight, the two groups did not differ for the total weight of the weaned rabbits per 100 AI (18h: 630 kg; 24h: 632 kg). Does survival did not differ significantly during the experimental period (83% and 81% in groups 18h and 24h, respectively, P=0.735). Reproductive performance of rabbit does housed in a routine (16L:8D = 24 hours) or proportionally shorter (12L:6D = 18 hours) lighting regime was similar.