Effect of spray application of Lactobacillus plantarum on in vivo performance, caecal fermentations and haematological traits of suckling rabbits

Two days before kindling, 228 New Zealand White rabbit does were homogeneously divided into two groups (114 does per group) and fed the same diet. After delivery, the litters were equalized to 8 pups. From 1 to 35 days of age (weaning), the control group (CONT) did not receive any treatment while in the experimental group (LAC) the nests were sprayed with a commercial product containing lyophilized Lactobacillus plantarum dissolved in water (12 g/L). L. plantarum was sprayed on the litters (5 mL per rabbit) once a day during seven consecutive days after delivery. After one week of rest, the treatment was repeated for another week according to the same experimental protocol. Mortality rate, recorded on all the litters (912 rabbits per group) was significantly lower in the LAC group (9.9 vs 17.2%; P<0.05). There were no significant differences in in vivo performance of the 24 litters per group, and rabbits of both groups reached a similar weight at weaning (938 vs 932 g for LAC and CONT groups, respectively). Rabbits from the LAC group showed fermentative activity of caecal microflora (total volatile fatty acids 24.8 vs 14.5 mmol/L; P<0.01) and higher percentage of lymphocytes (73.7 vs 63.9% of total white blood cells; P<0.05). Among the microflora population of rabbit caecal content from the LAC group, it was possible to identify L. plantarum (1.25x106 CFU/g). It might be supposed that the changes in caecal microflora can affect our results and improve the sanitary status of Lactobacillus-sprayed rabbits in the period 1-35 days of age.