Evaluation of the anticoccidial efficacy of Cycostat (R) in experimentally infected breeding rabbits housed under conventional conditions

The present study was designed in order to evaluate the effi cacy and safety of Cycostat (R) 66G in the prevention and control of coccidiosis in breeding does after experimentally induced infection with common Eimeria spp. at the age of 18 wk. The inoculum was prepared based on faecal samples collected on farms in the Czech Republic. A total of 94 young and pregnant does were divided into 4 groups and enrolled in the study. The zootechnical, clinical and parasitological results of 2 control groups were compared, a non-infected non-treated (NI-NT) and an infected non-treated (I-NT), and 2 infected and dietary supplemented groups, with 50 (I-50) and 66 mg/kg (I-66) robenidine, respectively. Does in the I-NT group showed a significant drop in weight gain and feed intake during the fi rst 14 d after inoculation. No treatment related effects on the weight development of the does were observed, although does in the I-NT group always had approximately ± 200 g lower body weight. Litter size (live born) was not signifi cantly different at either the fi rst or second parturition and amounted to 9.0, 8.2, 10.1 and 9.8 (1st litter) and 11.3, 10.4, 10.1 and 11.0 (2nd litter) in NI-NT, I-NT, I-50 and I-66 does, respectively. At weaning, both in the 1st and 2nd cycle, the highest litter weight was obtained in the I-50 and I-66 groups. Litter weaning weight values for I-66 (litter 2) were higher but not significant (P=0.069) compared to the NI-NT litters. The lowest young mortality was also observed in the I-66 litters, both in the first and second cycles. Between 6 to 11 d after inoculation, the oocyst excretion of both supplemented groups was reduced by more than 90% in comparison to the I-NT. Supplementation with Cycostat (R) 66G diminished the excretion of E. flavescens and E. intestinalis, the most pathogenic species, by 100%. The excretion of E. magna was reduced by >90 and 100% for the I-50 and I-66 groups, respectively. The reduction in oocyst excretion of E. media was less pronounced. It was concluded that Cycostat (R) 66G supplemented in the feed at a concentration of 50 or 66mg/kg was able to prevent coccidiosis in breeding does after experimental inoculation.Maertens, L.; Van Gaver, D. (2010). Evaluation of the anticoccidial efficacy of Cycostat (R) in experimentally infected breeding rabbits housed under conventional conditions. World Rabbit Science. 18(2). doi:10.4995/WRS.2010.18.0918

Effect of 3 dietary phytogenic products on production performance and coccidiosis in challenged broiler chickens

A pen trial using 1,080 male Ross 308 broiler chicks (6 treatments with 6 replicates each) was conducted to examine the effects of 3 dietary phytogenic products on avian coccidiosis. The dietary treatments included (1) a negative control (NC), (2) a positive control (PC) without feed additive, (3) Narasin at 0.7 kg/t (COCC), (4) PHYT1 (oregano) at 2.0 kg/t, (5) PHYT2 (combination of Curcuma, saponins, and inulin) at 1.0 kg/t, and (6) PHYT3 (Quillaja) at 1.0 kg/t. Treatments 2 through 6 were challenged with a mixture of Eimeria acervulina, Eimeria maxima, and Eimeria tenella at d 15 via feed. Standard performance parameters and coccidial lesion scoring (d 22) were conducted. One week after coccidial challenge, chicks BW of the COCC treatment and the NC were higher than all other treatments. Body weights on d 39 were 2.47 (NC), 2.34 (PC), 2.51 (COCC), 2.35 (PHYT1), 2.39 (PHYT2), and 2.41 kg (PHYT3) with an SEM of 0.033. For the entire trial period, Narasin yielded a significantly better FCR in comparison with the PC and PHYT3. Overall mean lesion score was 0.54 (NC), 0.91 (PC), 0.50 (COCC), 0.81 (PHYT 1), 1.02 (PHYT 2), and 1.13 (PHYT 3) with an SEM of 0.122. It was concluded that all 3 phytogenic products were not effective at the used dosage in alleviating the negative effects observed in coccidiosis-challenged bird

Effects of the feeding system on performance and myopathy occurrence in two broiler chicken genotypes

To evaluate whether performance and myopathy occurrence differed according to genotype (Cobb 500 vs. Ross 308) and feeding system (AL: ad libitum vs. ER: early restricted from 13 to 23 d of age, vs. LR: late restricted from 27 to 37 d; restriction rate: 80% of ad libitum), 828 day- old male chicks were assigned to 6 groups (2 x 3 arrangement), housed in 36 pens, and controlled for: individual live weight (weekly) and pen feed intake (daily) until slaughter (48 d); white striping and wooden breast occurrence at slaughter. Individual data were analysed by PROC MIXED of SAS (fixed effects: feeding system, genotype, and interaction; random effect: pen); pen feed intake and myopathy occurrence were analysed by PROC GLM and CATMOD, respectively. The feeding system affected performance: at the end of the first period (1-22 d), ER chickens showed lower weight gain (40.5 g/d vs. 47.8 g/d and 48.0 g/d), feed intake (50.8 g/d vs 61.0 g/d and 60.2 g/d) and weight (903 g vs 1056 g and 1059 g) than AL and LR broilers (P<0.001); at the end of the second period (23-48 d), ER chickens showed higher weight gain (98.3 g/d vs 93.6 g/d and 90.2 g/d) and feed intake (182 g/d vs. 177 g/d and 171 g/d) compared to AL and LR chickens (P<0.001). Final live weight was the highest in AL group, intermediate in ER group, and the lowest in the LR one (3482 g, 3454 g, and 3399 g; P<0.01). Feed conversion in the whole period did not change with the feeding system. At gross examination, white striping occurrence changed from 77.8% to 67.1%, and 81.7% in AL, ER and LR broilers (p<0.10). Differences between genotypes were evident from the first day and, at the end of the trial, weight gain (74.3 g/d vs 70.1 g/d), feed intake (126 g/d vs 114 g/d), feed conversion (1.69 vs 1.64), and live weight (3548 g vs. 3342 g) were higher in the Ross than in the Cobb chickens (P<0.001). At slaughter, the rate of white-striped breasts was similar (on average 75.5%), but the occurrence of severely white-striped breasts was higher in the Ross than in the Cobb chickens (25.9% vs. 7.41%; P<0.001). Wooden breast occurrence (on average 5.1%) did not change with the feeding system or the genotype. In conclusion, under our conditions, a late feed restriction did not permit to recover performance at the end of the trial nor to control white striping occurrence. Moreover, the genotype affected growth rate and white striping degree: the highest the growth rate, the highest the severity of white striping

Recommendations and guidelines for applied nutrition experiments in rabbits

[EN] The aim of this paper was to draw up a set of recommendations for applied nutrition and feeding trials with rabbits, in relation to certain aspects such as determining the nutritive value of raw materials or diets in growing or reproducing animals, studying digestive physiology and obtaining growth and reproduction parameters. We deal first with animals, size of the sample, housing conditions, diets, handling, measurements, and the data analyses relevant to the design of the experiment are described. Secondly, we give a list of recommended items and include some comments.This study was partly supported by the EUROPEAN COMMISSION (ERAFE program and the COST 848 Action).Fernández-Carmona, J.; Blas, E.; Pascual Amorós, JJ.; Maertens, L.; Gidenne, T.; Xiccato, G.; García, J. (2005). Recommendations and guidelines for applied nutrition experiments in rabbits. World Rabbit Science. 13. doi:10.4995/wrs.2005.516SWORD1

Development of hierarchy and rank effects in weaned growing rabbits (oryctolagus cuniculus)

[EN] Aggression among growing rabbits reduces production efficiency, and negatively affects the animal s welfare. Understanding hierarchy development may improve its predictive value with regard to differential access to resources and fitness. This could in turn lead to measures to reduce aggression. This study quantifies the development of a hierarchy among small groups of same-age rabbits kept in high density. We describe the development of the hierarchy in four mixed-sex groups formed after weaning at four weeks of age. The relationships between rank and aggressiveness, weight, sex and wound count were examined. To balance possible genetic effects, each group contained four full sibling dyads (N=8) with the male and female coming from the same litter (total N=32). Each group was housed in a wire mesh cage of 0.72 m² and was observed at 4, 6, 8, 10 and 12 wk of age. All activities of focal individuals were scored and antagonistic interactions among all group members were sampled continuously. For rank order analysis, submissive behaviours shown after receiving aggression were used. Females were heavier than males (3.2 kg vs 3.0 kg: wk 12); this difference was statistically significant from the sixth week onwards. Two of the four groups developed significantly linear hierarchies from the age of ten and twelve weeks onwards, respectively. In these two groups, rank order did not correlate with body weight, sex or wound count. The group with the steepest hierarchy had the highest number of wounds. The results show that growing rabbits can form linear hierarchies by 10 weeks of age, but this tendency differs strongly among groups. The male and female rabbits did not form separate hierarchies, in contrast to their natural tendencies. This may be due to the high density, and may imply a lack of interaction freedom.Vervaecke, H.; De Bonte, L.; Maertens, L.; Tuyttens, F.; Stevens, J.; Lips, D. (2010). Development of hierarchy and rank effects in weaned growing rabbits (oryctolagus cuniculus). World Rabbit Science. 18(3). doi:10.4995/wrs.2010.822918

Alternatives to antibiotic growth promoters in rabbit feeding: a review

[EN] This review is focused on the most studied and developed substances which are commonly knownas alternatives to dietary antibiotics, particularly as far as rabbit feeds are concerned. After a reminder of thereason to be and success of antibiotic growth promoters, and why they lately came to be banned in the European Union, we successively deal with probiotics, prebiotics, enzymes and organic acids. Data on rabbitsare, as expected, quite scarce when compared to species such as pigs and poultry. Nevertheless, theavailable performance results are discussed together with the possible mechanisms of action. Special mentionis made of the effects of these substances on digestibility and caecal activity.Falcão-E-Cunha, L.; Castro-Solla, L.; Maertens, L.; Marounek, M.; Pinheiro, V.; Freire, J.; Mourão, JL. (2007). Alternatives to antibiotic growth promoters in rabbit feeding: a review. World Rabbit Science. 15(3). doi:10.4995/wrs.2007.597SWORD15