World Rabbit Science - Vol. 23 (3)-2015
https://riunet.upv.es:443/handle/10251/58932
2024-03-29T02:21:03ZStimulate feed intake before weaning and control intake after weaning to optimise health and growth performance
https://riunet.upv.es:443/handle/10251/58963
Stimulate feed intake before weaning and control intake after weaning to optimise health and growth performance
Read, Tehya; Combes, Sylvie; Gidenne, Thierry; Destombes, Nicolas; Grenet, Luc; Fortun-Lamothe, Laurence
[EN] Post-weaning feed restriction is a common practice in rabbit farming to reduce mortality, but results in lower growth performance and slaughter weights. This study aimed to assess the influence of 2 diets both rich in fibre and low in starch, with high or low digestible energy (DE) and digestible protein (DP) contents for a constant DP/DE ratio offered from 18 to 70 d of age, on the growth performance and health parameters of rabbits. Eight hundred rabbit kits were divided in 2 experimental groups differing in the feed offered from 18 to 70 d: a high concentrate diet (HC group; 10.37 MJ DE/kg DM and 102 g DP/kg DM) or low concentrate diet (LC group; 9.63 MJ DE/kg DM and 95 g DP/kg DM). Feed was offered ad libitum before weaning (35 d) and from 63 to 70 d, while feed offered from 35 to 63 d was controlled to obtain similar DE intake in both groups. Feed intake, animal weights and health status were recorded weekly. Mortality was recorded daily. Feed intake was similar in both groups before weaning (P=0.204), and consequently the DE intake was higher in the HC group compared to the LC group before weaning (3.91 vs. 3.39 MJ, respectively; P=0.017). Feed intake from 63 to 70 d was lower in the HC than in the LC group (229 vs. 239 g/d/kit, respectively; P<0.001).Total DE ingested after weaning was similar in both groups (45.44 MJ; P=0.143). Kits were heavier in the HC group throughout the study (P<0.05). A higher average daily gain during the periods of 18-28, 35-42 and 56-63 d was seen in the HC group (+8.1%, +16.8% and +4.5%, respectively; P<0.05). Mortality and morbidity rates were similar between groups throughout the study (P=1.0 and P=0.104, respectively). Our results suggest that when the feed intake after weaning is controlled, i) the feeding strategy before weaning determines the weight at weaning and at slaughter age; and ii) rabbits fed a diet more highly concentrated but rich in fibre increase their growth performance without negative consequences on their digestive health.
2015-12-17T13:37:14ZStaphylococcus aureus nasal carriage could be a risk for development of clinical infections in rabbits
https://riunet.upv.es:443/handle/10251/58962
Staphylococcus aureus nasal carriage could be a risk for development of clinical infections in rabbits
Selva Martinez, Laura; Viana, David; Corpa Arenas, Juan Manuel
[EN] Although nasal carriage has been described as a risk factor for Staphylococcus aureus infections in humans, there is a scarcity of studies about S. aureus nasal carriers in animals. In rabbits, S. aureus is one of the most important pathogens responsible for a number of different types of infections. This study was designed to determine the extent of staphylococcal nasal carriage and to establish whether a relationship exists between nasal carriage and development of lesions. One hundred and sixteen rabbits with and without chronic signs of staphylococcosis from 6 industrial rabbitries were monitored. Nasal swabs for microbiological assessments were obtained from all animals. Microbiological results showed that 56% of the animals carried S. aureus in their nasal cavities with significantly higher incidence in animals with staphylococcal-related lesions (84.2%) compared to apparently healthy animals (28.8%). Additionally, the S. aureus strains isolated from the nasal cavity and lesions were clonally related in 91.7% of animals. This suggests that nasal carriage of S. aureus in rabbits could be a risk for development of clinical infections.
2015-12-17T13:30:05ZScreening of virulence genes in Staphylococcus aureus isolates from rabbits
https://riunet.upv.es:443/handle/10251/58961
Screening of virulence genes in Staphylococcus aureus isolates from rabbits
Viana Martín, David; Selva, Laura; Penadés, Mariola; Corpa, Juan Manuel
[EN] Staphylococcus aureus is a versatile pathogen able to cause disease in both humans and animals. In rabbits, this bacterium infects animals of different ages, producing several purulent lesions. The ability of S. aureus to cause disease depends on a combination of virulence factors. The aim of this study was therefore to investigate the distribution of bacterial virulence determinants in 69 S. aureus isolates from rabbits. Some virulence factors (7 adhesins, 1 toxin and 1 protease) were positive in all rabbit S. aureus isolates analysed, while others (1 adhesin and 10 toxins) were always negative. The remaining virulence factors were more variable among isolates. An association between genotype and the different profiles of virulence factors was observed, but not with the type of lesion (P<0.05). One strain of each genotype was further analysed by multilocus sequence typing, generating ST121, ST96 and ST2951, determining a greater number of enterotoxins in ST121 isolates compared to ST96 and ST2951 isolates, which could justify the different pathogenicity between strains.
2015-12-17T13:22:54ZPreliminary study of the individual variability of the sexual receptivity of rabbit does
https://riunet.upv.es:443/handle/10251/58960
Preliminary study of the individual variability of the sexual receptivity of rabbit does
Theau.Clément, M.; Tircazes, A.; Saleil, G.; Monniaux, D.; Bodín, L.; Brun, J.M.
[EN] The aim of this preliminary experiment was to investigate the individual variability of the sexual receptivity of a rabbit doe in the presence of a buck (lordosis position, 0-1 variable). Twenty primiparous does maintained without reproduction were tested over 4 mo (3 tests per week at a 2- or 3-day interval) after their first kindling. Out of 48 tests, the receptivity rate was 52.5±50.0% on average and varied from 20.0 to 73.3% depending on the test day. The does were lactating at the beginning of the test period and a strong receptivity decrease was revealed at the peak of lactation. Receptivity did not vary according to the tester buck or to the test operator. The individual receptivity of does varied from 8.6 to 81.3%; three of them had a receptivity rate lower than 30% and four of them a receptivity rate greater than 70%. No relationship was revealed between average receptivity and body weight or body weight variations around first litter weaning. The repeatability of sexual receptivity of non-lactating does was 23.2%. Lowly receptive does had a shorter average oestrus time (<2 tests) and a longer dioestrus time (≥6 tests), whereas highly receptive does had a longer oestrus time (>4 tests) and a shorter dioestrus time (≤3 tests). The correlation between average receptivity and average oestrus time was 0.80. These results indicate a fairly high individual variability of the expression of rabbit sexual receptivity and of its duration, and justify the exploration of an eventual genetic origin in a subsequent experiment.
2015-12-17T13:17:54ZGenetic and non-genetic factors affecting rabbit doe sexual receptivity as estimated from one generation of divergent selection
https://riunet.upv.es:443/handle/10251/58959
Genetic and non-genetic factors affecting rabbit doe sexual receptivity as estimated from one generation of divergent selection
Theau.Clément, M.; Sécula, A.; Saleil, G.; Monniaux, D.; Brecchia, G.; Boiti, C.; Bodin, L.; Brun, J.M.
[EN] Sexual receptivity of rabbit does at insemination greatly influences fertility and is generally induced by hormones or techniques known as “biostimulation”. Searching for more sustainable farming systems, an original alternative would be to utilise the genetic pathway to increase the does’receptivity. The purpose of the present study was to identify genetic and non-genetic factors that influence rabbit doe sexual receptivity, in the context of a divergent selection experiment over 1 generation. The experiment spanned 2 generations: the founder generation (G0) consisting of 140 rabbit does, and the G1 generation comprising 2 divergently selected lines (L and H lines) with 70 does each and 2 successive batches from each generation. The selection rate of the G0 females to form the G1 lines was 24/140. The selection tests consisted of 16 to 18 successive receptivity tests at the rate of 3 tests per week. On the basis of 4716 tests from 275 females, the average receptivity was 56.6±48.2%. A batch effect and a test operator effect were revealed. The contribution of females to the total variance was 20.0%, whereas that of bucks was only 1.1%. Throughout the experiment, 18.2% of does expressed a low receptivity (< 34%), 50.7% a medium one and 33.1% a high one (>66%). Some does were frequently receptive, whereas others were rarely receptive. The repeatability of sexual receptivity was approximately 20%. The results confirmed the high variability of sexual receptivity of non-lactating rabbit does maintained without any biostimulation or hormonal treatment. A lack of selection response on receptivity was observed. Accordingly, the heritability of receptivity was estimated at 0.01±0.02 from an animal model and at 0.02±0.03 from a sire and dam model. The heritability of the average receptivity of a doe was calculated as 0.04. In agreement with the low estimated heritability, the heritability determined was no different from zero. Nevertheless, the occurrence of pseudopregnancies due to uncontrolled ovulations and the presence of corpora lutea, as assessed by progesterone titrations, could have interfered with receptivity. Further studies would be necessary to confirm the low heritability of female rabbit receptivity.
2015-12-17T13:11:39ZEffects of rearing feeding programme on the young rabbit females’ behaviour and welfare indicators
https://riunet.upv.es:443/handle/10251/58938
Effects of rearing feeding programme on the young rabbit females’ behaviour and welfare indicators
Martínez Paredes, Eugenio Melchor; Ródenas Martínez, Luis; Pascual Amorós, Juan José; Blas Ferrer, Enrique; Brecchia, G.; Boiti, C.; Cervera Fras, Mª Concepción
[EN] Restriction of young rabbit females during rearing is a widespread management technique that could have negative consequences on their welfare and behaviour. In the present work, a total of 24 young rabbit females aged 9 wk were used to evaluate 3 rearing feeding programmes until first parturition: CAL, fed ad libitum with a control diet [C: 11.0 MJ digestible energy (DE) and 114 g digestible protein (DP) per kg dry matter (DM)]; CR, receiving the C diet restricted (140 g/d) from 12 wk of age; and F, fed ad libitum with a low energy/high fibre diet [F: 8.7 MJ DE and 88 g DP per kg DM]. F females presented lower body weight than CAL and CR females at week 18 (–0.4 kg and –0.2 kg; P<0.05), but differences in body weight disappeared at parturition. Feeding programme affected the daily feed intake of young females during rearing and gestation periods (on av. of 2 periods: 140, 127 and 179 g DM/d, for CAL, CR and F females, respectively; P<0.001). Blood levels of glucose and insulin decreased with the age of rabbits (from 97 to 73 mg/dL for glucose and from 11 to 6 μUI/mL for insulin at 13 and 20 wk, respectively; P<0.001). Concentration of non-esterified fatty acids was higher in the blood of CAL females (+0.13 mmol/L compared to F; P<0.05), while corticosterone was higher in F females (+0.7 μg/dL compared to CAL; P<0.05). The type of feeding schedule affected the lying still and eating behaviour (P<0.01) of CR females, especially before and after feeding supply, as well as their behavioural stressed indicators (stereotypies; P<0.01), which were more frequent in CR females before feeding supply at 20 weeks of age. Therefore, ad libitum use of a low energy/high fibre diet is an adequate feeding programme for young rabbit females, which does not alter their behavioural patterns.
2015-12-17T12:07:17ZComparison of degrees of maturity of rabbit lines selected for different traits
https://riunet.upv.es:443/handle/10251/58935
Comparison of degrees of maturity of rabbit lines selected for different traits
Pascual, M.; Calle Ayma, Eddy Wilfredo; Blasco Mateu, Agustín
[EN] The aim of this work was to study whether commercial nucleus lines of rabbits selected for different traits, and experimental lines having commercial purposes, have the same degree of maturity when compared at the same slaughter age. The study was carried out with 17897 rabbits from Universitat Politècnica de València. Rabbits came from the maternal lines A (3902 rabbits; 44th generation), V (4238 rabbits; 39th generation) and LP (6115 rabbits; 9th generation), selected for litter size at weaning; the paternal line R (2023 rabbits; 25th generation), selected for growth rate between 28 and 63 days of age; the maternal line OR (586 rabbits; 11th generation) selected for ovulation rate; and the lines High (503 rabbits; 5th generation) and Low (530 rabbits; 5thgeneration) lines, from a divergent selection for high and low intramuscular fat, respectively. Rabbits were weighted at 28 (W28) and 63 (W63) days of age. Rabbit does (42, 25, 39, 94, 14, 32 and 22 from lines A, V, R, LP, OR, High and Low, respectively) were weighed between 30 and 80 wk of age to determine adult weight (AW). Line R had higher W28 and W63, growth rate between 28 and 63 d of age and AW than lines A, V and LP (5802 g vs. 4410, 4222, and 4391 g for AW, respectively). No relevant differences between lines in degrees of maturity at 28 and 63 d of age and time to reach 40% of degree of maturity (percentage of weight compared to AW) were found between lines A, V, R and LP, but the degree of maturity at 2000 g and the time taken to reach that weight were lower in line R (34.7% and 55.2 d) than in lines A (45.5% and 71.1 d), V (47.4% and 69.6 d), and LP (45.8% and 68.0 d). No relevant differences were found between lines OR, High and Low in the traits analysed. A robustness analysis showed that results can be extrapolated to other commercial lines and other slaughter weights. In conclusion, comparison of lines at similar slaughter age could be considered a valid approach for comparisons at the same maturity stage.
2015-12-17T09:22:20Z