World Rabbit Science - Vol. 25 (2)-2017
Tabla de contenidos
- Effect of feed restriction and feeding plans on performance, slaughter traits and body composition of growing rabbits
- Effect of competitive exclusion in rabbits using an autochthonous probiotic
- Feeding rabbits (Oryctolagus cuniculus ) with tree fruits from tropical deciduous forest
- Diet density in rearing and reproductive phases influences carcass composition, pregnancy rate and litter performance of primiparous rabbit does
- Milk intake in kits: not only the total amount matters
- Superovulation and expression of follicle-stimulating hormone receptor in young rabbit females
- Changes in cytochrome P450 gene expression and enzyme activity induced by xenobiotics in rabbits in vivo and in vitro
- Polymorphisms of exon 5, exon 7 and intron 10 of MMP2 gene and their association with wool density in Rex rabbits
- The lipopolysaccharide from Escherichia coli O127:B8 induces inflammation and motility disturbances in rabbit ileum
- Evaluating skin quality of some rabbit breeds under Egyptian conditions
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Item type: Artículo , Access status: Abierto , Evaluating skin quality of some rabbit breeds under Egyptian conditions(Universitat Politècnica de València, 2017-06-28) Taha, Emad; Samia, A.H.; Nasr, Ahmed Ibrahim[EN] Histological skin parameters in addition to mechanical and chemical properties of chrome tanned rabbits’ furs were determined in this study to evaluate and compare the quality of some rabbit breeds. Seventy-nine male rabbits aged 3 mo of New Zealand White (NZW, n=27), Rex (RX, n=24) and Gabaly (GB, n=28) were used. Results showed that GB skins had the highest values in skin weight (P<0.01) and area (P<0.05) followed by NZW and RX skins, respectively. Moreover, NZW skins differed in histological structure from the other 2 breeds, as total thickness and thickness of papillary and hypodermis layers in NZW were more than twice those of RX and GB (P<0.05). This structure is caused by an increase in fine collagen fibre bundles in papillary layer and a limited increase in larger collagen fibre bundles in the reticular layer. Furthermore, finished tanned furs properties clarify the superiority of GB furs in values of tensile and tearing strengths followed by NZW and RX, respectively. These results point to the possibility of using the chrome tanned furs of the 3 breeds in leather garment manufacturing.Item type: Artículo , Access status: Abierto , The lipopolysaccharide from Escherichia coli O127:B8 induces inflammation and motility disturbances in rabbit ileum(Universitat Politècnica de València, 2017-06-28) Grasa, Laura; Gonzalo, Sergio; de Martino, Alba; Murillo, María Divina; Gobierno de Aragón[EN] The aim of this work was to evaluate the effects of lipopolysaccharide (LPS) from Escherichia coli O127:B8 on the expression of toll-like receptor 4 (TLR4), the histology, and motor function in rabbit ileum. Rabbits were injected intravenously with saline or LPS (100 μg/kg, 2 h). The mRNA expression and localization of TLR4 were determined by reverse transcriptase-PCR and immunofluorescence, respectively. Histological damage induced by LPS was evaluated in sections of ileum stained with haematoxylin and eosin. Contractility studies of ileum were performed in an organ bath. The mRNA expression of TLR4 decreased in the muscular but not in the mucosal layer of rabbits treated with LPS. TLR4 was localised in both the mucosal and muscular layers of rabbit ileum. LPS induced intestinal inflammation and altered the spontaneous contractions and the serotonin-, acetylcholine- and KCl-induced contractions. In conclusion, LPS from E. coli O127:B8 induced a decrease in the mRNA expression of TLR4, an inflammatory response, and changes in the contractility of rabbit ileum.Item type: Artículo , Access status: Abierto , Polymorphisms of exon 5, exon 7 and intron 10 of MMP2 gene and their association with wool density in Rex rabbits(Universitat Politècnica de València, 2017-06-28) Chen, S.J.; Liu, Y.J.; Liu, T.; Chen, B.J.; Gu, Z.L.; National Natural Science Foundation of China[EN] Wool density is an important index that influences Rex rabbit fur quality. In our earlier studies, we found some important differentially expressed genes in different wool density of Rex rabbit by cDNA microarray. Based on the outcome, we conducted an association study to identify single nucleotide polymorphisms (SNPs) of exon 1, 5, 7 and 10 of matrix metalloproteinase-2 (MMP2) gene and their ligands associated with wool density. The results showed that exon 1 and exon 10 of MMP2 gene did not occur mutation in 100 Rex rabbits, meanwhile 3 SNPs were identified in exon 5, exon 7 and intron 10 of MMP2 gene sequence respectively, the 3 mutation sites were as follows: MMP2-exon 5-26C/G, MMP2-exon 7-101C/T and MMP2-intron 10-6C/T. The 3 SNPs were all in Hardy-Weinberg equilibrium. Phenotypic correlation analysis results showed the 3 mutations lacked significant associations (P>0.05) with the wool density.Item type: Artículo , Access status: Abierto , Changes in cytochrome P450 gene expression and enzyme activity induced by xenobiotics in rabbits in vivo and in vitro(Universitat Politècnica de València, 2017-06-28) Palócz, Orsolya; Farkas, Orsolya; Clayton, Paul; Csikó, György; Szent István University, Hungría; Hungarian Scientific Research Fund[EN] As considerable inter-species differences exist in xenobiotic metabolism, developing new pharmaceutical therapies for use in different species is fraught with difficulties. For this reason, very few medicines have been registered for use in rabbits, despite their importance in inter alia meat and fur production. We have developed a rapid and sensitive screening system for drug safety in rabbits based on cytochrome P450 enzyme assays, specifically CYP1A1, CYP1A2 and CYP3A6, employing an adaptation of the luciferin-based clinical assay currently used in human drug screening. Short-term (4-h) cultured rabbit primary hepatocytes were treated with a cytochrome inducer (phenobarbital) and 2 inhibitors (alpha-naphthoflavone and ketoconazole). In parallel, and to provide verification, New Zealand white rabbits were dosed with 80 mg/kg phenobarbital or 40 mg/kg ketoconazole for 3 d. Ketoconazole significantly increased CYP3A6 gene expression and decreased CYP3A6 activity both in vitro and in vivo. CYP1A1 activity was decreased by ketoconazole in vitro and increased in vivo. This is the first report of the inducer effect of ketoconazole on rabbit cytochrome isoenzymes in vivo. Our data support the use of a luciferin-based assay in short-term primary hepatocytes as an appropriate tool for xenobiotic metabolism assays and short-term toxicity testing in rabbits.Item type: Artículo , Access status: Abierto , Superovulation and expression of follicle-stimulating hormone receptor in young rabbit females(Universitat Politècnica de València, 2017-06-28) Zhang, Hao; Cheng, Guo Hu; Li, Yong Jun; Cai, Miao Yin; Guo, Hai Yan; Qin, Kang Le; Priority Academic Program Development of Jiangsu Higher Education Institutions; Natural Science Research of Jiangsu Higher Education Institutions of China[EN] To optimise the use of juvenile in vitro embryo transfer technologies in young rabbit females, superovulation was performed in New Zealand White young rabbit females at different ages and the expression mode of follicle-stimulating hormone receptor (FSHR) was explored using real-time quantitative polymerase chain reaction, and in vitro maturation (IVM) together with fertilisation (IVF) was conducted immediately after superovulation. The results showed that (1) the age factor significantly affected superovulation in young rabbit females, with 60 d as an optimal age; (2) the mRNA level of FSHR exhibited a rising trend, though it was lower at 30 to 40 d of age; (3) the maturation rate of the oocytes from 60 d old rabbits was significantly higher than in those from 50 d old rabbits; (4) the fertilisation rate of oocytes was not significantly different among rabbits 50, 60 and 70 d old.Item type: Artículo , Access status: Abierto , Milk intake in kits: not only the total amount matters(Universitat Politècnica de València, 2017-06-28) Bonachera, Alberto Arnau; Cervera, C.; Martínez-Paredes, E.; Ródenas, L.; Pascual, J. J.; Blas, E.; Comisión Interministerial de Ciencia y Tecnología; Ministerio de Economía y Competitividad[EN] The aim of this work was to identify milk intake variation patterns in kits throughout lactation, to evaluate their permanent maternal component and their relationships with the performance of kits before and after weaning. To achieve this goal, we used 73 rabbit does, controlled between the 1st and the 4th lactation, which kindled 229 litters with a total of 2225 kits. The daily milk intake records per young rabbit were analysed using a principal component analysis (PCA). We found that 72.3% of the variability was explained by the first 3 principal components (PCs). PC1 explained 46.4% of the total variability, was associated with the total amount of milk intake during lactation and presented a repeatability of 0.27 (P<0.05) for litters from the same female. High values of PC1 were related to higher weight of kits until slaughter age and higher feed intake during lactation and growing period. Consequently, they were related to a higher average daily gain, but a worse feed conversion ratio. PC2 explained 17.8%, was associated with the asymmetry of the milk intake (early vs. late) and presented a repeatability of 0.26 (P<0.05). For a given total milk intake during lactation, those with a higher milk intake in early lactation and lower during late lactation (low values of PC2) presented lower risk of death and higher feed intake during lactation. PC3 explained 8.1% of the variability, was associated with flattening of the milk intake curve and presented a repeatability of 0.05 (P>0.05). This component was little related to performance traits. Therefore, it seems that milk plays 2 different roles at the beginning of feed intake; the most important would affect development of the kits and thus is related with high intake. The second one, for a given total amount of milk intake during lactation, would create a kind of competition between milk and feed intake at the end of lactation. The effects of both components still persist during the growing period and seem to be moderately affected by the mother.Item type: Artículo , Access status: Abierto , Diet density in rearing and reproductive phases influences carcass composition, pregnancy rate and litter performance of primiparous rabbit does(Universitat Politècnica de València, 2017-06-28) Teixeira, Paulo Sérgio dos Santos; Moura, Ana Silvia A.M.T.; Wechsler, Francisco S.; Fernandes, Simone; Mattaraia, Vânia G.M.[EN] The objective was to evaluate the effect of the interaction of diet density in the rearing phase×diet density in the reproductive phase on carcass composition, pregnancy rate, and litter performance of primiparous rabbit does. The experiment followed a 2×2×2 factorial (2 seasons, 2 diet densities in the rearing phase and 2 diet densities in reproductive phase, that is, from mating to weaning of the first litter). The reference diet (RD) contained 184 g/kg of crude protein (CP), 165 g/kg of acid detergent fibre (ADF) and 10.5 MJ/kg of digestible energy (DE). The low-density diet (LD) had 147 g/kg of CP, 24 g/kg of ADF and 8.4 MJ/kg of DE. The treatments were applied from 70 d of age until weaning of the first litter at 35 d of age. Ninety-six females from the Botucatu Genetic Group (24 females/experimental group) were mated at 142 d of age. On day 12 of gestation, 23 does were slaughtered to evaluate weights of carcass, organs and dissectible fat, and embryo implantation rate. No effects of diet density in the rearing or in the reproductive phases were detected on feed intake of does during the reproductive phase. Does fed LD during the rearing phase showed lower body weight at mating (3574±47 vs. 3866±43 g, P=0.0001) and during most of the reproductive phase, but they lost less weight in the peripartum. Perirenal fat was lighter in these does (72.8±10.0 vs. 102.1±9.6 g, P=0.048) and they showed a lower pregnancy rate (76.1 vs. 91.7%, P=0.045). The does fed RD in the reproductive phase were heavier during this phase (4055±40 g vs. 3887±41 g, P=0.0044). The does fed LD in rearing phase and RD in the reproductive phase showed larger litters at weaning, due to decreased kit mortality, than those fed RD in both phases (6.16±0.47 vs. 3.93±0.71, P=0.0361). Litters were lighter at weaning when LD was fed in the reproductive phase (3582±201 vs. 4733±187, P<0.0001). Feeding a low-density diet during the rearing phase and a reference diet during the reproductive phase is the best alternative to improve reproductive performance at the first parity.Item type: Artículo , Access status: Abierto , Feeding rabbits (Oryctolagus cuniculus ) with tree fruits from tropical deciduous forest(Universitat Politècnica de València, 2017-06-28) Hernández-Hernández, Eliceo; López-Ortiz, Silvia; Villarruel-Fuentes, Manuel; Pérez-Hernández, Ponciano; Velasco-Velasco, Joel; Salinas-Ruíz, Josafhat; Consejo Nacional de Ciencia y Tecnología, México[EN] The dietary preference and voluntary intake of fruits from Acacia cochliacantha, Caesalpinia cacalaco, Vachellia pennatula, Chloroleucon mangense, Senna atomaria and Guazuma ulmifolia [containing 8.5-13.6% crude protein (CP) and 25.9-72.9% neutral detergent fibre (NDF) on dry matter (DM) basis], and the partial replacement of a commercial diet with 0, 15, 30 and 45% G. ulmifolia fruit were studied in rabbits. Rabbits fed a standard diet (17.9% CP and 28.4% NDF) were used to study their preference (during 20-min periods) for 6 ground fruits (Experiment 1: 12 rabbits, from 45 to 56 d of age and 1180±114 g live weight [LW]), 6 pelleted fruits (Experiment 2: same rabbits from 57 to 68 d of age), and the voluntary intake of the 5 most preferred pelleted fruits (Experiment 3: 18 rabbits from 70 to 81 d of age and 2200±200 g LW). Then, we examined the inclusion of G. ulmifolia fruit up to 45% in the diet (Experiment 4: 12 rabbits/diet from 25 to 66 d of age, and 419±80 g initial LW). When ground fruits were offered, rabbits tended to prefer C. mangense (0.83±0.12 g DM; P<0.05), and when offered as pellets they preferred G. ulmifolia (4.50±0.47 g DM; P<0.05), as well as in Experiment 3 (36.9±3.11 g DM/d; P<0.05). Substitution of a commercial diet with 15, 30 and 45% G. ulmifolia fruits in Experiment 4 resulted in higher DM intake when fruits were included in the diet, across all experimental periods (25-38, 39-66 and 25-66 d; P<0.001). Feeding up to 30% of fruits improved growth rate from 25 to 38 d of age (P<0.001) and produced similar growth rates to the control treatment from 25 to 66 d of age. Feed efficiency was impaired above 15% substitution level during the 25-38 d period (P>0.05) and in all groups fed G. ulmifolia in the 25-66 d period (P<0.001). Guazuma ulmifolia appears to have the greatest potential as a supplementary feed for rabbits in the pelleted form. Its inclusion up to 15% in the diet might render a similar performance to that of rabbits fed commercial diets.Item type: Artículo , Access status: Abierto , Effect of competitive exclusion in rabbits using an autochthonous probiotic(Universitat Politècnica de València, 2017-06-28) Cunha, Sara; Mendes, Ângelo; Rego, Dinis; Meireles, Diana; Fernandes, Ruben; Carvalho, André; Martins da Costa, Paulo[EN] Animal nutrition has been severely challenged by the ban on antimicrobials as growth promoters. This has fostered the study of alternative methods to avoid colonisation by pathogenic bacteria as well as to improve the growth of animals and feed conversion efficiency. These new options should not alter the normal intestinal microbiota, or affect it as little as possible. The use of probiotics, which are live microorganisms that beneficially affect the host by improving its intestinal microbial balance, can be seen as a promising way to achieve that goal. In this study, New Zealand White rabbits were fed diets containing an autochthonous probiotic of Enterococcus spp., with the strains EaI, EfaI and EfaD, and Escherichia coli, with the strains ECI 1, ECI 2 and ECD, during a 25-d trial, to evaluate the impact of the probiotic on the faecal microbiota, including population dynamics and antimicrobial resistance profiles. A control group of rabbits, which was fed a diet containing a commonly used mixture of antimicrobials (colistin, oxytetracycline, and valnemulin), was also studied. To assess the colonisation ability of the mentioned probiotic, the faecal microbiota of the rabbits was characterised up to 10 d after the administration had ended. Isolates of enterococci and E. coli were studied for phylogenetic relationships using enterobacterial repetitive intergenic consensus (ERIC-PCR) and pulse-field gel electrophoresis (PFGE), respectively. Although partially affected by an unexpected clinical impairment suffered by the rabbits in the experimental group, our results showed the following. The difference between the growth rate of the animals treated with antimicrobials and those fed the probiotic was not statistically significant (P> 0.05). The competitive exclusion product was present in the faecal samples in a large proportion, but stopped being recovered by culture as soon as the administration ended and the housing conditions were changed. Multidrug-resistant strains of enterococci and E. coli were more commonly recovered from faecal samples of animals fed diets containing antimicrobials, than from rabbits fed diets with our probiotic formula. The use of E. coli probiotics to prevent infection by enteropathogenic strains must be carefully considered due to the possible occurrence of gastrointestinal signs. On the other hand, enterococci strains may be more effective, but lack the long-term colonisation ability.Item type: Artículo , Access status: Abierto , Effect of feed restriction and feeding plans on performance, slaughter traits and body composition of growing rabbits(Universitat Politècnica de València, 2017-06-28) Birolo, Marco; Trocino, Angela; Tazzoli, Marco; Xiccato, Gerolamo; Ministero dell'Istruzione dell'Università e della Ricerca, Italia[EN] Two feeding systems (L, ad libitum vs. R, feed restriction) were combined with 3 feeding plans (MM, MH, HH) to evaluate the effects on performance, slaughter results, body composition and nitrogen balance of 300 commercial crossbred rabbits kept individually from weaning to slaughter (34-70 d of age). The R rabbits were fed from 80% (first days on trial) to 100% (end of 3rd wk) of ad libitum intake, whereafter R rabbits had free access to feed. The 3 feeding plans were: MM plan, M diet with moderate digestible energy (DE) content, 10.6 MJ/kg, throughout the trial; HH plan, H diet with high DE content, 11.1 MJ/kg, throughout the trial; MH plan, M diet for the first 3 wk and H diet for the last 2 wk. Feed restriction did not affect nutrient digestibility, growth rate on the whole trial and slaughter results, but improved feed conversion (2.96 vs. 2.89 in L and R rabbits, respectively; P<0.01) and reduced N excretion (2.16 vs. 2.07 g excreted N/d, in L and R rabbits; P<0.05). At the end of the first period (55 d), R rabbits showed lower empty body protein, lipid, and gross energy gains than L rabbits, but differences disappeared within the end of the trial. The HH plan improved feed conversion (2.97 vs. 2.89 for MM vs. HH; P<0.05), but increased excreted N (2.03 vs. 2.17 g/d; P<0.001) in comparison with the MM plan due to the higher digestible protein/DE ratio of H diet, whereas the MH plan showed intermediate results. In conclusion, a moderate feed restriction during post weaning improved feed conversion and reduced N excretion without negative effects on growth or slaughter results. Moreover, N excretion was confirmed to depend largely on dietary nitrogen content.