World Rabbit Science - Vol. 19 (1)-2011
Permanent URI for this collection
Tabla de contenidos
- Efficacy of an autogenous vaccine against highly virulent Staphylococcus aureus infection in rabbits
- Use of VP60 RT-PCR to overcome the limitation of haemagglutination inhibition diagnosis of rabbit viral haemorrhagic disease
- Changes in behavioural and physiological parameters associated with Taenia pisiformis infection in rabbits (Oryctolagus cuniculus) that may improve early detection of sick rabbits
- Heterosis, direct and maternal additive effects on rabbit growth and carcass traits from a Canadian experiment
- Determination of faecal dry matter digestibility two weeks after weaning in twenty five day old weaned rabbits
- Characterization of the indoor environment and gas emissions in rabbit farms
Browse
Recent Submissions
- PublicationCharacterization of the indoor environment and gas emissions in rabbit farms(World Rabbit Science. ICTA. UPV, 2011) Calvet Sanz, Salvador; Cambra López, María; Estellés Barber, Fernando; Departamento de Ciencia Animal; Instituto Universitario de Ciencia y Tecnología Animal; Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural; Ministerio de Ciencia e Innovación[EN] There is a need to characterize gas concentrations and emissions from rabbit production. A study was conducted in order to determine ammonia, nitrous oxide and carbon dioxide concentrations and emissions in three rabbit farms in the Spanish Mediterranean area. Gas emissions were measured for 187 days in two different production stages (reproductive does and fattening rabbits). Gas concentrations were measured every two hours. Indoor temperature, relative humidity and ventilation flow were measured hourly. As a result, indoor temperature and relative humidity varied throughout the year, following a sinusoidal daily variation pattern. Maximum gas concentrations (14.3 mg/m3 of NH3, 7041 mg/m3 of CO2 and 5.10 mg/m3 of N2O) did not exceed the maximum recommended thresholds considering human health and animal welfare. Ammonia emissions were on average 55.9 and 10.2 mg/h per reproductive doe and fattening rabbit, respectively, and they were affected by temperature and relative humidity. The average carbon dioxide emission was 12588 mg/h per animal for does and 3341 mg/h for fattening rabbits. Nitrous oxide emission from does was 10.3 mg/h per animal, whereas for fattening rabbits the emission was negligible. Daily variation patterns of all measured parameters were observed and characterised in this study.
- PublicationDetermination of faecal dry matter digestibility two weeks after weaning in twenty five day old weaned rabbits(World Rabbit Science. ICTA. UPV, 2011) Gómez-Conde, M.S.; García, J.; Villamide, M.J; Carabaño, R.[EN] The aim of this work was to analyse the evolution from 26 to 40 d of age of apparent faecal dry matter digestibility (DMd) in rabbits weaned at 25 d of age to define how to determine nutrient digestibility in the post-weaning period. Fifteen New Zealand ' Californian rabbits from five litters (3 rabbits/litter) weaned at 25 d of age and weighing 602±75g were fed ad libitum a commercial diet containing 20.0% crude protein and 33.5% NDF (on DM basis). Feed intake and faeces excretion were recorded daily from 25 to 40 d of age and DM digestibility determined. Litter affected DM intake and excretion (P = 0.013 and 0.014, respectively), and tended to affect DMd (P = 0.061), whereas age influenced all these traits (P < 0.001). Dry matter intake and DM excretion increased from 26 to 40 d of age by 158 and 480%, respectively. During the first week after weaning, DM intake increased more slowly than DM excretion (55 vs. 245%), but in the second week after weaning both increased by 67%. The correlation between daily feed intake was higher with the faeces excretion of the same day than with faeces excretion of the next day, and the first values were used to determine daily DMd. A broken line regression model was fitted to daily DMd, which decreased linearly from weaning to 32 d of age (2.17 ± 0.25 percentage units per day), whereas from 32 to 40 d it remained constant (69.4 ± 0.47%). Accordingly, for 25-d old weaned rabbits it would be advisable to begin a digestibility trial not before 32 d of age, using the first week after weaning as adaptation period. Average standard deviation of DMd decreased by 54% when the length of the collection period increased from 2 to 6 d. Consequently, the number of animals required to detect a significant difference among means depends on the length of the collection period. For a conventional collection period of four days, a difference of 2 percentage units could be detected by using 14 animals/treatment.
- PublicationHeterosis, direct and maternal additive effects on rabbit growth and carcass traits from a Canadian experiment(World Rabbit Science. ICTA. UPV, 2011) Ouyed, Abida; Rivest, J.; Brun, Jean MichelA total of 479 male and female rabbits from the Californian (CA), American Chinchilla (CH) and New-Zealand White (NZ) breeds and nine crosses between them were used in this experiment. This study aimed to estimate heterosis and direct and maternal additive effects as well as some non genetic effects on rabbit growth and carcass traits in order to identify the most appropriate crossbreeding plan to use for rabbit meat production under Quebec conditions. Each rabbit was identified and weighed individually at weaning (35 d) and at slaughter (63 d). Rabbits were slaughtered after an 18 h fasting period from feed only. Statistical analyses were performed solving fixed models that allow different variances between genetic types. Significant statistical differences were obtained between genetic types for rabbit growth performance. Rabbits from purebred NZ females mated to CA and NZ males or from CAxNZ and NZxCH crossbred females mated to NZ males ranked first for live weight at 35 and 63 d body weight and for average daily gain (ADG). ADG of NZxNZ, NZx(NZxCH) and NZx(CAxNZ) rabbits reached around 50 g/d and their feed conversion ratio was about 3.4. Significant differences between genetic types were observed for all carcass traits except for meat/bone ratio. Rabbits from CH, NZ, CAxNZ and NZxCH does mated to NZ males, and from NZ does mated to CA males had the highest commercial carcass weight and the lowest commercial carcass yield (CCY), whereas CHxCA rabbits ranked first with a CCY higher by 4 to 8% than rabbits from other genetic types. The highest hind part yields were obtained with CHxCH, CHxNZ and NZxCH rabbits. Concerning the intermediate part percentages, the highest values corresponded to the highest CCY. The CH breed had unfavourable direct effects but favourable maternal effects on growth traits. The CA breed had negative maternal effects on weight traits from weaning to slaughtering. The CA and CH breeds had positive direct and negative maternal effects on intermediate part yield of the carcass compared to NZ. Direct heterosis effects were found for body weight traits, particularly in the crosses involving the NZ breed, with a magnitude ranging from 5 to 10% of the parental mean.
- PublicationChanges in behavioural and physiological parameters associated with Taenia pisiformis infection in rabbits (Oryctolagus cuniculus) that may improve early detection of sick rabbits(World Rabbit Science. ICTA. UPV, 2011) Betancourt-Alonso, Miguel-Angel; Orihuela, Agustín; Aguirre, Virginio; Vázquez, Reyes; Flores-Pérez, Fernando-Iván; Dirección General de Educación Superior para Profesionales de la Educación, México; Consejo Nacional de Ciencia y Tecnología, México[EN] The purpose of the present experiment was to describe rabbits' early behavioral responses to illness, and its relation with physiological changes to help improve early detection of infection, particularly those induced by Taenia pisiformis in rabbits. Twenty adult female New Zealand rabbits were randomly allocated in two groups, to determine whether changes in behavior and some physiological parameters can be induced in rabbits after a T. pisiformis infection. Infected animals were orally inoculated with 3,000 eggs of T. pisiformis, while controls only received saline solution. Behavioral activity was recorded daily from 19:00 to 21:00 h starting two days before infection. Mate choice and rank status were assessed, and blood samples were collected at -2, 7, 14 and 25 days post infection (dpi) for hematological and hepatic function determinations. All animals were observed for clinical signs every other day from the beginning of the experiment and euthanized 25 dpi after last sampling. Infected animals spent more (P<0.01) time lying down (87 vs. 17%) and less (P<0.05) time grooming (43 vs. 57%) and drinking (26 vs. 74%) than controls. These differences were noticeable 6 dpi and remained until the end of the experiment. No changes (P>0.05) were observed in the time spent at the feeder, rank status or mate choice. Leucocyte and lymphocyte concentrations increased (P<0.05) while heterophil counts decreased in infected rabbits as the experiment progressed. Furthermore, infected animals had larger concentrations of alkaline phosphatase as soon as 7 dpi. No clinical signs of the disease were detected. Necropsy findings corroborate hepatic lesions and presence of the parasite in all infected animals. It was concluded that an infection with 3,000 eggs of T. pisiformis induced changes in behavioral patterns, supported by some changes in hematological and hepatic parameters that could improve early detection of illness, regardless of clinical signs.
- PublicationUse of VP60 RT-PCR to overcome the limitation of haemagglutination inhibition diagnosis of rabbit viral haemorrhagic disease(World Rabbit Science. ICTA. UPV, 2011) Shakal, M.A.; Khelfa, D.E.-D.G; Salman, O.G.A.; Yousif, A.A.; Salwa, E.-A.A; Veterinary Serum and Vaccine Research Institute, Egipto; Cairo University[EN] Rabbit viral haemorrhagic disease (RVHD) is a highly contagious, highly fatal, peracute and acute viral disease of both wild and domestic rabbits caused by rabbit haemorrhagic disease virus (RHDV). Testing for haemagglutination (HA) activity in processed liver samples is one of the cornerstones for rapid diagnosis of RHDV outbreaks in national rabbitries. However, RHDV isolates exhibiting no HA activity are increasingly being reported. The extent of deviation from classical HA activity patterns for RHDV strains in Egypt has not been investigated. This study compared the HA activity patterns of samples collected from 61 RHDV outbreaks that occurred between 1999 and 2005 to determine whether dependence on HA test (HAT) for diagnosis of RHDV outbreaks needs to be reviewed. All samples were confirmed RHDV positive using SDS-PAGE and western blotting. Using slide HAT, only 36.1% of samples were positive (22 samples). Plate HAT conducted at 4 0C detected an additional 16 positive samples bringing the total HA-positive samples to 38 (62.3%). Plate HAT conducted at 22 0C failed to detect additional positive samples. The majority of samples detected after plate HA testing (62.5%) had HA titres comparable to those obtained from slide-HA-positive samples, indicating that the difference in HA activity is dependent on the nature of the HA antigen rather than its presence. Direct detection of HA activity failed in 37.7% of samples despite the presence of classical signs, pathology, and being RT-PCR positive for three different VP60 regions. Experimental infection of seronegative rabbits with 9 HA negative RHDV samples showed that 5 isolates were in-fact HA positive, while only 4 isolates remained HA negative. The increased detection of viruses lacking HA activity and the low HAT sensitivity mandates the use of molecular techniques for rapid confirmation of RHDV diagnosis in the Egyptian environment.