Commercial Rabbit Research Articles

Fluoroquinolone susceptibility of Staphylococcus aureus strains isolated from commercial rabbit farms in Spain

Staphylococcus aureus is one of the most important pathogenic Staphylococcus species in veterinary medicine. In rabbits, it mainly causes skin infections, pododermatitis and mastitis with subsequent economic losses in industrial...

Association between a polymorphism in the IGF2 gene and finishing weight in a commercial rabbit population

Association between a polymorphism in the <i><scp>IGF</scp>2</i> gene and finishing weight in a commercial rabbit population

Immunohistochemistry for ERG Expression as a Surrogate for TMPRSS2-ERG Fusion Detection in Prostatic Adenocarcinomas

TMPRSS2-ERG fusions have been identified in about one-half of all prostatic adenocarcinomas (PCas). Fluorescence in situ hybridization (FISH) and reverse transcription polymerase chain reaction have been the most commonly used techniques in this setting. The aim of this study was to evaluate the utility of ERG immunoexpression as a surrogate for TMPRSS2-ERG fusion in a large series of PCa cases. Four hundred twenty-seven radical retropubic prostatectomy tissue samples were used to construct 10 tissue microarrays (TMAs). FISH analysis was previously conducted using dual-color interphase break-apart probes for the 5' and 3' regions of the ERG gene. ERG expression was evaluated using a commercial rabbit anti-ERG monoclonal antibody (clone EPR3864; Epitomics, Burlingame, CA). Each TMA spot was independently assessed, and any nuclear staining positivity was considered as indicative of ERG expression. TMPRSS2-ERG fusions were detected by FISH in 195 (45.7%) of the PCa cases. ERG immunoexpression was found in 192 (45.0%) of the PCa cases and in none of the nontumoral tissue samples. Mean ERG H-scores were significantly higher in tumors harboring FISH-detected TMPRSS2-ERG fusions (P<0.00001), and there was a strong association between ERG immunohistochemical expression and the TMPRSS2-ERG status defined by FISH (P<0.00001), with a sensitivity of 86% (95% CI, 80%-90%) and a specificity of 89% (95% CI, 84%-93%). Receiver-operating characteristic curve analysis showed that ERG immunoexpression had a high accuracy for identifying TMPRSS2-ERG fusions detected by FISH, with an area under the curve of 0.87 (95% CI, 0.84%-0.91; P<0.00001). We found that ERG immunohistochemical expression has a high accuracy for defining the TMPRSS-ERG fusion status. ERG immunohistochemistry may offer an accurate, simpler, and less costly alternative for evaluation of ERG fusion status in PCa than FISH.

Effects of nilvadipine, a calcium antagonist, on intimal thickness of vascular grafting in cholesterol-fed rabbits

The effects of nilvadipine on intimal thickness in expanded poly-tetrafluoroethylene grafts were examined in 21 rabbits undergoing infrarenal aorta reconstruction. Seven rabbits received commercial rabbit chow (control group), seven, a regular diet supplemented with 1% cholesterol (cholesterol group); and seven, the cholesterol diet with 98.9% pure nilvadipine 1 mg/kg/day (nilvadipine group). Grafts were harvested 3 months after surgery for histologic examination. Intimal thickness at the proximal and distal anastomosis was, respectively, 225±76 and 273±110 m in the control group, 525±236 and 600±250 m in the cholesterol group, and 284±94 and 241±86 m in the nilvadipine group. Intimal thickness in the cholesterol group was significantly greater than in the nilvadipine group (p<0.01). The smooth muscle cell values in the intima at the proximal and distal anastomosis were, respectively, 10.6±3.6 and 12.6±3.2 %Extinction (%E) in the control group, 15.5±4.0 and 16.1±4.5 %E in the cholesterol group, and 9.1±3.1 and 9.6±2.1 %E in the nilvadipine group. The smooth muscle cell value in the intima of the cholesterol group was greater than that of the nilvadipine group (p<0.01). These data suggest that nilvadipine significantly reduces the degree of intimal thickness in expanded polytetrafluoroethylene grafts in cholesterol-fed rabbits, and that this effect is due to inhibition of smooth muscle cell migration and proliferation.

Diminished neointimal thickness in cholesterol-fed rabbits receiving cyclosporine

The author studied the effect of cyclosporine on suppression of anastomotic and graft intimal hyperplasia, using 10-mm-long and 3-mm-internal-diameter expanded polytetrafluoroethylene (EPTFE) infrarenal aortic grafts in rabbits. A control group (n=6) received commercial rabbit chow; a cholesterol group (n=6) received rabbit chow with 1% cholesterol; and a cyclosporine group (n=6) received the cholesterol diet plus cyclosporine 5 mg/kg daily subcutaneously. All animals were killed three months after grafting. The intimal thickness was measured in the central portion of the graft and at the proximal and distal anastomosis. In the control group and the cyclosporine group, the intraluminal surface of the EPTFE graft was smooth and more even than in the cholesterol group. The initial thickness in the central portion was 10.3±3.5, 145±60.3, and 86.1±29.6 µm in the control, cholesterol, and cyclosporine groups, respectively. The intimal thickness in the central portion was significantly less in the control and cyclosporine groups than in the cholesterol group (p<0.05). However, no significant difference in intimal thickness between cholesterol and cyclosporine groups was observed at the proximal and distal anastomoses. The author concluded that cyclosporine inhibits intimal thickening in arterial grafts.

618 IMMUNOHISTOCHEMISTRY FOR ERG EXPRESSION AS A SURROGATE FOR TMPRSS2-ERG FUSION DETECTION IN PROSTATIC ADENOCARCINOMA

You have accessJournal of UrologyProstate Cancer: Basic Research1 Apr 2011618 IMMUNOHISTOCHEMISTRY FOR ERG EXPRESSION AS A SURROGATE FOR TMPRSS2-ERG FUSION DETECTION IN PROSTATIC ADENOCARCINOMA Alcides Chaux, Roula Albadine, Antoun Toubaji, Michael Haffner, Jessica Hicks, Alan Meeker, Angelo Demarzo, Elizabeth Platz, and George J. Netto Alcides ChauxAlcides Chaux Baltimore, MD More articles by this author , Roula AlbadineRoula Albadine Baltimore, MD More articles by this author , Antoun ToubajiAntoun Toubaji Baltimore, MD More articles by this author , Michael HaffnerMichael Haffner Baltimore, MD More articles by this author , Jessica HicksJessica Hicks Baltimore, MD More articles by this author , Alan MeekerAlan Meeker Baltimore, MD More articles by this author , Angelo DemarzoAngelo Demarzo Baltimore, MD More articles by this author , Elizabeth PlatzElizabeth Platz Baltimore, MD More articles by this author , and George J. NettoGeorge J. Netto Baltimore, MD More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.1471AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES We previously demonstrated the presence of TMPRSS2-ERG gene fusions in 46% of prostatic adenocarcinomas in a large cohort, using a break-apart fluorescence in situ hybridization (FISH) technique. In the current study, we assess expression of ERG fusion protein product using immumonhistochemistry (IHC) and correlate it with our previous FISH findings in the same cohort. METHODS The cohort consisted of 10 TMAs containing paired tumor and normal tissues from radical prostatectomies (RRP) performed at our hospital between 1993 and 2001. They included 441 cases. IHC was performed using a commercial rabbit anti-ERG monoclonal antibody (clone EPR 3864; Epitomics, Burlingame, CA), FISH analysis was previously performed using break-apart probes for 5' and 3' regions of ERG (Albadine, et al 2009). An IHC score (H score = intensity X percentage of positives cells) was assigned in each spot and averaged per tumor spots. When comparing fusion status by FISH and IHC techniques, any positive ERG expression on IHC was considered positive. Association strength was evaluated using the Fisher's exact test; classifier performances were calculated for IHC against FISH. RESULTS ERG overexpression was detected in 204 (46.3%) of all PCa and in none of the paired benign prostate samples while TMPRSS2-ERG fusion (either by split or deletion) were observed in 202 (45.8%) cases. There was a strong association between ERG IHC overexpression and TMPRSS2-ERG fusion status (P<0.00001); ERG IHC overexpression was detected in 87.1% of all cases with TMPRSS2-ERG fusion while 88.3% of cases with no TMPRSS2-ERG fusion were also ERG IHC negative. IHC for ERG overexpression had a sensitivity of 86% (95% CI 81–91%) and a specificity of 89% (95% CI 84–93%) in detecting TMPRSS2-ERG fusions. CONCLUSIONS We found a strong association between ERG IHC overexpression and TMPRSS2-ERG fusion detected by FISH. ERG IHC may offer an accurate, simpler and less costly alternative for evaluation of ERG fusion status in PCa. The significance and possible mechanisms of ERG overexpression in tumors with no TMPRSS2-ERG fusions merits further investigation. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e249 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Alcides Chaux Baltimore, MD More articles by this author Roula Albadine Baltimore, MD More articles by this author Antoun Toubaji Baltimore, MD More articles by this author Michael Haffner Baltimore, MD More articles by this author Jessica Hicks Baltimore, MD More articles by this author Alan Meeker Baltimore, MD More articles by this author Angelo Demarzo Baltimore, MD More articles by this author Elizabeth Platz Baltimore, MD More articles by this author George J. Netto Baltimore, MD More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Identification of polymorphisms in the rabbit (Oryctolagus cuniculus) myostatin (MSTN) gene and association analysis with finishing weight in a commercial rabbit population

Table S1 PCR primers, PCR conditions, amplified and sequenced regions, and genotyping protocols. Table S2 Allele frequencies for three rabbit MSTN SNPs. Table S3 Association analysis between genotypes of three rabbit MSTN SNPs and weight at 70-days of age in a paternal rabbit line. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer-reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Quality control of Toxoplasma gondii in meat packages: Standardization of an ELISA test and its use for detection in rabbit meat cuts

Toxoplasma gondii causes severe disease both to man and livestock and its detection in meat after slaughtering requires PCR or biological tests. Meat packages contain retained exudate that could be used for serology due to its blood content. Similar studies reported false negative assays in those tests. We standardized an anti-T. gondii IgG ELISA in muscle juices from experimentally infected rabbits, with blood content determination by cyanhemoglobin spectrophotometry. IgG titers and immunoblotting profiles were similar in blood, serum or meat juice, after blood content correction. These assays were adequate regardless of the storage time up to 120days or freeze-thaw cycles, without false negative results. We also found 1.35% (1/74) positive sample in commercial Brazilian rabbit meat cuts, by this assay. The blood content determination shows ELISA of meat juice may be useful for quality control for toxoplasmosis monitoring.

Effect of aguamiel (agave sap) on hematic biometry in rabbits and its antioxidant activity determination

In this work, we analysed the effect of aguamiel (sap from Agave salmiana) on haematic biometry in rabbits as well as its antioxidant activity with the objective of determining its nutritional value. Nine male Landrace 55-day-old rabbits were sorted into three groups of three rabbits each, which had access to fresh aguamiel, boiled aguamiel and water instead of aguamiel. Commercial rabbit food was supplied ad libitum to each experimental unit. Fresh aguamiel promoted weight increases of about 13% by the seventh week. Haemoglobin counts increased by 4.5% and 9% when rabbits were fed with fresh and boiled aguamiel, respectively. Haematocrit counts increased from 2.6% to 5.3%. Mean corpuscular volume did not show a change. Mean corpuscular haemoglobin significantly increased up to 12% above that previously reported on rabbits. Observed Fe (fixed to transferrin), transferrin and ferritin content increased slightly when fresh aguamiel was included in the diet, as compared to the control. In bone, Fe increased 79.3% (boiled aguamiel) while P increased 23.6% (fresh aguamiel). In antioxidant activity determination, the aguamiel showed 20% with respect to that found in coffee and/or grape juice (commercial beverages with a high antioxidant capability), 226.2 µmol gallic acid equivalent and 35.1 mg ascorbic acid in 250 mL, respectively. These results showed that aguamiel is an innocuous beverage to feed animals, conferring some beneficial properties, and it could be considered as a nutraceutical product.

Epistasis for Founder-Specific Inbreeding Depression in Rabbits

Inbreeding depression is a topic of main interest in experimental and domestic species, although previous studies simplified this genetically complex effect to the linear (or quadratic) regression coefficient linked to the inbreeding coefficient of each individual or, in more recent studies, to founder-specific inbreeding coefficients. Going beyond generalizing to these traditional scenarios, our research focused on the analysis of gene-by-gene interactions leading to epistasis for inbreeding depression effects. Under a Bayesian context, inbreeding depression effects were evaluated for weaning weight (WW) in a commercial rabbit population founded from 4 bucks and 1 doe (MARET population). Founder-specific inbreeding depression effects for the 4 bucks ranged between -81.1 and 38.3 g for each 1% inbreeding. More interestingly, 2 epistatic interactions between the partial inbreeding coefficient of 2 bucks were also significant and negative, showing a -1.9 and -1.0 g reduction on WW. These results provide the first evidence of epistatic inbreeding depression phenomena in domestic species, emphasizing the complexity of the genetic architecture in mammals.

Effects of ricinoleic acid esters from castor oil of Ricinus communis on the vitellogenesis of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) ticks

This study examines the effects of ricinoleic acid esters from Ricinus communis castor oil on the vitellogenesis of Rhipicephalus sanguineus ticks attached to hosts that were fed with commercial rabbit food containing these esters. The oocytes of ticks from the treatment group (TG) showed cytoplasmic changes that inhibited the development of oocytes I and II to the advanced stages (IV and V) in addition to preventing the maturation of oocytes V, resulting in small ones. In addition, sperm was not observed in ampoules. Our findings confirm the acaricide potential of ricinoleic acid esters.

A comparison of reproductive traits of four maternal lines of rabbits selected for litter size at weaning and founded on different criteria

The objective of this study was to compare four Spanish maternal lines of rabbits (A, V, H and LP) on different criteria but selected for litter size at weaning, since their foundation until present for 39, 35, 16 and 4 generations, respectively. The comparisons among the lines were performed for litter size traits and kindling interval. The first comparison made was at the foundation time of the lines, using mixed animal models (additive and non-additive permanent effects) involving the complete data set (from June 1980 to February 2009) and the full pedigree to take into account the process of selection. A second comparison was made at fixed times and location (during the six year-seasons shared at the same farm and similar conditions for lines A, V and H involving data from March 1997 to August 1998, and A, V and LP lines from September 2007 to February 2009. The models used in the second comparison did not include the complete data set nor the additive genetic effects so that line comparisons were not dependent on the genetic model. The raw means for 47,132 parities produced from 12,639 does were 9.80, 9.07, 7.79 and 6.95 rabbits for total born, number bon alive, number weaned and number marketed per litter, respectively, demonstrating high levels of prolificacy among the lines, and with a kindling interval of 49.80 days. At their respective times of foundation, line A showed the lowest litter size with mean differences (1.39 rabbits/litter for total born, 1.20 for number born alive, 0.84 for number weaned and 1.06 for number marketed) among the combined means of the other lines being important Lines V and H did not show significant differences for litter size traits, but for kindling interval the contrast was 3.30 ± 0.72 days, which was significant and favourable to line H. LP exceeded V by approximately one rabbit for all litter size traits. The differences between the lines for kindling interval were negligible. Some interactions between lines and farm-year-seasons were important. In comparison of lines A, V and H from March 1997 to August 1998, the pattern of the differences between the line A and the others was similar to the one observed at the origin, and the only significant difference was found between lines V and H for the kindling interval (4.62 days in favour of line V). The comparison between the lines A, V and LP from September 2007 to February 2009 showed an approximation in their reproductive performance compared to the differences at the origin. Overall, good agreement was observed between the comparisons of lines for litter size traits at fixed times, using a model without genetic effects and data recorded during the time of comparisons, and the predictions derived from the model with genetic effects. Another point is the importance of the criteria in the sample of founders of lines that were used to determine the initial or starting performance levels. Therefore, it is recommended that commercial rabbit producers utilize line populations selected for the traits of economic interest rather than on a popular breed.

Controlled doe exposure as biostimulation of buck rabbits

Female exposure of males could be a low-cost biostimulation option that benefits AI in commercial rabbit operations by improving buck rabbits reproductive performance. The objective of the study was to evaluate exposure of buck rabbits to females as a biostimulation option to improve reproductive potential. Treatments were: exposure (biostimulated) or not (control) of bucks to does. Bucks were New Zealand White, 15-month-old, sexually experienced and fertile. Experimental design was completely random with nine replications, experimental unit was one buck. Doe exposure was permanent using replacement pubertal does housed in an adjacent wire-mesh cage and changed for new ones every other week. Semen collection lasted 14 weeks (late winter and early spring) twice a week with two ejaculates at each collection. Analyses of variance were under a mixed model: treatments, ejaculate number and season were fixed and rabbit random effects and buck weight at each collection as covariable. Biostimulated bucks showed greater ( P < 0.05) reproductive potential due to: 7% lesser reaction time (greater libido); and increased semen volume (40%), sperm motility (29%), sperm per ejaculate (31%), normal alive motile sperm (65%) and number of semen doses (64%). Semen characteristics differed by season in control bucks but not in doe exposed bucks (treatment × ejaculate number, P < 0.05). Reproductive potential in spring was greater ( P < 0.05) than in winter in both treatments. Doe exposure is a biostimulation method that improves sexual drive and sperm production and quality of buck rabbits.

Critical points in the transport of commercial rabbits to slaughter in Spain that could compromise animals' welfare.

The welfare of commercial rabbits depends on the attitudes and handling procedures used by farmers, hauliers and abattoir personnel, as well as the transport logistics. Many studies have been performed on commercial rabbit production but less attention has been paid to identifying critical points during the whole transport procedure. In this study, a survey of rabbit transport was performed in Spanish abattoirs to determine the parts of the process that most compromise the animal?s welfare. Data were collected for the methods for loading, unloading, transporting, holding and slaughter. Handling procedures differ widely among farms, especially regarding cage size (ranging from 1430 cm² to 10000 cm²). Loading facilities were adequate and transport time was short. Only a few hauliers had received specific training courses. The average time before the unloading was short (4.5±13.8 min) but holding time before slaughter was usually longer than one hour and varied widely between abattoirs (ranging from 0 min to 420 min).

Study of urgent visits to commercial rabbit farms in Spain and Portugal during 1997-2007

This is a report on work carried out on 4307 visits to 868 commercial farms with domestic rabbits in Spain and Portugal from January 1997 to December 2007. Of the total visits, 2237 (52%) were emergencies on 660 farms. The median size of the farms ranged between 450 does in 1997 and 750 in 2007. This retrospective study measures the clinical disease occurrence using the Monthly Risk of urgent visits (MR), i.e. the percentage of visits made as a result of each clinical disease in comparison with the total number of urgent visits made each month. The main reasons for the emergencies were mucoid enteropathy (similar to Epizootic Rabbit Enteropathy), with a MR: 25.0%, enteritis-diarrhoea (24.1%), myxomatosis, (11.1%), reproductive troubles (8.6%), respiratory diseases (7.2%) and staphylococcosis (4.2%). Fifty-four percent of the urgent visits were due to diseases of the digestive system. Mucoid enteropathy was still one of the main diseases faced by the commercial rabbit industry during the study period. No significant yearly or monthly variations were observed in the analysis of the MR. A seasonal effect was only found in respiratory diseases during the summer (MR: 11.06±0.01) and myxomatosis in autumn (MR: 14.60±0.02), in comparison with spring (MR: 7.44±0.02). It is therefore concluded that farms should be permanently protected as they might be affected by any of these diseases at any time during the year.

Protein, fat and moisture content of retail cuts of rabbit meat evaluated with the nirs methodology

Thirty commercial rabbit carcasses weighting 836-1413 g were sealed in the Spanish market and were retailed according to the WRSA norms to obtain four parts: fore legs, thoracic cage, loin and hind part. The loin was separated into abdominal walls, Longissimus dorsi (LD) muscles and spine cut; hind legs and sacrum were separated from the hind part. Each joint was carefully dissected to separate edible meat from bone. Meat of each of the 210 samples (180 from joints and 30 representing meat from the whole carcass) was ground and was scanned by NIRS reflectance in quadruplicate; the four spectra from each sample were averaged. 36 samples were selected according to spectra characteristics and chemically analysed for crude protein, crude fat and moisture content and then used for re-calculating some previously obtained equations of calibration. With the new equations, the chemical composition of the 174 samples not analysed was determined. Meat from the fore legs had 20.2% of protein, 7.4% of fat and 71.2% of moisture; thoracic cage meat had 18.7%, 12.8% and 66.9% respectively; LD muscle: 22.1%, 1.2% and 75.6%; abdominal walls 20.9%, 7.6% and 70.1%; spine meat: 20.7%, 7.9% and 70.0%; hind leg meat: 21.2%, 3.0% and 74.7%; meat from the whole carcass: 20.8%, 7.1% and 71.2%. Correlation analysis indicates that meat from the fore leg is a good predictor of the chemical composition of the whole carcass meat (r = 0.82 for crude protein, r = 0.92 for crude fat and r = 0.95 for moisture).

Nitrogen and phosphorus excretion on commercial rabbit farms: calculations based on the input-output balance.

Manure is no longer exclusively considered as a fertiliser in areas with high densities of farm animals. Efforts are being made to reduce mineral excretion or to stimulate a more environmentalfriendly use. In such a context, both from the governmental side and for the producer, a reliable calculation of the on-farm production is very useful. Based on the balance between input (feed) - output (produced rabbits, dead rabbits), the nitrogen and phosphorus on farm excretion have been calculated for different production systems, production levels and slaughter weights. For a closed farm (breeding + fattening) the most convenient expression of mineral excretion is per female on average present on the farm. The excretion amounts to 7.42 kg N and 4.76 kg P2O5 per doe/year on a commercial rabbit farm based on an average production/doe of 45 fatteners of 2.5 kg. The excretion decreases from 76 to 61 g N and from 48 to 40 g P2O5 /kg rabbit produced with increasing productivity of the farm (35 vs 50 delivered fatteners/doe/year, respectively). In an exclusively fattening unit (between 0.8 and 2.5 kg weight and a feed conversion ratio of 3.40), the excretion amounts to 38 g N and 26 g P2O5, per kg rabbit produced.

THE EFFECTS OF ALFAPROSTOL (PGF2a analogue) AND eCG ON REPRODUCTIVE PERFORMANCES IN POSTPARTUM RABBITS

The aim of this study was to verify the effectiveness of post partum pharmacological oestrus synchronisation with alfaprostol or eCG in improving rabbit doe reproductive performances and to evaluate the incidence of pseudopregnancy in this species. One hundred and eighty commercial hybrid rabbit does, multiparous and lactating, were randomly divided into three groups (n=60) and treated on day 8 post partum (pp) as follows: Group A, 1 mL s.c. vitaminic solution with 200 mg alfaprostol, a synthetic analogue of PGF2a; Group B, 1 mL sc vitaminic solution with 20 I.U eCG; Group C (Control) 1 mL sc vitaminic solution. On day 11 pp (3 days after treatment), all the rabbits were artificially inseminated (AI), and injected with 0.8 mg of buserelin i.m. to induce ovulation. Concurrently, blood samples were taken for progesterone (P4) analysis by RIA with the following schedule: day 8 pp (before treatment), day 11 pp (before AI and the induction of ovulation) and day 16 pp (5 days after AI). Fertility was not influenced by hormonal treatments (71.7% and 71.2% respectively) compared to control (66.1%). Conversely, both PGF2a and eCG hormonal synchronisation treatments increased (P 1 ng/mL). On day 5 after insemination 95.5% had P4 values, which attest to the presence of functional corpora lutea (CL) (P4>2 ng/mL). The results of this study show that as long as rabbitry is properly managed zootechnically and sanitarily, drugs such as alfaprostol and eCG, while not ameliorating fertility rate when used for post partum oestrus sychronisation, can increase litter size.

SMALL-SCALE RABBIT MEAT PRODUCTION IN THE WESTERN HEMISPHERE : BACK TO BASICS ?

In the Western Hemisphere, in countries where the demand for rabbit meat is low, and where intensive livestock production systems are common (e.g., commercial broiler, swine, and cattle production), it may not be appropriate for rabbit scientists to recommend commercial rabbit production. Commercial-scale rabbit operations might only be justified, at best, when located in proximity to processing plants and(or) to large cities where there is a strong tradition of rabbit meat consumption. The high cost of producing rabbits translates into high consumer prices, which tends to limit sales to that of a luxury or specialty commodity. An alternative, "back to basics" approach is to recommend small-scale or backyard rabbit enterprises. There are a number of clear advantages to this approach. Such a down-scaled unit could represent a more favorable "economy of scale" of production. Generally, feed costs could be reduced through the utilization of homegrown or less expensive feedstuffs, labor could be shared among family members, and less expensive housing and equipment would be needed. Although productívity may decline, economic retums may exceed costs at a higher rate than for commercial operations. In addition to family consumption, local meat sales could become mote competitive because of lower costs of processing and transportation, especially if there are no rabbit meat inspection laws. Small-scale rabbit production would also support integrative practices (e.g., gardening and vermiculture) and potential local markets for rabbit meat and by­products (e.g., tanned skins and rabbit manure as "organic fertilizer''), which could supplement farm revenue. In addition, there are opportunities to develop poor communities through small-scale rabbit projects. This paper propases a "cottage industry'' model of rabbit micro-enterprise development to secure food and economic stability for rural-based small farm families throughout the Western Hemisphere, and to improve the image of rabbit production as a viable activity.

MORTALITY IN YOUNG RABBITS : A REVIEW

Mortality rate of young rabbits is of vital importance in commercial rabbit farming, since it determines the net income of the rabbitries. However, there is no definite proportion for mortality in young rabbits, since it may be less than 10% in one situation in a given breed and reaches 100% in other situations, in the same breed. This may be due to susceptibility of the genotype to diseases and to the numerous uncontrollable external environmental factors. The significant differences between breeds confirm that mortality can be genetically improved. Within the same breed, kit mortality during the suckling period decreases during the period between 4 and 12 months of doe production, then increases thereafter as age advances up to certain parity. The increase of pre-weaning mortality associates the increase in litter size at birth and reduction of remating interval period, although doe milk yield appeared to be the most important factor, in this respect. Thus, ali factors which may decrease doe rabbit milk yield (nutrition, management of the rabbitry, climatic conditions and doe diseases), increase pre-weaning mortality. lmprovement of nutrition (by using feed additives, antibiotics, probiotics, green fodder or natural sources) increases rabbit doe milk. Heat stress and diseases are the most important factors that affect post-weaning mortality. lt is worthy to note that young rabbits loss may be avoided to a large extent and health and vigour in the stock can be maintained by applying simple methods for cleanliness and in management. Prevention of diseases is also very important, because curative treatment is less successful in rabbits than in many other livestock classes.