World Rabbit Science <p style="text-align: justify; text-justify: inter-ideograph; margin: 0cm 0cm 6.0pt 0cm;">World Rabbit Science is the official journal of the World Rabbit Science Association (WRSA). One of the main objectives of the WRSA is to encourage communication and collaboration among individuals and organisations associated with rabbit production and rabbit science in general.</p> Universitat Politècnica de València en-US World Rabbit Science 1257-5011 <p><a href="" target="_blank" rel="noopener"><img src="" alt="" /> </a></p> <p>This journal is licensed under a "<a href="" target="_blank" rel="noopener">Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)</a>".</p> <p> </p> A method to estimate endogenous losses of nitrogen and amino acids at the ileal level in growing rabbits <p>Apparent ileal digestibility can be corrected to give the true ileal digestibility of the nitrogen and amino acids provided by the diet, by determining the flow of endogenous nitrogen and amino acids (from desquamated epithelial cells of gastrointestinal mucosa, mucins and digestive enzymes). This flow of nitrogen and amino acids has been studied in adult rabbits fitted with a T-cannula, but remains unknown for growing rabbits. The aim of this work was to propose a method to estimate endogenous nitrogen and amino acid losses in the ileum of growing rabbits slaughtered at 64 d of age from 20:00 h. For this purpose, two experiments were carried out. The first was performed with 10 weaned rabbits fed with a diet with casein as the only source of protein (whose ileal digestibility is 100%) and labelled with ytterbium. This experiment allowed us to identify the relationship between the ileal flow of endogenous nitrogen (IF<sub>EN</sub>) and the dry matter intake in the last 24 h before slaughter (DMI), which fits the equation: IF<sub>EN</sub> (mg/d)=5.99 DMI (g/d) +133; (R<sup>2</sup>=0.778, residual standard deviation=138, <em>P</em>&lt;0.001, n=10). The second experiment was carried out with 36 rabbits fed the same diet but without ytterbium, with whose ileal content 9 pools were constituted to determine the amino acid profile of endogenous nitrogen, which was found to be rich in glutamic acid, serine, aspartic acid, glycine, valine and threonine (15.97±1.33; 8.00±0.80; 7.06±0.72; 6.24±0.77; 5.48±0.51 and 4.97±0.47 g/16 g of N, respectively) and poor in methionine and histidine (1.05±0.06 and 1.34±0.16 g/16 g of N, respectively). Knowing the DMI of a certain growing rabbit in the 24 h prior to slaughter, the combined use of the equation and the amino acid profile obtained makes it possible to estimate the ileal endogenous losses of each amino acid.</p> Pablo Jesús Marín-García Mireia Rodríguez Luís Ródenas Vicente Javier Moya Eugenio Martínez-Paredes María del Carmen López-Luján María Cambra-López Juan José Pascual Enrique Blas Copyright (c) 2024 Pablo Jesús Marín-García, Mireia Rodríguez, Luís Ródenas, Vicente Javier Moya, Eugenio Martínez-Paredes, María del Carmen López-Luján, María Cambra-López, Juan José Pascual, Enrique Blas 2024-03-28 2024-03-28 32 1 1 9 10.4995/wrs.2024.19654 Use of dehydrated sainfoin (Onobrychis viciifolia) in rabbit feeding. 2 - Effects of a high dietary incorporation on performance and health of does and growing rabbits, under a sub-optimal breeding commercial environment <p>The effects of a high dietary (26%) incorporation of dehydrated sainfoin (DS) (Perly cultivar) on the performance and health of reproductive does and growing rabbits were analysed in a sub-optimal professional breeding environment (presenting previous coccidiosis), and over two non-consecutive reproductive cycles (2 replicates). Performance and health of does and growing rabbits were compared for 2 groups of 194 does and associated litters, when fed isonutritive feeds containing either 0 or 26% DS (DS0 and DS26 groups). Dietary DS incorporation had no effect on doe live weight, fertility rate, mortality, culling rate and doe coccidia excretion levels (<em>P</em>&gt;0.05). In replicate 1, kit growth before weaning was similar among the two groups, but was 12% lower for the DS26 group in the 2<sup>nd</sup> replicate (significant interaction). Similarly, a significant interaction was detected between the effect of the diet and the replicate for the mortality rate of kits before weaning, i.e. a higher mortality was detected for DS26 (3.3 <em>vs</em>. 1.8%) in replicate 1, while in replicate 2 it was lower (2.1 <em>vs</em>. 4.4%). After weaning, the post-weaning growth rate was improved by 4% (<em>P</em>=0.02) for the DS26 group, while the mortality rate decreased (7.1 <em>vs</em>. 4.5%, <em>P</em>&lt;0.001). Coccidia excretions of growing rabbits were not affected by dietary sainfoin or by replicates. A high incorporation of DS (26%) should be recommended after weaning to improve the performance of growing rabbits without impact on reproducing does.</p> Cécile Gayrard Antoine Bretaudeau Pascale Gombault Hervé Hoste Thierry Gidenne Copyright (c) 2024 Cécile Gayrard, Antoine Bretaudeau, Pascale Gombault, Hervé Hoste, Thierry Gidenne 2024-03-28 2024-03-28 32 1 11 20 10.4995/wrs.2024.19848 Growth performance and carcass characteristics of rabbits fed concentrate diets containing graded levels of Brassica oleracea outer leaves and Musa paradisiaca leaves <p>Ninety-six (96) 8-wk-old “mixed breed” of New Zealand white, California white and chinchilla rabbits were used to determine the growth performance, carcass and organ percentages of rabbits fed concentrate diets containing graded levels of <em>Brassica oleracea</em> outer leaves and <em>Musa paradisiaca</em> leaves. The rabbits were assigned to two groups of 48. Those in group 1 were allotted to four dietary treatments with concentrate diets containing 0, 10, 20 and 30% inclusion levels of <em>B. oleracea</em> outer leaves for one week and 12-wk adaptation and testing periods, respectively, for growth performance evaluation. Similar treatment and design were adopted for group 2 rabbits using graded levels of <em>M. paradisiaca</em> leaves. Six rabbits were randomly selected from each treatment group for slaughter at the end of the testing period for carcass and internal organ characteristics evaluation. There were no dietary effects on the parameters of rabbits fed graded levels of <em>B. oleracea</em> outer leaves except for <em>M. paradisiaca</em>, where the control diet had the lowest feed intake and the least (<em>P</em>&lt;0.05) feed conversion ratio comparable to 30% inclusion level and final body weight, which was the highest (<em>P</em>&lt;0.05) for rabbits fed diets containing 10 and 20% inclusion levels of <em>M. paradisiaca</em> leaves. The cost of feed was highest for the control diets, and reduced with increasing inclusion levels of the leaves in the diets. None of the rabbits died during the experimental period. The findings suggest that rabbits can be fed concentrate diets containing <em>B. oleracea</em> outer leaves and <em>M. paradisiaca</em> leaves up to 30% inclusion level for good growth performance and high carcass characteristics at a lower production cost than concentrate diets, while maintaining good health.</p> Doris Yaa Osei Samuel Obeng Apori Julius Kofi Hagan David Amedorme Raphael Ayizanga Copyright (c) 2024 Doris Yaa Osei, Samuel Obeng Apori, Julius Kofi Hagan, David Amedorme, Raphael Ayizanga 2024-03-28 2024-03-28 32 1 21 29 10.4995/wrs.2024.19616 Potential, challenges and prospects of rabbit farming in urban and peri-urban areas of Dodoma city, Tanzania <p>This study highlights the current status of rabbit production, potential challenges facing the industry and the prospects for rabbit farming in Dodoma city, Tanzania. Data from 60 individuals keeping rabbits were collected through a structured questionnaire and direct observation. Results showed that 60% of the respondents were men and 40% women. Rabbits were kept mainly as a source of meat for families and income generation. Main sources of rabbit stock were local breeders (55%) and missionaries (25%), while the remainder were from agricultural institutes. The dominant rabbit breeds reared were California white (50%), New Zealand white (30%), Chinchilla (10%) and Dutch (10%). Ninety-five percent of the farmers kept rabbits in cages, while 5% confined them at night and let them out during the day to forage for feed. Fifteen percent of the respondents fed commercial rabbit pellets, 5% vegetables and kitchen waste only, whereas 80% fed both rabbit pellets, vegetables and kitchen waste. The number of rabbits kept by an individual farmer ranged from 5 to 180, with mean stock size of 22.80±11.20 (mean±standard deviation). Rabbits were sold at 8 to 12 wk of age and each rabbit was sold for 20 000 to 30 000 Tanzanian shillings (8.00 – 12.00 USD). Major challenges in rabbit production were lack of feed resources, lack of readily available market, poor quality of breeding stock, low knowledge of rabbit production techniques and lack of technical support from extension services. Although rabbit farming in Dodoma is carried out at subsistence level, it is associated with a decrease in poverty among urban and peri-urban farmers. In conclusion, rabbit production in urban and peri-urban areas of Tanzania has the potential to contribute to food and nutrition security and poverty alleviation, thus improving living standards.</p> Edward Moto Copyright (c) 2024 Edward Moto 2024-03-28 2024-03-28 32 1 31 42 10.4995/wrs.2024.20238 Preference and acceptance of fresh rabbit, pork and chicken meat sausages among young consumers <p>The rabbit sector has proposed sausages as a suitable presentation format to increase rabbit meat consumption among young people in a context in which it is declining in several traditionally-consuming countries. In order to confirm its suitability in this context, this work compares the acceptability and preference of commercial fresh rabbit sausages with those of chicken and pork meat, using an untrained panel of 70 young Spanish consumers (22.1 yr old on average; 57.1% male and 42.9% female). In the first part of the trial, cooked sausages were evaluated for: a) acceptability of organoleptic characteristics (odour, colour, appearance, texture, flavour, elasticity and juiciness) and the overall rating using a 9-point hedonic scale, and b) order of preference of sausages (first to third). Overall acceptance and sensory attributes were rated in the medium-high range (6.1-7.9 points) and differed among the cooked sausages, except for odour and appearance. Rabbit sausage was rated at the same level as chicken and pork sausages in terms of odour, appearance, texture, flavour and overall assessment, outperformed pork sausage in colour, elasticity and juiciness acceptance, and was only rated lower than chicken sausage in terms of juiciness. Cooked chicken sausage was preferred in first place, followed by rabbit sausage, while pork sausage came last. In the second part of the trial, raw sausages were evaluated visually for: a) acceptability of colour and visual appearance, and b) order of preference of the sausages. No difference was found between the raw sausages in terms of colour, while the appearance of the raw pork sausage was rated better than that of the rabbit and chicken sausages, with no difference between the latter two. The visual appearance of the raw pork sausage was ranked first, followed by the chicken sausage, while the raw rabbit sausage came last. Only 40% of the young panellists could identify the meat ingredient of the rabbit sausage in both cooked and raw sausages. No interaction was found between the type of sausage and the gender of the panellists in evaluation of either the cooked or raw sausages. Young women rated the texture, flavour, elasticity, juiciness and overall assessment of the cooked sausages lower than men, regardless of meat type, whereas no gender difference was found for the visual assessment of the raw sausages. In conclusion, cooked rabbit sausage was accepted as well as chicken sausage overall and better than pork sausage, while raw rabbit sausage was accepted as well as chicken sausage overall and worse than pork sausage in the visual assessment, showing its potential to promote rabbit meat consumption among young people.</p> Pedro González-Redondo María Fierro-Raya Copyright (c) 2024 Pedro González-Redondo, María Fierro-Raya 2024-03-28 2024-03-28 32 1 43 55 10.4995/wrs.2024.20236 Mange in farmed rabbits <p>In this study we determined occurrence of mange in breeding rabbits on 1368 commercial farms in Portugal and Spain during 1996-2022. We obtained our information by carrying out 11 737 visits to 1334 doe farms, 11 farms only with growers, and 23 artificial insemination (AI) centres. The median size of the visited doe farms was 450 does (minimum to maximum: 100–2500 does) and 1175 does (ranging from100 to 6000 does) in 1996 and 2022, respectively. AI was used on 9% of the farms visited in 1996 and 95% in 2022. For our diagnoses we used (1) clinical observations on all visited farms to detect sarcoptic mange; (2) examination of the outer ear of breeding rabbits on a subset of farms to assess the prevalence of otodectic clinical mange (OCM); and (3) the examination of breeding rabbits and youngstock does (2.5 to 5.5 mo old) on a subset of 72 farms during 2018 to estimate prevalence of body mange compatible with cheyletiellosis. They were mainly clinical diagnoses, supported sometimes by a laboratorial confirmation. Over the course of the 27-yr clinical study, the cumulative incidence of sarcoptic mange was low; we recorded a total of 13 affected doe farms. The percentage of farms affected by OCM dropped from 55% in 1996 to 28% in 2022. OCM mean prevalence for the period 1996-2022 and 95% binomial confidence interval (CI) were 3.2% (95% CI [3.1-3.3%]), and 3.9% (95% CI [3.7-4.1%]) in does and bucks, respectively. We observed an improvement over time; the OCM yearly mean prevalence decreased from 7% in 1996 to 2.3% in 2022 in females and from 7.2% to 2.2% in males, respectively. This progress was compatible with the use of semen coming from AI centres; biosecurity measures and medical management also contributed. Genetic type was predisposing risk factor for OCM. Enabling risk factors were year and season (more affected in summer). Hair and skin disorders along the back, compatible with cheyletiellosis, were also assessed during 2018; we detected 50% of positive farms with various prevalence results in females, males or young does. In this study, we describe protocols observed in the control of benign and severe cases of mange in rabbitries, which included the use of ivermectin and synthetic acaricides. Ivermectin was used on 36% of doe farms visited during 2018-2022; we suggest that it should be used less often to lower its negative impact on the environment.</p> Joan M. Rosell Luis F. de la Fuente Rosa Casais Copyright (c) 2024 Joan M. Rosell, Luis F. de la Fuente, Rosa Casais 2024-03-28 2024-03-28 32 1 57 71 10.4995/wrs.2024.20624 Niche partitioning and competition between different rabbit breeds using stable isotopes <p>Stable isotope analysis (SIA) is an evolving method for determining diet, understanding food web and resolving biogeochemical issues in the ecosystem. This study aims to trace out ecological niche preferences/partitioning and competition among the lagomorphs, including two different breeds of European rabbit (<em>Oryctolagus cuniculus</em>), New Zealand rabbit and American Dutch rabbit, using SIA. Thirty-two samples of tooth enamel were analysed, which were collected from different districts of Punjab, Pakistan, including Okara, Sahiwal and Kasur. Among these samples, 16 belonged to the New Zealand breed (08 male and 08 female rabbits) and 16 to the American Dutch breed (08 male and 08 female rabbits). Significant (<em>P</em>&lt;0.001) intergender differences in the isotope content of δ<sup>13</sup>C in the enamel for New Zealand and American Dutch rabbit were found. The European rabbits showed significant differences for both genders in the stable isotope of oxygen in the enamel (δ<sup>18</sup>O) values (<em>P</em>=0.05). Nitrogen stable isotope results showed no significant intergender differences between American Dutch and New Zealand rabbits (<em>P</em>=0.24). The stable isotope results for δ<sup>13</sup>C, δ<sup>15</sup>N, and δ<sup>18</sup>O indicate that the trophic niche partitioning of both breeds overlaps, which can potentially cause competition for resources, whereas the water intake may differ among different genders, which may reflect differential gender-related activities. The archaeological and fossilised data of lagomorphs is present, but there is no significant literature available for living lagomorphs (rabbits). In general, this study provides a basic and first dataset for δ<sup>13</sup>C, δ<sup>15</sup>N, and δ<sup>18</sup>O of living lagomorphs, which can serve as a comparative dataset for future studies.</p> Usama Shouket Rana Manzoor Ahmad Muhammad Tahir Waseem Abdul Majid Khan Sania Zubaid Copyright (c) 2024 Usama Shouket, Rana Manzoor Ahmad, Muhammad Tahir Waseem, Abdul Majid Khan, Sania Zubaid 2024-03-28 2024-03-28 32 1 73 81 10.4995/wrs.2024.19934