World Rabbit Science - Vol. 29 (3)-2021
Tabla de contenidos
- Hierarchical clustering as a tool to develop a classification scheme for rabbit meat quality
- Effect of source and concentration of zinc on growth performance, meat quality and mineral retention in New Zealand rabbits
- Pituitary and ovarian hormones: is their plasma concentration affected by litter size in primiparous lactating rabbit does?
- Health, performance and soiling of breeding does and their kits kept in two different housing systems on a German rabbit farm
- Pathological changes and antigen localization in the small intestine of rabbits infected with Eimeria magna
- Molecular genetic diversity of some rabbit breeds based on mitochondrial 16S rRNA sequences
URI permanente para esta colecciónhttps://riunet.upv.es/handle/10251/173605
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Item type: Artículo , Access status: Abierto , Hierarchical clustering as a tool to develop a classification scheme for rabbit meat quality(Universitat Politècnica de València, 2021-09-30) Larivière-Lajoie, A. -S.; Cinq-Mars, Dancy; Guay, Frederic; Binggeli, Simon; Dalmau, Antoni; Saucier, Linda; Ministère de l'Agriculture, des Pêcheries et de l'Alimentation, Canadá; Agriculture and Agri-Food Canada[EN] This study aimed to characterise the quality of meat from commercially-raised rabbits. Animals came from five different producers and were laughtered in three different plants under provincial or federal inspection jurisdiction. Animal behaviour evaluated by scan sampling prior to feed withdrawal (FW) and transport, as well as blood lactate concentration at exsanguination, did not raise concerns with respect to stress. Stomach pH was higher (P=0.047) when the FW time was short (≤13.5 h), at a mean value of 2.23. All pH values measured 1 h post-mortem from the Biceps femoris (BF) and almost all (97.6%) from the Longissimus lumborum (LL) were higher than 6. Values for ultimate pH measured 24 h postmortem(pHu) ranged from 5.80 to 6.83 and from 5.70 to 6.70 for BF and LL muscles, respectively. The maximum meat drip loss recorded was 2.6%, while cooking loss reached 30%. Meat lightness (L*) and colour intensity (C*) for the long FW times (≥23 h) were no different from those with short and intermediate (15.5 to 17.3 h) FW times. However, these colour parameters were higher for the short FW time class compared to the intermediate FW time class (P<0.02). A hierarchical cluster analysis based on pHu, cooking loss and lightness (L*) from 200 rabbit loins was performed. Of the four clusters created, clusters 1 and 2 had the best and second-best meat quality, respectively. Clusters 3 and 4 had the lowest meat quality and presented DFD-like (dark, firm and dry) characteristics. Meat did not exhibit PSE-like (pale, soft, exudative) characteristics, even for the slaughter lot with the minimum mean pHu. Of the eight slaughter lots evaluated, more than 50% of the meat from three of them fell into clusters 3 and 4; all three were in the intermediate FW time class. Overall, the quality of rabbit meat analysed was acceptable for commercial use, but rather variable. This suggests that there are factors within the value chain that are not yet fully controlled and require further investigation.Item type: Artículo , Access status: Abierto , Health, performance and soiling of breeding does and their kits kept in two different housing systems on a German rabbit farm(Universitat Politècnica de València, 2021-09-30) Rauterberg, Sally Luisa; Bill, Joana; Kimm, Sarah; Kemper, Nicole; Fels, Michaela; Agricultural European Innovation Partnership (EIP-AGRI)[EN] The aim of the present study was to compare a new housing (NC) for rabbit does and their kits that complies with German welfare regulations with established wire mesh cages (CC) on a commercial rabbit farm. Rabbit does were single-housed from five days antepartum until weaning at 31 d postpartum either in large pens (80×80 cm with an open top) with slatted plastic flooring (11 mm slats and 11 mm gaps), nestbox, elevated platform (15% perforated) and different manipulable materials (NC) or in cages (70×50×30 cm) with wire mesh flooring (12×70 mm holes and 3 mm wire diameter), nestbox and one gnawing stick (CC). Skin lesions, weight development, fertility, morbidity, cleanliness and kit performance of 272 rabbit does in a total of six batches were investigated. While there was no difference in performance of their kits, rabbit does showed an impaired performance with less weight gain and less body weight at weaning, lower fertility, more injuries and a higher incidence of mastitis and diarrhoea at the end of the rearing period in NC housing compared to CC housing. Additionally, soiling of hind feet was higher in NC than in CC housing. Overall, the poor hygienic conditions may have affected the animals’ health and make an improvement in the new housing system necessary, especially with regard to the floor design.Item type: Artículo , Access status: Abierto , Molecular genetic diversity of some rabbit breeds based on mitochondrial 16S rRNA sequences(Universitat Politècnica de València, 2021-09-30) Allam, Mohammad; Mahrous, N. S.[EN] The present study was performed to assess the genetic variations among six rabbit breeds in Egypt based on mitochondrial 16S rRNA sequences. The length of partial mitochondrial 16S rRNA in the six rabbit breeds ranged from 546 bp to 558 bp. The sequenced regions were submitted to GenBank/NCBI under accession numbers (MW052052 - MW052057). The average content of A+T was 57% in all breeds. Among breeds, the percentages of genetic distance values were ranged from 0.000 to 0.004. The highest P-distance (0.004) was found between the New Zealand White breed and all other breeds. The results support the suitability of mitochondrial 16S rRNA for genetic diversity analysis of rabbit breeds and the applicability for future research on genetic relationships and the phylogeny of rabbit breeds.Item type: Artículo , Access status: Abierto , Pathological changes and antigen localization in the small intestine of rabbits infected with Eimeria magna(Universitat Politècnica de València, 2021-09-30) Yuan, X.; Liu, J.; Wang, F.; Hu, X. F.; Wen, F.; Tang, X. E.; Yang, S. S.; Zhong, S. W.; Zhou, Z. H.; Li, Yong; National Natural Science Foundation of China; Natural Science Foundation of Jiangxi Province[EN] Coccidiosis is a major disease caused by various Eimeria species in rabbits. The aim of the present study was to investigate the haematological and pathological changes in rabbits infected with E. magna. Moreover, the localisation of coccidial antigens was examined in the intestines of rabbits with two kinds of serum as primary antibodies. In the present study, forty-five 28-day-old weaned rabbits were randomly divided into three groups and reared in three separate places. Group A was infected with 20×103 sporulated oocysts of E. magna, group B was only used to produce anti-E. intestinalis serum by infecting them with 3×103 sporulated oocysts of E. intestinalis, and group C was designated as the control group. According to histopathological evaluation of group A, the epithelial cells of the jejunum and ileum were parasitised with a large number of oocysts and other stages of E. magna. The haematological results showed that red blood cell counts, haemoglobin counts, haematocrit levels and the percentage of lymphocytes were significantly decreased in group A compared with group C (P<0.01), but white blood cell counts and the percentage of neutrophils were significantly increased (P<0.01). The weight of group A began to decrease on the 5th day after infection, and this decrease continued until the 9th day. Immunohistochemistry staining revealed that two kinds of coccidial antigens were basically located at the same sites of the intestine when anti-E. intestinalis serum and anti-E. magna serum were used as primary antibodies. Most likely, E. magna and E. intestinalis antigens have some similar antigenic determinants; this finding provides a theoretical basis for screening for common antigens of these two coccidian species.Item type: Artículo , Access status: Abierto , Pituitary and ovarian hormones: is their plasma concentration affected by litter size in primiparous lactating rabbit does?(Universitat Politècnica de València, 2021-09-30) Fernández-Pacheco, Carlota; Millán, Pilar; Rodríguez, María; Formoso-Rafferty, Nora; Velasco, Beatriz; Rebollar, Pilar G.; Ministerio de Economía y Competitividad[EN] Genetic selection in commercial rabbit lines based on litter size has positively improved the number of kits suckling, presumably to weaning. Although it has been proven that the energetic balance of primiparous does is due to the need to satisfy pregnancy, lactation and growth requirements, litter size adjustment from 7 to 12 kits is applied as a routine in commercial rabbit farms. The suckling stimulus provokes a prolactin (PRL) secretion, which in turn can modulate the preovulatory release of luteinising hormone (LH) and, consequently, the ovulatory and productive responses of the does. This study aimed to determine if litter size of prolific primiparous rabbit does during lactation [Group HL, with high litter density (10-12 kits; n=21) and Group LL, with low litter density (7-9 kits; n=29)] influences plasma concentration of PRL. Blood samples from lactating does were taken weekly throughout lactation starting on day 4 post-partum, until day 32 post-partum, before and immediately after suckling. In addition, the does were re-inseminated after weaning (day 32 post-partum), and sampled at 0 and 60 min after induction of ovulation to determine whether litter size affected the peak of LH, progesterone (P4) concentrations and the main productive parameters of their second pregnancy. All hormones were determined by enzyme immunoassay. Statistical analysis of the results revealed that the PRL concentrations of hyperprolific rabbit does before and immediately after a suckling stimulus from 7-9 or 10-12 kits were significanltly different, as we only detected basal levels, with a rise after weaning in both groups. More studies are necessary, delaying blood sampling to later periods of time after the suckling stimulus, in order to conclude whether the peak release of this hormone is altered or not. There were also no differences in plasma LH and progesterone levels after artificial insemination, or in productive performance of these females after their second pregnancy. In conclusion, the litter size adjustment of prolific primiparous rabbits with 7 to 12 kits determines adequate pituitary, ovarian and reproductive responses at second parturition if the does are inseminated after weaning.Item type: Artículo , Access status: Abierto , Effect of source and concentration of zinc on growth performance, meat quality and mineral retention in New Zealand rabbits(Universitat Politècnica de València, 2021-09-30) Luis-Chincoya, Hector; Herrera-Haro, Jose Guadalupe; Pro-Martínez, Arturo; Santacruz-Varela, Amalio; Jerez-Salas, Martha Patricia[EN] Zinc supplementation in rabbit diet favours deposition of this mineral in meat and, therefore, contributes to satisfying the daily requirements of Zn in humans that consume it. A trial was conducted to study the effect of two sources (ZnSO4 and Zn-methionate) and two concentrations of Zn, along with a control (without Zn supplementation), on weight gain, meat quality and muscle retention in New Zealand White (NZW) rabbits during fattening stage. Treatments were randomly assigned to 100 NZW rabbits 40 days old, in a completely randomised experimental design using a factorial arrangement of treatments (2×2+control). The experimental period was 30 d. In each experimental treatment, weight gain, feed consumption and meat quality were recorded, as well as the retention of Zn in serum, liver, loin and hind leg. Results showed no differences (P>0.05) in weight gain and food consumption, which can be attributed to diet-added Zn sources (ZnSO4 and Zn-methionate). Food conversion was better with the organic source at the highest concentration (P<0.05). Regarding meat quality, no differences were found (P>0.05) in hind legs for source effect and Zn concentration, while in loin, differences (P=0.02) were found in the colour parameter of L* and B* when the organic source of Zn (Zn-methionate) was supplied. Most retention of Zn on the loin occurred when a concentration of 25 mg Zn kg–1 of Zn-methionate was added, which could be important to provide larger amounts of Zn for human consumption.