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The role of rabbit meat as functional food

Increasing consumer knowledge of the link between diet and health has raised the awareness and demand for functional food ingredients. Meat and its derivatives may be considered functional foods to the extent that they contain numerous compounds thought to be functional. This review will attempt to outline the excellent nutritional and dietetic properties of rabbit meat and offer an overview of the studies performed on the strategies adopted to improve the functional value of rabbit meat. Dietary manipulation has been seen to be very effective in increasing the levels of essential FA, EPA, DHA, CLA, branched chain FA, vitamin E, and selenium in rabbit meat. Dietary fortification with vitamin E or natural products such as oregano essential oil, chia seed oil, and Spirulina platensis microalga seem promising in improving the oxidative stability of rabbit meat while also adding functional ingredients.

Effect of dam and sire genotypes on productive and carcass traits of rabbits

The aim of the experiment was to study the effect of dam and sire genotypes on the production and slaughter performance of growing rabbits. The experiment was carried out at Kaposvár University. Pannon White (PW) and maternal line (M) does were inseminated with the sperm of PW, M, large body line (LB), terminal line of Hycole hybrid (H), or colored line (CL) bucks. The mature body size of the M, PW, and CL genotypes was medium. The mature body size of the LB and H genotypes was large. Only PW and LB rabbits were selected for carcass traits based on computer tomograph (CT) scanning data. The rabbits (n = 320) were weaned at the age of 5 wk and housed in a closed climate-controlled rabbitry in wire cages. Rabbits were fed ad libitum a commercial pellet. Rabbits were slaughtered at 78 d of age. Daily BW gain (5.7%, P < 0.001) and G:F (6.2%, P < 0.001) of the progeny of PW does were better than those of the progeny of the M does. The weight of the chilled carcass and body parts was greater for the progeny of the PW does (P < 0.001). The ratio of the hind part compared with the reference carcass was greater in the PW group (P < 0.001); however, the ratio of the fore part was greater in the M group (P < 0.05). Examining the effect of the genotype of the sires, the BW and daily BW gain were greater in groups H and LB, whereas the progeny of M and CL sires were inferior (P < 0.05). Body weights at 11 wk of age were H: 2,918 g, LB: 2,793 g, PW: 2,678 g, CL: 2,636 g, and M: 2,585 g (P < 0.001). Similar differences were found for daily feed intake (P < 0.05). The G:F differed (P < 0.05) significantly between groups H and CL. The weights of the chilled carcass and of the body parts were the greatest for the progeny of the H sires, and the smallest in the M group. The differences between the dressing out percentages of the groups were not significant. The ratio of the fore part was greater (P < 0.05) in groups LB, H, and CL, but the ratio of the middle part was not different. The ratio of hind part related to the reference carcass was largest in progeny of PW and least in LB and CL groups (P < 0.05). It was concluded that the production of growing rabbits was affected by the adult BW of their sires, but the carcass traits were influenced by their own adult BW and by the CT-based selection.

Effect of turmeric powder (Curcuma longa L.) and ascorbic acid on physical characteristics and oxidative status of fresh and stored rabbit burgers

The objective of this study was to evaluate the effect of Curcuma longa powder and ascorbic acid on some quality traits of rabbit burgers. The burgers (burgers control with no additives; burgers with 3.5 g of turmeric powder/100g meat; burgers with 0.1g of ascorbic acid/100g meat) were analyzed at Days 0 and 7 for pH, color, drip loss, cooking loss, fatty acid profile, TBARS, antioxidant capacity (ABTS, DPPH and FRAP) and microbial growth. The addition of turmeric powder modified the meat color, produced an antioxidant capacity similar to ascorbic acid and determined a lower cooking loss than other formulations. Turmeric powder might be considered as a useful natural antioxidant, increasing the quality and extending the shelf life of rabbit burgers.

Genetic diversity and population structure of the synthetic Pannon White rabbit revealed by pedigree analyses

Demographic history, current status, and efficiency of the mating strategy were analyzed using the pedigree of Pannon White (PW) rabbits born between 1992 and 2007. Potential accumulation of detrimental effects and loss of genetic diversity were also considered. Calculations and estimates were done most often for rabbits born in 2007, whereas other reference populations (REFPOPXXXX) were specified explicitly. The pedigree contained 4,749 individuals and 580 founders, and its completeness was 82.1% up to 10 and 94.5% up to 5 generations, respectively. Generation intervals through different pathways averaged 1.2 yr. When adjusted to the pedigree completeness, the amount of inbreeding (F(i)) of rabbits was comparable (5.54%) with that of other livestock populations, whereas the 10 (30) founders contributing the most to inbreeding explained a large part of the population inbreeding [i.e., 42.24% (73.18%)]. The ancestral inbreeding coefficient of REFPOP2004 (10.67%) was one-half that of REFPOP2007 (20.66%), showing its strong dependence on pedigree length. Family variance, inbreeding, and realized effective population size were 84.18 (REFPOP2006; this variable could not be calculated for the last year examined), 37.19, and 91.08, respectively. The effective numbers of ancestors, founders, and founder genomes were 48, 26, and 7.33, respectively. Although the circular mating scheme applied was generally effective, the large accumulated reduction in genetic variability indicates the need to revise and improve the current breeding strategy.

Dietary Spirulina (Arthrospira platensis) and Thyme (Thymus vulgaris) supplementation to growing rabbits: Effects on raw and cooked meat quality, nutrient true retention and oxidative stability

The study evaluated the effect of Spirulina and Thyme dietary supplementation on rabbit meat quality, nutrient true retention and protection against oxidative stress. Rabbits in the control group (C-C) received a non-supplemented pellet throughout the experiment (5-11weeks of age). In the other groups, the pellet contained 5% Spirulina (S), 3% Thyme (T), or both (ST) for either the entire (groups S-S, T-T, ST-ST) or only the final part of the growing period (8-11weeks: groups C-S, C-T, C-ST). Spirulina supplementation increased the γ-linolenic acid content of rabbit meat, whereas Thyme improved the oxidative stability of raw and freeze-dried meat.

Effect of adult weight and CT-based selection on carcass traits of growing rabbits

Abstract The aim of this study was to compare the carcass traits of different genotypes. Maternal line (M; n=31; adult weight/AW/4.0-4.5kg) (selected for number of kits born alive), Pannon White (P; n=32; AW: 4.3-4.8kg), and Large type line (L, n=32; AW: 4.8-5.4kg) (P and L were selected for carcass traits based on CT/Computer tomography/data) rabbits were analysed. Rabbits were slaughtered at 11 wk of age. P rabbits showed the highest dressing out percentage (M=60.2, P=61.3 and L=61.1%, with a significant difference between groups M and P, P<0.05), the lowest ratio of fore part (M=26.0, P=25.7 and L=26.9%, differences were significant between groups M-P and L, P<0.05), and the largest ratio of the hind part (M=37.3, P=38.2 and L=37.2%, differences were significant between groups M-L and P, P<0.05) to the reference carcass. It can be concluded that carcass traits were influenced by CT-based selection.

Effect of adult weight and CT-based selection on the performances of growing rabbits

Abstract The aim of the study was to compare the productive performance of different genotypes. Maternal (M; n=32, adult weight /AW/ 4.0-4.5kg, selected for number of kits born alive), Pannon White (P; n=32, AW: 4.3-4.8kg), and Large body line (L; n=32, AW: 4.8-5.4kg) (P and L were selected for carcass traits based on CT /Computer tomography/data) rabbits were analysed. Average daily gain between 5-11wk of age, body weight at 11wk of age and feed intake were significantly (P<0.001) highest for L rabbits. For M, P and L rabbits, the following values were observed: average daily gain=38.6, 43.1 and 47.4g/d; body weight=2458, 2667 and 2949g; feed intake=115, 121 and 138g/d, respectively. Mortality of growing rabbits was unaffected by genotype. It can be concluded that production traits were mainly affected by the adult weight of the genotypes.

Effect of different weaning ages (21, 28 or 35 days) on production, growth and certain parameters of the digestive tract in rabbits

The effect of different weaning ages, that is, 21 (G21), 28 (G28) or 35 (G35) days, on growth and certain parameters of the digestive tract was examined in rabbits to assess the risk of early weaning attributable to the less-developed digestive system. On days 35 and 42, G35 rabbits had 10% to 14% and 10% higher BW, respectively (P < 0.05), than those weaned at days 21 and 28. In the 4th week of life, early weaned animals had 75% higher feed intake than G28 and G35 rabbits (P < 0.05). The relative weight of the liver increased by 62% between 21 and 28 days of age, and thereafter it decreased by 76% between 35 and 42 days of age (P < 0.05), with G21 rabbits having 29% higher weight compared with G35 animals on day 35 (P < 0.05). The relative weight of the whole gastrointestinal (GI) tract increased by 49% and 22% after weaning in G21 and G28 rabbits, respectively (P < 0.05). On day 28, the relative weight of the GI tract was 19% higher in G21 than in G28 rabbits, whereas on day 35 G21 and G28 animals had a 12% heavier GI tract compared with G35 rabbits (P < 0.05). Age influenced the ratio of stomach, small intestine and caecum within the GI tract; however, no effect of different weaning age was demonstrated. The pH value of the stomach and caecum decreased from 5.7 to 1.6 and from 7.1 to 6.3, respectively, whereas that of the small intestine increased from 6.8 to 8.4 (P < 0.05); the differences between groups were not statistically significant. Strictly anaerobic culturable bacteria were present in the caecum in high amounts (108), already at 14 days of age; no significant difference attributable to weaning age was demonstrable. The concentration of total volatile fatty acids (tVFA) was higher in G21 than in G28 and G35 throughout the experimental period (P < 0.05). The proportion of acetic and butyric acid within tVFA increased, whereas that of propionic acid decreased, resulting in a C3 : C4 ratio decreasing with age. Early weaning (G21) resulted in higher butyric acid and lower propionic acid proportions on day 28 (P < 0.05). No interaction between age and treatment was found, except in relative weight of the GI tract and caecal content. In conclusion, early weaning did not cause considerable changes in the digestive physiological parameters measured, but it resulted in 10% lower growth in rabbits.

Comparison of pens without and with multilevel platforms for growing rabbits

Abstract This experiment compared the productive performance and location of growing rabbits in pens without and with two-level platforms (wire-mesh or plastic-mesh). A total of 174 rabbits of both sexes weaned at 5 weeks of age were randomly divided into three groups (n = 58 rabbits/group, 2 pens/treatment, 29 rabbits/pen). The floor area of pens was 1.0 × 1.83 m, and the floor was made of wire-mesh. Two pens were equipped with wire-mesh (WP) and two pens with plastic-mesh elevated platforms (PP) on two levels, and two pens were without platforms (NoP). Treatment had no effect on the productive performance of growing rabbits. Based on video recordings, animal density (rabbits/m2 in each location) was higher (p < .001) on the floor than on the platforms (in WP: 12.0 vs. 5.2, in PP: 10.2 vs. 7.4 rabbits/m2, respectively). Animal density on the floor was higher (p < .001) in front of the platforms than under the platforms (in WP 15.7 vs. 9.8 rabbits/m2 and in PP 13.3 vs. 8.3 rabbits/m2, respectively). The animal density on platforms was 1.4 times higher in group of PP than in WP (p < .001). The animal density was 1.6 and 2.9 times higher on the second floor than on the first one (p < .001), in group of PP and WP, respectively. The concentration of cortisol metabolites in faeces and the ratio of injured rabbits were similar in the three groups. The rabbits showed higher preference staying on the floor compared to the platform. Pens with platforms were not influencing productive performance.

Effect of adult weight and CT-based selection on rabbit meat quality.

Abstract This study compared the meat quality of different genotypes. Maternal (M; adult weight/AW/=4.0-4.5kg; selected for the number of kits born alive), Pannon White (P; AW=4.3-4.8kg) and Large type (L; AW=4.8-5.4kg) rabbits were analysed. P and L genotypes were selected for carcass traits based on CT/Computer tomography/data. Rabbits were slaughtered at 11wk of age and hindleg (HL) meat and M. Longissimus dorsi (LD) were analysed for proximate composition and fatty acid (FA) profile. Proximate composition was unaffected by the selection programme, even though the meat of P rabbits was leaner and had higher ash content (P<0.10). The LD meat of P rabbits exhibited significantly lower MUFA contents compared to M and L rabbits (25.4 vs 28.0 vs 27.7%; P<0.01) and higher PUFA content compared to M rabbits (31.9 vs 24.9%; P<0.05). This study revealed that long-term CT-based selection is effective in increasing meat leanness and PUFA content.