Zs. Szendrő

Effect of dietary supplementation of Spirulina (Arthrospira platensis) and Thyme (Thymus vulgaris) on rabbit meat appearance, oxidative stability and fatty acid profile during retail display

The objective of this study was to evaluate the effect of Spirulina and Thyme supplementation on rabbit meat during retail display. At weaning 294 rabbits were allocated to 7 different treatments (42 rabbits/treatment). Rabbits of the control group (C) received a diet without any supplementation throughout the experiment (5-11 weeks of age). The other groups were fed diets containing 5% Spirulina (S), 3% Thyme (T) or both supplements (ST) for the whole trial (5-11 weeks; treatments S, T and ST), or for a part of the growing period (8-11 weeks; treatments C-S, C-T and C-ST). Colour parameters, pH, water holding capacity and drip loss were determined on fresh and stored Longissimus dorsi muscle of 5 rabbits/treatment. Spirulina- and Thyme-supplemented diets had a significant effect on redness and yellowness of Longissimus dorsi. Drip loss was significantly reduced in C-T and T groups that also showed the highest content of α-tocopherol and n-3 fatty acids content and the lower lipid oxidation.

Effect of housing conditions on production, carcass and meat quality traits of growing rabbits

Production, carcass traits and meat quality of rabbits housed in cages or in different pens were compared. Rabbits (n=579) were sorted into 5 groups: C=cage (2 rabbits/cage); pen without platform: P11=9 rabbits/pen; P16=14 rabbits/pen; pen with platform: PW=wire net platform, 14 rabbits/pen; PD=platform with straw-litter, 14 rabbits/pen. Feed intake and average daily gain between 5 and 11 weeks, and body weight at 11 weeks were significantly higher in C rabbits than that of the mean of pen-housed groups, while the PD group had the lowest growth performance. C rabbits had the smallest hind part to reference carcass (P<0.001) and the largest percentage of perirenal and scapular fat (P<0.001). The meat/bone ratio was the largest in group C (P<0.05). Differences were recorded in a* value and lipid content of m. Longissimus dorsi. Rabbits housed in cages generally had the best performance whereas those housed in pens with platform exhibited the worst.

Comparison of performance and welfare of single-caged and group-housed rabbit does

Although rabbit does are generally single housed on rabbit farms worldwide, it has been suggested by some specialists and recommendation of organic rabbit production systems that group housing of does is more comfortable and similar to the living conditions of the European wild rabbits. The aim of this experiment was to compare production of single-caged (S) and group-housed does (G). The S does were housed in commercial rabbit cages (floor area 0.32 m(2) and 0.3 m high). In treatment G, four does and one buck were housed in four pens measuring 7.7 m(2) (half of the floor was deep litter and the other half was plastic slat), with four nest boxes in each pen (n = 16). In treatment S, approximately half of the does (n = 18) were inseminated 2 days after kindling (S-33), whereas in the remaining does (n = 16) AI was done 11 days after kindling (S-42). A single-batch system (all of the does in the group were inseminated on the same day) was used in both S treatments. Kindling rates were 77.6%, 85.2% and 45.6% in treatments S-33, S-42 and G, respectively (P < 0.05). During the experiment, the percentage of does that kindled 0, 1, 2, 3, 4 and 5 times were 17%, 25%, 17%, 25%, 17% and 0% (G); 0%, 0%, 0%, 8%, 69% and 23% (S-33); and 0%, 0%, 17%, 58% and 25% (S-42, in this treatment does had a maximum of four kindlings). There were no significant differences among treatments for litter size. In treatments S-33, S-42 and G, suckling mortality was 14.0%, 15.2% and 38.5%, respectively (P < 0.001); survival of does was 71%, 81% and 50% (P = 0.084); and faecal corticosterone concentrations were 61, 54 and 175 nmol/g (P < 0.001). The high mortality of kits was associated with stress and aggressive behaviour of does, including scratching, biting or killing the kits, which resulted in the high rates of mortality and culling, as well as shorter lifespan of does. Because of high stress, increased mortality and morbidity, and low productivity, group housing of rabbit does resulted in poorer animal welfare and increased production costs, and therefore is not recommended.

The effect of dietary Digestarom® herbal supplementation on rabbit meat fatty acid profile, lipid oxidation and antioxidant content.

The experiment tested the effect of Digestarom® herbal supplementation on the antioxidant content, lipid oxidation and fatty acid profile of rabbit meat. At kindling, rabbit does and litters were divided into two dietary groups (N=162 kits/dietary group) and fed either a control diet (C) or the C diet supplemented with Digestarom® (D: 300mg/kg). At weaning (35days) four experimental fattening groups (54 rabbits each) were considered: CC, CD, DC and DD. After slaughtering (12weeks of age), Longissimus thoracis et lumborum muscles were dissected from 20 rabbits/group and analyzed. Rabbit meat of DD group was enriched in essential C18:3 n-3 fatty acid and in other long-chain PUFA of n-3 series. Despite meat of DD group displayed the highest peroxidability index, TBARs value was the lowest. Meat antioxidant content followed the rank order: DD>CD>DC>CC. Digestarom® improved fatty acid composition and oxidative status of rabbit meat, particularly when administered from weaning throughout the growing period.

Effect of genotype, housing system and hay supplementation on carcass traits and meat quality of growing rabbits

The aim of the study was to examine the effects of genotype (Pannon Large × Pannon Ka/Large/or Hungarian Giant × Pannon Ka/Hung), housing system (Cage or small Pen) and hay supplementation (Pellet without or with Hay/P+Hay/) on carcass and meat (Longissimus dorsi/LD/ and hind leg/HL/) quality of growing rabbits. Large rabbits showed higher carcass weights, as well as higher fatness and meatiness compared to Hung rabbits. Caged rabbits were heavier, with higher prevalence of the mid part of the carcass, and showed higher fatness and lower meat toughness than Penned rabbits. Caged rabbits meat was richer in MUFA, but poorer in PUFA and Σ n-6 FA. Hay supplementation impaired carcass weight, carcass fatness, L* and a* color, and lipids content. P+Hay increased the HL meat content of C18:3 n-6 and C20:5 n-3 FA. Overall results offer further information on how alternative breeds, housing systems and feeding strategies can affect carcass traits and meat quality.

Effect of pre- and post-weaning dietary supplementation with Digestarom® herbal formulation on rabbit carcass traits and meat quality

This study evaluated effects of Digestarom® (D) dietary inclusion before weaning (0-5weeks old; BW) and/or after weaning (5-12weeks old; AW) on growing rabbit carcass traits and meat quality. During BW, Pannon-Ka rabbits (does, kits) received two diets: a control diet (C) and one supplemented with 300mg Digestarom®/kg (D). At weaning, each group was divided into 3 dietary sub-groups: CC and DD received C and D diets from 5 to 12weeks of age, whereas DC was fed D from 5 to 8weeks and C from 8 to 12weeks of age (54 rabbits/group; AW). Rabbits were slaughtered at 12weeks of age. Digestarom® supplementation improved carcass yield and body mid part proportion only when administered BW. Rabbits fed D BW had higher hind leg meat cooking losses. Loin meat spiciness and rancidity increased with D both BW and AW. In conclusion, Digestarom(®) herbal formulation was ineffective in improving growing rabbit carcass traits or meat quality.