Effect of trisodium phosphate, ascorbic acid and lactic acid on bacterial load, sensorial characteristics and instrumental colour of rabbit meat

The effect of 8% trisodium phosphate (TSP), 2% ascorbic acid (AA) and 2% lactic acid (LA) on microbial load, pH values, sensorial characteristics and instrumental colour of rabbit shoulders was determined. Measurements were performed immediately after dipping (Day 0) and every 24 h over seven days of storage at 7 °C. The microorganisms present naturally (total aerobic counts, TACs) and the levels of artificially inoculated pathogenic bacteria were studied. Microbial contamination showed a trend towards lower values on decontaminated samples than on control (water-dipped) samples from Day 1 of storage onwards. Average TACs (log10 cfu/cm2) throughout storage were higher (P < 0.05) on control samples (5.94 ± 2.06) than on decontaminated ones (3.69 ± 1.75, 3.77 ± 2.01, and 3.10 ± 1.85 on TSP-, AA-, and LA-treated samples, respectively). On the basis of TACs, all the decontaminants allowed the shelf-life of rabbit meat to be extended from Day 4 to Day 7. From the viewpoint of sensory scores, no treatment achieved any prolongation of the shelf-life of rabbit meat, which was 6 days (control and TSP-treated samples), 5 days (AA) or one day (LA). LA reduced (P < 0.05) scores for colour, odour and overall acceptability from Day 0 of storage, since these samples presented whitening and a slight acid smell. Treatments with organic acids increased lightness (L*), and TSP brought a reduction in redness (b*), vividness (C*) and hue angle (h) values with respect to controls. This research work offers new insights into the chemical decontamination of rabbit meat.

Effects of incorporating agro-industrial by-products into diet of New Zealand rabbits: Case of rebus of date and apricot kernel meal

Aim

The aim of this study was to determine the effects of incorporating the by-products complex of date and apricot on the fattening performance of the New Zealand breed of rabbits, to reduce the economic costs of the food formula.

Materials and Methods

A total of 288 young New Zealand rabbits aged 35 days were divided into four equal groups each containing 72 animals and into sub-groups of 6 rabbits per cage, depending on the rate of substitution of corn by date rebus and of soybean meal by apricot kernel meal (0%, 10%, 20%, and 30%).

Results

The change in weight from day 35 to 77 and the average daily gain are not significantly different, regardless of the diet. The pH and water content are proportional to the substitution rates (6.4-6.6% and 66.5-68.8%). Meat protein levels increased significantly, in particular for the 10% and 30% groups (+8.1% and 6%) while the fat and mineral content levels decreased significantly, in particular for the 30% group displaying -16% and -17%, respectively. Incorporation of dates and apricot kernel meal into the ration of rabbits reduces the cost of the kilogram of food produced of -9%, with an opportunity cost of 165 Algerian dinars (DZD).

Conclusion

The date rebus/apricot kernel meal complex can be used as an alternative to the corn/soybean meal complex at substitution rates of up to 30% without adverse effects on growth rates, feed contribution, or slaughter yield. It improves the chemical composition of the meat and reduces the cost price of the quintal of feed produced.

Effects of plant extracts and essential oils as feed supplements on quality and microbial traits of rabbit meat

The effects of dietary supplementation of onion, cranberry,  strawberry and essentials oils on meat quality were analysed. Five groups of 48 Grimaud female weaned rabbits received the supplemented or the control ration; the experimental unit was a cage of 6 rabbits. Each experimental diet contained 10 ppm of added active ingredients.  Rabbits were fed with the experimental diets for 4 wk before determining slaughter and carcass traits and determining the pH at 1 and 24 h post mortem (pHu) of the <em>Longissimus dorsi</em> (LD) and the <em>Biceps femoris</em> (BF) muscle, left and right, respectively. Cooking loss, drip loss and L*, a* and b* color parameters were obtained of the right<em> </em>LD and for ground meat and antioxidant status (TBARS, DNPH, Folin Ciocalteu). Only the pHu of the LD muscle for the strawberry supplemented group was significantly lower when compared to the control group (P=0.04). However, we note that for the pH of the LD, the average was less than 6 for the meat of animals who received a diet enriched in polyphenols, compared to the control group. Plant extract supplementation did not influence meat quality traits, growth performance or oxidative stability. But under aerobic and anaerobic conditions, our results indicate that diet supplementation with extracts rich in polyphenols, especially with essential oils, had a small bot sporadic positive effect in reducing bacterial microflora compared to the control group (P&lt;0.05). In conclusion, plant extracts and essential oils can be used in a rabbit diet without adverse effects on performance and meat quality traits. This effect could be optimized by investigating higher doses.

Comparison of Carcass and Meat Quality Traits among Three Rabbit Breeds

The objective of this study was to compare carcass composition and meat quality traits in the longissimus dorsi and biceps femoris muscles in the Hyla, Champagne and Tianfu Black rabbit breeds. Tianfu Black rabbits had the heaviest head, skin, thoracic viscera and commercial carcass percentage (p<0.05). In addition, Tianfu Black had the highest pH_{0 h} value, followed by the Champagne and Hyla breeds (p<0.01) in the longissimus dorsi and biceps femoris muscles. Tianfu Black had a higher a* (0 h and 24 h) than the other two breeds in both longissimus dorsi and biceps femoris muscles (p<0.05). The Hyla, Champagne, and Tianfu Black breeds showed a similar pattern of differences for meat quality traits (pH, L*, a* and b*) measured in fresh meat (0 h) and meat stored for 24 h. Hyla had the highest IMF values of the three breeds (p<0.01). The lower intramuscular fat of Tianfu Black and Champagne rabbits gives them an advantage over Hyla rabbits among most consumers seeking lean rabbit meat.

Quality of meat of rabbits after application of epicatechin and patulin

The aim of the present study was to determinate the effect of epicatechin and patulin on selected parameters of meat quality of rabbits. Adult female rabbits (n=25), maternal albinotic line (crossbreed Newzealand white, Buskat rabbit, French silver) and paternal acromalictic line (crossbreed Nitra's rabbit, Californian rabbit, Big light silver) were used in experiment. Animals were divided into five groups: control group (C) and experimental groups E1, E2, E3, and E4. Animals from experimental groups E1, E2, E3, E4 received patulin through intramuscular injection (10 µg.kg-1) twice a week and animals from groups E2, E3, E4 received epicatechin three times a week through intramuscular injection. After 30 days animals were slaughtered. For analysing of meat quality the samples of Musculus longissimus dorsi (50 g) were used. Application of  epicatechin and patulin to rabbits had slight or no effect on the pH levels in stomach, small intestine, large intestine and urinary bladder contents, however differences among the groups were insignificant (p ˃0.05). Application of epicatechin and patulin to rabbits had slight or no effect on total water, protein, fat   and differences among the groups were insignificant (p >0.05). The values of amino acids concentrations were not influenced after application of epicatechin and patulin. The fatty acid profiles in animals after application of different doses of epicatechin and 10 µg.kg-1 patulin were similar (p >0.05). Concentration of cholesterol increased in experimental groups in comparison with the control group, but differences were insignificant (p >0.05). pH levels of meat of rabbits in experimental group E3 was lower when compared with the control group, but differences was not significant (p >0.05).  Electric conductivity parameter was increased in each experimental group (in E3 the highest) against the control but without significant differences (p >0.05). Colour L parameter was slightly decreased in experimental groups with comparison to the control group (in E3 the lowest). Generally we can conclude that intramuscular application of epicatechin or patulin did not affect parameters of meat quality as well as pH values of internal organs content. Further investigations are needed to prove the final answer concerning the health promoting effects of epicatechin and patulin.

Carcass composition and meat characteristics of two rabbit breeds of different degrees of maturity

Carcass and meat characteristics of rabbits from two synthetic breeds of different size were compared. Breed R had a higher adult weight and reached slaughter weight 1 week before breed V. Sixty rabbits of each breed were slaughtered when they (approximately) reached the Spanish commercial liveweight of 2 kg in order to compare their carcasses and meat quality. The carcasses were measured and retailed according to the norms of the World Rabbit Scientific Association. Breed R had a considerably more developed liver, a less developed hind part, and a more developed thoracic cage. Dissectible fat content was 3.1% and 2.5% of the carcass weight for the breeds V and R, respectively. Meat content was higher in the V breed than in the R breed (53 and 51% with respect to the chilled carcases). The ratio meat bone was better for breed V (2.18 and 2.05, respectively). Muscular fat content, estimated in the meat of one side of the carcass, was higher for breed V. All these differences are related to the lower degree of maturity of breed R at equal weights. Muscular pH, measured on the B. femoris and on the M. Longissimus lumborum at the level of the 5th lumbar vertebra, was the same for both breeds. Colour was measured on the carcass surface and in cuts of the M. Longissimus lumborum. Some colour differences were found for the carcass surface, but not for the meat.

Total iron, heme iron, zinc, and copper content in rabbit meat and viscera

The aim of this study is to determine the content of total iron (TFe), heme iron (HeFe), zinc (Zn), and copper (Cu) in different cuts of meat and viscera from rabbit. Five young New Zealand rabbits were used in the study. Samples in triplicate were obtained from three meat cuts (foreleg, hind leg, and loin) and from main viscera. TFe, Zn, and Cu concentrations from samples were determined by wet acid digestion followed by atomic absorption spectrophotometry (AAS), while HeFe was determined by acid extraction followed by AAS. Mean TFe, HeFe, Zn, and Cu in meat was 0.83 ± 0.09, 0.56 ± 0.11, 0.95 ± 0.35, and 0.08 ± 0.01 mg/100 g, respectively. TFe content was less than 1 mg/100 g in all meat cuts. Sixty-seven percent of iron content was HeFe. The cut of meat with highest Zn concentrations was the foreleg with 1.33 ± 0.12 mg/100 g. Cu content was low for all meat cuts. TFe, HeFe, Zn, and Cu content in viscera varied greatly. The spleen was the organ with the highest TFe and Zn concentrations (82.79 ± 9.22 mg/100 g and 3.49 ± 0.63 mg/100 g, respectively). Nevertheless, the lungs had the highest concentration of HeFe (5.79 ± 0.90 mg/100 g), accounting for 91% of the total iron. The liver had the highest Cu content (3.89 ± 0.89 mg/100 g). Rabbit meat has low TFe concentration, similar to that of poultry, and most of the iron is HeFe. The amount of minerals in viscera closely depends on their function.