M D'Agata

Effect of an outdoor rearing system on the welfare, growth performance, carcass and meat quality of a slow-growing rabbit population

The effect of Outdoor or Indoor housing systems on the growth, welfare and carcass and meat quality of a local rabbit population was investigated. The slaughter age was 103±2days. Open-field tests showed an effective capacity of the Outdoor group to combat stressors. Compared to Indoor rabbits, Outdoor rabbits showed better growth performance and higher slaughter weight (SW) (2535 vs 2137g; P<0.01). Outdoor housing conditions increased the physical activity of rabbits and their hind legs were more developed (36.1% vs 34.9%; P<0.01). Slaughter yield was lower in Outdoor rabbits (57.8% vs 58.4% SW; P<0.05) due to the higher skin proportion (17.2% vs 15.6% SW; P<0.05). Outdoor rabbit meat showed lower L∗ value (L. lumborum: 55.6 vs 59.2; P<0.01; B. femoris: 53.0 vs 55.5; P<0.01) and cooking loss (L. lumborum: 15.9% vs 18.1%; P<0.05). Outdoor rabbit hind leg meat was characterized by lower water (74.5% vs 75.1%; P<0.01) and higher protein (22.9% vs 22.6%; P<0.01) and fat (1.4% vs 1.1%; P<0.01) contents; lipids were lower in SFA and higher in MUFA. Outdoor rearing seems to be a possible alternative housing system that allays the ethical concerns of modern consumers while also providing good meat quality.

Effect of Islamic ritual slaughter on beef quality.

Abstract The aim of this study was to evaluate several quality characteristics of meat obtained from 20 Limousine calves slaughtered either according to conventional methods (n=10) or by the Islamic ritual slaughtering procedure (n=10). After 7 days of ageing under vacuum, pH, drip loss, colour and oxymyoglobin percentage were measured on longissimus dorsi muscle after 2h, 2 and 6 days of storage to study their evolution. With conventional slaughter pH remained stable until the 6th day of storage, while with ritual slaughter it increased from the 2nd to 6th day of storage. Drip loss increased considerably from the 2nd to 6th day of storage in conventional slaughter, while in ritual slaughter the drip loss increase was lower. Meat colour was not influenced by the slaughtering system but only by the different lengths of storage.

Effect of rearing technique in outdoor floor cage on slow growing rabbit population performance

Abstract The aim of this research was to test the effect of floor cage in outdoor pen on productive performance and carcass characteristics of a rabbit local population characterized by slow growing rate. A sample of 48 rabbits female 57 days old was divided into two groups: Indoor group, housed in colony cages indoor at the density of 14 animals/m2 and Outdoor group, in wire net floor colony cages in outdoor pen, at the density of 5 animals/m2. The animals were fed a commercial feed and ad libitum alfa-alfa hay. Individual live weight and cage feed consumption were checked every week and feed conversion ratio was calculated; at 103 ± 2 days old a sample of 24 animals was slaughtered and carcass traits were recorded. The results showed that the Outdoor group had the highest live weight and the best daily weight gain, together with an higher feed intake. Outdoor group showed the lower mortality, the higher slaughtering weight, the higher reference carcass incidence and hind leg percentage. These favourable results encouraged this kind of rearing system characterized also by lower investment costs.

Oxidation and antioxidant status: effects on shelf-life of meat from Limousine cattle fed with supplements of α-tocopherol

Abstract The purpose of this study was to evaluate the antioxidant status of meat from cattle fed diets supplemented with vitamin E (α-tocopherol acetate) during the finishing period and to evaluate the effect of this treatment on meat shelf-life. Twenty purebred Limousine calves reared in the same farm, were randomly selected, divided into control group (n=10) and treated group (n=10) and fed a total mixed ration: treated group received a supplementation of vitamin E (900 mg/kg of CMF) for a period of 150 days before slaughter. Meat quality was evaluated by the following analyses: pH, water holding capacity (drip loss), colour (L*, a*, b*, C*, H*), chemical forms of myoglobin, substances reactive to thiobarbituric acid (MDA) and enzymatic antioxidant activity (superoxide dismutase, catalase and glutation peroxidase). Dietary vitamin E supplementation had a positive effect on water holding capacity; in the control group a considerable increase in drip loss from the 2nd to 6th day of conservation was observed (2.83% vs 7.54%), while in the treated group during the same time period this increase appeared to be much more gradual and occurred to a lesser degree (2.31% vs 4.15%). Moreover, administration of vitamin E led to greater stability of colorimetric coordinates and reduced discoloration of the longissimus dorsi muscle during conservation as indicated by the redness a* (control: 23.85 and 23.87 vs 19.34 at 2h, 2 and 6 days, respectively; treated: 24.88, 23.91 and 24.01 at 2h, 2 days and 6 days, respectively) and in the Chroma* (control: 26.89 and 26.77 vs 21.90 at 2h, 2 days and 6 days, respectively; treated: 27.67, 26.57 and 26.77 at 2h, 2 and 6 days, respectively). Superoxide dismutase activity was significantly greater in the meat from cattle treated with vitamin E compared to that observed in the meat from controls (0.204 vs 0.167). The study showed that vitamin E supplementation in the finishing diets of calves caused only slight modifications in the antioxidant status of the meat; however, it positively influenced several qualitative characteristics which appeared to be more stable over time, thus extending the shelf-life of the meat.

Performance of Large White x Duroc pigs reared indoors and outdoors: meat and fat quality

Abstract During recent years, in order to satisfy consumer’s demand at meat quality and animal welfare, it has become popular to raise pigs outdoors. As reported by various authors this kind of rearing system may affects chemical-physical traits of meat but mainly the adipose tissue, characterised by an higher content of unsaturated fatty acids (Pugliese et al., 2004). The aim of this work is to verify the effect of rearing system on some meat and subcutaneous fat quality traits. For this reason, twelve Large White x Duroc pigs were raised under two different farming system following the organic regulations: six pigs were reared indoors while six pigs were reared outdoors on woodland pastures of 5000 m2. Both group were fed the same diet but, during the months of October and November, the pigs raised outdoors received 1kg/die of chestnuts (Castanea sativa) instead of maize. All animals were slaughtered at the target weight of about 140kg, reached at the age of 12 months for the indoor group and at the age of 13 months for the outdoor group. 24 hours after slaughtering, from all carcasses the left loin (muscle longissimus lumborum) was excised and vacuum packaged. The meat was analysed for the determination of: pHu, colour, water holding capacity (drip loss, water-bath loss and M/T ratio) and shear force on water-bath cooked meat; the subcutaneous fat was analysed for colour and shear force. To verify the effect of the different rearing system, data underwent to variance analysis (SAS, 1995). As regard the main results, the rearing conditions do not affect pHu values (5.43 vs 5.47), in agreement with results of other authors (Lebret et al., 2002; Pugliese et al., 2004). The colour parameters of meat are similar between indoor and outdoor pigs, in spite of the different age and of the attended different content of myoglobin. Shear force on water-bath cooked meat is significantly higher for the outdoors pigs (12.82kg vs 10.94kg) probably due to the higher exercise and to the older age at slaughter. Results of water-holding capacity show that outdoors pigs have a significantly lowest drip loss (2.78% vs 4.86%) and a significantly highest value of water-bath loss (32.36% vs 20.12%); no differences are revealed for the M/T ratio. These contradictory results on water-holding capacity are in agreement with other authors and may be related to the different methodologies used (Pugliese et al., 2004). As regard the quality of subcutaneous fat, it is possible to note that the outdoors pigs show lower value of C* (2.77 vs 4.56) and higher value of H* (58.33 vs 41.01) thus their fat is less coloured and clearer, in agreement with the results of Pugliese et al. (2004). No differences are revealed for shear force parameters: it seems that the consistence of fat is not influenced by rearing system even if it is well known that outdoors pigs have a different fatty acid composition than indoors pigs, mainly in terms of polyunsaturated fatty acid content. In conclusion it seems that the outdoor rearing system, further on influences the consumer perception of quality, effectively modifies some meat and fat quality traits, making interesting an ulterior deepening of this argument.