C. Castellini

EFFECT OF ORGANIC PRODUCTION SYSTEM ON BROILER CARCASS AND MEAT QUALITY

The effect of organic production on broiler carcass and meat quality was assessed. Two hundred and fifty Ross male chickens were assigned to two different systems of production: conventional, housing in an indoor pen (0.12 m(2)/bird); organic, housing in an indoor pen (0.12 m(2)/bird) with access to a grass paddock (4 m(2)/bird). At 56 and 81 days of age, 20 chickens per group were slaughtered to evaluate carcass traits and the characteristics of breast and drumstick muscles (m. pectoralis major and m. peroneus longus). The organic chickens had carcasses with a higher breast and drumstick percentages and lower levels of abdominal fat. The muscles had lower pHu and water holding capacity. Instead cooking loss, lightness values, shear values, Fe, polyunsaturated fatty acids of n-3 series and TBA-RS were higher. The sensory quality of the breast muscle was better. Organic production system seems to be a good alternative method, due to better welfare conditions and good quality of the carcass and meat. A negative aspect was the higher level of TBA-RS in the muscles, probably due to greater physical activity.

Qualitative attributes and consumer perception of organic and free-range poultry meat

The effect of the organic production (OP) system on the qualitative characteristics and consumer perception of poultry meat is reviewed in the following paper. Age at slaughtering, genetic strains (fast- and slow-growing), physical activity, and pasture intake are key factors in determining meat quality. In conventional farming, fast-growing chicks are generally used, but these are not suitable for OP, since they may develop health and welfare problems, the most recurrent of which are leg disorders and lameness. Conversely, use of slow-growing strains in OP has positive repercussions on both animal welfare and product qualitative characteristics (eating quality and appearance) perceived by consumers. From the published data it can be concluded that organic poultry can be a viable production method, especially if suitable changes in EU Regulation. 1804/99 are made. The market opportunity for both organic and free range poultry products does not yet seem to be fully developed. We suggest that structured integration between production and consumption stages could resolve this problem.

Effect of dietary vitamin E on the oxidative stability of raw and cooked rabbit meat

The effect of dietary α-tocopheryl acetate supplementation (200mg/kg diet) on plasma and muscle levels of α-tocopherol and the oxidative stability of raw and cooked rabbit meat was determined. Two groups of 20 male hybrid rabbits were fed the experimental diets from 35 to 80 days of age. Feed intake, live weight, feed efficiency and qualitative traits of the carcass and meat were recorded. The α-tocopherol levels in plasma and muscle were significantly higher (p≤0·01) in the supplemented group, which also showed an increase in oxidative stability in both raw and cooked meat. The higher α-tocopherol level improved the physical traits of the meat, significantly reducing shear value and increasing water-holding capacity; n-3 fatty acids in raw and cooked meat increased (p≤0·05) and the thrombogenic index decreased (p≤0·05). Dietary vitamin E did not influence weight gain, feed intake and dressing yield.

Environmental impact evaluation of conventional, organic and organic-plus poultry production systems using life cycle assessment

The concept of environmental sustainability is crucial for the development of human actions, and it is one of the most important concerns of the European Union that requires attention in all of the economic sectors. In particular, the potential environmental impact of livestock is well known and has been one of the most important constraints on the development of animal breeding in certain areas. The main aim of this paper is to compare the environmental impact of different poultry production systems: conventional, organic and organic-plus. Organic-plus has more restrictive requirements than the organic system for improving animal welfare (i.e., use of slow-growing strains and 10 m2 pasture/bird), and the quality of the product. For environmental evaluation, life cycle assessment (LCA) has been used in this review, which is a method to evaluate the environmental impact of products, activities and services, based on a ‘cradle-to-grave’ approach. This article provides information for improving the environmental impacts in a process of assessing the sustainability that is specific for poultry production. An important recommendation can be drawn from this study: great attention has to be paid to the feed production phase, since it contributes more to the systems than animal rearing does to the environmental impact of the overall system. With reference to the comparison among the systems, our results show that the organic system has the best environmental performance because it not only has the lowest impact values for two of the most important impact categories (i.e., respiratory inorganics and fossil fuels), but it also has the lowest values for most of the remaining categories. LCA provides important data and specific indicators that can be used in a wider process for the analysis of sustainability, and to adapt and improve production systems. Taking into account the entire life cycle, the organic system has shown a better environmental performance than the organic-plus system. On the other hand, the organic-plus system improves animal welfare and meat quality, which are not considered by LCA. Therefore, to reach an equilibrium among all of these factors (namely environment protection, animal welfare and meat quality), it would be necessary to find a production system that conciliates them into one coherent scheme.

Performance and behaviour of chickens with different growing rate reared according to the organic system

Abstract The performance and the behaviour of three different chicken strains, reared according to the EEC-Regulation 1804/1999 on organic system, were compared. The strains had very slow (Robusta maculata), slow (Kabir) and fast (Ross) growing rates, respectively. The trial was carried out on 200 chickens (male and female) per strain. Rearing lasted 81 days as required by the EEC Regulation. At slaughter age, 20 birds per group were killed. Robusta maculata and Kabir chickens showed more intense walking activity and better foraging aptitude; their antioxidant capacity was also superior. Ross chickens had a good growth rate and feed conversion index, reaching an excellent body weight, but the mortality and the culling rate were high indicating that fast-growing strains do not adapt well to organic production. Robusta maculata showed the worst productive performance although the mortality was low and Kabir birds gave intermediate results. The carcass traits were the best in Ross and the poorest in Robusta maculata. Male chickens were heavier and leaner than females.

Effect of dietary n-3/n-6 ratio on fatty acid composition of liver, meat and perirenal fat in rabbits

The metabolic pathways of dietary fatty acids were studied in rabbits by analysing the fatty acid profile of different tissues (liver, perirenal fat, longissimus lumborum muscle). Four groups of 24 hybrid males each were assigned to four semi-purified diets, varying in the source oflipids which differed in n-3/n-6 ratios: 180 g/kg sunflower (S), 80 g/kg flaxseed + 90 g/kg sunflower (SF), 160 g/kg flaxseed (F) and 60 g/kg fish oil (FI). The liver showed a very important role in fatty acid syntheses and was the tissue richest in long-chain (≥20 C) polyunsaturated fatty acids (LCP) of n-3 and n-6 series. The S diet gave the highest mono-unsaturated fatty acids and n-6 LCP (respectively, 201·9 and 384·9 g/kg, P P P P

Effect of number of motile sperms inseminated on reproductive performance of rabbit does

The relationship between the number of motile sperms inseminated and fertility rate and litter size at birth in rabbits was investigated. A total of 651 artificial inseminations on multiparous rabbit does in different physiological states (lactating or not; sexually receptive or not) were inseminated with a number of motile cells/dose varying from about 1-20 x 10(6). The statistical model computed the following traits: maximum expected value (a), rate of approach to this value (b) and number of motile spermatozoa/dose needed to obtain threshold level (95% of the maximum). The physiological condition of the doe affected the reproductive performance. The sexual receptivity had significant effect during lactation: non-receptive does had the lowest fertility (a: 43.70%; P < 0.05) while no significant differences were found in non-lactating ones (73.80 vs. 89.11%). Also the rate of approach to this maximum was different: non-receptive does showed a higher dependence on spermatozoa number than receptive females (b: 0.69 and 0.58, respectively, in lactating and non-lactating does) and consequently more spermatozoa (13.1 and 11.1 x 10(6) motile/dose) were needed to reach the threshold value. The physiological state of the does did not affect litter size and only 4.1 x 10(6) of motile spermatozoa/dose are needed to reach the threshold value.

Effect of genotype and rearing system on chicken behavior and muscle fiber characteristics

The effect of the organic production system and genotype on chicken behavior and muscle fiber characteristics was assessed. Three hundred day-old male chicks from slow-growing (Leghorn), medium-growing (Kabir), and fast-growing (Ross 208) genotypes were assigned to 2 different production systems: conventional, housing in an indoor pen (0.12 m(2)/bird); and organic, housing in an indoor pen (0.12 m(2)/bird) with access to a grass paddock (4 m(2)/bird). Behavioral observations were recorded from 73 to 80 d of age in the morning and afternoon. At 81 d of age, blood samples were collected to measure lactate dehydrogenase and creatine kinase, and 20 birds per strain and rearing system were slaughtered. Samples of pectoralis major, ileotibialis lateralis, and semimembranosus muscles were obtained for histological evaluations. Behavioral observations showed that genetic selection of animals for a better growth rate modified their behavior, reducing kinetic activity. Indeed, Leghorn birds were characterized by moving activities, whereas Kabir and Ross strains were discriminated on the basis of their lying, standing, and eating activities, and these activities were strongly associated with energy conservation, growth, and muscle fiber characteristics. Fiber characteristics and muscle enzyme functions were affected by rearing system only in animals adapted to the organic system. Interesting results relative to Leghorn chickens are the presence of alpha-Red fiber in breast muscle and the increased cross-sectional area of the ileotibialis lateralis muscle, which together with behavioral data could affirm that this genotype is the most adapted to the organic rearing system.

Comparison of two chicken genotypes organically reared: oxidative stability and other qualitative traits of the meat

Abstract The effect of genotype on the oxidative stability and other qualitative traits of chicken meat was studied. Two groups of 200 chicks (Ross 205 and Kabir) were reared according to the organic farming system. At 81 d of age 20 birds per group were slaughtered and after refrigeration (24 h at 4°C) of the carcasses, Pectoralis major muscles were excised for analyses. Samples were analysed after 0, 24, 48, 72 and 96 hours of storage at 4°C under continuous fluorescent illumination (2300 lux). The analyses concerned the chemical composition and the shear force (only at time 0) and the progress of several traits as pH, CIELAB values, Thiobarbituric Acid Reactive Substances (TBARS), panel test and fatty acid composition (at 0 and after 96 h). Genotype greatly affected the physico-chemical characteristics and the sensory evaluation. The meat from Ross chickens showed high TBARS values, perhaps due to selection for growth rate that reduced their adaptability to greater space allowance and to poorer environmental conditions; these higher TBARS values were also negatively correlated to lightness and yellowness. The initial level of TBARS affected the oxidative stability of breast meat during storage. The amount of TBARS showed significantly negative relationship with the sensory evaluation; breast meat of Kabir had higher scores for liking when the level of malondialdehyde (MDA) was less than 2.5 mg kg-1.

Effect of seminal plasma on the characteristics and fertility of rabbit spermatozoa.

The effects of different dilutions of seminal plasma (SP) on the qualitative characteristics of rabbit spermatozoa and on their fertilising ability were analysed. Ejaculated semen was centrifuged twice and the sperm resuspended in media with decreasing ratios of SP/Tris: (1/2; 1/5; 1/10; 1/20; 1/30; 1/100) until the complete substitution was with SP. The control constituted sperm in undiluted SP. Samples were maintained at 37 degrees C and kinetic analysis done at fixed intervals (0-6h). Also the thiobarbituric reactive substances (TBA-RS) values were determined. Rabbit sperm suspended in Tris, or with extremely low content of SP, lost motility and viability within 1-3h, while sperm suspended in SP either undiluted or diluted up to 10-fold, showed similar motility during the 6h period (from 39 to 49%). Further dilutions of SP (1/20-1/30) had no effect during the initial 2h of storage but thereafter the decline of motility was more marked (after 6h: from 0 to 17%). Kinetic parameters followed the same trend and differences were particularly marked after storage: the highest values were in samples diluted up to 1/10; a sharp decline in motility characteristics was observed at higher dilutions. The addition of SP (1/2 v/v) to immotile sperm reactivated 35.5% of cells. However, SP did not significantly affect fertility rate or litter size possible involving an interaction with the female reproductive tract. SP reduced lipid oxidation (TBA-RS) of semen only after storage. A positive correlation between final TBA-RS and cell viability indicated that peroxidation was one of the cause of rabbit sperm deterioration during conservation.