PERFORMANCE AND BEHAVIOUR OF CHICKENS WITH DIFFERENT GROWING RATE REARED ACCORDING TO THE ORGANIC SYSTEM

The performance and the behaviour of three different chicken strains, reared according to the EEC-Regulation 1804/1999 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 Regulations. 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

MEAT QUALITY OF THREE CHICKEN GENOTYPES REARED ACCORDING TO THE ORGANIC SYSTEM

The meat quality of three poultry genotypes with differing growth rates (fast-growing Ross; medium and slow growing Kabir and Robusta maculata, respectively) was compared. All the birds were reared according to the organic production system which requires a paddock with grass pasture (4 m2/bird) and a slaughter age greater than 81 d. The trial was carried out on 100 female chickens per strain. The meat quality was affected by the 20 different degree of maturity of the strains at slaughter age, which was 70% for Ross, 52 % for Kabir and 78% for Robusta maculata. Ross and Kabir were slaughtered at 81 d, whereas Robusta maculata, required 120 d to reach a commercial weight (>2 kg). The meat of all the three genotypes showed good qualitative traits. The main differences of the three genotypes regarded moisture, lipid, pHu, colour, iron, oxidative stability and overall acceptance. Compared with Kabir and Robusta maculata Ross meat had more fat, lower pHu and iron, and was 25 paler. The oxidative stability during display (24-96 h at 4° C) and acceptance were the worst. Kabir chickens, being the least mature strain, had the highest moisture content with a high cooking loss. The slower-growing genotypes showed a good adaptation to the extensive rearing conditions, while the fast-growing genotype showed unbalanced muscle response to the greater activity and the oxidative stability of the meat was reduced

COMPARISON OF TWO CHICKEN GENOTYPES ORGANICALLY REARED: OXIDATIVE STABILITY AND OTHER QUALITATIVE TRAITS

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 was less than 2.5 mg kg-1

WELFARE, PRODUCTIVITY AND QUALITATIVE TRAITS OF EGG IN LAYING HENS REARED UNDER DIFFERENT REARING SYSTEMS

The welfare, production performance and some qualitative characteristics of eggs obtained under three different rearing systems (conventional, organic and organic-plus) were compared. Three homogeneous groups, each of 120 White Leghorn hens, fed the same diets, were assigned to different rearing systems and data were recorded for 1 year. The welfare indicators were the following: first impact, behavioural patterns, tonic immobility and plumage status. Productive performance was recorded (% deposition; egg weight) and some qualitative traits (Haugh index, yolk colour, yolk, albumen and egg shell weight) were evaluated. Well-being was greatly affected by rearing system. The best welfare status was observed in hens of the organic-plus group, whereas the worst was in the conventional group (caged hens). Caged hens showed little interest or fear of observers, at times they had high tonic immobility and some aggressive pecking; the status of their plumage was very poor. On the contrary, caged hens produced more eggs, even if their qualitative traits (Haugh index and yolk colour) were worse than the organicplus eggs. The intense motor activity of organic hens and the concurrent intake of grass reduced their productive level; further egg deposition seemed more affected by seasonal variation

SUSTAINABILITY OF POULTRY PRODUCTION USING THE EMERGY APPROACH: COMPARISON OF CONVENTIONAL AND ORGANIC REARING SYSTEMS

The organic production system is an important strategy, compatible with sustainable agriculture, avoiding the use of chemical compounds,limiting the intensity of production and providing controls along the entire chain of production. The aim of this study is to compare conventional and organic poultry production in terms of emergy analysis. The main differences in the two systems were the emergy cost for poultry feed and for cleaning/sanitization of the buildings between successive productive cycles. In both production systems the poultry feed represented more than 50% of the emergy flow. Regarding the agronomic phase, it was shown that almost all the organic crops, avoiding chemical fertilizers and pesticides, saved around 60% emergy. The emergetic costs for housing of the birds were very similar in both systems. Relating the emergy results with productive performance it is possible to show that, although the annual productive performance was much lower in organic than in conventional (206%), transformity of organic poultry was around 10% lower. Comparison of the organic poultry system with a conventional one from the viewpoint of sustainability showed that all the emergy-based indicators are in favour of the organic farming system with a higher efficiency in transforming the available inputs in the final product, a higher level of renewable inputs, a higher level of local inputs and a lower density of energy and matter flows

EFFECT OF CONVENTIONAL VERSUS ORGANIC METHOD OF PRODUCTION ON THE BROILER CARCASS AND MEAT QUALITY

The effect of the organic production system 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 m2/bird); organic, housing in an indoor pen (0.12 m2/bird) with access to a grass paddock (4 m2/bird). At 56 and 81 days of age twenty chickens per group were slaughtered to evaluate the carcass traits and the characteristics of breast and drumstick muscles (pectoralis major and peroneus longus). The organic chickens had carcasses with a higher breast and drumstick percentages and lower level 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

Effect of range enrichment on performance, behavior, and forage intake of free-range chickens

SUMMARY The aim of the present study was to analyze the effect of range enrichment (trees or tall grass stand) on the performance and herbage intake of free-range chicken. This trial was conducted in 2 different seasons (winter and summer) comparing a standard free-range system with 2 kinds of range enrichment: a stand of sorghum (a tall grass) and olive trees. Two hundred fifty male naked neck chickens were used in each season and system; performance, behavior, forage intake, and body lesions were recorded. Productive performance was not affected by range enrichment. However, in the presence of trees or tall grass stand, no predation losses were experienced; whereas, in the standard paddock, cases of predation by raptors or crows were registered, mainly during the first period of rearing. Consequently, mortality rate was significantly lower in the enriched environment. Control chickens stayed indoors more rather than forage in the pasture, whereas, in enriched environments, birds spent more time outdoors and widely exploited the available pasture. Forage intake was significantly influenced by rearing system and season; chickens reared under olive trees had higher herbage ingestion, exploring the available area up to almost 50 m from the hut. With the olive trees, chickens also showed the lowest frequency of foot and breast damage