ORGANIC POULTRY PRODUCTION SYSTEM AND MEAT CHARACTERISTICS

The effect of the organic poultry production system on some qualitative characteristics of the meat is reported. The effect is mainly due to the greater age and physical activity of animals but it is largely modulated by the farming protocols used e.i., genetic strain (fast and slow-growing strains) and pasture availability. Due to economic reasons and chicks availability, generally fast or intermediate growing chicks are used. Such animals are not adapted to the organic system and health and welfare problems caused by leg disorders and lameness are recurrent. Nevertheless, compared to conventional chickens, the carcasses have higher breast and drumstick percentages and a lower level of abdominal fat. Even the physical-chemical characteristics of the meat are affected: muscles have lower final pH and water holding capacity. Instead cooking loss, lightness, shear values, Fe, and polyunsaturated fatty acids increase. Unfortunately, the greater physical activity increases the oxidative metabolism of the body and determines a higher level of TBA-RS. Slow-growing strains, probably due to their particular behaviour (more kinetic activity, foraging) and metabolism, show larger differences in qualitative traits, compared to both conventional and organic fast-growing strains. In particular, with respect to fast-growing strains, they have a higher antioxidant level (715 vs 522 nmol HClO mL-1), serum a-tocopherol (19.0 vs 17.2 mg L-1) and grass ingestion. As a result, the oxidative stability of fresh and stored meat is much higher than fast-growing strains (2.0 vs 3.05 mg MDA kg-1).In conclusion, the organic poultry production system seems to be an interesting alternative method especially if suitable farming protocols will be developed and used

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

Improved texture of breast meat after a short finishing feeding period of broilers in an organic free-range system

In order to develop an organic broiler product with high ethical value, high meat quality and based on locally produced feed, we tested if a long period without high quality protein feed followed by a finishing period with a high quality protein ration would affect the meat quality. Two genotypes were included in the experiment (The Hubbard breed ‘JA757’ and the Sasso breed ‘T851’), and only female broilers were included. The chickens were raised in groups in a free range system with more than 10 square meters per chicken covered with grass and herbs. The chickens were offered free access to either an optimized organic concentrate ration (HP) or an organic ration based on locally produced ingredients (peas, rapeseed, lupine, wheat and oat) (LP). The broilers were slaughtered at 90 days (HP) or 118 days (LP). At 90 days the LP broilers were allocated to the high quality protein ration (HP) for either four weeks (LP4) or two weeks (LP2) before slaughter. At slaughter the JA757 HP broilers were the heaviest (2827 g), and the JA757 LP broilers were not able to catch up after either 2 or 4 weeks finishing feeding with the HP ration (2248 g and 2292 g, respectively). This was different for the T851 genotype where there was no difference in slaughter weight between the T851 HP and LP2 and LP4 (average 1592 g). A sensory panel evaluated the sensory quality of the breast meat and found less firmness and fibrousness, lower chewing time and more tenderness in both genotypes offered high quality protein feed in the finishing feeding for 2 weeks in comparison with the 4 weeks finishing feeding, with the HP in between. This pattern is reflected in the daily gains the last two weeks before slaughter and suggests a positive linkage between daily gain before slaughter and tenderness post mortem

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

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

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

Adaptive learning to speed-up control of prosthetic hands: A few things everybody should know

Domain adaptation methods have been proposed to reduce the training efforts needed to control an upper-limb prosthesis by adapting well performing models from previous subjects to the new subject. These studies generally reported impressive reductions in the required number of training samples to achieve a certain level of accuracy for intact subjects. We further investigate two popular methods in this field to verify whether this result also applies to amputees. Our findings show instead that this improvement can largely be attributed to a suboptimal hyperparameter configuration. When hyperparameters are appropriately tuned, the standard approach that does not exploit prior information performs on par with the more complicated transfer learning algorithms. Additionally, earlier studies erroneously assumed that the number of training samples relates proportionally to the efforts required from the subject. However, a repetition of a movement is the atomic unit for subjects and the total number of repetitions should therefore be used as reliable measure for training efforts. Also when correcting for this mistake, we do not find any performance increase due to the use of prior models

Angiotensin II and Aldosterone Increase with Fasting in Breeding Adult Male Northern Elephant Seals (Mirounga angustirostris)

The renin‐angiotensin‐aldosterone system (RAAS) appears to contribute significantly to osmoregulation of fasting northern elephant seal (Mirounga angustirostris) pups; however, RAAS has not been characterized in fasting adult seals. Therefore, this study examined the contribution of RAAS to water turnover rates in fasting adult male northern elephant seals. Blood samples were obtained twice during their breeding fast at an interval of 6.5 wk, and water efflux rate was estimated by isotopic dilution during the same period. Serum electrolytes (Na+, K+, Cl−) and osmolality were unaltered between the two sampling periods, indicating ionic and osmotic homeostasis during the fast. Despite the lack of an increase in vasopressin, serum angiotensin II and aldosterone were increased and were significantly and positively correlated. Changes in aldosterone concentration and water efflux rate were significantly and negatively correlated, suggesting that the greater the increase in aldosterone, the smaller the loss of water. Adult male seals maintain ionic and osmotic homeostasis similar to that of fasting weaned pups, and this homeostasis appears to be mediated, at least in part, by RAAS, which probably contributes to increased water retention as well. The hormonal mechanisms by which northern elephant seals maintain water and electrolyte balance during fasting conditions appear to be similar regardless of age

Envisioning sea level rise in Golden Gate National Recreation Area

A step-by-step explanation of how Golden Gate National Recreation Area developed a set of complementary climate change exhibits for various sites in the park, focused on the impacts of sea level rise