effect of rearing system and season on the performance and egg characteristics of ancona laying hens

Productive performance and egg characteristics of Ancona laying hens reared under three different rearing systems (conventional, organic and organic-plus) were compared during an experimental period of one year. Three-hundred-sixty Ancona female chicks at 28 days of age were divided in three groups and assigned to different rearing systems. The organic group had 4m2 pasture/hen according to the requirements imposed by the EC Regulation 1804/99, whereas the organic-plus group had a larger grass paddock (10m2/hen). The Control group was reared in cages under standard housing conditions. The following egg characteristics were recorded and analysed during the year-long cycle: egg weight and egg mass laid/d, weight of egg components, shell thickness, Haugh index and yolk colour. Egg quality was affected by the pasture available. The hens that ingested grass (organic-plus), produced eggs with higher shell weight and percentage, darker yolk colour and higher α-tocopherol, carotenoid and polyphenol contents. The other egg traits were not affected by rearing system

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

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 majormuscles were excised for anal- yses. Samples were analysed after 0, 24, 48, 72 and 96 hours of storage at 4°C under continuous fluorescent illumina- tion (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 com- position (at 0 and after 96 h). Genotype greatly affected the physico-chemical characteristics and the sensory evalua- tion. 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 different management protocols for grouping does on aggression and dominance hierarchies

The study aimed at evaluating different management protocols of grouping does in regard to aggressive interactions and the establishment of a hierarchy under commercial conditions. Fifty-seven multiparous rabbit does of the Hycole hybrid maternal line were randomly distributed into three different management protocols (MP) for a total of 5 consecutive trials: MP12 with grouping 12 days after parturition, MP18 after 18 days and MP22 after 22 days. Video recordings were made during the first 24 h after grouping and after 6 and 10 days, and used to score aggressive interactions of the animals with exception of treatment 3 where day 10 was omitted because it was after the weaning of the kits. For MP12 and MP18 the frequency of different categories of aggressive interactions were significantly higher on the day of grouping than afterwards, with a strong decrease on day 6 (P < 0.02), but almost no change was found between days 6 and 10. This was especially true for biting, with a high frequency of occurrence just after grouping and a subsequent decrease on day 6 under all management schedules (P = 0.005). The change in the number of aggressive interactions between 6 and 10 days after grouping was not significantly different between MPs. However, the time point of 6 days after grouping seemed to be fundamental in reducing the number of aggressive events. Although a longer separation for 18 and 22 days after parturition did not reduce the total number of aggressive interactions, MP18 and MP22 showed more mild aggressive interactions with respect to MP12 on the day of regrouping. Moreover, when comparing MPs concerning the development of hierarchy, hierarchies appeared very stable independently of the length of grouping (P < 0.01)

Native immunity and oxidative traits of growing rabbits

[EN] The evaluation of animal welfare through innate immunity (Serum Bactericidal Activity - SBA, Hemolytic Complement Assay - HCA, lysozyme) and the antioxidant status of the body (Reactive Oxygen Substances - ROS and Antioxidant Power of plasma, AP) offers a reliable prognostic and diagnostic tool. The aim of the present study was to investigate trends and correlations between some traits of innate immunity and the oxidative status of fattening rabbits at different ages. Blood samples from 120 New Zealand White fattening rabbits at 45, 55, 65, and 75 d of age were collected and analyzed. The results showed that SBA did not have a normal distribution because of numerous 0 values. Data distribution was normal when only SBA > 0 values were considered. Lysozyme (mean value 27.19 microg/mL) and HCA (mean value 50.84 CH50% ) had stable trends at different ages and showed a tendency that was comparable to that obtained in other animal species. On the contrary, SBA (mean value 42.15%) showed an unexpected positive correlation with lysozyme (P<0.001) and a negative correlation with HCA (P<0.001). Oxygen free-radicals are involved in the pathogenesis of several diseases and oxidative stress alters immune competence. In this experiment, ROS and AP showed mean values of 0.60 mmol H2 O2 and 421.67 micromol HClO, respectively. In this context positive correlation coefficients between oxidative status traits and immune traits (P<0.001) were found, although at a very low level; and surprisingly, only ROS and SBA did not show any significant correlation. In this study it emerged that, even in the absence of evident pathologies, the immune and oxidative traits of fattening rabbits could be affected by environmental stress (weaning, cage, neighbors)Funded by Ricerca Corrente 2006 Istituto Zooprofilattico Sperimentale dell’Umbria e MarcheMoscati, L.; Dal Bosco, A.; Battistacci, L.; Cardinali, R.; Mugnai, C.; Castellini, C. (2008). Native immunity and oxidative traits of growing rabbits. World Rabbit Science. 16(4). doi:10.4995/wrs.2008.616SWORD16