Partial budget analysis of laying hens' transition from cages to production systems of improved welfare: a case study in Greece.

1. In recent years, public concern regarding animal welfare has increased while, at the same time, cage systems for animal production have been greatly criticised by EU citizens. In addition, large food retailers promote food products that are made with eggs produced in cage-free systems.2. The objective of this study was to evaluate the economic viability of the transition of laying hens' to production systems; from conventional to alternative systems with improved welfare. Three independent scenarios were assumed as follows: transition from enriched colony cages to barn (S1), transition from barn to free-range (S2), and transition from free-range to organic (S3). Economic assessments of each transition was applied to a model farm in Greece with 12 000 hens, through partial budget analysis and net benefits and costs were estimated.3. The results showed a positive economic impact in all transitions to a production system of improved animal welfare (€12,044 in S1, €18,957 in S2 and €7,977 in S3) which indicated that they are economically sustainable. In all scenarios, unit cost increased by 19% in S1, 12% in S2, and 85% in S3.4. In conclusion, transitioning towards improved animal welfare production systems in laying hen farms could be an economically viable option for egg producers in compliance with societal demands and market trends.

Influence of citrus flavonoids on laying hen performance, inflammatory immune response, egg quality and yolk oxidative stability.

1. The objective of this study was to investigate the effects of dietary supplementation with natural flavonoids (naringin and hesperidin) on laying hens' performance, cellular immunity and egg quality parameters. 2. A total of 72 individually caged laying hens were allocated into 1 of 6 treatment groups: a control (C) group that was fed with a basal diet and groups that were offered the same diet further supplemented with hesperidin at 0.75 g/kg (E1), or 1.5 g/kg (E2), or naringin at 0.75 g/kg (N1), or 1.5 g/kg (N2) or α-tocopheryl acetate at 0.2 mg/kg (VE) for 67 d. 3. Supplementation with naringin or hesperidin did not affect the performance and egg quality (P > 0.05) apart from an improvement in the yolk colour that was more orange in naringin and hesperidin groups in comparison to the controls (P-linear < 0.05). Egg yolk and plasma cholesterol levels were not affected by citrus flavonoids (P-linear > 0.05). 4. Inflammatory immune response, measured by phytohaemagglutinin skin test (PHA), was suppressed in laying hens that were fed with either naringin (P-linear < 0.05) or hesperidin (P < 0.05). Egg yolk oxidative stability was improved from the 4th d after naringin or hesperidin supplementation. This beneficial effect was comparable to that of α-tocopheryl acetate and was observed in eggs that were stored for up to 120 d. 5. In conclusion, naringin and hesperidin may favourably prolong the shelf life of eggs, appear to possess anti-inflammatory properties and could improve the yolk colour without any side effects on the performance or egg quality traits.

The effects of quercetin dietary supplementation on broiler growth performance, meat quality, and oxidative stability.

The present study was conducted to describe the effects of quercetin dietary supplementation, at levels of 0.5 and 1 g/kg of feed, on growth performance, internal organ weights, meat quality, and meat oxidative stability during storage of broiler chickens reared from hatching to 42 d of age. Body weight and cumulative feed intake were not affected by quercetin supplementation (P > 0.05). However, poorer feed conversion ratio values were obtained with increasing levels of dietary quercetin (P-linear < 0.05). Relative heart weight was significantly higher for chickens that were given quercetin in comparison with the controls (P < 0.05). The rest of the internal organ weights measured (liver, spleen, and fat pad) and meat quality traits were not affected by dietary supplementation with quercetin, except for meat lightness and redness. Meat oxidative stability, expressed as nanograms of malondialdehyde per gram of meat, was improved (P < 0.05) during refrigerated storage for 3 and 9 d, when birds were fed quercetin at a level of 1 g/kg of feed. It is concluded that the incorporation of quercetin in broiler diets could prolong meat shelf life by reducing the rate of lipid oxidation, and increase relative heart weight, potentially contributing to improved animal health.

Effect of hesperidin dietary supplementation on hen performance, egg quality and yolk oxidative stability.

1. The purpose of this study was to evaluate the effects of dietary supplementation with hesperidin (one or 3 g/kg of feed) for 31 d on the performance, egg quality and yolk oxidative stability of brown and white laying hens (26-wk old). 2. Supplementation with hesperidin did not affect egg production, egg weight and egg quality traits. 3. No hesperidin effect on yolk and plasma cholesterol was observed. A strain effect was found with lower total and per g yolk cholesterol of brown hens in comparison to the white ones. 4. Oxidative stability of egg yolk, expressed as ng MDA/g yolk, was significantly improved in the hesperidin groups even from the first week of supplementation. At the same time, a significant improvement in the oxidative stability of egg yolk due to the incorporation of hesperidin in hens' diet was observed after 30 and 90 d of storage at 20°C and 4°C, respectively. 5. No hesperidin by strain interaction was detected for any of the traits measured. 6. In conclusion, incorporation of hesperidin to laying hens' feed did not affect productive and egg qualitative traits. On the other hand, dietary hesperidin supplementation significantly improved oxidative stability of both fresh and stored eggs. Antioxidant properties of hesperidin seem to make it a promising natural agent for improving the shelf life of eggs.

Impact of stocking density on broiler growth performance, meat characteristics, behavioural components and indicators of physiological and oxidative stress.

1. The study was designed to assess the impact of stocking density (6 and 13 birds/m² equivalent to 12·6 or 27·2 kg/m², respectively) on growth performance, meat quality, behaviour, and indicators of physiological and oxidative stress as measures of bird welfare. 2. The higher stocking density negatively affected final body weight and feed intake but not cumulative feed conversion rate. Muscle colour traits, pH24, cooking loss and shear values were not affected. Birds reared at the lower density showed higher intramuscular fat, liver weight, liver NADP-isocitrate and NADP-malate dehydrogenase activity. 3. Higher stocking density was associated with decreased locomotor activity and increased physiological (H:L ratio and bursa weight) and oxidative (glutathione concentrations and reduced:oxidised glutathione ratios) stress indicators. 4. The results show that stocking density did not significantly affect broiler meat quality characteristics but higher density decreased growth performance, increased physiological and oxidative stress levels and decreased locomotor activity.

Influence of gestational maternal feed restriction on growth performance and meat quality of rabbit offsprings.

The purpose of the present study was to evaluate the effect of feed restriction during pregnancy on reproductive performance of rabbit does and growth performance and meat quality of their offspring. A total of 26 primiparous non lactating does were equally divided into two treatment groups: the control group (C, n=13) that was fed ad libitum throughout gestation and the feed restricted group (R, n=13) that was fed to 75% of maintenance energy requirements from the 7(th) to the 26(th) day of gestation. Rabbit offsprings were weaned at 35 days of age and grown until the 72 days of age when they were slaughtered for meat quality assessment. Meat quality traits measured were pH(24), colour (L*, a*, b*), percentage of released water, cook loss, shear values and intramuscular fat. At kindling, R does produced smaller litter weights compared with those of does from group C, 447.8 and 591.4 g, respectively, and smaller individual kit birth weights, 56.2 and 71.5 g, respectively (P0.05). Performance and meat quality characteristics of fattening rabbits at 72 days of age were not influenced by gestational feed restriction of their mothers (P>0.05). Taking into consideration that, simultaneous gestation and lactation in rabbit does may be simulated by gestational feed restriction, results of the present study suggest that lactating does can support a simultaneous gestation without any adverse effect on the offsprings' quantitative and qualitative performance at the expense of increased mortality rates at parturition and until weaning.

Growth curves for body weight and major component parts, feed consumption, and mortality of male broiler chickens raised to maturity.

Body weight; yield of the major carcass component parts of breast, leg, thigh, drumstick, breast meat, thigh meat, and drumstick meat; feed consumption; feed conversion; and mortality of male broiler chickens from two commercial strains were measured from hatching to 154 d of age. As no differences were observed between the two strains, for any of the traits measured, the statistical analysis was made using pooled data. Growth curves for BW, breast weight, and leg weight were calculated. The Richards function was chosen to fit the data. The type of the curves predicted was typically sigmoid. Asymptotic weights for BW, breast weight, and leg weight were estimated at 6,870.2, 1,744.2, and 851.5 g, respectively. Age at point of inflection, at which maximum growth rate is attained, was predicted at 44.4, 47, and 49.1 d, respectively. The percentage of breast and breast meat increased with age, whereas percentages of leg, thigh, and drumstick remained roughly constant. Weekly feed conversion was determined, and polynomial functions were applied to relate feed consumption and feed conversion to the age of the birds. Cumulative mortality increased with age, especially beyond 70 d of age, rising to 50% by the end of the experiment. Mortality was related to high incidence of leg weakness observed in the same period. The results of the current study provide information on the growth potential of contemporary, genetically improved broiler chickens by means of a mathematical model.