Effects of strain and stocking density on leg health, activity, and use of enrichments in conventional broiler chicken production.

Conventional broiler production needs to evolve towards more animal-friendly production systems in order to meet increasing consumer concerns regarding animal welfare. Genetics and stocking density are 2 of the most promising leads to make this change possible. In this study, 6 strains with different growth rates (42-61 g/d) were reared at contrasting densities: 37 kg/m² (HD) and 29 kg/m² (LD). At the same body weight of 1.80-1.95 kg, we evaluated how growth rate and stocking density influenced broiler behaviors (general activity, interactions with enrichments), broiler health (mortality, leg problems, cleanliness and plumage growth) and litter quality. Density did not affect body weight, mortality or behaviors. For all strains, LD was associated with a lower prevalence of hock burns, a better gait score, and improved litter quality and broiler cleanliness. For the 3 strains most affected by pododermatitis, a lower prevalence was observed in LD than in HD pens. Fewer birds were inactive and more birds were standing and interacting with the enrichments (as proposed in the experiment) as soon as the growth rate was lower than that of the control strain (Ross 308). Others welfare indicators such as gait score, plumage growth improved as well. Litter humidity decreased with growth rate, contributing to better leg conditions and cleaner breasts. The prevalence of hock burns and certain behaviors (i.e., the proportion of birds grooming or walking/running) were not affected by growth rate. The proportion of birds foraging was higher at a lower growth rate. These results suggest that reducing growth rate as a preliminary measure, and reducing density as a supplementary one, would improve conventional broiler welfare.

[Blueberry Muffin Baby and spontaneous remission of neonatal leukaemia]. / Leucémie aiguë néonatale et Blueberry Muffin syndrome: à propos d'un cas spontanément régressif.

Blueberry Muffin baby is a rare neonatal skin disorder. Many causes are known, examples are congenital infections, hemolysis and tumors. We report on a newborn presenting with Blueberry Muffin syndrome and an adrenal mass which lead to the diagnosis of neuroblastoma. Actually, it corresponded to an acute monoblastic leukaemia with an adrenal localization and a cerebrospinal fluid involvement. Leukaemia should always be considered in such patients, even in the absence of blasts on white blood cells count and bone marrow examination, as in this patient. This observation was also unusual due to spontaneous remission. The patient is in complete remission at 1 year follow-up.

Determinants of aortic cyclic guanosine monophosphate in hypertension induced by chronic inhibition of nitric oxide synthase.

Nitric oxide (NO) and atrial natriuretic factor (ANF) cause vascular relaxation by generating cyclic guanosine monophosphate (cGMP) via activation of the soluble and particulate guanylate cyclases, respectively. The chronic effects of NG-nitro-L-arginine methyl ester (L-NAME), an L-arginine antagonist and NO synthase inhibitor, on the blood pressure and plasma and aortic cGMP levels of rats were tested. Wistar rats (n = 10 per group) were given doses of L-NAME (0, 1, 5, 10, 20, 50, and 100 mg/kg.d) by gavage twice a day for 4 wk. Chronic L-NAME induced a time- and dose-dependent increase in blood pressure. The total heart weight/body weight ratio did not change in any group, despite the hypertension. The plasma levels of cGMP did not change significantly in any group, and were correlated with the plasma ANF levels (r = 0.51, P less than 0.0001). Aortic cGMP decreased in negative correlation with increasing L-NAME from 0 to 10 mg/kg.d, culminating in a 10-fold drop arterial wall cGMP. The aortic cGMP content of rats in the four highest dose groups (from 10 to 100 mg/d) tended to increase slightly and was positively correlated with endogenous ANF (r = 0.48, P less than 0.002, n = 40). Intravenous L-arginine decreased arterial blood pressure and reversed the decline in aortic cGMP. Exogenous ANF and sodium nitroprusside both significantly increased aortic cGMP. Neither the arterial wall concentrations of cGMP-dependent kinase nor cAMP was changed by L-NAME. Thus, chronic blockade of NO synthase with L-NAME induces a dose-dependent increase in blood pressure and decrease in aortic cGMP. The in vivo basal aortic cGMP seems to be mainly dependent on NO synthase: soluble guanylate cyclase activity and to a minor extent on particulate guanylate cyclase activity.

Outdoor stocking density in free-range laying hens: radio-frequency identification of impacts on range use.

The number and size of free-range laying hen (Gallus gallus domesticus) production systems are increasing within Australia in response to consumer demand for perceived improvement in hen welfare. However, variation in outdoor stocking density has generated consumer dissatisfaction leading to the development of a national information standard on free-range egg labelling by the Australian Consumer Affairs Ministers. The current Australian Model Code of Practice for Domestic Poultry states a guideline of 1500 hens/ha, but no maximum density is set. Radio-frequency identification (RFID) tracking technology was used to measure daily range usage by individual ISA Brown hens housed in six small flocks (150 hens/flock - 50% of hens tagged), each with access to one of three outdoor stocking density treatments (two replicates per treatment: 2000, 10 000, 20 000 hens/ha), from 22 to 26, 27 to 31 and 32 to 36 weeks of age. There was some variation in range usage across the sampling periods and by weeks 32 to 36 individual hens from the lowest stocking density on average used the range for longer each day (P<0.001), with fewer visits and longer maximum durations per visit (P<0.001). Individual hens within all stocking densities varied in the percentage of days they accessed the range with 2% of tagged hens in each treatment never venturing outdoors and a large proportion that accessed the range daily (2000 hens/ha: 80.5%; 10 000 hens/ha: 66.5%; 20 000 hens/ha: 71.4%). On average, 38% to 48% of hens were seen on the range simultaneously and used all available areas of all ranges. These results of experimental-sized flocks have implications for determining optimal outdoor stocking densities for commercial free-range laying hens but further research would be needed to determine the effects of increased range usage on hen welfare.

Impact of food labelling systems on food choices and eating behaviours: a systematic review and meta-analysis of randomized studies.

Food labels are considered a crucial component of strategies tackling unhealthy diets and obesity. This study aims at assessing the effectiveness of food labelling in increasing the selection of healthier products and in reducing calorie intake. In addition, this study compares the relative effectiveness of traffic light schemes, Guideline Daily Amount and other food labelling schemes. A comprehensive set of databases were searched to identify randomized studies. Studies reporting homogeneous outcomes were pooled together and analysed through meta-analyses. Publication bias was evaluated with a funnel plot. Food labelling would increase the amount of people selecting a healthier food product by about 17.95% (confidence interval: +11.24% to +24.66%). Food labelling would also decrease calorie intake/choice by about 3.59% (confidence interval: -8.90% to +1.72%), but results are not statistically significant. Traffic light schemes are marginally more effective in increasing the selection of healthier options. Other food labels and Guideline Daily Amount follow. The available evidence did not allow studying the effects of single labelling schemes on calorie intake/choice. Findings of this study suggest that nutrition labelling may be an effective approach to empowering consumers in choosing healthier products. Interpretive labels, as traffic light labels, may be more effective.