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Janzé, France

Gidenne T.,French National Institute for Agricultural Research | Gidenne T.,University Paul Sabatier | Kerdiles V.,ITAVI | Jehl N.,ITAVI | And 7 more authors.
Animal Feed Science and Technology | Year: 2013

The fattening performances, nitrogen excretion and health status of growing rabbits were studied in response to a linear reduction of the digestible fibre (DgF. = water-insoluble pectins + hemicelluloses) to crude protein ratio (DFP) in four diets (from 1.01 to 1.55). As the crude protein level was reduced from 17.7% to 13.9% (in diets DFP1-DFP4), the DgF level was increased from 18.5% to 22.1%, without changes to poorly-digestible fibre levels (ADF. = 19%). A total of 644 rabbits per diet were used in a multi-site study (n= 6). Between weaning (28d-37d according to sites) and 49d of age, reduction of the DFP ratio led to a linear decrease in weight gain (-4. g/d between DFP1 and DFP4, P<0.001), associated with a reduced feed intake (-5.7% between DFP1 and DFP4). However, for the whole fattening period, growth and intake did not differ significantly among the diets. Over the whole fattening period (35d-70d old), the mean faecal nitrogen output was of 1. g/N per day and per rabbit, and remained similar for the four diets, while the urinary N output was reduced by 55% between DFP1 and DFP4 (P<0.001). Accordingly, the total N output per rabbit was of 82.4. g, 75.5. g, 63.2. g and 57.4. g (P<0.001) in animals fed with DFP1-DFP4 diets, respectively. The nitrogen output per kg of live weight of rabbit produced was 52.0. g, 47.9. g, 40.7. g and 36.9. g for DFP1-DFP4, respectively. At the same time, an increase of the DFP ratio of over 1.3 (CP<16% and DgF > 20%) reduced the mortality by diarrhoea for the two highest DFP ratios when compared to the two lowest ratios (5.2% vs. 7.8%, P<0.05), and led to a 40% reduction of the health risk index between weaning and slaughtering (20.0% vs. 12.6% for DFP1 and DFP4, respectively, P<0.01). A significant reduction of mortality from rabbit epizootic enteropathy (3 sites) was also observed when the DFP ratio was increased to over 1.3. A reduction of the protein level in favour of a higher digestible-fibre level is therefore a useful feeding strategy which improves the resistance of the growing rabbit to enteropathy, without major impairment of performances, and with a reduced nitrogen output. © 2013 Elsevier B.V. Source


Briere S.,GRELIER | Brillard J.-P.,FERTILAVI | Panheleux M.,CCPA | Froment P.,CNRS Physiology of Reproduction and Behaviors | Froment P.,University of Tours
Productions Animales | Year: 2011

In birds, as in other species, nutrition and energy influence the function of reproduction. The hyperphagic models have shown the negative effect of over-feeding in both sexes, and the potential rescue by food restriction treatment which can increase the length of the fertile period. However, the mechanisms underlying the relationship between nutrition, energy metabolism and reproductive functions are poorly understood. These changes in metabolic and nutritional status can be transmitted to the gonadotrope axis (hypothalamus, pituitary and gonads) by changes in hormone levels (insulin, adipokines...), or directly by the energy substrates (glucose, fatty acids and amino acids). Briefly, we discuss the effects of different components of the diet on fertility. Finally, we discuss alternative methods involving qualitative restriction rather than quantitative methods on feeding in order to improve animal welfare and in particular by reducing the behaviour of frustration and hunger. Source


Merlot E.,French National Institute for Agricultural Research | Merlot E.,Agrocampus Ouest | Vincent A.,French National Institute for Agricultural Research | Vincent A.,Agrocampus Ouest | And 13 more authors.
Animal | Year: 2012

Since decades, production traits such as growth rate, feed efficiency or body composition have been drastically increased in pigs by genetic selection. Whether this selection impacted animal robustness is still unclear. In this study, we compared Large White (LW) pigs, a breed submitted to intense genetic selection for production traits, and Basque (B) pigs, a local rustic breed, reared in two different housing environments (conventional v. enriched). Adaptation to housing conditions among each breed was evaluated at the level of endocrine and immune traits. These are known to be impacted by housing conditions and breed; however, the interaction effects between genotype and environment are less described. Animals (20 per breed and housing environment) entered the experiment at 35 kg of live weight. Levels of cortisol, acute-phase inflammatory proteins, immunoglobulins and hydrogen peroxide, blood formula, lymphocyte proliferation and in-vitro cytokine expression were measured at â̂115 kg of live weight. Animals were checked for skin injuries during the growing period. At slaughter, at the average live weight of 145 kg, carcasses were examined for pathological conditions of the respiratory tract. The major result was that the two breeds exhibited differences in response to the housing environment. Among the 24 sanitary, endocrine or immune traits investigated, the housing conditions affected eight variables in both breeds (salivary cortisol at 0700 and 1900 h, severity of pneumonia at slaughter) or only in B pigs (severe skin lesions) or LW pigs (salivary cortisol at 1500 h, granulocyte numbers and lymphocyte/granulocyte ratio and lymphocyte proliferation). These observations strengthen the hypothesis that selection for high meat production level might be associated with an increased susceptibility of animals to environmental stressors. © Copyright The Animal Consortium 2012. Source


Montagne L.,Agrocampus Ouest | Arturo-Schaan M.,CCPA | Le Floc'h N.,Agrocampus Ouest | Guerra L.,Agrocampus Ouest | Le Gall M.,Agrocampus Ouest
Livestock Science | Year: 2010

At weaning, the intestinal microbial ecosystem has to adapt to new feeds and to a new environment. The diverse and abundant commensal microbiota and its production of volatile fatty acids (VFA), especially butyrate, are involved in the prevention of diarrhoea and defence against pathogens. This study investigated the effects of the level of dietary fibre (DF) and sanitary housing conditions on the microbiota of weaned pigs. Forty-eight piglets, weaned at 28days of age, were housed in clean or poor conditions. They were fed during two consecutive phases, two diets containing a high level (16.9 then 21.7% total dietary fibre-TDF, mainly soluble) or a low level DF (control, 12.1 then 14.6% TDF). Five weeks after weaning, microbiota was analysed using counting techniques and VFA profiles were determined by gas chromatography in faeces collected from the rectum. When compared with the clean conditions, the faeces of piglets housed in the poor environment contained significantly more Lactobacillus and Enterobacteria and less anaerobic sulphite-reducing bacteria (+0.9, +1.1, -2.1Log10 CFU/g faeces), 60% more total VFA, with proportionally less acetate and more butyrate (-3%, +4%). The introduction of DF did not affect the composition of the microbiota, tended to increase total VFA (25%), and decreased the level of branched-chain VFA (-1.4%). To conclude, the degraded sanitary housing conditions and to a lesser degree DF, stimulated the bacterial ecosystem in a way that could be beneficial for digestive balance, despite their negative impact on animal performances. © 2010 Elsevier B.V. Source


Knudsen C.,French National Institute for Agricultural Research | Knudsen C.,National Graduate School of Agronomy, Toulouse | Knudsen C.,National Polytechnic Institute of Toulouse | Combes S.,French National Institute for Agricultural Research | And 12 more authors.
Journal of Nutrition | Year: 2015

Background: Short-term feed restriction strategies are used in rabbits to reduce postweaning digestive disorders, but little is known about the involvement of the immune system in these beneficial effects. Objective: In the present study, the consequences of feed and energy restriction on immune response were investigated. Methods: At weaning, 320 male and female rabbits were assigned to 4 groups differing in dietary digestible energy (DE) concentrations and intake levels: a low-energy ad libitum-feed (LE100) group, a low-energy restricted-feed (LE75) group, a high-energy ad libitum-feed (HE100) group, and a high-energy restricted-feed (HE75) group. The high-energy groups consumed 10.13 MJ DE/kg of feed, whereas the low-energy groups consumed 9.08 MJ DE/kg (formulated values). Intake amounts for the restricted groups were 75% those of the ad libitum groups. Rabbits consumed these diets until age 63 d, after which they consumed feed ad libitum for 9 d. Ten rabbits per group and per age were killed at ages 42, 50, 63, and 72 d. Spleens and appendixes were weighed; Peyer's patch surface area was determined by image analysis; plasma total immunoglobulin (Ig) G and anti-ovalbumin IgG; and fecal and plasma IgA concentrations were determined by ELISA; and ileal expressions of cytokines were measured by quantitative reverse transcriptase-polymerase chain reaction at ages 50 and 63 d. Results: The relative weight and size of the lymphoid organs were not affected by treatments. Concentrations of plasma total IgA (-41% at 63 d and -29% at 72 d), IgG (-22% at 72 d), and anti-ovalbumin IgG (-41% at 63 d) were lower with feed restriction. Fecal IgA concentrations were lower with quantitative restriction (-40%, -52%, and -65% at age 42, 50, and 63 d, respectively) and energy restriction (-56%, -46%, and -73% at ages 50, 63, and 72 d, respectively). Feed-restricted rabbits tended to have greater expressions of interleukin (IL) 1ß and IL-2 and lower expressions of tumor necrosis factor a (P < 0.1). Conclusion: These results demonstrated that, in rabbits, restriction and, to a lesser extent, dietary energy concentration modulate gut immunity. © 2015 American Society for Nutrition. Source

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