Search

International audience; The objective of this study was to evaluate the effects of diet and age on finishing performances and carcass characteristics of male Creole goats. A total of 91 weaned male Creole kids [84 days old ± 7 days, 9.2 kg live weight (LW) ± 0.5 kg] were randomly allocated in a 2 × 3 experimental design. The animals were fed individually with two diets: C0: a 28-day-old Digitaria decubens grass alone, or C50: the same grass plus a commercial concentrate (50% of the total diet) and then slaughtered at 7, 11, or 15 months of age. Significant feeding regimen and age at slaughter effects were observed on the goat carcass characteristics. The addition of concentrate improved the average daily gain (ADG), the dressing percentage, and the conformation score (1–5 scale) from 46 to 88 g/day, 52.8 to 62.4%, and 2.2 to 4.9, respectively. Moreover, carcasses of the C0 group appeared lean with less developed fat than the C50 group and lighter than visceral fat. The meat color was significantly more affected by diet than age. Our data suggested that the production of heavy carcasses with low proportions of fat in the meat is possible in this local breed. The valorization of such a forage feeding system until 11 months of age or with the addition of concentrate from 7 to 11 months of age should be evaluated economically.

International audience; The endemic biodiversity, also in domestic species, represents a very useful resource for research and for the development of economic activities in agriculture. In the French West Indies, the different livestock species include a variety of local breeds, known as Creole breeds. These breeds have developed very original features, since the introduction of the first specimen 5 centuries ago, in relation with their origin, the selection pressure of their natural environment and the influence of traditional agricultural practices.The Biological Resource Center CARARE (Caribean Animal genetic Resources), has been created in 2006, in order to fulfil two distinct missions: i) to preserve original biological samples for the purpose of investigation programs of the local research teams; ii) to maintain the genetic diversity of the local breeds, by the conservation of reproductive material.A total of more than 30000 samples are stored in the facilities of the BRC CARARE, separated in “genomic” material (blood, tissues samples) and reproductive material (sperm, embryos). Several research programs have been implemented thanks to this BRC. It also contributes to the preservation and valorisation of the genetic diversity of the local breeds, in complementarity with the management programs based on in vivo / in situ conservation in nucleus herds or on private breeder herds.

National audience

National audience; Reduction of feed intake is a common physiological response of growing pigs facing stressful environmental conditions. The aim of the present experiment was 1) to study the effects of a short-term drastic feed restriction and subsequent refeeding on pig metabolism, and 2) to study the differential response between 2 breeds, the Large White (LW) breed that has been selected for high growth performance and the Creole (CR) breed, which is characterized by its good adaptation to harsh tropical environmental conditions. An assay with a total of 36 castrated male pigs (18 LW and 18 CR) was carried out. For each breed, half of the animals were restrictively-fed at 50% of the standard allowance for 7 days and were then fed normally for the next 15 days. Growth performance, thermoregulatory responses and plasma metabolites were measured before, during and after feed restriction in the 2 groups. Results show that for all the measured traits, the difference in the response between the 2 breeds is small and rarely significant. Irrespective of breed, during feed restriction, ADG and feed efficiency were reduced (-75%, P< 0.001; -58%, P< 0.05, respectively), but that was counterbalanced by an increase in those same parameters during refeeding (+25%, P< 0.001 ; +49%, P< 0.001, respectively). Feed restriction also reduces skin temperature (-0.6°C, P< 0.01), rectal temperature (-0.4°C, P< 0.01) and respiratory rate (-12 breaths per minute, P< 0.01). Moreover, the results suggest that certain metabolites, such as alkaline phosphatase and blood urea, could be potential biomarker candidates for feed restriction.

Cet article décrit un dispositif expérimental conçu pour peser, effectuer des mesures et des prélèvements sur des porcs après le sevrage. Ce dispositif a été conçu et réalisé par les techniciens animaliers de la Plateforme Tropicale d’Expérimentation sur l’Animal (PTEA) de Duclos, Petit-Bourg. Il est constitué d’un ensemble de cellules et d’un dispositif de contention associé à une balance.

National audience

National audience; To our knowledge, there are few references on the pig production integrated into a mixed farming- system. In which farmers try to minimize inputs (in particular on feed purchase d). Feeding is one of the most important elements of the production cost. It is even more the case in tropical small countries, where the cost of the raw material included also the cost of transports. Farmers in these countries are looking for alternative solutions to reduce or replace the utilization of industrial concentrates, by the use of local resources (e.g. roots and tubers, sugar cane, banana). The main objective of this study was to compare fattening pigs’systems (outdoor vs. indoor, local vs. industrial feedings, local vs. exotic breeds). We performed two trials on a total of 54 fattening pigs, reared either in outdoor in a sweet potatoes field (n=18) or indoor with diet based on sweet potatoes (n=18) or indoor with industrial concentrates (n= 18). Our results show that the growth is significantly affected by the production system. The outdoor animals have a growth rate of 240 g/d, against 360 and 580 g/d for the indoor pigs fed with local or industrial feed, respectively (P < 0.001). Our findings on the physiological responses (blood profiles) highlighted the best adaptation of the local breed (Creole pig) when they passed from indoor to outdoor system. Indeed, adaptive hematologic response is faster in Creole pigs than in the exotic breed (Large White pigs). Unlike Creole pigs, the arrival of exotic pigs in outdoor conditions caused firstly a weakening of the hematologic status suggesting that Large White pigs are stressed by the change. Regarding the interaction between digging activities of pigs with macrofauna, in our experimental conditions (gradual discovery of plots and grazing period of 28 days), it seems that the presence of pigs on the plots (manure) is beneficial to soil macrofauna and thus the quality of the land from the farmer for future planting.The alternative systems (outdoor and/or diet based on local resources), although less powerful in a zootechnical point of view, should suit to mixed farmers who are looking for an economic gain on animal production by using crop residues and minimizing human interventions. These studies are the beginning of trials that aimed at meeting mixed farmers requirements in terms of techno-economic references on outdoor pig systems and alternatives to preserve and develop a niche market for the local pig breed.

To our knowledge, there are few references on the pig production integrated into a mixed farming- system. In which farmers try to minimize inputs (in particular on feed purchase d). Feeding is one of the most important elements of the production cost. It is even more the case in tropical small countries, where the cost of the raw material included also the cost of transports. Farmers in these countries are looking for alternative solutions to reduce or replace the utilization of industrial concentrates, by the use of local resources (e.g. roots and tubers, sugar cane, banana). The main objective of this study was to compare fattening pigs’systems (outdoor vs. indoor, local vs. industrial feedings, local vs. exotic breeds). We performed two trials on a total of 54 fattening pigs, reared either in outdoor in a sweet potatoes field (n=18) or indoor with diet based on sweet potatoes (n=18) or indoor with industrial concentrates (n= 18). Our results show that the growth is significantly affected by the production system. The outdoor animals have a growth rate of 240 g/d, against 360 and 580 g/d for the indoor pigs fed with local or industrial feed, respectively (P < 0.001). Our findings on the physiological responses (blood profiles) highlighted the best adaptation of the local breed (Creole pig) when they passed from indoor to outdoor system. Indeed, adaptive hematologic response is faster in Creole pigs than in the exotic breed (Large White pigs). Unlike Creole pigs, the arrival of exotic pigs in outdoor conditions caused firstly a weakening of the hematologic status suggesting that Large White pigs are stressed by the change. Regarding the interaction between digging activities of pigs with macrofauna, in our experimental conditions (gradual discovery of plots and grazing period of 28 days), it seems that the presence of pigs on the plots (manure) is beneficial to soil macrofauna and thus the quality of the land from the farmer for future planting.The alternative systems (outdoor and/or diet based on local resources), although less powerful in a zootechnical point of view, should suit to mixed farmers who are looking for an economic gain on animal production by using crop residues and minimizing human interventions. These studies are the beginning of trials that aimed at meeting mixed farmers requirements in terms of techno-economic references on outdoor pig systems and alternatives to preserve and develop a niche market for the local pig breed.

International audience; Heat stress is one of the major limiting factors of production efficiency in the swine industry. The aims of the present study were 1) to observe if hemorheological and hematological parameters could be associated to physiological acclimation during the first days of heat stress exposure and 2) to determine if water restriction could modulate the effect of thermal heat stress on physiological, hematological and hemorheological parameters. Twelve Large White male pigs were divided into an ad libitum and a water restricted group. All pigs were submitted to one week at 24 °C (D-7 to D-1). Then, at D0, temperature was progressively increased until 32 °C and maintained during one week (D1 to D7). We performed daily measurements of water and feed intake. Physiological (i.e., skin temperature, rectal temperature, respiratory rate), hematological and hemorheological parameters were measured on D-6, D-5, D0, D1, D2 and D7. Water restriction had no effect on physiological, hematological and hemorheological parameters. The first days of heat stress caused an increase in the three physiological parameters followed by a reduction of these parameters suggesting a successful acclimation of pigs to heat stress. We showed an increase in hematocrit, red blood cell aggregation and red blood cell aggregation strength during heat stress. Further, we observed an important release of reticulocytes, an increase of red blood cell deformability and a reduction of feed intake and blood viscosity under heat stress. This study suggests that physiological acute adaptation to heat stress is accompanied by large hematological and hemorheological changes.

International audience

Chantier qualité GA; International audience; This study aimed to compare the growth performances and carcass characteristics of tropical-breed steers reared in 2 contrasted feeding systems (indoor vs. pasture) and slaughtered at different ages (early vs. late). A total of 309 Creole steers (growing at an initial BW of 173 +/- 3 kg and an initial age of 252 +/- 4 d) were used over a continuous 12-yr study. Indoor steers were housed in a cattle shed, fed fresh-cut grass plus concentrate, and slaughtered at 14.5 or 17.1 +/- 0.1 mo of age. Pasture steers were pasture grazed without supplemental feed, and slaughtered at 17.6 and 21.2 +/- 0.1 mo of age. Indoor-fed steers had a greater ADG (786 vs. 517 +/- 29 g.d(-1); P < 0.0001) and more carcass fat (164 vs. 145 +/- 4.5 g.kg(-1); P = 0.001) than pasture-fed steers. Late-slaughtered steers had decreased ADG (630 vs. 673 +/- 27 g.d(-1); P = 0.001) but greater dressing percentages (hot dressing percentage = 55.7 vs. 54.7 +/- 0.34%; chilled dressing percentage = 54.5 vs. 53.4 +/- 0.34%; P < 0.0001) than early-slaughtered steers. The interaction between feeding system and slaughter age was significant for carcass tissue composition. Whole-carcass muscle content was greater in late-slaughtered steers than early-slaughtered steers, especially in pasture-fed steers (720 vs. 698 +/- 6.0 g.kg(-1); P < 0.0001), but less so in indoor-fed steers (707 vs. 700 +/- 5.9 g.kg(-1); P = 0.046). Furthermore, increasing slaughter age had no effect on carcass fat in indoor-fed steers (162 vs. 166 +/- 4.8 g.kg(-1); P = 0.342), but decreased carcass fat in pasture-fed steers (150 vs. 140 +/- 5.0 g.kg(-1); P = 0.014). The results showed that slaughter age and feeding system are 2 major factors that independently affect most of the growth and carcass traits of tropical-breed steers but jointly influence tissue deposition. Our study found that in tropical-breed steers that are grazing, late slaughtering grazing steers increased carcass muscle content without extra fat, thus yielding a carcass quality better suited to consumer choices.

"Chantier qualité spécifique "Auteurs Externes" département de Génétique animale : uniquement liaison auteur au référentiel HR-Access "; il s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : REPORT; The climate is changing and according to the recent estimates from the IPCC, the likelihood of heatwave events is expected to increase both in number and in intensity. Temperature is projected toincrease from 1.8 to 4.0°C from 1980-1999 to 2090-2099. Hence, heat stress-related costs in pigproduction will be amplified in the future, both in temperate areas (summer heat waves) and tropicalareas (hot and humid environment). Meanwhile, world pig production is moving rapidly to tropicaland subtropical regions reaching now more than 50% of the total production. The world developmentof pig production has been achieved through improvement of animal genetics and management intemperate countries. However, selection performed in optimally controlled conditions has increasedthe sensitivity of animals to high ambient temperature. Heat stressed pigs reduce their feed intakewhich impair their growth or reproduction performances. Management solutions are available toattenuate the effect of heat stress on pigs, such as environmental solutions (water or feedingmanagement). However, these solutions are technically and economically difficult to implement. Thegenetic selection for improving environmental adaptation in pig production is the most promising longterm option. The PigHeaT project aims 1) at identifying QTLs for heat adaptation, by examining directresponses to find genes involved in metabolic ways, indirect responses to find genes affecting growthor robustness to environmental variations, 2) at better understanding the physiological mechanismsunderlying heat adaptation. It will provide tools for improving breeding strategies to face theupcoming global warming, and knowledge to better comprehend the physiological reactions ofanimals submitted to short and long term heat stress. The PigHeaT project is based on originalbiological resources and original experimental facilities. The studied population will be a backcrossbetween Large White pigs, productive but poorly thermotolerant breed, and Creole pigs, lowproductive but highly thermotolerant breed. The progeny issued from this backcross will express allpossible levels of thermal tolerance and production performances when submitted to heat stress,depending on the alleles received from their parents. High throughput phenotyping, metabolomics onall the progeny, and transcriptomics on a subset of extreme pigs selected on thermal toleranceresponse, will be applied. It will allow to refine the phenotypes and to achieve a high level of accuracyin QTL detection in the frame of the PigHeaT project. Additionally, the design will benefit from theunique combination of experimental facilities available at INRA: the first part of the project will relyon the backcross population raised in the experimental facilities located in the West Indies(Guadeloupe, tropical environment). The concomitant production of the same population in theexperimental facilities available in temperate France (Charente Maritime) will allow the detection ofgenetic by environment (GxE) effects for the QTL detected in Guadeloupe. Moreover, a heat wavephenomenon will be systematically simulated in the temperate environment at the end of the growingperiod. As a result, chromosomal regions robust or susceptible to GxE interactions will be identified,GxE being either tropical vs temperate, or tropical vs heat wave. Finally, an integrated analysis of the(fine) phenotypes and QTL will be proposed to better understand the metabolic pathways involved inheat stress responses. The respective use of the QTL and biological knowledge in further breedingstrategies will finally be considered.

National audience; Le caprin Créole de Guadeloupe est élevé pour la viande. Il est réputé pour ses capacités d’adaptation (Mandonnet et al., 2001) et sa productivité (Alexandre et al., 1999). Cependant, les agents de la filière organisée lui reprochent une faible conformation de carcasse (Alexandre et al., 2008), alors même que ces carcasses ont été peu décrites. Au cours de deux essais d'engraissement intensif (thèse en cours), des abattages ont été réalisés où des découpes et des mensurations linéaires ont été relevées. Ces variables font l'objet de cette présente analyse afin de fournir des données factuelles à partager par les acteurs de la filière.

International audience

International audience

Session 5 : Bases biologiques de la qualité des viandes; National audience

International audience; A total of one hundred and twenty seven lactations were used to study the effect of genotype (Creole vs Large White) on lactating performance. This experiment was conducted in Guadeloupe (F.W.I., 16° Lat. N., 61° Long. W) between June 2001 and April 2003. Over a 28-d lactation length, average daily feed intake was significantly lower (p