Genotype by environment interactions in relation to growth traits in slow growing chickens

Since feed conversion ratio (FCR) is higher in slow-growing "Label Rouge" chickens than in broiler chickens, it is important to work on its improvement in this breed. However, this involves rearing animals in cages (C), an environment very different from that used for selection (in floor pens, S) and production (outdoor, E). The aim of this study was to evaluate the importance of genotype by environment (G × E) interactions between S, C, and E environments, to find the best way to select for FCR, using 2002 related animals. Growth curve parameters were estimated and body composition measured. Individual feed conversion ratios (FCR) were recorded between 8 and 10 weeks in C. The presence of G × E interactions was assessed by the genetic correlations between the same trait recorded in different environments. Moderate but significant G × E interactions were detected for carcass traits, a significant one was observed between E and S or C for growth curve parameters but none between C and S. If G × E interactions are set aside, i.e. selecting on traits recorded in C, abdominal fatness is the best indirect selection criterion for FCR but if they are taken in account then leg yield or growth curve parameters in S and growth curve parameters in E are better

A review of methods to measure animal body temperature in precision farming

The authors wish to thank colleagues from INRA, Eric Bobillier, Alain Ducos and Pierre-Yves Lebail for their helpful discussion, Michael Bertoldo (INRA) and Sandra Martin (Texas A&M University) for English proofreading.Automation of phenotypic measurements of livestock has become a more important goal for scientists and also for farmers who need a more precise, real-time knowledge of their animals. Among physiological measures, body temperature and its variations are key indicators of the physiological health and well-being of animals. Although measuring the body temperature may seem a trivial matter, its implementation is faced with many difficulties both at biological and technological levels in a field of constant progress. Today, there are many studies reporting taking temperature measurements without restraining animals. The present report focuses on the two main approaches to temperature measurements that use direct contact or radiation sensors. Specifically, we investigated the use of thermocouples, thermistors and infrared radiation sensors. A wide literature review using one of these techniques was conducted in which different animal species, different purposes, different experimental designs, various equipments, and different devices and gold standard methods are discussed. These technologies will continue their dizzying development, leading to new communication protocols, sensors miniaturization and a more efficient management of energy. These developments will have a direct impact on the increase of reading distances and the amount of information stored. In response to the request of farmers and researchers, integrated monitoring systems are already marketed with user-friendly interfaces and softwares for complex data storage and treatments

Rationnement alimentaire de l'oie avant et pendant la ponte

National audienceDifferents programmes of feed restriction have been evaluated on goose breeders kept outdoor in order to evaluate whether the spontaneous overconsumptions of feed which occur before the beginning of laying and after the peak of lay, play an important role on performances. During two successive trials, a limitation of the energy intake at 700 kcal ME/day/bird (320 g/day of a feed containing 2200 kcal ME and 170 g CP/kg) was applied from mid-november up to the date on which the laying rate reached 20% (about midfebruary). This treatment induced a small, non significant reduction in the number of laid eggs and a large increase (+10 to +15%) in fertility with a positive balance of +4 goslings/goose. Two other levels of restriction (500 and 1000 kcal ME/day/bird) were tested on the same part of the laying cycle ; they appeared to be too much and not severe enough respectively. A restriction level which limits the geese body weight increase to 1.0 - 1.2 kg could be recommended. After the peak of lay (end of march), a limitation of the energy intake at 660 kcal ME/day/bird was detrimental to the laying rate (-6 eggs/goose) but is still largely favourable to the fertility rate (+15%). For this period, different feeding programmes would be probably justified for geese and ganders.Trois essais de rationnement alimentaire ont été réalisés sur des parquets (15) d’oies reproductrices grises des Landes, pendant leur saison naturelle de reproduction (printemps) et en plein air, afin d’évaluer si les surconsommations spontanées d’aliment observées avant l’entrée en ponte puis après le pic de ponte jouent un rôle déterminant sur les performances. Une limitation de l’ingéré énergétique à 700 kcal/jour/animal (320 g/jour d’un aliment contenant 2200 kcal d’énergie métabolisable/kg et 17% MAT) appliquée de mi-novembre jusqu’au stade 20% de ponte, entraîne une légère réduction du nombre d’oeufs (-2 oeufs/oie) mais une augmentation de 10 à 15% de leur taux de fertilité avec un bilan positif de +4 oisons par mère. Deux autres niveaux de rationnement testés (500 et 1000 kcal/jour/animal) sont ou trop ou trop peu sévères. Un rationnement préalable à la ponte et limitant la prise de poids des femelles à 1,0 -1,2 kg paraît donc recommandable. Après le pic de ponte (fin mars), la limitation de l’ingéré énergétique à 660 kcal/oie pénalise fortement la ponte (moins 6 oeufs par femelle) mais accroît fortement le taux de fertilité (+ 13%). A ce stade, un rationnement différent des mâles et des femelles mériterait d’être développé

L'insemination artificielle chez l'oie grise des Landes : bilan et perspectives

National audienceIn France, artificial insemination of geese is rarel practiced. It could, however, increase the number of goslings produced. Different studies have been conducted at the Experimental Station of Palmipedes a Foie Gras in order to establish physiological and technical basis for artificial insemination. Dorso-abdominal massage of the ganders allowed the collection of about 0.3 ml of semen containing 150 million spermatozoa. About 40 % of the males do not respond to this stimulation. The best male donors could be selected at the beginning of the reproductive season. Three to five times a week was determined to be the most efficient frequency of collection. The highest fertility rate (80 % eggs fertile/incubated) was obtained with doses of 20 x 1 10 spermatozoa, inseminated twice a week separated by an interval of 72 or 96 hours. Dilution of the semen increased its fertilizing ability and consequently decreased the number of spermatozoa required for insemination. Semen can be diluted and stored for a short time (6 hours) without inducing a significant decrease in the fertility rate (71.9 % vs 75.1 % with undiluted fresh semen).L’insémination artificielle chez l’oie, actuellement peu utilisée, pourrait permettre une amélioration de la productivité numérique de cette espèce. Une série de travaux a été réalisée à la Station Expérimentale des Palmipèdes à Foie Gras,visant à en établir les bases physiologiques et techniques. La méthode de massage dorso-abdominale permet de récolter chez le jars gris des Landes en moyenne 0,3 ml de sperme renfermant 150 millions de spermatozoïdes. L’adaptabilité des mâles à la méthode de collecte est très variable (environ 40 %de « mauvais » ou non-donneurs), mais un tri en début de saison de reproduction pourrait permettre de ne garder que les bons donneurs. La fréquence de prélèvement optimale des mâles se situe entre 3 et 5 fois par semaine. Les taux de fécondation les plus élevés (80 % oeufs fécondés / incubés) sont obtenus avec deux inséminations hebdomadaires (espacées de 72 ou 96 heures) de 20 millions de spermatozoïdes. L’emploi d’un dilueur adapté semble améliorer le pouvoir fécondant des spermatozoïdes,ce qui permet d’envisager la réduction du nombre de spermatozoïdes inséminés. Par ailleurs, la semence peut être diluée et conservée pendant une courte période (6 heures) sans entraîner une chute importante du taux de fertilité(71,9 % vs 75,1 % avec du sperme frais non dilué), assouplissant ainsi les « chantiers» d’insémination artificielle

Genetic architecture of duration of fertility of the common duck (Anas Platyrhynchos)

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Influence des conditions d'abattage et de réfrigération sur la qualité des foies gras d'oie

Les conditions d’abattage, d’éviscération et de refroidissement des oies gavées ont une incidence importante sur la production quantitative et qualitative des foies gras. La mise à jeun des animaux avant l’abattage est nécessaire pour préserver leur qualité sanitaire. Toutefois, un jeûne prolongé entre le dernier repas de gavage et l’abattage peut entraîner une importante diminution du poids du foie gras et une altération de sa qualité technologique par augmentation de sa fonte lipidique. Un optimum pourrait être trouvé autour de 12 h La réfrigération rapide des foies gras après l’abattage des oies gavées est nécessaire pour limiter leur fonte lipidique et ceci d’autant plus que leur qualité technologique initiale est meilleure (foies de 600 à 900 g). L’éviscération à chaud (immédiatement après l’abattage), qui permet d’isoler rapidement le foie des risques de contaminations intestinales et une réfrigération rapide hors de la carcasse, conduit à une meilleure qualité technologique des foies gras. Sa mise en oeuvre exige toutefois une parfaite maîtrise des conditions d’hygiène.Slaughtering, evisceration and cooling conditions of force-fed geese have an important impact on the quality and weight of “foie gras”. Before slaughtering, the animals must fast to maintain a low bacteriological count in the liver. However, an extended fasting period between the last force-feeding meal and time of slaughter can lead to a large loss in liver weight and also an alteration of its physical qualities by raising the melting point of the fat. The optimum fasting period is probably of the order of 12 hours. Rapid refrigeration of “foie gras”, immediatly after slaughtering the force-fed geese is necessary to limit melting of lipids. This is especially important for larger livers (livers weighing between 600 and 900 grams). Evisceration immediately after slaughtering eliminates the possibility of intestinal contamination, and quick refrigeration of the removed liver leads to a better quality liver. To implement this technique perfect control of bacteriological conditions is essential

Genetic parameters of digestibility of wheat- or corn-based diets in chickens

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