Chromosomal evolution in allopatric populations of the <i>Odontophrynus occidentalis</i> group (Amphibia, Anura) from western Argentina

A karyological study of some populations of the Odontophrynus occidentalis group (2n=22) from Argentina is reported. Ammoniacal silver (Ag-AS) and alkaline Giemsa (CBG) staining have been performed on specimens from La Rioja, Mendoza, Malargue, Tamelen, Tapiluque, Valcheta, and Meseta de Somuncura. All populations showed active ribosomal cistrons (NORs) on chromosome 11. Some metaphases of three specimens from Mendoza and five from La Rioja also showed bands on 9. Centromeric and telomeric C-bands were common to all populations, and a block of heterochromatin on both sides of the centromere of 2 was remarkable in all but the La Rioja populations. The specimens from La Rioja showed a similar block of heterochromatin on the short arm of 1. Taxonomic studies of several specimens from these localities revealed differences in larval development, glandular pattern, the size of specimens, etc. As a whole, biological as well as karyological features suggest that the isolated population at La Rioja is a separate entity, at the species level, as described elsewhere.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Chromosomal evolution in allopatric populations of the <i>Odontophrynus occidentalis</i> group (Amphibia, Anura) from western Argentina

A karyological study of some populations of the Odontophrynus occidentalis group (2n=22) from Argentina is reported. Ammoniacal silver (Ag-AS) and alkaline Giemsa (CBG) staining have been performed on specimens from La Rioja, Mendoza, Malargue, Tamelen, Tapiluque, Valcheta, and Meseta de Somuncura. All populations showed active ribosomal cistrons (NORs) on chromosome 11. Some metaphases of three specimens from Mendoza and five from La Rioja also showed bands on 9. Centromeric and telomeric C-bands were common to all populations, and a block of heterochromatin on both sides of the centromere of 2 was remarkable in all but the La Rioja populations. The specimens from La Rioja showed a similar block of heterochromatin on the short arm of 1. Taxonomic studies of several specimens from these localities revealed differences in larval development, glandular pattern, the size of specimens, etc. As a whole, biological as well as karyological features suggest that the isolated population at La Rioja is a separate entity, at the species level, as described elsewhere.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Chromosomal evolution in allopatric populations of the <i>Odontophrynus occidentalis</i> group (Amphibia, Anura) from western Argentina

A karyological study of some populations of the Odontophrynus occidentalis group (2n=22) from Argentina is reported. Ammoniacal silver (Ag-AS) and alkaline Giemsa (CBG) staining have been performed on specimens from La Rioja, Mendoza, Malargue, Tamelen, Tapiluque, Valcheta, and Meseta de Somuncura. All populations showed active ribosomal cistrons (NORs) on chromosome 11. Some metaphases of three specimens from Mendoza and five from La Rioja also showed bands on 9. Centromeric and telomeric C-bands were common to all populations, and a block of heterochromatin on both sides of the centromere of 2 was remarkable in all but the La Rioja populations. The specimens from La Rioja showed a similar block of heterochromatin on the short arm of 1. Taxonomic studies of several specimens from these localities revealed differences in larval development, glandular pattern, the size of specimens, etc. As a whole, biological as well as karyological features suggest that the isolated population at La Rioja is a separate entity, at the species level, as described elsewhere.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Effets du parasitisme gastro-intestinal et de l’alimentation chez les petits ruminants en croissance. Production de viande caprine en conditions d'élevage locales

Préciser financement N° thèse : 2017ANTIO155Small ruminants mainly raised on pasture-based systems are exposed to gastrointestinal nematode parasites (GIN). Therefore, they can be a major cause of economic losses, as morbidity and mortality, on animal productivity. There is thus an active debate on new farming practices that could produce more food in a sustainable way. This is necessary for an increasing demand for good quality meat products such as goat meat in Guadeloupe. Farming systems need to be adapted to their environmental constraints and field practices could be redesigned to be more efficient and sustainable. Hence, integrated parasite management practices are advocated, such as different complementary feeding strategies. Complementary feeding can improve the ability of animal to tolerate the negative effects of parasitism (resilience) or to control infestations by GIN (resistance). The objective of the thesis was to define some feeding practices to supplement growing small ruminants (SR) according to their parasitic status and production performance which directly influence the income of livestock producers. A literature review was conducted by a meta-analysis of 101 publications and 466 treatments (dietary and parasitic) for growing sheep and goats. Results confirm that GIN infections for SR, significantly increase energy and protein requirements. However, this database did not make it possible to distinguish and prioritize protein vs. energy supply. In sheep compared to goats, a higher impact of nutrition is described on resistance. Different interactions were dissociated in the experimental trials (3 devices): the impact of parasitic history, the effect of nutritional history, and the changes of nutritional status on the functions of productions and of defenses of the host. The long-term effects of nutritional status would depend on the animal model (Creole goat compared to Black Belly sheep). As for Creole goat, complementary feeding during the growing period (3-11 months) would have an immediate beneficial effect on their level of parasitism. Changes in nutritional status occur under normal rearing conditions. However, this improvement appears to depend on the protection mechanisms that control parasitism (increase in OPG). Interactions between parasitism and complementary feeding were also evaluated on meat animals reared in indoor conditions or, in the last trial, the effect of optimized feeding practices was assessed in natural conditions at grazing. Discussion has focused on the targeted complementary strategies and attempt to answer questions: how (in energy, in protein or both) and when (effect not simultaneous or effect simultaneous during an established infestation) to do complementary feeding? The aim was also, at the field level, to quantify the effects of dietary recommendations on several variables (physio-pathological and production responses as carcass characteristics). In this way, the research work has presented certain originality. No significant effect of parasitism was observed statistically on the quality of carcass. However, the carcass of any infected animals was more degraded and so was with low-protein diet. A balanced energy/protein supplementation would improve carcass results (included in resilience). Complementary feeding practices were combined in a set of recommendations of integrated parasite management (genetic selection, Famacha method) and solely pasture management of mixed grazing systems with heifers. Better results were obtained for production performance (growth and carcass), body condition score and physiological responses (hematocrit rate). Furthermore, it was observed that the number of anthelmintic treatments has decreased. This research experiment addressed issues of complementary feeding practices appropriated for small ruminant breeders. Further studies are required to investigate questions on interaction between protein complementation and GIN. It is also recommended to address studies on feasible and field techniques for this feeding strategy.Les petits ruminants, principalement élevés au pâturage, sont exposés aux infestations par les nématodes gastro-intestinaux (NGI) qui constituent une cause majeure de morbidité et de mortalité, entrainant des pertes économiques importantes dans les élevages. Compte tenu des nouvelles orientations agroécologiques et de la demande en produits carnés de qualité à forte valeur patrimoniale comme la viande caprine en Guadeloupe, des systèmes d’élevage adaptés aux contraintes environnementales sont élaborés à partir de techniques efficaces et applicables sur le terrain. Ainsi, les méthodes de gestion intégrée du parasitisme sont préconisées, comme par exemple les stratégies d’alimentation des animaux. La complémentation alimentaire améliore la capacité de l’animal à tolérer les effets négatifs du parasitisme (résilience) ou à contrôler les infestations par les NGI (résistance). L’objectif de la thèse était de définir comment complémenter au mieux des chevreaux en croissance selon leur statut parasitaire. En effet, ce stade physiologique est le plus atteint par les NGI or leurs performances zootechniques conditionnent directement la production de viande donc le revenu des producteurs. Un bilan bibliographique a été conduit par le biais d’une meta-analyse portant sur 101 publications et 466 traitements (alimentaires et parasitaires) concernant des ovins et caprins en croissance. Les résultats confirment (et fournissent des données factuelles, équations de prédiction) que les infestations par les NGI augmentent significativement les besoins en énergie et en protéines. Cependant la base de données n’a pas permis de les distinguer et hierarchiser. Chez les ovins (comparativement aux caprins) un impact plus élevé de l’alimentation sur la résistance est décrit. Les différentes interactions ont été dissociées dans les premiers essais expérimentaux (3 dispositifs): impact de l’histoire parasitaire, de l’histoire nutritionnelle, et des changements de statut nutritionnel sur les fonctions de productions et de défenses. Les effets à long terme du statut nutritionnel dépendraient du modèle animal (Caprin Créole comparé au mouton Black Belly). Pour les premiers, une complémentation au cours de la période de croissance (3-11 mois) aurait un effet bénéfique immédiat sur leur niveau de parasitisme. Des changements de statut nutritionnel s’opèrent en conditions naturelles d’élevage. Une complémentation équilibrée énergie/azote améliorerait les résultats d’élevage et de carcasse. Cependant cette amélioration semble se mettre en place au dépend des mécanismes de protection qui contrôlent le parasitisme (augmentation des OPG). Les interactions entre le niveau de parasitisme et de complémentation ont aussi été évaluées lors d’un essai en conditions contrôlées hors sol. Dans le dernier essai les effets des stratégies optimisées ont été évaluées en conditions naturelles au pâturage. Les discussions portent sur la mise au point de stratégies de complémentation ciblée et tentent de répondre aux questions: comment complémenter? (en énergie, azote ou les deux); quand complémenter ? (effets-retard ou effets durant une infestation établie). Il s’agissait aussi de tester les recommandations grandeur nature et sur plusieurs variables (réponses physio-pathologiques et réponses zootechniques dont les caractéristiques de carcasse). En ce sens ce travail a présenté une certaine originalité. Aucun effet du parasitisme, statistiquement significatif, n’a été observé sur la qualité des carcasses. Cependant chez les animaux infestés les carcasses étaient plus dégradées et ce d’autant plus avec une ration pauvre en protéine. L’apport de la complémentation a été combinée à une série de recommandations de la gestion intégrée du parasitisme (voie génétique, méthode Famacha) et singulièrement à une stratégie de gestion du pâturage mixte avec des génisses. Ont été obtenus, un accroissement des résultats zootechniques (croissance et carcasse), de la note d’état corporel ainsi qu’une amélioration de la réponse physiologique ( taux d’hématocrite). Une diminution du nombre de traitements anthelmintiques est observée aussi. Cet essai a abordé l’opérationnalité de la complémentation pour un éleveur. D’une façon générale, ce travail a ouvert aussi des questionnements scientifiques sur l’interaction nutrition*parasitisme avec un focus sur la nutrition azotée à déconnecter de l’alimentation énergétique

<i>Odontophrynus barrioi</i>, a New Species of Anuran from Argentina

A new species of Odontophrynus from 2200 m altitude in the Sierra de Famatina, Argentina, is described. Morphological as well as cytogenetic features differentiate the new species, O. barrioi, from the populations of the O. occidentalis group.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

<i>Odontophrynus barrioi</i>, a New Species of Anuran from Argentina

A new species of Odontophrynus from 2200 m altitude in the Sierra de Famatina, Argentina, is described. Morphological as well as cytogenetic features differentiate the new species, O. barrioi, from the populations of the O. occidentalis group.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

<i>Odontophrynus barrioi</i>, a New Species of Anuran from Argentina

A new species of Odontophrynus from 2200 m altitude in the Sierra de Famatina, Argentina, is described. Morphological as well as cytogenetic features differentiate the new species, O. barrioi, from the populations of the O. occidentalis group.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Effect of Experimental Infection with Haemonchus contortus on Parasitological and Local Cellular Responses in Resistant and Susceptible Young Creole Goats

This study was carried out to evaluate the relationships of cellular changes in the abomasal mucosa and parasitological parameters, by comparing resistant and susceptible young Creole goats (kids) after experimental infection with Haemonchus contortus. The kids were infected over 2 periods (challenges 1 and 2) of 7 and 6 weeks, respectively. Fecal egg count (FEC), blood eosinophilia, packed cell volume (PCV), and body weight were weekly monitored. At the end of both challenges a subgroup of kids was slaughtered for nematode burden measurements and analysis of inflammatory cell infiltration in the abomasal mucosa. The average daily gain was higher in resistant kids after both challenges. Blood eosinophilia and FEC were higher in susceptible kids after both challenges. The number of immature worms and the means of female length were lower after challenge 2 whatever the genetic status. No differences were observed in the eosinophil and mononuclear cell infiltration between challenges 1 and 2 and resistant and susceptible kids. Globule leukocyte infiltration was found higher after the challenge 1 in resistant kids. This effect of the genetic status on globule leukocytes counts but not on the other inflammatory cell highlights the need for further study on the functional activity of these cell populations

Comparing the effects of single or trickle experimental infections with Haemonchus contortus on digestibility and host response in naïve Creole kids reared indoor

Communication faite au cours de International Symposium on Sustainable Animal Production in the Tropics: Farming in a Chnaging World : Gosier (Guadeloupe), France ; 2010/11/15-2010/11/18International audienc

Growth and carcass attributes of growing Creole kids according to experimental infection level and type of diet

International audienceIn the tropics one of the major constraints to goat production is infection by gastrointestinal nematodes (GIN). One promising alternative to chemotherapy is the improvement of host nutrition. The aim of this study was to assess the effects of infection and supplementation on packed cell volume (PCV), average daily gain (ADG) and carcass quality in growing Creole kids. Sixty male goats were reared indoors following a 2 × 3 factorial design: two experimental infection levels, (infected (I) and non-infected (NI)) and three diets D (G, kids were fed exclusively with tropical forages; B, kids were supplemented with dried and crushed banana and C, kids were supplemented with commercial pellets). Faecal egg counts did not vary among I groups (on average 2,200 ω/g). The PCV and ADG were improved (P < 0.001) for NI vs. I animals. There was a D effect (P < 0.001) and no I × D interaction was observed. There was no significant effect of GIN on the main carcass data, except the weights of liver, white offal and abdominal fat, which increased slightly in I compared with NI goats (P < 0.05). All carcass data increased significantly with the addition of supplement in the diet (P < 0.001), except for carcass-cut proportions. Meat physical parameters were degraded when I kids received low N diets (B or G) with higher lightness and water loss than in the C groups. Given that GIN affect the animal’s N metabolism it is recommended to avoid the use of unbalanced diet such as those banana-based. Further research is necessary to assess the nutrition × parasitism interactions on physiological features and carcass quality of Creole goats