The influence of sex-linked dwarf (dw) and incompletely dominant frizzle (F) genes on growth, egg production and quality were investigated. The experimental stock comprised 100 chicks of four genotypes: normal feathered, normal size (ffDw): normal feathered, dwarf (ffdw); frizzle, normal size (FfDw); and frizzle, dwarf (Ffdw). The dwarf gene reduced the body weight, shank length, feed intake, egg production and egg weight. The frizzle gene also reduced most of these traits, except for egg production, the interaction between the two genes being positive only for growth traits and egg number. Neither of the two genes significantly influenced egg quality. It was concluded that the dwarf gene may have some practical interest in tropical environments, while more needs to be known about the frizzle gene.

Jatropha curcas is a drought-resistant shrub belonging to the Euphorbiaceae family. The kernel contains approximately 60 % lipid in dry matter, and the meal obtained after oil extraction could be an exceptional source of protein for family poultry farming, in the absence of curcin and, especially, some diterpene derivatives phorbol esters that are partially lipophilic. The nutrient digestibility of J. curcas kernel meal (JKM), obtained after partial physicochemical deoiling was thus evaluated in broiler chickens. Twenty broiler chickens, 6 weeks old, were maintained in individual metabolic cages and divided into four groups of five animals, according to a 4 × 4 Latin square design where deoiled JKM was incorporated into grinded corn at 0, 4, 8, and 12 % levels (diets 0, 4, 8, and 12 J), allowing measurement of nutrient digestibility by the differential method. The dry matter (DM) and organic matter (OM) digestibility of diets was affected to a low extent by JKM (85 and 86 % in 0 J and 81 % in 12 J, respectively) in such a way that DM and OM digestibility of JKM was estimated to be close to 50 %. The ether extract (EE) digestibility of JKM remained high, at about 90 %, while crude protein (CP) and crude fiber (CF) digestibility were largely impacted by JKM, with values closed to 40 % at the highest levels of incorporation. J. curcas kernel presents various nutrient digestibilities but has adverse effects on CP and CF digestibility of the diet. The effects of an additional heat or biological treatment on JKM remain to be assessed.

L’insuffisance des ressources fourragères naturelles constitue une contrainte majeure au développement de l’élevage des ruminants dans le Centre et Nord bassin arachidier sénégalais. Pour y faire face, il faut recourir à des techniques telles que la culture fourragère. L’objectif est donc d’étudier la production de fourrage de Mucuna pruriens dans la zone et de déterminer sa valeur nutritive. Du fourrage frais de 79-84 jours et des foins de 60, 75 et 90 jours ont été produits. Les rendements ont été mesurés, les fourrages analysés, les compostions chimiques et les valeurs nutritives déterminées. Les rendements sont globalement faibles, 1,16 à 1,50 t MS/ ha, mais comparables à certains rapportés dans la littérature. Le fourrage frais est plus riche en protéines brutes que les foins, soit 19,56 contre 14,16 à 18,65% de la MS, moins fibreux, soit 27,26 contre 33,82 à 35,27% de la MS et plus nutritif, soit 150,65 contre 96,60 à 141,48 g/ kg MS de protéine brute digestible et 0,70 contre 0,67 à 0,69 UF/ kg MS. Parmi les foins, celui de 75 jours offre un léger avantage. En définitive, cette culture reste possible dans cette zone et peut y être préconisée en vue d’une atténuation du déficit fourrager. Mots clés : Rendement, composition chimique, fourrage frais, foins, valeur azotée, valeur énergétique. English Title: Production and nutritional value of Muscat pea fodder (Mucuna pruriens (L.) DC. var. utilis (Wall. ex Wight) Baker ex Burck) cv. Ghana cultivated in the Center and North senegalese groundnut basin The insufficiency of natural fodder resources constitutes a major constraint to the development of ruminant farming in the Central and Northern senegalese groundnut basin. To deal with this, techniques such as forage cultivation must be used. The objective is therefore to study the forage production of Mucuna pruriens in the area and determine its nutritional value. Fresh forage of 79-84 days and hay of 60, 75 and 90 days were produced. Yields were measured, forages analyzed, chemical compositions and nutrient values determined. Yields are generally low, 1.16 to 1.50 t DM / ha, but comparable to some reported in the literature. Fresh forage is richer in crude protein than hay, 19.56 against 14.16 to 18.65% DM, less fibrous, 27.26 against 33.82 to35.27% DM and more nutritious, 150.65 against 96.60 to 141.48 g/kg DM of digestible crude protein and 0.70 against 0.67 to 0.69 UF /kg DM. Among the hays, that of 75 days offers a slight advantage. Ultimately, this crop remains possible in this area and can be recommended there with a view to reducing the fodder deficit.Keywords: Yield, chemical composition, fresh fodder, hay, nitrogen value, energy value.

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