The objectives of this study were to investigate the relationships between body weight and morpho-structural indices to predict body weight from their orthogonal body shape characters using principal component analysis and to morphologically classify the chicken genotypes using multivariate discriminant analysis. Data used were from 273 randomly selected 12-weeks-old indigenous chickens of normal-feathered (NF), frizzle-feathered (FF), naked-neck (NN) and Anak Titan (AT) genotypes. Phenotypic correlation among body weight and most biometric traits ranged from 0.227-0.876, -0.7-0.901, 0.034-0.968 and -0.207-0.849 for NF, NN and AT chickens, respectively. Factor analysis with varimax rotation of interrelated traits revealed three principal components which accounted for 83.1%, 74.4%, 78.8% and 76.5% of the total variance in NF, FF, NN and AT chickens in the order listed. Breast girth, keel length, thigh length, shank length and wing length were found to be the most discriminating variables to separate the chicken genotypes. The longest distance (72.54) occurred between AT and NF genotypes while the shortest distance (4.27) was recorded for FF and NN genotypes. Classification results showed that 85.2% of AT genotype was correctly classified into their source population. However, 22.7% of NF was misclassified as NN, while 33.3% of NN was misclassified as NF chickens. These results suggest that there is high rate of gene flow between these two indigenous chicken genotypes. Information obtained from this study may be considered useful in breed improvement programmes for selection, characterization, conservation and better management of Nigerian indigenous chickens.

No abstract

Genetic improvement of goat breeds in growth and other traits (e.g. milk production) is limited by the demographics of the goat herds, extensive production system and the seemingly long-term nature of improvement through traditional genetics and breeding methods. We studied the genetic morphometry in Nigerian goats and South African Kalahari Red goat breeds. A total of 192 goats belonging to three Nigerian breeds (Red Sokoto (RS), Sahel (SH) and West African Dwarf (WAD)) and one South African Kalahari Red (KR) goat breed were analysed. Animals were classified into four age groups: A group – less than 1 year, B group – between 1 and 2 years, C group – between 2 and 3 years and C group – older than 3 years based on dentition. Analysis of variance, correlation matrix, regression and discriminant analyses were used to evaluate morphological variability. Results revealed that the effect of breed on the measured morphometric traits was significant (P < 0.05). The best prediction equation for body weight (BW) with R2 = 0.84 was obtained when body length (BL), withers height (WH) and chest depth (CD) were included in the model for KR goat. Growth traits were positively correlated with each other with the highest correlation coefficients found between BL and BW (r = 0.877, P < 0.01), WH and BW (r = 0.541, P < 0.01), WH and BW (0.661, P < 0.01) and CD and BW (0.738, P < 0.01) in KR, RS, SH and WAD goats, respectively, which are important for a conscious selection and breeding programme for desired traits. Stepwise discriminant procedure showed that WH, CD and BL were the most discriminating variables to separate KR, RS, SH and WAD goats. In accessing morphological diversity, efforts should be made to include phenotypic variables of at least ≥ 3 in order to minimize ambiguity in classification. Based on the pair-wise distances from the Discriminant function, the study provided informed decision, reference information on goat breeding and conservation strategy.

Genetic improvement of goat breeds in growth and other traits (e.g. milk production) is limited by the demographics of the goat herds, extensive production system and the seemingly long-term nature of improvement through traditional genetics and breeding methods. We studied the genetic morphometry in Nigerian goats and South African Kalahari Red goat breeds. A total of 192 goats belonging to three Nigerian breeds (Red Sokoto (RS), Sahel (SH) and West African Dwarf (WAD)) and one South African Kalahari Red (KR) goat breed were analysed. Animals were classified into four age groups: A group – less than 1 year, B group – between 1 and 2 years, C group – between 2 and 3 years and C group – older than 3 years based on dentition. Analysis of variance, correlation matrix, regression and discriminant analyses were used to evaluate morphological variability. Results revealed that the effect of breed on the measured morphometric traits was significant (P < 0.05). The best prediction equation for body weight (BW) with R2 = 0.84 was obtained when body length (BL), withers height (WH) and chest depth (CD) were included in the model for KR goat. Growth traits were positively correlated with each other with the highest correlation coefficients found between BL and BW (r = 0.877, P < 0.01), WH and BW (r = 0.541, P < 0.01), WH and BW (0.661, P < 0.01) and CD and BW (0.738, P < 0.01) in KR, RS, SH and WAD goats, respectively, which are important for a conscious selection and breeding programme for desired traits. Stepwise discriminant procedure showed that WH, CD and BL were the most discriminating variables to separate KR, RS, SH and WAD goats. In accessing morphological diversity, efforts should be made to include phenotypic variables of at least ≥ 3 in order to minimize ambiguity in classification. Based on the pair-wise distances from the Discriminant function, the study provided informed decision, reference information on goat breeding and conservation strategy.

Des exons de gènes contrôlent l’information génétique qui est transcrite et traduite en un produit protéique qui produit, directement ou indirectement, des phénotypes observés de caractères. La nécessité de disposer d’informations génétiques, en relation avec les locus qui affectent les caractères de performance, peut être un outil important dans le programme de sélection. La recherche s’est concentrée sur la génétique, l’amplification et le séquençage du gène de la myostatine à partir du sang de la race de chèvre Red Sokoto du Nigéria et sur l’association avec les caractères morphologiques. Les caractères morphologiques, y compris le poids corporel, la hauteur du garrot, la longueur du corps et la profondeur de la poitrine ont été évalués à l’aide d’un équipement standard simple. Le résultat du séquençage des exons 1 et 3 du gène de la myostatine provenant de la chèvre Red Sokoto, largement gérée, a révélé que les régions des exons 1 et 3 sont polymorphes, l’exon 1 étant plus polymorphe. Trois des cinq polymorphismes mononucléotidiques non synonymes obtenus dans l’exon 1 ont eu des effets non neutres possibles sur la fonction protéique. Inversement, un polymorphisme mononucléotidique non synonyme trouvé dans l’exon 3 avait un effet neutre possible sur la fonction de la protéine. La régression logistique a révélé qu’un variant non-synonyme à la région de l’exon 1 du gène de la myostatine était associé à la longueur du corps chez la chèvre rouge Sokoto largement gérée. Cette étude préliminaire sur le gène de la myostatine dans la race chèvre rouge Sokoto au Nigeria a comblé un manque en fournissant une référence valable sur le gène de la myostatine et / ou ses régions intermédiaires, par exemple les exons 1 et 3. Ces connaissances seraient utiles présenter de précieuses ressources pour de futures études sur la génomique caprine.