Information from a scrapie epidemic in a closed INRA Romanov flock is presented. Performances, pedigree, histopathological diagnoses and PrP genotypes were recorded from the beginning of the outbreak (in 1993). Between 1st of April, 1993 and 1st of May, 1997, 1015 animals were exposed to scrapie, and 304 died from this disease. A major influence of the polymorphisms at codons 136, 154 and 171 is shown, A136H154Q171 allele carriers proving to be nearly as resistant as A136R154R171 carriers. A possible relationship between gastrointestinal parasitism and scrapie is discussed. There is evidence of maternal transmission, with a risk ratio for artificially fed lambs of 67 percent of the risk of lambs fed by their mother. Our results strongly suggest that resistant animals were not healthy carriers or at least were less infectious when comparing risk for lambs born to healthy dams either of resistant (risk = 0.431) or of susceptible (risk = 1.000) genotype.
a b s t r a c tA total of 6440 female sheep from Burkina Faso were scored for seven body measurements and four qualitative morphological traits. Sampling included the three main environmental areas and sheep breeds of Burkina Faso: the Sahel area (Burkina-Sahel sheep), the SudanSahel area (Mossi sheep) and the Sudan area (Djallonké sheep). Canonical analyses showed that differences in body measurements between the Sudan and the Sudan-Sahel sheep were small even though most body traits showed higher average values in the Burkina-Sahel sheep: the shortest Mahalanobis distance was found between the Sudan and the SudanSahel populations (1.54), whilst that between the Sudan and the Sahelian populations was the largest (7.88). Discriminant analysis showed that most Sudan (Djallonké) individuals (60.85%) were classified as Sudan-Sahel (Mossi) individuals whilst most Burkina-Sahel individuals were classified into their environmental area of sampling (89.46%). Correspondence analyses indicated that the Burkina-Sahel sheep population clustered together with dropping ears, black and brown colour patterns and presence of wattles, the Sudan sheep were closely associated with long hair and vertical and curled ears and that the Sudan-Sahel sheep did not have clear associations with qualitative phenotypic traits. At the morphological level, the Sudan-Sahel (Mossi) sheep population can be considered a geographical subpopulation belonging to the Djallonké breed, showing some particularities, namely larger body size, due to the particular environmental condition of the area in which it is managed and a continuous gene flow from Sahelian sheep, The information reported in this study will be the basis for the establishment of further characterization, conservation and selection strategies for Burkina Faso sheep.
The objectives of this research were to evaluate gender differences and selection on body weight as they affect growth curves of chickens. Marginal posterior densities of growth curve parameters were studied by Gibbs sampling on 10,671 male and female chickens originating from five lines. Line X-+ was selected on low body weight at 8 wk (BW8) and high body weight at 36 wk (BW36), line X+- on high BW8 and low BW36, X++ on high BW8 and BW36, X-- on low BW8, and BW36, and X00 was an unselected control line. Growth was modeled by a Gompertz function. Heritabilities and genetic correlations among parameters of the Gompertz curve were estimated. Marginal posterior densities were drawn for parameters of the growth curve and for sexual dimorphism at ages ranging from hatching to 1 yr. Lines selected for a higher BW8 had higher initial specific growth rates (L), higher maturation rates (K), and lower ages at inflection (T(I)). Lines selected for a higher BW36 had higher asymptotic body weights (A). Estimates of A, L, and T(I) were higher in males and K was higher in females. Difference between sexes for A was greater in the line selected for a lower BW8 and a higher BW36. Dimorphism for L and K was the lowest in lines X++ and X--, respectively. The greatest difference in T(I) was observed in the line selected for lower BW8 and BW36. Sexual dimorphism of body weight was lower at most ages in the lightest line. Before 15 wk, sexual dimorphism in X++ line was lower than in the line selected for higher BW8 and lower BW36. The increase in sexual dimorphism with body weight could be reduced by selecting animals on body weight at two ages instead of one, as is usually done in commercial lines.
A total of 10,147 female goats from Burkina Faso were scored for 7 body measures and 12 qualitative traits. Sampling included the three main environmental areas and goat breeds of Burkina Faso: the Sahel area (Sahelian goat), the Sudan-Sahel area (Mossi goat) and the Sudan area (Djallonké goat). Overall, the Sahelian goat had the highest values for the all the analysed body measures. Differences between the Sudan and the Sudan-Sahel goat were little. The Burkina Faso goat is mainly spotted (61.92 %) with horns type "Spanish Ibex" (84.05 %), frequent absence of beard (75.33 %) and wattles (70.92 %) and poorly developed udder (73.72 %). The Sahelian population included most individuals with dropping (95.60 %) and curled (73.62 %) ears, whilst most Sudan-Sahel individuals had horizontal ears (73.14 %) and most Sudan individuals had vertical ears (97.88 %). The largest Mahalanobis distance was found between the Sahelian and Sudan areas (7.50) whilst the Sudan and the Sudan-Sahel populations were poorly differentiated (1.15). Discriminant analysis showed that most Sahel and Sudan-Sahel individuals were classified into their source population (79.29 % and 82.69 %) whilst the Sudan individuals (93.40 %) were classified as Sudan-Sahel individuals. Both the canonical and the correspondence analyses showed that the Sahelian and Sudan individuals tended to cluster separately whilst the Sudan-Sahel individuals showed an intermediate distribution but clearly biased toward the Sudan individuals. The Sudan-Sahel (Mossi) population can be considered a result from the genetic contact between Sahelians and Sudan goats Keywords: Djallonké goat, Mossi goat, Sahel goat, Africa, local breed, morphological traits, genetic resources ZusammenfassungTitel der Arbeit: Multivariate Analyse von morphologischen Merkmalen der Burkina-Faso-Ziege An insgesamt 10.147 weiblichen Ziegen aus Burkina Faso wurden 7 Körpermaße und 12 qualitative Merkmale bewertet. Die Probennahme wurde in den drei Haupthabitaten an den wichtigsten Ziegenrassen von Burkina Faso durchgeführt: Sahelzone (Sahel-Ziege), Sudan-Sahelzone (Mossi-Ziege) und Sudangebiet (Djallonké-Ziege). Insgesamt erreichte die Sahel-Ziege die höchsten Werte bei allen untersuchten Körpermaßen. Die Unterschiede zwischen der Sudan-Ziege und der Sudan-Sahel-Ziege waren gering. Die Burkina-Faso-Ziege ist überwiegend gefleckt (61.92 %), mit Hörnern vom Typ "Spanish Ibex" (84.05 %), häufig bartlos (75.33 %) und ohne Kehllappen (70.92 %) sowie unzureichend entwickeltem Euter (73.72 %). Die meisten der Individuen der Sahel-Population wiesen hängende (95.60 %) und gekrauste Ohren (73.62 %) auf, während die meisten der Individuen aus der Sudan-Sahel-Zone waagerechte Ohren (73.14 %) und die Mehrheit der Individuen aus dem Sudangebiet aufrecht stehende Ohren (97.88 %) hatten. Die größte Mahalanobis-Distanz wurden zwischen den Sahel-und Sudangebieten gefunden (7,50), während sich die Sudan-und Sudan-Sahel-Populationen nur geringfügig voneinander unterschieden (1,15). Diskriminanzanalysen zeigten, d...
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