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Merino lambs of 90 days of mean age (standard deviation - s.d. - 6 days) and 22.0. kg of mean live weight (s.d. 2.7. kg) were used to explore the effects of pre-slaughter stressors on physiological characteristics and meat quality attributes. Three stressors were studied in a controlled experiment: fasting (food deprivation for 24. h before slaughter), physical exercise (keeping animals walking for 30. min at approximately 3. km/h) and fear stress (exposing animals to barking dogs for 5. min). A fourth treatment was kept as a control. Fasted lambs had greater (P0.05) in physiological indicators and lambs exposed to barking dogs had greater (P

Crossbred Criollo Neuquino castrated male kids, 6 months of age and 24 kg of live weight, were used to investigate the effects of pre-slaughter stressors on physiological characteristics and meat quality attributes. On four separate days, 16 kids were randomly assigned to one of the four pre-slaughter stressor treatments (4 kids per treatment per day): (A) no stress (control); (B) 24 h of food deprivation (fasting); (C) physical stress of forced exercise by an animal handler for 30 min at approximately 3 km/h (exercise); or (D) psychological stress by placing kids in a pen with barking dogs for 5 min (fear). Fasted goats had greater ( P P P

International audience; A quantitative trait loci (QTL) analysis of wool traits from experimental half-sib data of Merino sheep is presented. A total of 617 animals distributed in 10 families were genotyped for 36 microsatellite markers on four ovine chromosomes OAR1, OAR3, OAR4 and OAR11. The markers covering OAR3 and OAR11 were densely spaced, at an average distance of 2.8 and 1.2 cM, respectively. Body weight and wool traits were measured at first and second shearing. Analyses were conducted under three hypotheses: (i) a single QTL controlling a single trait (for multimarker regression models); (ii) two linked QTLs controlling a single trait (using maximum likelihood techniques) and (iii) a single QTL controlling more than one trait (also using maximum likelihood techniques). One QTL was identified for several wool traits on OAR1 (average curvature of fibre at first and second shearing, and clean wool yield measured at second shearing) and on OAR11 (weight and staple strength at first shearing, and coefficient of variation of fibre diameter at second shearing). In addition, one QTL was detected on OAR4 affecting weight measured at second shearing. The results of the single trait method and the two-QTL hypotheses showed an additional QTL segregating on OAR11 (for greasy fleece weight at first shearing and clean wool yield trait at second shearing). Pleiotropic QTLs (controlling more than one trait) were found on OAR1 (clean wool yield, average curvature of fibre, clean and greasy fleece weightand staple length, all measured at second shearing).

With the aim of identifying QTL affecting wool production and wool quality in Merino sheep, specific regions of chromosomes 3, 4, 11 and 25 were analyzed in eight half-sib families, with an average of 63 offspring per sire. Greasy fleece weight and body weight were recorded at hogget and adult shearing. Individual mid-side fleece samples were collected to measure seven wool traits. The regression interval mapping analysis evidenced QTL related to fiber diameter on chromosome 3, on the region of type II keratin genes (KRT2) and fleece weight on chromosome 4, both in two families. We detected a QTL segregating for yield on chromosome 25, being the first description of QTL related to this trait. A second QTL was found for coefficient of variation of fiber diameter, in concordance with previous references. These results contribute to the understanding of the variability of wool traits. The reduction of the confidence intervals for QTL positions, would allow including them on marker-assisted selection schemes accelerating genetic progress of wool sheep.

The Neuquén-Criollo goat is a significant genetic resource, adapted to the singular harsh environment of North Patagonia. Its present gene pool was built up from different breeds since the Spanish colonization being Angora the latest introduced. High phenotypic diversity and their geographical distribution suggest a subdivision of this goat population into four close sub-areas. As phenotypic characterization was carried out on 827 Criollo adult goats. Analyse were based on fourteen quantitative (morphostructural) and eight qualitative (morphological) variables. Correspondence analyses for qualitative and canonical discriminant analysis for quantitative traits were performed, using hair types as classification variable. Results were consistent in differentiating the four considered sub-areas. Neuquen Criollo breed could be characterized in two ecotypes: Short and Long hair goats, a mixed type area and a crossbred area fulfil the types distribution. Principal divergence factors would be isolation, natural and artificial selection, transhumance and exotic breeds introduction.

Forty female Angora goats were selected at random from the experimental nucleus of the National Institute of Agricultural Technology (Pilcaniyeu, Argentina), with the aim of analyzing the variability of main fleece characteristics of the Angora goats and establishing an optimum sampling site. Samples were taken at the first and second shearings (12 and 18 months of age) from the following parts of the fleece: neck, midrib, back, britch, belly and shoulder. For each sample the following determinations were made: oven-dry yield (YLD); average (AFD); standard deviation (SDAFD) and coefficient of variation (CVAFD) of fiber diameter; percentage of medullated fibers (MFT); characterization of three types of medullated fibers: continuous (MFC), interrupted (MFD) and kemp (KEMP) by estimating their proportion, average fiber diameter, standard deviation and coefficient of variation of fiber diameter; wax (WAX); suint (SUINT); humidity (HMD); staple length (STAPLE); degree of brightness (Y) and degree of yellowness (Y-Z). All variables studied showed statistically significant variability among to the sampling position (P

The objective of this study was to estimate genetic parameters for fleece traits in an experimental Angora goat flock. The fleece traits analyzed in this study were: greasy fleece weight (GFW), average fiber diameter (AFD), percentage of medullated fiber (MF) and corrected greasy fleece weight (CGFW). Direct and maternal variance components and resulting heritabilities were estimated using an animal model and DFREML procedures on the first shearing. Six different animal models were fitted ranging from a simple model with animals as the only random effect to the most comprehensive model allowing for both genetic and environmental maternal effects and a genetic correlation between genetic direct and maternal effects. The models were tested by the Likelihood Ratio Test which indicated that the maternal effects (genetic and environmental) can be ignored. Direct heritabilities estimated with a single trait model were 0.26±0.06, 0.33±0.06, 0.10±0.04 and 0.22±0.06 for GFW, AFD, MF and CGFW, respectively. Genetic correlations were estimated with a multivariate model. The pattern of correlations showed that GFW was positively correlated with AFD and CGFW, 0.51 and 0.53 respectively and negatively correlated with MF −0.72. AFD was negatively correlated with MF and CGFW (−0.18 and −0.37, respectively) and MF was negatively correlated with CGFW −0.65. The repeatability estimates were based upon other files containing information on all shearings. The repeatabilities were 0.64, 0.70, 0.58 and 0.68 for GFW, AFD, MF and CGFW, respectively. Genetic parameters estimated in this study appear reliable and provide a better basis for the Argentina genetic Angora goat improvement program. The moderate heritability level for CGFW added to the negative genetic correlation with AFD may be an alternative solution for selection programs based on a single trait. The high levels of repeatability estimates confirm the benefits of the selection program based on objective measurements observed at the age of year.

Information collected over a fifteen-year period on an experimental flock were analyzed to evaluate the effect of year, age of dam, sex, and type of birth on the characteristics of the fleece at first shearing and the effects of year, age at shearing, and sex on the characteristics of the fleece at subsequent shearings. The variables analyzed were greasy fleece weight (GFW), average fiber diameter (AFD), percentage of medullated fibers (MF) and corrected greasy fleece weight (CGFW). At first shearing significant statistical differences were detected (P

En este estudio, informamos sobre los resultados obtenidos en la busqueda de regiones cromosomicas que afectan a las caracteristicas del vellon en una poblacion de cabras de Angora en la Patagonia Argentina. Se utilizaron seiscientos treinta y cuatro crias de 14 familias parentales de medios hermanos. A la edad de 4 meses y de 11 meses, se registraron nueve rasgos fenotipicos en relacion al vellon. Se realizo una inspeccion del genoma utilizando 85 marcadores moleculares informativos. Se llevo a cabo un analisis de ligamiento utilizando un analisis de regresion de intervalo. Nuestro estudio identifico diez regiones genomicas que afectaban al diametro promedio de fibra, coeficiente de variacion de diametro promedio de fibra, porcentaje de fibra con diametro superior a 30 �Em, peso de lana suarda, longitud de la fibra, valor promedio de la curvatura de la fibra, porcentaje de fibras meduladas continuas y porcentaje de fibras kemp localizadas en cinco cromosomas caprinos (1, 2, 5, 13 y 19). Estos resultados indican que el tamano promedio del efecto QTL era de 1.6 desviaciones estandar fenotipicas para diferentes rasgos y familias. La deteccion de QTL tiene como proposito el uso potencial de estos marcadores moleculares para aumentar la precision a la hora de pronosticar el merito genetico en la crianza, y su utilizacion en proyectos de crianza de animales a traves de la seleccion asistida por marcadores.

With the aim to detect chromosome segment (quantitative traits loci, QTL) affecting fleece traits in Angora goats, a genome scan using 76 microsatellite markers spanning 1261 cM on 21 chromosomes was conducted. Eight paternal half-sib families were used, which included a total of 288 kids from a dispersed nucleus herd. Mid-side mohair samples were taken from kids at 4 months of age and eight phenotypic fleece traits were measured. We found putatives QTL for coefficient of variation of average fiber diameter (CVAFD) in chromosome 1 and 13, for kemp fiber (KEMP) in chromosome 5 and for discontinuous medullated fibers (DISC) and staple length (SL) in chromosome 2. These results demonstrate the segregation of quantitative traits involved in mohair production. Further studies will concentrate on these regions to characterize the variation of these QTL.

A genomic screen for quantitative trait loci (QTL) affecting conformation traits was performed by genotyping 288 Angora goatsoffspring from 8 half-sub families with 76 microsatellite markers. The following traits were recorded: weaning weight (WW, Kg);stature (S, cm); chest depth (CD, cm); shoulder width (SW, cm); rump length (RL, cm); rump width (RW, cm); head length (HL,cm); head width (HW, cm); shin circumference (SC, cm); chest circumference (CC, cm) and body length (BL, cm). Data wereanalyzed using the QTLExpress program. A total of 5 QTL were detected in five chromosomes with chromosome wide significancelevel. For the 11 analysed traits the results were: evidence of two possible QTL for HL were found in chromosomes 1 and 4, aputative QTL for trait CD was found in chromosome 2, evidence for BL was found in chromosome 8 and a possible QTL was foundfor trait CC in chromosome 9. The results reported here show the existence of chromosomal regions in Angora goats involved inconformation traits and represent the first in depth search in some specific-genome sections in order to identify and characterize thegenetic variability involved in these traits.© 2006 Elsevier B.V. All rights reserved.