Kefyalew Alemayehu

Genetic diversity studies using microsatellite markers and their contribution in supporting sustainable sheep breeding programs: A review

Abstract Microsatellites have been widely accepted and employed as useful molecular markers for measuring genetic diversity and divergence within and among populations. The various parameters developed so far to measure genetic diversity within and among populations are observed and expected heterozygosities (Ho and He), the mean number of alleles per locus, polymorphic information content, genetic distance and phylogenetic or tree building approach. The objective of this review was therefore to quantify the genetic diversity studies of domestic sheep populations using microsatellite markers and their contribution in supporting sustainable sheep breeding programs. From the review, it is possible to see that there was high within population genetic variations in all the studied sheep populations, poor level of population differentiations and high levels of inbreeding. On the other hand, low estimates of heterozygosities and mean number of alleles and employing only few and weak markers were observed in some of the studies. The gaps observed in the previous genetic diversity studies of the sheep populations may demand further works to reveal more information on the population structures and to start appropriate and sustainable breeding programs.

Phenotypic characterization, population structure, breeding management and recommend breeding strategy for Fogera cattle ("Bos indicus") in Northwestern Amhara, Ethiopia

espanolEl incremento individual de los coeficientes de endogamia (ΔFi) ha sido recomendado como una medida alternativa de la endogamia ya que tiene en cuenta las diferencias en el conocimiento que se tiene de la genealogia de animales individuales y evita la sobreestimacion debida a un mayor numero de generaciones conocidas. El efecto de la endogamia (F) y de la endogamia equivalente (EF), calculadas a partir de ΔFi, sobre los parametros de crecimiento fue estudiado en rebanos de ovejas Nilagiri y Sandyno. El estudio se baso en datos conservados en la Estacion de Investigacion para la Mejora del Ganado Ovino (Sandynallah). Se dispuso de menos informacion sobre la genealogia y el numero equivalente de generaciones fue menor para las ovejas Sandyno que para las ovejas Nilagiri. Los valores medios de F y EF para la poblacion Nilagiri fueron de 2,17 y 2,44, respectivamente, y los valores correspondientes para las ovejas Sandyno fueron de 0,83 y 0,84, respectivamente. En ambas poblaciones, la evolucion seguida a lo largo de los anos por la endogamia hizo ver que EF era mayor en las generaciones tempranas, en las que la informacion sobre la genealogia fue escasa. Entre los efectos significativos de la endogamia, la depresion del crecimiento vario de 0,04 kg en el peso al destete a 0,10 kg en el peso al ano de vida por cada 1 por ciento de incremento de la endogamia. En general, fueron mas los caracteres que se vieron afectados por la endogamia en las ovejas Nilagiri, en las cuales se observo una mayor depresion de los parametros de crecimiento con F que con EF. La deteccion de mayores valores para EF que para F en generaciones tempranas de ambas poblaciones indica que EF evito la posible sobreestimacion del coeficiente de endogamia en generaciones recientes. La depresion detectada en parametros de crecimiento por un efecto significativo de la endogamia fue mayor en la poblacion Sandyno. Se discuten debidamente las diferencias advertidas en las dos poblaciones en la respuesta a F y EF y las posibles causas de estas diferencias. Palabras clave: ovejas, endogamia, incremento individual de la endogamia, depresion, crecimiento EnglishThe study was carried out in selected districts in the Northwestern Amhara, from October 2012 to May 2013. The objective of the study were to undertake on-farm and on-station phenotypic characterization of Fogera Cattle in comparison with two different local cattle population, to characterize the population structure and to identifying trait preferences, breeding management and to recommend breeding strategy for Fogera cattle. Both purposive and random samplings were employed. Data were gathered through semi-structured questionnaire, focus group discussions, field observations, census data, direct count and body measurements. About 126 smallholder farmers were interviewed. About 21 quantitative and 17 qualitative phenotypic data types were also generated from 332 cattle. The Effective population size (Ne) and rate of inbreeding (ΔF) were calculated from the counted population structure data. Both GLM procedures of SAS and descriptive statistics of SPSS software’s were employed for data analyses. The results indicated that Fogera cattle were kept mostly for milk (97.62 percent). The main threats identified for the survival of Fogera cattle were scarcity of feed resources and interbreeding with other indigenous cattle, which are less demanding in terms of feed. Fogera cattle population has specific morphological appearance. Generally about 65.2 percent of male pure-Fogera cattle population are having large hump and large dewlap (93.5 percent) with cervico-thoracic (82.6 percent) hump position and long tail (97.8 percent), respectively. The coat pattern of male pure-Fogera cattle is dominated by the spotted coat pattern (82.6 percent) with 43.5 percent white black and 39.1 percent black white coat colour. Female Fogera cattle have medium (94.4 percent) hump size at cervico-thoracic positions (73.2 percent), large dewlap (62.7 percent) and long tail which is well below the hock (91.5 percent). The coat pattern of female pure-Fogera cattle is dominated by white spotted (80.3 percent) with 43.0 percent white black and 33.1 percent black white coat colour Most of the quantitative traits were highly significantly (P≤0.001) affected by breed type. Except horn length and horn space all of quantitative traits for both sexes of pure-Fogera cattle from on-station were significantly (P≤0.05) larger than those of the on-farm. The average linear body measurement taken on a total of 46 male pure-Fogera cattle populations were 42.68 ± 0.56 cm (mouth circumference), 16.35 ± 0.72 cm (horn length), 37.04 ± 1.16 cm (dewlap width) and 129.17 ± 1.33 cm (height at wither). The average linear body measurements for female pure-Fogera cattle were 38.23 ± 0.18 cm (mouth circumference), 13.81 ± 0.37 cm (horn length), 27.20 ± 0.42 cm (dewlap width) and 123.68 ± 0.52 cm (height at wither). The population structure were dominated by Pure-Fogera constituting 37.02 percent, Interbred with Fogera (33.71 percent) and non-Fogera (29.23 percent). The effective population size of pure-Fogera cattle was 4295, with 9016 total population. The average inbreeding level for the population was 0.012 percent. Inbreeding is at a low level and the effective population size is large. The calculated parameters indicate satisfactory genetic diversity in Fogera cattle. Milk yield, colour, power, body size and growth rate of Fogera were the most dominant traits perceived to be good by the respondents. The special quali- fication of this breed is to live at high amount of flooding areas with adapting other very challenging environment. Pure breeding of pure-Fogera, interbred with Fogera and non-Fogera type of breeds was used for breeding practice with natural mating. The Andassa Research Center established in 1964 as Fogera cattle population improving centre, but according to different source, population viability and population structure indicated that the population are not viable and highly admixture with other indigenous cattle breeds. According to this in order to improve the population status of Fogera cattle we recommended control with open-nucleus breeding strategy. So in order to minimize the risk status of this breed and conserve for the future generation any responsible agent should be given priority. Keywords: breeding strategy, characterization, Fogera cattle, inbreeding, quantitative traits francaisL’accroissement individuel des coefficients de consanguinite (ΔFi) a ete recommande comme une mesure alternative de la consanguinite du fait qu’il tient compte des differences dans la connaissance que l’on a de la genealogie des animaux individuels et vu qu’il evite la surestimation resultant d’un plus grand nombre de generations connues. L’effet de la consanguinite (F) et de la consanguinite equivalente (EF), celles-ci calculees a partir de ΔFi, sur les parametres de croissance a ete etudie dans des troupeaux de moutons Nilagiri et Sandyno. L’etude s’est basee sur des donnees conservees a la Station de Recherche pour l’Amelioration des Ovins (Sandynallah). La genealogie etait moins connue et le nombre equivalent de generations etait plus faible pour les moutons Sandyno que pour les moutons Nilagiri. Les valeurs moyennes de F et de EF pour la population Nilagiri ont ete respectivement de 2,17 et 2,44, avec les valeurs correspondantes pour les moutons Sandyno ayant ete respectivement de 0,83 et 0,84. Dans les deux populations, l’evolution suivie au cours des annees par la consanguinite montre que EF etait plus elevee dans les premieres generations, pour lesquelles moins d’information sur la genealogie etait disponible. Parmi les effets significatifs de la consanguinite, la depression de la croissance a varie de 0,04 kg pour le poids au sevrage a 0,10 kg pour le poids a un an de vie pour chaque 1 pour cent d’augmentation de la consanguinite. En general, les caracteres affectes par la consanguinite ont ete plus nombreux chez les moutons Nilagiri, pour lesquels une plus forte depression des parametres de croissance avec F qu’avec EF a ete observee. L’obtention de valeurs plus elevees pour EF que pour F dans les premieres generations des deux populations revele que EF a evite la possible surestimation du coefficient de consanguinite dans les generations recentes. La depression de la croissance par l’effet significatif de la consanguinite a ete plus forte dans la population Sandyno. Les differences decelees dans les deux populations pour ce qui est de la reponse a F et a EF et les causes possibles de ces differences sont dument discutees. Mots-cles: moutons, consanguinite, accroissement individuel de la consanguinite, depression, croissance

Comparative reproductive performance evaluation of Holstein Friesian cattle breeds in two different agro ecological conditions, Oromia region, Ethiopia

Comparative study was conducted at Alage and Ardaita Agricultural Technical and Vocational Education Training College dairy farm to evaluate the reproductive performance of Holstein Friesian (HF) and associated factors in the two farms. The data collected from 2000 to 2015 on reproductive traits ( n = 1688) were analyzed using general linear model procedures of SAS version 9.2 (SAS, 2008). The result revealed that an overall least square means and standard errors for Age at first Service (AFS), Age at first calving (AFC), Calving interval (CI), Days open (DO) and Number of services per conception were 29.70 ± 0.49 months, 39.75 ± 0.53 months, 465.76 ± 7.22 days, 188.11 ± 7.22 days and 1.31 ± 0.04, respectively. AFC was significantly influenced by agro ecology ( P P P P P P P