Indigenous cattle genetic resources, their husbandry practices and breeding objectives in North-western Ethiopia

Phenotypic as well as genetic characterization of indigenous livestock genetic resources provides the basis for any livestock development intervention. However, in Ethiopia, little attention has been given to identify, characterize and conserve the diversity of the various livestock breed types. It is with this understanding that the present study was initiated and conducted in North and South Gondar zones with the view to characterize indigenous cattle breeds/population, identify.’ the main problems, and outline intervention for genetic improvement of the identified breed populations based on farmer trait preferences. Six sample sites were selected based on initial rapid survey conducted at the start of the study. Three defferent survey techniques; namely focus group discussion, administration of semi—structures questionnaires on husbandiy practices and indicative production and reproduction performance, and phenotypic distance measurements were employed. Findings of the focus group revealed that each of the cattle breed types of the respective study sites were markedly dfferent in phenotypic characteristics. Findings from the semi-structured interviews revealed that the indigenous cattle breed types are multipurpose production and input functions, adapted to wide range of environments, and managed under traditional and largely subsistent mode of production. Furthermore, farmers were interested to improve their local genotypes and suggested different target traits for improvement. Based on these farmers traits preferences village breeding scheme is proposed through the provision of genetically selected breeding bulls. Overall lactation length, and average daily milk yield of this study are higher than national average figures of 1.17 litre per day and 6.33 months, respectively. Reported figures for age at first calving from the different study sites have been found longer than the overall estimated value for Bos indicus. The over all mean value of 14.5 years for longevity exceeds the figure for most African cattle of 10 to 13 years. The reported critical constraints of traditional cattle production were seasonal feed shortage, high disease challenges, weak infrastructure, lack or shortage of working capital, weak cattle markets and cattle raiding. For a phenotypic distance study a total of 1623 sample animals were recorded and ident ified by sex, dentition, and some discrete variables. Linear measurements on 12 traits were taken from 708 female and 146 male mature animals. Categorical body forms and types were recorded from these as well as the rest of the sample animals too. The general linear model was used to analyse variance on the 12 quantitative traits between sites for males and females separately. Tukey’s multiple comparison test showed that each of the 12 quantitative traits were highly significant (p<. 0001). The model filled for the male populations explained variation ranging from 35.2 to 67.2%, whereas the model explained 34.7 to 56.1% of the variation in the female population. For the categorical variables chi -square test was employed, and found, for most of the variables, highly significant (p<.0001,). Following this other statistics derived from the Pearson chi-square were used to measure the level of association. Furthermore, multiple mean comparisons were also made for these categorical variables using Bonferroni ‘s correction. Mulltivariate analyses were applied separately to females and males. The resultant discriminant function resulted in a hit ratio of 73.8 and 80.5% for female and male populations, respectively. Canonical discrimninant analysis for females and males showed highly significant (p<.0001) Mahalanobis distances between sites. The multivariate test for differences between the sites is also highly significant (p<.0001 ) in all of the four types of multivariate tests. The step-wise discriminant analysis for both male and female sample populations showed that all variables had highly significant (P<. 0001) contribution for explaining the variation in the model. Trees/phenogram constructed separately for male and female populations revealed the existence of four distinct clusters in both sexess. The tree topologies as well as the branch length somehow differ between the sexes. The reliability of the phenogram/dendrogram was tested by the bootstrap method and the result showed that both trees were supported by the high to moderate bootstrap values. In general both the categorical and quantitative variables have dfferentiated the sample populations in, to four to six different classes. Thus, indigenous cattle populations under traditional management in North Gondar as well as parts of South Gondar zones are heterogomzous populations divisible into distinct breed types based on phenotypic distance of some quantitative traits and analysis of qualitative variables

The Mahibere-Silassie composite: A new cattle breed type in north-western Ethiopia

This study was conducted to identify and describe the cattle genetic resources in South and North Wollo zones of Amhara Region, North Eastern Ethiopia based on their descriptive morphological characteristics. A total of seven sampling sites were selected based on the information obtained about the distributions of cattle types in the area. Quantitative and qualitative characters were taken from 1,321 mature animals and subjected to multivariate analysis of variance. The results showed significant (p<0.0001) differences in quantitative traits between sites for both female and male populations. Chi-square tests also showed very strong (p<0.0001) associations between qualitative variables and sites. Horn length and navel flap were the best discriminating variables from quantitative and qualitative variables, respectively. The canonical discriminant analysis applied to calculate the Mahalanobis’ distances between sites using quantitative variables showed significant (p<0.0001) distances between the sites. The maximum and minimum distances were obtained between Were-Ilu and Afar sites (46.96) and Gimba and Kutaber sites (0.49) for female populations. The validity of discriminant analysis was assessed by reclassification statistics putting equal a priori probability levels for all sample populations and the results showed the overall classification rate (hit rate) was 55.2% and 60.1% for female and male populations, respectively. Sample populations from Kobo and Afar were highly divergent from other cattle populations in the other sites. Based on results of cluster analysis, it is concluded that, morphologically, at least three distinct cattle types are found in the area, namely the Wollo Highland Zebu (comprising of cattle from Gimba, Were-Ilu and Kutaber sites), the Raya Sanga (Raya/Kobo site) and the Afar Sanga (Afar site). The fourth cluster is considered as intermediate cattle that are found in the adjacent areas of Sanga and highland zebu cattle types. The Wollo highland zebu cattle type comprises compact animals with short legs, ears and horns with coat color being dominantly black. On the other hand, the Raya and Afar Sanga cattle types found in lower altitude areas have longer legs, ears and horns reaching to maximum measurements for the Afar cattl

Assessment of physiological adaptation of indigenous and crossbred cattle to hypoxic environment in Ethiopia

High altitude pulmonary hypertension is common in cattle at high altitude areas. The extent of proneness, epidemiology, and genetics of the disease is not, however, known in Ethiopia where a large proportion of the area is at altitudes above 2700 m. To learn about adaptive characteristics of cattle towards altitude, a study of physiological adaptation, measured via pulmonary artery pressure (PAP) score from 218, hematological parameters from 672, and arterial oxygen saturation predicted by pulse oximeter from 241 animals was conducted in North Western Ethiopia. Local breeds and their crosses with Holstein Friesian and Jersey were investigated. Results showed that all PAP scores (21 to 47 mm Hg) fall under low to moderate risks. No sign of pulmonary hypertension was observed among all the cattle genotypes. Crosses of the local cattle with Holstein Friesian and Jersey were not more prone to the disease than local cattle. A statistically significant (P 0.05) in % SaO2. We report a new clinically relevant range of oxygen saturation, ≥ 68%, for the high altitude cattle which is far below the threshold value usually assumed for temperate cattle, > 80%. Hematological values of the studied genotypes lie within normal ranges set for temperate breeds despite suffering from heavy parasitic infestation. The significantly greater (P < 0.001) red blood cell counts, hemoglobin and hematocrit values of Simien cattle measured at 3500 m compared to the other genotypes in this study were not different when compared to other breeds studied elsewhere at lower altitudes and around sea level. Simien cattle probably have unique adaptations of oxygen uptake and delivery that result in the absence of hypoxemic stimulus to increase red blood cell production and hemoglobin concentration. We concluded that indigenous cattle of the Simien Plateau of Ethiopia are adapted genetically to high altitude by largely eliminating the hypoxic pulmonary vasoconstrictor response. The good adaptation is most likely due to natural selection. Understanding this adaptation model requires investigation of the biological mechanisms and the underlying genetics

Genetic parameters for reproduction traits and correlation with pre weaning growth traits of Fogera cattle at Metekel ranch, north west Ethiopia

The objective of this study was to estimate genetic parameters of reproduction traits of pure Fogera cattle at Metekel Ranch. Metekel cattle Breeding and Improvement Ranch has so far been engaged in maintenance of Fogera cattle population outside their adapted environment (ex-situ conservation). The breeding program has two components: selection and crossbreeding. The establishment of the pure breed unit is meant for the improvement of the Fogera breed and for providing heifers to cross- breed to exotic dairy sires (by Artificial insemination). In cross breeding program; crossbred animals are produced through artificial insemination of Fogera cows with Friesian semen. Around three to six months of pregnancy, the F1 cross heifers are sold to farmers for milk production (Melaku et al., 2011a, b). Very recently the ranch started to distribute non pregnant F1 cross heifers. WOMBAT software was used to estimate genetic parameters. The variance components and heritability were estimated using a Uni-variate animal model using four models which fitted direct additive, dam genetic and permanent environmental effect as a random effect and the fixed effects (year, season, sex and parity). Parameter of age at first calving (AFC) were estimated using Model 1 (Y= Xb + Z1a + e), Model2 (Y= Xb + Z1a + Z3c + e), Model3 (Y= Xb + Z1a + Z2m + e (cova, m = 0), and Model4 (Y= Xb + Z1a + Z2m + Z3c + e (cova, m = 0) whereas parameters of reproductive traits including gestation length (GL), calving interval (CI) and days open (DO) were estimated using model 2 and 4 which fit permanent environmental effect due to repeated records per cow. Correlations (genetic and phenotypic) among the different traits were estimated from bi--variate analysis by using model 1 for growth traits and AFC and model 2 to estimate the correlation between CI, GL and DO and birth weight (BWT) and GL. Correlation between birth weight and gestation length were estimated by treating gestation length as a trait of calf. Due to record limitation correlation between AFC with other reproductive traits were not estimated. Estimates of direct heritability of reproductive performance traits from the best model were 0.003 ± 0.05 for AFC, 0.00 ± 0.03 for GL and CI and 0.013 ± 0.03 for DO. The phenotypic correlations between reproductive traits were 0.003 ± 0.034 for CI and GL, 0.37 ± 0.041 for CI and DO and 0.167 ± 0.036 for DO and GL and the genetic correlation between reproductive traits ranged from -0.94 ± 0.2 for DO and GL to 0.83 ± 0.579 for CI and DO. Genetic correlation between growth and AFC ranged from 0.77 ± 0.24 for BWT and AFC to 0.87 ± 0.03 for pre-weaning average daily gain (PADG) and AFC. The phenotypic and genetic correlations between BWT and GL were 0.03 ± 0.05 and -0.84 ± 0.013 respectively. The results of genetic correlation between considered traits was ranged from moderate to high and it indicates that selection for one trait would have a significant effect on the other traits not considered however selection must be done with caution. The heritability estimates confirmed the presence of high environmental effect among the study population and it masks the individual animal genetic difference. Given the low heritability estimates obtained, effective improvement in reproduction performance of Fogera cattle could be achieved by improving the production conditions and through crossbreeding