Response of four indigenous cattle breeds to natural tsetse and trypanosomosis challenge in the Ghibe valley of Ethiopia

A comparative study on the response of four indigenous cattle breeds of Ethiopia, namely Abigar, Horro, Sheko and Gurage, to natural challenge of trypanosomosis in the Tolley-Gullele area of the Ghibe valley has been undertaken from August 2000 until August 2004. Fifty female yearlings each of Horro, Sheko and Abigar and 31 of the Gurage were purchased from their natural habitats and introduced in to medium to high tsetse-trypanosomosis challenge area of the Ghibe valley. While the natural habitats of first three breeds are naturally infested with tsetse flies and trypanosomosis, that of the Gurage is known to be very minimal, if any, and hence the Gurage breed was used in this study as the known susceptible breed. During the study animal health, production performance and tsetse fly situation were monitored monthly. The Sheko breed has manifested very significantly (p<0.001) high overall average packed cell volume (PCV) values (25%) compared to that of Abigar (24%), Horro (23%) and Gurage (22%). It also had the lowest mean trypanosome prevalence rate of 9% against 23% of Horro, 26% of Abigar and 27% of Gurage, and the least number of Berenil treatments (1.36) compared to Abigar (4.0), Horro (4.6) and Gurage (6.7). While the Abigar manifested high sensitivity and frequent death to PCV depression, the Horro showed strong resilience to PCV depression and better response to Berenil treatment assistance. At this stage the Sheko breed was also found to be equal to the other breeds in its reproductive performance. These results need to be substantiated with further in-depth investigation including immune response, animal behavior and environmental influences.     

Comparative clinico-haematological analysis in young Zebu cattle experimentally infected with Trypanosoma vivax isolates from tsetse infested and non-tsetse infested areas of Northwest Ethiopia

Background

Ethiopia, particularly in the Northwest region, is affected by both tsetse and non-tsetse fly transmitted trypanosomosis, with significant impact on livestock productivity. The aim of this study was to determine and compare clinical findings and haematological values between experimental infections induced by Trypanosoma vivax isolates from areas of either transmission mode. Sixteen young (aged between 6 and 12 months) Zebu cattle (Bos indicus), purchased from a trypanosome-free area and confirmed to be trypanosome-negative, were randomly assigned into four groups of four animals. Groups 1, 2 and 3 were infected with an isolate from a tsetse infested or one of two isolates from a non-tsetse infested area, and group 4 was a non-infected control. All animals in the infected groups were inoculated intravenously with 2 × 10⁶ trypanosomes from donor animals. The experimental animals were monitored for eight consecutive weeks post infection for clinical signs, parasitaemia and haematological changes in packed cell volume (PCV), haemoglobin concentration (Hgb), total red blood cell (RBC) and white blood cell (WBC) counts, differential WBC count and blood indices (mean corpuscular volume [MCV], mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration).

Results

Infection was characterized by reduced feed intake, weakness, pyrexia, parasitaemia, rough hair coat, enlarged prescapular lymph nodes, lacrimation, weight loss, pallor mucus membrane and dehydration. Body weight loss in all infected groups was significantly higher than in the non-infected control. Similarly, body weight loss was higher (P < 0.001) in animals infected with the tsetse infested isolate than with the non-tsetse infested isolates. The mean PCV, Hgb, total RBC and WBC counts were lower (P < 0.001), and mean MCV was higher (P = 0.01) in all infected groups than in non-infected control animals at different time points during the study period. Except for minor variations in haematological values, the overall changes were similar in all infected groups.

Conclusion

Clinical signs and significant reduction in haematological values in the infected groups indicated the pathogenicity of the T. vivax parasites. Pathogenicity of T. vivax from the non-tsetse infested area can be considered as nearly as important as that of its counterpart derived from the tsetse infested area.     

Community-based alternative breeding plans for indigenous sheep breeds in four agro-ecological zones of Ethiopia

Based on the results of participatory approaches to define traits in the breeding objectives, four scenarios of ram selection and ram use were compared via deterministic modelling of breeding plans for community-based sheep breeding programmes in four diverse agro-ecological regions of Ethiopia. The regions (and production systems) were Afar (pastoral/agro-pastoral), Bonga and Horro (both mixed crop-livestock) and Menz (sheep-barley). The schemes or scenarios differed in terms of selection intensity and duration of ram use. The predicted genetic gains per year in yearling weight (kilograms) were comparable across the schemes but differed among the breeds and ranged from 0.399 to 0.440 in Afar, 0.813 to 0.894 in Bonga, 0.850 to 0.940 in Horro, and 0.616 to 0.699 in Menz. The genetic gains per year in number of lambs born per ewe bred ranged from 0.009 to 0.010 in both Bonga and Horro. The predicted genetic gain in the proportion of lambs weaned per ewe joined was nearly comparable in all breeds ranging from 0.008 to 0.011. The genetic gain per year in milk yield of Afar breed was in the order of 0.018 to 0.020 kg, while the genetic gain per generation for greasy fleece weight (kg) ranged from 0.016 to 0.024 in Menz. Generally, strong selection and shorter duration of ram use for breeding were the preferred options. The expected genetic gains are satisfactory but largely rely on accurate and continuous pedigree and performance recording.     

Trypanosomosis and phenotypic features of four indigenous cattle breeds in an Ethiopian field study

We conducted a two-part study in the native home areas of four cattle breeds, Abigar, Gurage, Horro and Sheko, in south-western Ethiopia. The first part of the study investigated livestock keeper knowledge about trypanosomosis and trypanotolerance. For each breed 60 livestock keepers were interviewed, resulting in a total of 240 interviews. The second part of the study focused on biological evidence for trypanotolerance. Blood samples of about 100 head of cattle per breed were collected during peak trypanosomosis challenge period and analyzed for packed cell volume (PCV) and parasitaemia. In addition individual body measurements of the sampled animals were taken and the keepers provided some information regarding their animals. Livestock keeper interviews revealed that trypanosomosis was considered a major problem in all areas (95-100%). Almost all Abigar livestock keepers knew how trypanosomosis is transmitted, whereas only 34-52% of the keepers of the other breeds had that knowledge. Most Sheko keepers (75%) knew of trypanotolerance and claimed to have trypanotolerant animals in their own herds. Among the other three breeds the knowledge of trypanotolerance was much less (8-18%). A majority of the keepers were interested in purchasing trypanotolerant animals. PCV was highest among Horro (26.2) and Sheko (25.1) cattle whereas Abigar had the lowest PCV (20.0). Sheko were least infected by trypanosomes (6%) and had the lowest number of trypanocidal treatments per year (1 treatment/animal and year). Abigar cattle were most infected (23%) followed by Gurage (20%) and Horro (17%). Gurage had by far the highest number of treatments per animal and year (24). There were large differences between the number of cattle perceived by the keepers to be infected, and the number detected from blood sampled, among Abigar, Gurage and Horro. Sheko livestock keepers were better at correctly diagnosing trypanosomosis in their animals. It is concluded that Sheko cattle have higher trypanotolerance attributes of the breeds investigated and a better use of this breed could improve cattle health and household welfare in tsetse-infested areas.     

Maintaining zebu maure cattle in a tsetse infested area of Mali

Summary A study was initiated to evaluate two trypanocidal drugs, the prophylactic isometamidium chloride (Trypamidium) and the curative diminazene aceturate (Berenil) as to their potential for long-term maintenance of zebu cattle in a tsetse infested area of Mali. Trypamidium was administered quarterly and Berenil was administered only as animals were found to be positive for trypanosomes. During the 21-month study trypanosomiasis was the most frequently encountered disease in the cattle in the Berenil treatment group with an average of 5·5 reinfections. The predominant trypanosome species encountered wasTrypanosoma vivax and the most important vector wasGlossina palpalis gambiensis. The results indicate that, even though the direct costs for drugs under the two maintenance regimens were almost identical, the use of Trypamidium resulted in a significantly greater annual weight gain, prevented death loss due to trypanosomiasis and resulted in a herd with a greater market value.

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Mantenimiento De Ganado Cebu Maure En Una Zona Infestada Por Moscas Tsetse

Resumen Se evaluaron dos drogas contra la tripanosomiasis en Mali. Una profiláctica, Trypamidium, y la otra curativa, Berenil. El Trypamidium (cloruro de isometamidium) se aplicó cada tres meses y el Berenil solo cuando los animales se encontraron positivos. Durante los 21 meses del estudio, tripanosomiasis fue la enfermedad más comunmente encontrada en el grupo tratado con Berenil, con un promedio de reinfección de 5·5. Los tripanosomas predominantes fueron elTrypanosoma vivax y el vector más importante laGlossina palpalis gambiensis. Los resultados del estudio indican que aunque el costo de las drogas para los dos grupos fue casi idéntico, el uso del Trypamidium resultó en un aumento significativo de peso de los animales tratados, previniendo muertes por tripanosomiasis.

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Maintien De Bovins Zebu Maure Dans Une Region Du Mali Infestee De Glossines

Résumé Une étude fut entreprise pour évaluer deux médicaments trypanocides, le chlorure d'isometamidium (Trypamidium) à titre préventif et l'acéturate de diminazène (Bérénil) à titre curatif, en ce qui concerne leur valeur potentielle pour le maintien à long terme de bovins zébu dans une zone infestée de glossines au Mali. Le Trypamidium était infecté tous les trois mois et le Bérénil seulement lorsque les animaux s'avéraient porteurs de trypanosomes. Pendant les 21 mois de l'étude, la trypanosomose a été la maladie la plus fréquemment rencontrée dans le groupe traité au Bérénil avec en moyenne 5,5 réinfections. L'espèce trypanosomienne prédominante étaitT. vivax et le vecteur le plus importantGlossina palpalis gambiensis. Les résultats montrent que, bien que le coût direct des médicaments dans les deux régimes de maintien ait été presque identique, l'emploi du Trypamidium a engendré un gain de poids annuel significativement plus grand, a prévenu les mortalités dues à la trypanosomose et conduit à un troupeau de valeur marchande plus élevée.

     

The successful use of work oxen in agricultural development of tsetse infested land in Ethiopia

Summary For the past five years a herd of work oxen, now numbering some 450 individuals, has been maintained under the protection of trypanocidal drugs on a settlement scheme in an area of western Ethiopia infested with tsetse. This paper describes the environmental conditions and the epizootiology of trypanosomiasis in the oxen and in the vector, Glossina morsitans. It is concluded that with the strategic use of drugs, oxen can be kept alive and perform useful agricultural work, in areas of high tsetse challenge, provided reasonable standards of veterinary supervision and management are maintained.

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El Uso Exitoso De Bueyes En El Desarrollo Agricola De Tierras Infestadas De Tsetse En Etiopia

Resumen Se ha mantenido un número aproximado de 450 bueyes, bajo el efecto de drogas contra la tripanosomiasis (quimioprofiláxis), en una concentración rural bajo el flagelo de la mosca tsetse, en el oeste de Etiopía. Este trabajo describe las condiciones ambientales y epizootiológicas de la tripanosomiasis en bueyes y vectores (Glossina morsitans). Se concluye, que el uso estrátegico de drogas preventivas proteje a los bueyes en áreas infestadas por tsetse, siempre y cuando se mantenga una supervisión veterinaria y de manejo animal aceptable.

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Succes De L'Utilisation Des Boeufs De Travail Dans Le Developpement De L'Agriculture D'Une Region D'Ethiopie Infestee De Tse-Tse

Résume Au cours des cinq dernières années, un troupeau de boeufs de travail, maintenant au nombre de quelque 450 têtes, a été maintenu sous protection de produits trypanocides à l'occasion d'un essai d'implantation du bétail dans une région de l'Ouest de l'Ethiopie infestée de tsé-tsé. Ce document traite des conditions de l'environnement, de l'épizootologie des trypanosomoses du bétail ainsi que du vecteur:Glossina morsitans. La conclusion est qu'avec l'utilisation des trypanocides, les boeufs peuvent vivre et donner les performances habituelles au niveau des travaux agricoles dans les zones à haute infestation glossinaire pourvu du'un encadrement vétérinaire et de gestion suffisant soit maintenu.

     

Maintaining zebu Maure cattle in a tsetse infested area of Mali. II. Epidemiological considerations

Summary Scheduled monitoring of tsetse and other biting flies at Tienfala Forest, Republic of Mali from December 1979 until June 1981 yielded more than 14,500 specimens. Comparisons of the monthly totals of tsetse and other biting flies with the monthly incidence of bovine trypanosomiasis in sentinel cattle suggested that biological transmission by a single riverine species of tsetse,Glossina palpalis gambiensis, accounted for most if not all disease transmission at the study site. The data obtained also suggested that human decisions had contributed to the magnitude if not the degree of the disease problem at the study site and that viable solutions to the disease problem exist.

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Resumen En un estudio programado de moscas tsetse y otras moscas picadoras en el bosque de Tienfala, República de Malí, de diciembre 1979 hasta junio 1981, se colectaron 14.500 especímenes. La comparación de los totales de tsetse y otras moscas picadoras con la incidencia mensual de tripanosomiasis en ganado centinela, sugiere que la transmisión biológica de la enfermedad, casi en su totalidad, esta ligada a laGlossina palpalis gambiensis. Los datos obtenidos tambien sugieren que las decisiones humanas han contribuido a la magnitud del problema en el sitio de estudio, y que existen soluciones al problema planteado.

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Résumé Le suivi planifié des tsé-tsé et d’autres mouches piqueusus dans la forêt de Tienfala, République du Mali, de décembre 1979 à juin 1981 a permis la récolte de plus de 14 500 échantillons. La comparaison des captures mensuelles de tsé-tsé et d’autres mouches piqueuses avec l’incidence mensuelle de la trypanosomose sur des bovins sentinelles permet de suggérer que la transmission biologique par une seule espèce de glossine riveraine,Glossina palpalis gambiensis, explique en grande partie, si ce n’est en totalité la transmission de la maladie dans le site d’étude. Les données enregistrées suggérent également que les décisions humaines ont contribué à l’ampleur, si ce n’est au degré, des problèmes pathologiques dans le site d’étude, mais aussi que des solutions existent pour le résoudre.

     

Non-conventional indigenous mineral supplements used for cattle feeding in the pastoral rangelands of Ethiopia

Salt licks, soil licks and well waters from various parts of Ethiopia used by pastoral nomads for cattle feeding were sampled and assessed for composition and quality. Most of the licks were alkaline and had low solubility both in water and acid. All the salt licks and some of the soil licks contained a considerable amount of sodium and these could constitute a reasonable and cheap source of the element. Except for iron which had a concentration in most of the supplements much in excess of requirements the rest of the essential elements assayed occurred in the licks in quantities too small to satisfy estimated requirements of cattle. This particularly applied to phosphorus and copper which are below critical ranges in the pastures of the region. The excessive amount of Fe could have an antagonistic effect on P and Cu. The well waters contained elements in safe limits but water from Medecho contained total soluble salts exceeding safe limits. Except as sources of Na the licks especially soil licks can be considered unsatisfactory sources of other essential minerals. The widespread use of soil licks in the region should be discouraged until thorough assessment has been done since these licks may have deleterious direct and indirect effects on performance of cattle.     

Use of indigenous breeds of cattle and their crosses in Uganda as recipients for importedBos taurus embryos

Summary In July 1991, 29 frozen imported Holstein Friesian embryos were transferred into synchronised recipients in Uganda. Recipient cows and heifers from indigenous breeds of cattle and their crosses in Uganda were used. The project resultéd in 17 pregnancies confirmed by rectal palpation at 8 weeks. Twelve live calves were born of which 7 were heifers and 5 were bulls. One heifer calf died at one month of age from East Coast fever. One pregnant recipient died of East Coast fever 2 months before calving. Two recipients aborted in late gestation as a result of trauma incurred during fighting. Two calves were lost as a result of dystocia. The transfer work and calvings were performed at 3 different farms under varying conditions. The 11 surviving animals are being reared on a single unit where growth rates and performance data are being recorded.

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El Uso De Razas De Ganado Criollo Y Sus Cruces En Uganda Como Recipientes De EmbrionesBos Taurus Importados

Resumen En julio de 1991, se transfirieron 29 embriones importados de Holstein Friesian, en recipientes sincronizadas en Uganda fueron usadas como recipentes vacas y vaquillas de razas criollas y sus cruces. El proyecto resultó en 17 preñeces confirmadas mediante palpación rectal a las ocho semanas. Doce terneros nacieron, de los cuales siete fueron hembras y cinco fueron machos. Una de las terneras murió al mes de nacida de Fiebre de la Costa Este. Una de las recipientes preñadas murió la de la misma enfermedad dos meses antes del parto. Dos recipientes abortaron en el tercer tercio de la gestación, debido a traumas al pelear. Dos neonatos murieron durante partos distócicos. La transferencia se llevó a cabo en tres granjas differentes, bajo condiciones distintas. Los once sobrevivientes estan criándose en una sóla unidad, donde se estan registrando las tasas de crecimiento y otros parámetros.

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Utilisation En Ouganda De Races Bovines Locales Et De Leurs Croisements Comme Receveuses D'embryons Importes DeBos Taurus

Résumé En juillet 1991, 29 embryons Frison × Holstein importés ont été transférés à des vaches et génisses receveuses synchronisées appartenant à des races locales et croisées en Ouganda. Il en a résulté 17 gestations confirmées par palpation rectale à 8 semaines. Douze veaux vivants sont nés dont 7 étaient des femelles et 5 des mâles. Une velle est morte de theileriose à un mois, ainsi qu'une vache receveuse 2 mois après vêlage. Deux receveuses ont avorté en fin de gestation à cause d'un traumatisme provoqué durant une lutte. Deux veaux ont été perdus à la suite d'une dystocie. Le transfert d'embryons et les vêlages ont été réalisés dans 3 fermes différentes dans des conditions variées. Les 11 animaux survivants ont été élevés dans un seul lieu où leurs taux de croissance et les données de performance ont été enregistrés.

     

Risk factors for brucellosis in indigenous cattle reared in livestock-wildlife interface areas of Zambia

Transmission of Mycobacterium avium subsp. paratuberculosis (Map) to susceptible animals is primarily considered to occur via faeces and milk originating from infectious cows. However, studies of factors resulting in increased transmission of Map are difficult to perform due to a long and unpredictable incubation period and inaccurate diagnostic tests. A multi-level Bayesian mixture model has been shown to predict the infection status of an individual cow more precisely than traditional cut-off based methods used for interpretation of diagnostic test-information, thereby increasing the precision of the diagnostic information.

The objective of our study was to assess management-related risk factors for within-herd transmission of Map. Management-related risk factors were recorded in 97 Danish dairy herds. Twenty-six months following that recording, the antibody status of all lactating cows (n = 7410) in the same herds was measured by the use of an ELISA. A multi-level Bayesian mixture model was used to assess the association between the probability of infection of individual cows and 41 herd-level management-related risk factors using univariable analyses. In this model, the continuous OD value was used to estimate the probability of infection, corrected for known animal covariates and laboratory factors. The statistical significance of the potential risk factors was assessed by calculating odds ratios and their 95% credibility posterior intervals.

Four significant risk factors were identified: housing of cows in bed stalls compared to housing in tie stalls; low level of hygiene in the feeding area of calving areas; low amounts of straw in the bedding of the calving area; high animal density among young stock >12 months of age. Surprisingly, the hygiene level in the calving area was not found to affect the odds of infection.     

Assessment of impacts of tsetse and trypanosomosis control measures on cattle herd composition and performance in southern region, Ethiopia

This study was conducted to assess the impact of tsetse and trypanosomosis control measures on cattle herd size and composition, herd dynamics, and milk yield in Wolaita and Gamogofa Zones, southern Ethiopia. The study showed that the average number of cattle herd size in tsetse challenged areas was significantly higher than those in tsetse-controlled areas. The number of non-pregnant dry cows, bulls and oxen were significantly higher in tsetse challenged areas than the other two study areas. The rate of cattle addition to and disposal from the herd were significantly higher in tsetse challenged areas. Cows in Southern Tsetse Eradication Project (STEP) and community tsetse controlled areas were able to give 26-27?%, 25-29?% and 17-21?% more daily milk yield at the beginning, middle and end of lactation, respectively, than those in tsetse-challenged areas. In addition, cows in STEP and community tsetse controlled areas had lactation length longer by 1.20 to 1.35?months; age at first calving was shorter by 5.30 to 5.10?months; and calving interval was shorter by 4.20 to 3.20?months than cows in tsetse-challenged area, respectively. Hence, tsetse and trypanosomosis control both by the community and project would play key role in the improvement of cattle productivity.     

Statistical analysis of individual assignment tests among four cattle breeds using fifteen STR loci

Assignment tests based on multilocus genotypes are becoming increasingly important to certify quality and origin of livestock products and assure food safety and authenticity. The purpose of this study was to determine the potential of microsatellites (STR) for determining the breed origin of beef products among cattle breeds present in the market. We typed 19 STR in 269 animals from 4 cattle breeds. Based on Wright's F-statistics, 4 loci were discarded, and the remaining 15 loci (FIT = 0.101, FST = 0.089, and FIS = 0.013) were used to compute the likelihood that each multilocus genotype of the total sample was drawn from its true breed instead of another breed. To avoid occurrence of zero likelihood when one or more alleles were missing from a tested breed, sample allele frequencies were estimated assuming uniform prior distributions. Log-likelihood ratio [log(LR)] distributions of the individual assignments were determined for all possible breed contrasts, and their means and SD were used to infer the true-positive and false-positive rates at several values of the log(LR). The posterior probability that the animals of a presumed breed were actually drawn from that breed instead of any another breed was then calculated. Given an observed value of log(LR) > 0 and assuming equal priors, these probabilities were > 99.5% in 10 of 12 possible breed contrasts. For the 2 most closely related breeds (FST = 0.041), this probability was 96.3%, and the probability of excluding the origin of an animal from an alleged breed when it was actually derived from another breed was similar.     

Host resistance to ticks (ACARI: Ixodidae) in different breeds of cattle at Bako,Ethiopia

Summary European cattle breeds are being introduced into Ethiopia in an effort to improve the productivity of indigenous breeds. The Ethiopian cattle breeds Horro and Boran were compared for tick burdens with their crosses with Friesian, Jersey and Simmental. Horro animals had the lowest tick burdens and the Horro × Friesian the highest. Adaptation to their environment and long-term natural selection for tick resistance in Horro cattle is the most likely explanation.Repeatability of tick burdens in all animals considered as one herd were only statistically significant forBoophilus decoloratus, the most abundant tick species. Statistically significant correlations between burdens of femaleB. decoloratus, Amblyomma cohaerens andRhipicephalus praetextatus were observed and the addition of the males resulted in all inter-species correlations becoming significant.Care should be taken when crossing Ethiopian with more productive European cattle breeds in order not to lower their tick and disease resistance.

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Resistencia En Diferentes Razas De Ganado Vacuno A Garrapatas (ACARI: Ixodidae) En Bako Ethiopia

Resumen Ganado de raza europea estan siendo introducidos en Etiopia en un esfuerzo de mejorar la produccion de las razas indigenas. Las razas etiopes Horro y Boran fueron comparadas por sus cargas de garrapatas con sus cruzas con Friesian, Jersey y Simmental. El ganado Horro mostró las cargas mas bajas y las cruzas con Friesian las mas altas. La adaptacion al medio ambiente y la seleccion a largo plazo de este tipo de ganado es la explicacion mas probable de los resultados.La repitabilidad de las cargas de garrapatas en todos los animales agrupados en un rebaño fueron estadistícamente significativas paraB. decoloratus, la garrapata mas abundante. Correlaciones estadísticamente significativas entre las cargas de hembras deBoophilus decoloratus, Amblyomma cohaerens y Rhipicephalus praetextatus fueron observadas y la adicion de los machos resulto en que todas las correlaciones entre especies se volvieron significativas.Se debe tener cuidado cuando las razas de ganado etiopes se cruzan con las mas productivas razas europeas para no reducir su resistencia a las garrapatas y enfermedades.

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Resistance De L'hote Aux Tiques (ACARI: Ixodidae) Chez Differentes Races De Betail A Bako, Ethiopie

Résumé Des races bovines européennes sont actuellement introduites en Éthiopie dans le but d'accroître la productivité des races indigènes. Ainsi, les races Horro et Boran ont été comparées du point de vue du taux d'infestation par les tiques avec les produits de levi croisement avec les races Frisonne, Jersiaise et Simmenthal. Les animaux de race Horro avaient le taux d'infestation le plus bas et le croisement Horro × Frisonne le taux le plus elevé. L'explication la plus vraisemblable de ces résultats est l'adaptation du bétail Horro à son environnement en meme temps qu'une sélection naturelle de longue date à la résistance aux tiques. La répétabilité de la pression ixodienne chez tous les animaux considérés comme formant un troupeau unique, n'a été statistiquement significative que pourBoophilus decoloratus, espèce la plus abondante. Les auteurs ont observé des corrélations statistiquement significatives entre les taux de charge relatifs aux femelles deBoophilus decoloratus, Amblyomma cohaerens etRhipicephalus praetextatus. La prise en compte des mâles a eu pour effet de rendre significative toutes les corrélations inter-espèces. Il faut donc prendre des précautions lors de croisement du bétail éthiopien avec des races européennes plus productives afin de ne pas diminuer leur résistance aux tiques et aux maladies.

     

Genetic diversity in Swiss cattle breeds

Introduction First attempts at establishing the genetic relationships among cattle populations relied on archeological evidence (Epstein 1971; Epstein and Mason 1984) and protein polymorphisms (Baker and Manwell 1980, 1991). Loftus et al. (1994) examined mitochondrial DNA to determine the divergence time between Bos taurus and Bos indicus. Today most studies on genetic diversity are based on microsatellite analysis (Litt and Luty 1989; Tautz 1989; Weber and May 1989). Microsatellites were used in, e.g. man (Bowcock et al. 1994), canids (Roy et al. 1994; Fredholm and Winter ø ; 1995) and sheep (Buchanan et al. 1994). Recent studies in cattle are also microsatellite based (e.g. Machugh et al. 1994; Ciampolini et al. 1995; Moazami -Goudarzi et al. 1997) and aim at facilitating the development of management programs for endangered breeds (FAO 1981). Our microsatellite-based investigation on the genetic diversity between and within Swiss cattle breeds included Original Swiss Brown, purebred Simmental, Holstein, Hérens and Evolènard. Previous studies in Swiss breeds made use of blood group systems (Reuse 1969), serum transferrin and hemoglobin (Krummen 1964), amylase (Buser 1970) and carboanhydrases (Kä ;stli et al. 1980). The Hérens breed is endemic to the canton of Wallis. The Evolènard, which are very few in numbers and restricted to a single valley in the canton of Wallis, are phenotypically very similar to the Hérens with the exception of the coat colour. In the Aosta valley (Italy) which borders the canton of Wallis these two breeds find their counterparts. The phenotype of the Aosta Chestnut fits the Hérens and the Aosta Black Pied fits the Evolènard. The Holstein breed replaced the Fribourg breed which was a colour variant of the purebred Simmental breed (Engeler et al. 1961) and is now extinct. The Original Swiss Brown and the purebred Simmental are endemic to Switzerland.     

Analysis of genetic and cultural conservation value of three indigenous Croatian cattle breeds in a local and global context

It is widely accepted that autochthonous cattle breeds can be important genetic resources for unforeseeable environmental conditions in the future. Apart from that, they often represent local culture and tradition and thus assist in the awareness of ethnic identity of a country. In Croatia, there are only three indigenous cattle breeds, Croatian Bu?a, Slavonian Syrmian Podolian and Istrian Cattle. All of them are threatened but specialized in a particular habitat and production system. We analysed 93 microsatellites in 51 animals of each breed to get thorough information about genetic diversity and population structure. We further set them within an existing frame of additional 16 breeds that have been genotyped for the same marker set and cover a geographical area from the domestication centre near Anatolia, through the Balkan and alpine regions, to the north‐west of Europe. The cultural value was evaluated regarding the role in landscape, gastronomy, folklore and handicraft. The overall results recognize Croatian Bu?a being partly admixed but harbouring an enormous genetic diversity comparable with other traditional unselected Bu?a breeds in the Anatolian and Balkan areas. The Podolian cattle showed the lowest genetic diversity at the highest genetic distance to all remaining breeds but are playing an important role as part of the cultural landscape and thus contribute to the tourist industry. The genetic diversity of the Istrian cattle was found in the middle range of this study. It is already included in the tourist industry as a local food speciality. Current and future conservation strategies are discussed.     

二、奶牛的品种特征

1、世界奶牛品种 世界奶牛品种主要有:荷斯坦牛(主要是黑白花牛,也有红白花牛)、娟姗牛(毛色为淡黄色或黄褐色)、更赛牛(毛色为黄褐色或褐黄色,带有白斑,腹下、四肢下部、尾稍多为白色)、爱尔夏牛(毛色为白色与桃红或深红相间,头部额至鼻梁、腹下、四肢下部及尾稍多为白色)。 2、我国奶牛品种