Susceptibility of the namchi and kapsiki cattle of cameroon to trypanosome infection

Summary Two indigenous Cameroonian taurine cattle breeds (Namchi and Kapsiki) were evaluated for trypanosusceptibility following inoculation withTrypanosoma congolense. The degree of zebu ancestry in the experimental animals was assessed using 6 microsatellite markers which are known to have certain unique alleles which are diagnostic ofBos indicus genetic input. Their response to the infection was compared to that of known trypanotolerant (N’Dama) and trypanosusceptible (Ngaoundere Gudali) cattle. The Namchi and the N’Dama controlled the development and severity of anaemia and parasitaemia better than the Kapsiki and the Gudali. For these parameters, there was no significant difference between the N’Dama and Namchi nor between the Kapsiki and Gudali. Similarly, weight loss showed significant breed variation. The N’Dama lost the least weight and the Kapsiki the most. Zebu introgression in the Namchi was comparable to that in the N’Dama while that of the Kapsiki breed was higher, indicating a high level of cross breeding. From the results, the Namchi are considered trypanotolerant while the Kapsiki are trypanosusceptible. The potential exploitation of the indigenous Namchi cattle is discussed.

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Susceptibilidad Del Ganado Vacuno De Raza Namchi Y Kapsiki De Camerun A La Tripanosomiasis

Resumen Dos razas de ganado vacuno de Camerún pertenecientes al tronco europeo (Namchi y Kapsiki) fueron evaluadas para determinar su tripanosusceptibilidad tras ser inoculadas conTrypanosoma congolense. El porcentaje de sangre cebú en los animales experimentales se evaluó mediante microsatélites que contienen alelos específicos deBos indicus. La respuesta de los animales a la infestación se comparó con la de animales tripanotolerantes (N’Dama) y tripanosusceptibles (Ngaoundere Gudali). Los animales de raza Namchi y N’Dama controlaron el desarrollo y severidad de la anemia y de la parasitemia mejor que los animales de raza Kapsiki y Gudali. En relación a estos parámetros no hubo diferencias significativas entre las razas N’Dama y Namchi por una parte ni tampoco entre las razas Kapsiki y Gudali por otra. Igualmente, la pérdida de peso mostró un efecto significativo de la raza. Los animales de raza N’Dama fueron los que perdieron menos peso, mientras que los animales de raza Kapsiki fueron los que perdieron más peso. El porcentaje de sangre cebú en las razas Namchi y N’Dama fue similar, mientras que el de la raza Kapsiki fue superior, indicando un alto nivel de cruzamiento. A partir de los resultados obtenidos, puede concluirse que la raza Namchi es tripantotolerante y la raza Kapsiki es tripanosusceptible.

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Susceptibilite Des Races Bovines Namchi Et Kasiki Aux Infections Par Les Tryanosomes Au Cameroun

Résumé La suceptibilité aux trypanosomes fut évaluée chez 2 races indigènes de bétail camerounais (Namchi et Kapsiki) après infection avecTrypanosoma congolense. Six microsondes furent utilisées chez les animaux pour conna?tre leur filiation avec la race zebu, ces sondes étant connues comme présentant des allèles particuliers permettant de suivre l’apport genétique d? àBos indicus. Leur réaction à l’infection fut comparée à celle observée chez une race resistante (N’Dama) et une race susceptible (Ngaoundéré Gudali). Le développement et la sévérité des anèmies et des parasites furent mieux controlés chez les races Namchi et N’Dama que chez les races Kapsiki et Gudali. Pour ces paramètres il ne fut pas observé de différence significative entre les races appartenant au même groupe. De même, la perte en poids fut liée à la race étudiée. La race N’Dama montra la plus faible perte de poids et la race Kapsiki, la plus importante. Les races Namchi et N’Dama montrèrent des niveaux de croisement identique, la race Kapsiki étant la plus génétiquement modifiée. D’après ces résultats la race Namchi est considérée comme résistante aux trypanosomes alors que la race Kapsiki est susceptible aux infections par trypanosomes. Les utilisations potentielles de la race indigène sont discutées.

     

Tissue Doppler imaging and gradient echo cardiac magnetic resonance imaging in normal cats and cats with hypertrophic cardiomyopathy

Cats with hypertrophic cardiomyopathy (HCM) often develop diastolic dysfunction, which can lead to development of left congestive heart failure. Tissue Doppler imaging (TDI) echocardiography has emerged as a useful, noninvasive method for assessing diastolic function in cats. Cardiac magnetic resonance imaging (cMRI) has been performed in cats and accurately quantifies left ventricular (LV) mass in normal cats. However, assessment of cardiac function in cats by cMRI has not been performed. Six normal Domestic Shorthair cats and 7 Maine Coon cats with moderate to severe HCM were sedated, and TDI of the lateral mitral annulus was performed. Peak early diastolic velocity (Em) was measured from 5 nonconsecutive beats. Cats were anesthetized with propofol and electrocardiogram-gated gradient echo cMRI was performed during apnea after hyperventilation. Short-axis images of the LV extending from the mitral annulus to the apex were obtained throughout the cardiac cycle. LV mass at end systole and LV volumes throughout the cardiac cycle were quantified according to Simpson's rule. To assess the possible influence of propofol on diastolic function, TDI was performed on the 7 cats with HCM while sedated and then while anesthetized with propofol. Em was significantly lower in cats with HCM than normal cats (6.7 +/- 1.3 cm/s versus 11.6 +/- 1.9 cm/s, P < .001, respectively). There was no difference in the cMRI indices of diastolic function in normal and HCM cats. Propofol did not reduce diastolic function (Em) in cats with HCM but mildly reduced systolic myocardial velocity (S) in Maine Coon cats with HCM that were anesthetized with propofol (P = .87 and P = .03, respectively).     

Geographical and age-stratified distributions of foot-and-mouth disease virus-seropositive and probang-positive cattle herds in the Adamawa province of Cameroon

Six of the seven known serotypes of foot-and-mouth disease (FMD) virus occur in Africa. This paper describes the results of a population-based cross-sectional study of the seroprevalence of FMD and the persistence of the virus in cattle herds and associated sheep flocks in the Adamawa province of Cameroon. Antibody titres measured by the virus neutralising test indicated that serotypes O, A and SAT2 viruses had been circulating in the province. The estimates of apparent seroprevalence in cattle herds, based on five juvenile animals (eight to 24 months old) per herd, were 74.8 per cent for serotype SAT2, 30.8 per cent for serotype A and 11.2 per cent for serotype O, indicating recent exposure; the estimates based on animals more than 24 months of age were 91.1 per cent for SAT2, 83.6 per cent for A and 34.2 per cent for serotype O. Epithelial and oropharyngeal samples were collected from cattle and small ruminants, cultured and typed by ELISA; serotypes A and SAT2 were isolated from both types of sample. The herd-level estimate of apparent prevalence of probang-positive herds was 19.5 per cent and the animal-level estimate of apparent prevalence was 3.4 per cent. The geographical distribution of the seropositive herds based on juveniles suggested that recent SAT2 exposure was widespread and particularly high in the more northern and western parts of the province, whereas recent exposure to serotype A was patchy and more concentrated in the south and east. This distribution corresponded very closely with the distribution of herds from which virus was recovered by probang, indicating recent exposure or infection. No serotype O viruses were recovered from cattle, and the distribution of seropositive herds suggested very localised recent exposure. The apparent prevalence of probang-positive animals declined with the age of the animal and the period since the last recorded outbreak in the herd.     

Application of marker‐assisted selection and genome‐wide association scanning to the development of winter food barley germplasm resources

Barley (Hordeum vulgare) is an important component of heart‐healthy whole grain diets because it contains β‐glucan. All current US barley varieties with high β‐glucan are spring habit and have waxy starch. Winter varieties have agronomic advantages but require low‐temperature tolerance (LTT). Vernalization sensitivity (VS) is associated with higher levels of LTT. To rapidly develop fall‐sown varieties with LTT and higher grain β‐glucan, we therefore used marker‐assisted selection (MAS) at the WX and VRN‐H2 loci. The MAS‐derived lines, together with unrelated non‐waxy germplasm developed via phenotypic selection (PS), were used for a genome‐wide association scan (GWAS). The panel was phenotyped for grain β‐glucan, LTT and VS. It was genotyped with 3072 single‐nucleotide polymorphisms (SNPs) and allele‐specific primers. Marker‐assisted selection fixed target alleles at both loci but only one of the target phenotypes (higher β‐glucan percentage) was achieved. Variation for VS and LTT is attributable to (i) incomplete information about VRN‐H1 at the outset of the project and (ii) unexpected allelic variation at VRN‐H3 with a large effect on VS and LTT.     

Assessing carcass and meat characteristics of Damara, Dorper and Australian Merino lambs under restricted feeding

Seasonal weight loss (SWL) is the most pressing constraint in ruminant production systems in tropical climates. SWL is controlled using supplementation, which is costly and difficult to implement in extensive systems, or using breeds adapted to tropical hot dry climates, like the Damara and Dorper. Albeit 15 years in Australia, little is known on how these sheep compare to Australian Merino. Here, the responses of the Damara, Dorper and Merino breeds to nutritional stress were compared. Seventy-two 6-month-old ram lambs, 24 from each breed, were allocated to growth (gaining 100 g/day) or restricted diets (losing 100 g/day, 85 % of maintenance needs). Animals were weighed and carcass and meat characteristics determined. Results point out to the existence of important differences between the three genotypes, in particular between the Merino and the Southern African breeds. Additionally, Merino ram lambs seem to have been more influenced by SWL than the other two, with consequences on meat characteristics.     

Foot and Mouth Disease and Livestock Husbandry Practices in the Adamawa Province of Cameroon

Foot and mouth disease (FMD) is a highly contagious viral disease of even-toed ungulates and is endemic in most of the tropics. A cross-sectional study using a stratified, two-stage random sample design was undertaken in the Adamawa Province of Cameroon. The objectives were to measure the reported herd-level prevalence of FMD and a range of husbandry practices important for its transmission. The owner-reported prevalence for the previous 12 months was 57.9% (50.4–65.4%), although there was a significant variation across the Province. During the previous dry season, 46.5% (38.6–54.4%) of herds had gone on transhumance. Herds had high numbers of contacts with other herds while on transhumance (98.6%), at pasture (95.8%) and at night (74.4%), with medians of 7–10, 4–6 and 1–3 daily contacts, respectively. The high level of endemic FMD and potential for disease spread presents a significant challenge for control and eradication. Locally sustainable methods need to be developed upon which larger regional control programmes could be built in the future.     

Multicentric leiomyosarcoma in a young male horse

A 2-year-old male Thoroughbred was evaluated for multiple firm, raised nodules of the maxilla and mandible that had been present since 6 months of age. The horse was evaluated as a yearling with a final histologic diagnosis of fibrosarcoma. As a 2-year-old, the colt made a loud upper airway sound and was agitated after strenuous exercise. Results of upper airway endoscopy indicated severe narrowing of the nasal passages and pharynx with normal resting function. Radiography revealed multiple circular bony lesions in the mandible, maxilla, multiple long bones, and cervical vertebrae. Biopsy specimens of the left mandible and right facial bone were obtained. A diagnosis of leiomyosarcoma with extensive metastatic bone formation was made on the basis of histologic features and the immunohistochemical staining properties of the biopsy specimens. Because of the diffuse distribution of the lesions, prognosis was guarded; 4 years after diagnosis, the horse had not pursued an athletic career.