[Prevalence of tuberculosis and brucellosis in intra-urban and peri-urban dairy cattle farms in Ouagadougou, Burkina Faso]. / Prévalence de la tuberculose et de la brucellose dans les élevages bovins laitiers intra-urbains et périurbains de la ville d'Ouagadougou au Burkina Faso.

A study of the prevalence of bovine tuberculosis and brucellosis was conducted in dairy cattle farms in and around the city of Ouagadougou, Burkina Faso. It reveals the potential economic and health impact of these two major zoonoses in the study area. Three farming systems were included in the study. A total of 1,420 cattle were tested for tuberculosis and 1,689 cattle were tested for brucellosis. The intradermal tuberculin test was used for tuberculosis, and the buffered antigen test and indirect enzyme-linked immunosorbent assay were used for brucellosis. The overall prevalence rate is estimated to be 6.05% for tuberculosis and 3.61% for brucellosis. The prevalence rates of tuberculosis and brucellosis in urban and peri-urban dairy cattle farms in Ouagadougou were found to be high. As these two production-linked diseases are zoonotic, they could pose a major risk to human health and contribute significantly to reducing animal production and productivity in the areas covered by the study. Animals should be checked systematically prior to introducing them into dairy herds, with the ultimate goal of eradicating these two zoonoses.

Effect of supplementation on the feed intake and performance of confined and scavenging crossbred growing chickens in Burkina Faso.

An experiment was conducted to evaluate the performance of crossbred growing chickens (Rhode Island Red x indigenous Burkina Faso hens) from 6 to 17 weeks of age, under five feeding/management regimes: (1) CMx(+), confined and given a mixed feed containing cracked maize and cowpea and a vitamin-mineral premix ad libitum; (2) CS(+), confined and offered ad libitum a choice of cracked maize and cowpea with the premix; (3) ScS(+), scavenging from 09:00 to 16:00 with the diet in treatment (2) available from 16:00 to 09:00; (4) ScS(-), treatment (3) but without the premix; and (5) ScO, scavenging only, with no supplements provided. Daily dry matter (DM) intake was highest for CS(+) (43.5 g), and lowest for CMx(+) (33.6 g) (p < 0.05), with intermediate intakes for ScS(+) and Sc(-) of 36.7 g and 36.2 g, respectively. The ratios of intakes of cowpea to maize were 50:50, 21:79, 27:73 and 22:78 for CMx(+), CS(+), ScS(+) and ScS(-), respectively (p < 0.05). Dietary concentrations of crude protein (CP) were 15.7%, 11.5%, 12.3% and 11.6% of DM for CMx(+), CS(+), ScS(+) and ScS(-), respectively. Average daily gains (ADG) were 8.15 g, 5.24 g, 6.03 g, 5.36 g and 4.45 g for CMx(+), CS(+), ScS(+), ScS(-) and ScO, respectively, and were significantly higher for CMx(+) (p < 0.05). Feed conversion ratio was highest for CS(+) and lowest for CMx(+). ADG of the males (6.44 g) was significantly (p < 0.05) higher than that of the females (5.86 g). Breast and thigh muscle weights were highest for ScS(+) (p < 0.05).

Scavenging pullets in Burkina Faso: effect of season, location and breed on feed and nutrient intake.

A study on scavenging local (n = 64) and crossbred (n = 64) pullets was undertaken in the dry and rainy seasons in two villages in Burkina Faso: Korea in the arid northern Sahelian region and Bounouna in the sub-humid south. After 4 weeks of scavenging, the birds were killed and the crop contents were subjected to physical and chemical analysis. Cereal grains, brans, green and dry forages, insects/worms and household leftovers were the main physical components. The proportion of cereal grains was higher in the rainy season, whereas the proportion of bran, peanut and sand/grit was higher in the dry season (p < 0.05). The proportion of kitchen waste and millet/milo grains was higher in local than in crossbred birds, whereas the opposite was the case for millet/milo bran (p < 0.05). Rice and local beer residues were not found in the crops of birds from Korea. Dry matter, ash, crude fibre and potassium contents were higher in the dry season (p < 0.05), while calculated metabolizable energy content was higher in the rainy season (p < 0.05). There were no location or breed effects on chemical composition parameters (p > 0.05), except that potassium content was higher in Korea. Mean live weight at slaughter was 806 +/- 22.0 g (local breed) and 881 +/- 22.0 g (crossbreds) (p < 0.05). Digestive organ weights, including contents, were higher for crossbred birds (p < 0.05). Gastrointestinal tract percentage was higher in the rainy season and in Bounouna (p < 0.05). The nutrient composition of the crop contents indicates the need for supplementation, particularly of protein, for higher levels of production.

Characteristics of peri-urban dairy herds of Bobo-Dioulasso (Burkina Faso).

Peri-urban dairy cattle farms within 50 km of Bobo-Dioulasso were studied to assess herd type, disease incidence, management, feeding and breeding strategy. Out of 417 cattle farmers, 42% had dairy objectives and were studied. Among these peri-urban dairy farmers, 60% were settled, 36% semi-settled, and 4% transhumant. In total, they held 4558 dairy cows, of which 32% lactated during the study. The prevalence of mastitis (55%) increased (p<0.05) with herd size. Advanced strategies for supplementary feeding and breeding were most frequent in small herds (<30 cattle). None of the large herds (>60 cattle) had advanced breeding strategies. Bulls and cows were culled at younger ages in herds with better breeding strategy. Overall, this resulted in higher individual milk offtake in small herds (2.46 L/day) compared with large herds (1.25 L/day). Pure breeds were rarely used, and the presence of Bos taurus baoulé naturally selected for trypanotolerance was low. The prevalence of trypanosomosis (40%) in herds dominated by Bos indicus zebu and Méré (Zebu x Baoulé) is an argument for maintenance of biodiversity and selection of Baoulé for milk production.

Comparative pathogenicity of three genetically distinct types of Trypanosoma congolense in cattle: clinical observations and haematological changes.

The pathology of African bovine trypanosomosis was compared in Zebu cattle subcutaneously inoculated with three clones of trypanosomes corresponding to the three genetically distinct types of Trypanosoma congolense; savannah-type, west African riverine/forest-type and kilifi-type. All inoculated animals became parasitaemic between 7 and 11 days post-infection (dpi). The savannah-type showed consistently higher levels of parasitaemia and lower packed red cell volume percentages and leukocyte counts than the other two types. The syndrome was also more severe in the savannah-type and led inexorably to death between 29 and 54 dpi while animals with the forest or the kilifi-types recovered from earlier symptoms and haematological alterations after 3 months of infection. By the end of the experiment, the animals self-cured from the forest-type infection and the kilifi-type passed under control. The results of the present study indicated clear difference in pathogenicity between the three types of T. congolense; the savannah-type was virulent while the forest-type was of low pathogenicity and the kilifi-type was non-pathogenic.

Comparative pathogenicity of three genetically distinct Trypanosoma congolense-types in inbred Balb/c mice.

Inbred Balb/c mice were infected with three clones of Trypanosoma congolense (Sam.28.1, Dind.3.1 and K60.1A) corresponding, respectively, to the three genetically distinct types (savannah, forest and kilifi) defined within this species, for the purpose of comparing their pathogenicity for a better understanding of the epidemiology of African trypanosomosis. Another clone of savannah type, IL 3000, was also tested simultaneously to study a probable strain variation. Both the clones of savannah type were found of extreme virulence with loss of appetite, rough hair, rapid respiration, lethargy, and all mice died within a week. Parasitaemias evolved rapidly to the first peak by day 3-5 post-inoculation without any remission and the course of disease was correlated positively with the prepatent period. The clones of the forest type and the kilifi type were of low virulence with chronic infection and symptoms progressively less patent throughout the infection; only one mouse died in each experimental group.

Effects of Trypanosoma congolense infection on the pituitary gland of Baoulé bulls: immunohistochemistry of LH- and FSH-secreting cells and response of plasma LH and testosterone to combined dexamethasone and GnRH treatment.

The effects of Trypanosoma congolense infection were investigated at the pituitary level on trypanosome resistant Baoulé bulls (aged 3-6 years), using immunohistochemistry of LH- and FSH-secreting cells and a combined dexamethasone and GnRH challenge. The pituitaries of two control and five naturally infected Baoulé bulls were removed after slaughter and the LH- and FSH-secreting cells were examined immunohistochemically, using specific polyclonal antibodies against beta LH and beta FSH. No significant impairment of the labelling and distribution of LH- and FSH-secreting cells was seen in infected bulls when compared with control animals. No parasites were found in the pituitary glands. Plasma LH and testosterone concentrations were determined in eight control and eight infected bulls by enzymeimmunoassay and radioimmunoassay techniques, respectively. Blood samples were collected at intervals of 30 min two times before and nine times after dexamethasone treatment (20 mg i.m.). GnRH (Busereline: 20 micrograms, i.m.) was injected 4.5 h later and samples were collected every 15 min for 180 min. After dexamethasone treatment, LH and testosterone concentrations declined dramatically in both groups. Four hours after treatment, the mean testosterone concentration for both groups was 0.44 ng ml-1. After GnRH injection, LH concentrations in the infected group increased rapidly to a mean maximum value of 30 ng ml-1 by 165 min. In contrast, the increase in LH concentration in non-infected bulls was more gradual and the mean maximum value, reached at the same time, was only 20 ng ml-1. Testosterone concentration increased rapidly and in a similar manner in both groups for the first 90 min (0.08 +/- 0.04 ng ml-1).(ABSTRACT TRUNCATED AT 250 WORDS)

[Pathogenic effects of Trypanosoma congolense on the testis of Baoulé bulls: quantitative and morphometric histology]. / Effets pathogènes de Trypanosoma congolense sur le testicule des taurins Baoulé: histologie quantitative et morphométrique.

The effect of Trypanosoma congolense on testis was studied in 53 trypano-resistant "Baoulé" bulls by quantitative histology and morphometry. The daily spermatozoa production per testis of control groups (n = 45) was 382 +/- 334 x 10(6) (m +/- sd) and the epididymis contained 0.6 +/- 1 x 10(9) spermatozoa in the caput, 0.3 +/- 0.3 x 10(9) in the corpus and 1.2 +/- 1.8 x 10(9) in the cauda. The infected bulls (n = 8) showed no significant difference (P > 0.05) when compared to the control despite their average low value. The morphometric analysis during infection revealed a significant (P < 0.05) decrease (32%) of total Leydig cell volume per testis, 4.4 +/- 0.9 cm3 for the control (n = 5) and 3.0 +/- 0.8 cm3 for infected bulls (n = 8). The number of round spermatids per Sertoli cell and the daily round spermatid production (DRSP) per testis were also significantly reduced in infected bulls when compared to controls (P < 0.05), 5.2 +/- 0.7 and 2.8 +/- 2 for round spermatid per Sertoli cell and 6.1 +/- 2.0 and 3.1 +/- 1.9 x 10(8) for DRSP. These observations indicate that Trypanosoma congolense infection alters the interstitial tissue and meotic divisions of germinal cells leading to low daily round spermatid production per gram of testis in "Baoulé" bulls.

[Comparison of experimental trypanosomiasis in various breeds of small ruminants in Burkina Faso]. / Comparaison de la trypanosomose expérimentale chez certaines races de petits ruminants au Burkina Faso.

Twenty-four dwarf Djallonké sheep and goats, and 16 Sahelian Fulani sheep and goats, were inoculated with strains of Trypanosoma vivax and Trypanosoma congolense to compare their degree of susceptibility to trypanosomosis. One animal from each breed was used as a control. Anaemia was observed in all inoculated animals. In the group of animals inoculated with T. vivax, 1 Djallonké goat out of 6, 3 Sahelian goats out of 4 and 2 Fulani sheep out of 4 died within the experimental period of 16 weeks. One single Sahelian Fulani sheep out of 4 died among animals inoculated with T. congolense. During a period of 8 weeks, no significant difference was observed between Djallonké and Fulani Sahelian in the decrease of body weight and leucocyte count. Results in this study show a better resistance of Djallonké sheep and goats to infection by T. vivax, whereas there was no significant difference between all sheep and goats inoculated with T. congolense.