Holstein cattle of a small scale dairy production systems were screened for Brucella abortus antibodies in 21 villages in Cameroon by ELISA. Results show a general seroprevalence of 8.4% in Holstein cattle. Of the 192 cows tested, 14 were infected giving a within-sex seroprevalence of 7.3% while 6/74 bulls were infected with a seroprevalence of 8%. There was no evidence (P=0.11) of differences in seroprevalence between age groups although animals above one year and below three years accounted for nearly half of the infected animals. 64% of infected animals were found in three locations (P=0.015): Kutaba (32%), Bamendankwe (16%) and Finge (16%). A specific control programme should be organized at these locations. Measures should be taken to ensure the eradication of the disease within the population and sound control measures adopted to avoid a further spread of the disease to larger cattle populations. Infected animals should be slaughtered systematically. All farmers should be advised to boil milk before consumption. Vaccination against Brucella abortus should be instituted and use of artificial insemination propagated. In order to ensure a productive and healthy population of Holstein cows within the dairy production scheme, regular Brucella testing should be instituted.Abbreviations OIE World organization for animal health -ELISA enzyme-linked immunosorbent assay

Des données sur 275 lactations collectées entre 1981 et 1991 ont été analysées. Le but de ce projet a été d’étudier l’effet de la saison de vêlage, de quelques paramètres zootechniques, de l’intervalle entre vêlages des races Holstein et Jersiaise et de leurs croisements avec le zébu Goudali et le zébu Peul blanc (White Fulani) sur la production laitière dans les hauts plateaux de l’ouest du Cameroun. Les résultats suivants ont été obtenus : - la production laitière des races pures Holstein (n = 73) et Jersiaise (n = 32), sans être comparable à celle de leur pays d’origine, a été significativement supérieure à celle des autres types génétiques étudiés, la Holstein ayant été plus performante que la Jersiaise (2 508 ± 105 l en 291 ± 10 jours, contre 1 818 ± 137 l en 251 ± 13 jours) ; - en croisement de première génération avec le zébu local, la Holstein (n = 52) a produit significativement plus de lait que la Jersiaise (n = 57). La Holstein x le zébu Goudali a produit plus de lait que la Jersiaise x le zébu Peul blanc (1 940 ± 109 l en 270 ± 10 jours, contre 1 550 ± 106 l en 257 ± 10 jours). La production laitière des races croisées trois quarts Jersiaises (n = 61) a été plus élevée (1 774 ± 117 en 250 ± 11 jours) ; - l’année et le numéro de lactation ont influencé significativement la production laitière et la durée de lactation, alors que la saison de vêlage n’a pas eu d’effet significatif sur ces deux paramètres. L’analyse financière et les recherches sur la composition du lait devraient se poursuivre pour des recommandations plus concrètes.

A study was carried out to evaluate the impact of interventions to solve constraints in smallholder dairy farms of the Western Highlands of Cameroon. The interventions consisted of improved breeding through introduction of artificial insemination, better feed supplementation, farmers training in milk processing and better veterinary services. Results show that there was a decrease in average monthly expenditures of 18% relative to the month before interventions started. Much of the expenditures were related to feed (38% of all costs). There was an overall increase in farm income. Close to 2/3 of the income were derived from milk products from home processed milk and culled animals. Only 7% income came from milk sold to the processing plant. The partial budget shows that before interventions, farmers lost $4.5/cow/month but gained $38/cow/month because of the interventions. The return was 2.32 and included opportunity income for milk home consumed and shared. When this opportunity income was ignored, the return stood at 1.93. The positive impact of interventions led to poverty alleviation and some farmers acquired more cows. A spill over effect is that more crop farmers are willing to be engaged at least partially in dairy farming. It will be good if many more farmers could benefit from these interventions.

A study aimed at validating a human progesterone enzyme immunoassay kit was carried out on cattle at Bambui, Cameroon. Progesterone ELISA Kits (EH-511) were obtained from Clinpro International. Forty-one cows were selected, of which 19 were pregnant and 22 within 14 days post partum. Blood samples were analysed and progesterone levels were deduced from a curve obtained from standard absorbance values (A450). Results show that 95.5% of postpartum cows had progesterone levels below 1 ng/ ml, with the highest level being 0.75 ng/ml. The mean level was 0.5 +/- 0.26 ng/ml. The cows in the 'pregnant group' had progesterone levels ranging from 3.5 to 17.5 ng/ml. This kit can be used for measuring progesterone levels in cattle. Levels of 1 ng/ml for two consecutive samples or one sample at or above 3 ng/ml are an indication of the presence of corpus luteum, while cows below 1 ng/ml will be in anoestrus.