Three hundred and thirty (330) records from 363 lactations and 104 cows born between 1979 and 1991 from crossbreeding Holstein-Friesian (H) bulls with H, Ngaoundere Gudali (G) and Holstein × Gudali F1 (H1G1) cows, Montbeliard (M) bulls with G and Montbeliard × Gudali Fl (M1G1) cows and M1G1 bulls with M1G1 cows and raised in the Dairy Herd Unit of the Wakwa Animal and Veterinary Research Station in the sub-humid highlands of Cameroon were analysed to investigate the effects of genotype and environment on lactation and reproductive traits. Fixed effects of genotype season and year of calving parity and age of cow at calving were studied. Lactation milk yield (LMY), lactation length (LL), annualized milk production (AMP), calving interval (C1), dry period (DP) and age at first calving (AFC) were amongst the traits analysed. F1 crosses (H1G1, M1G1), backcrosses (¾ Holstein — ¼ Gudali; ¾ Montbeliard — ¼ Gudali) (H3G1, M3G1) and F2 crosses (MGF2) were compared. Results showed that H1G1 cows were proportionately 0·49 and 0·23 better than their corresponding backcross in LMY and AMP, respectively, while M1G1 cows were proportionately 0·12 and 0·24 inferior to M3G1 in these traits. M1G1 were proportionately superior to MGF2 in LMY (0·05), AMP (-0·04) and AFC (-0·14). M3G1 were superior (0·18 to 0·19) to MGF2 in LMY and AMP. H1G1 were consistently superior to M1G1 for most traits, suggesting that H1G1 may be better than M1G1 for dairy production.

Les auteurs présentent dans cet article une révision détaillée des populations locales de bovins, ovins et caprins en relation avec les possibilités de programmes de conservation. Bien que les populations de zébus et de zébus similaires soient plus nombreuses, c'est sûrement les populations de Bos taurus qui présentent un intérêt tout particulier. Cette population représente seulement 1% de la population bovine mais a l'avantage d'être trypanotolérante. Les ovins et caprins sont élevés dans les familles en petit nombre (5 animaux approximativement), le plus souvent pour l'abattage lors des célébrations spéciales (fêtes nationales ou religieuses) ou comme monnaie d'échange. On trouve également une briève présentation des schémas nationaux de sélection de race et d'introduction de matériel génétique exotique utiliséla plupart du temps pour le croisement.