The three breeds of goat in Nigeria -Sahel (Sh), Red Sokoto (RS) and West African Dwarf (WAD) -are described. The performance of the latter two is illustrated in the tables. RESUMELes trois races caprines du Nigéria -Sahélienne (Sh) , Sokoto rouge (RS) et naine d'Afrique orientate (WAD) -sont décrites; des tableaux illustrent les performances des deux dernières races. RESUMENSe describen las tres razas de ganado caprino de Nigeria: Sahel (Sh), Red Sokoto (RS) y West kfrican Dwarf (WAD). En los cuadros se expone el rendimiento de las dos Gitimas.

A study was made of some aspects of reproduction in the Nungua Black Head and the Ghanian variety of the West African Dwarf sheep. The gestation period of the two breeds was similar: 150 and 148 days respectively. Ewes mated in August and September tended to have slightly longer gestation periods than those mated in March. The mean birth weights were 2-2 kg in the Nungua Black Head and 13 kg in the West African Dwarf. Type of birth affected the weight of lambs at birth. The Nungua Black Head had no triplets, 0132 twins and 0-868 singles. The West African Dwarf was more prolific: 0-402 singles, 0-557 twins and 0041 triplets. The weight advantage of the Nungua Black Head lambs at birth was maintained to weaning and they also had better survival rates. The adjusted 12-week weaning weights averaged 9-8 and 5-8 kg respectively for the Nungua Black Head and West African Dwarf. What the West African Dwarf lost in individual weight it appeared to make up in numbers so that, when the breeds were compared in terms of kg of lamb weaned per ewe mated, there was no significant difference between them.

Studies were carried out on the incidence of dystocia and parturition losses during a crossbreeding experiment involving 96 West African Dwarf (WAD) ewes mated with rams of 4 breeds--WAD, Ouda, Permer and Yankassa. Results obtained indicated 8 (5.7%) cases of dystocia and 20 (10.64%) cases of stillbirths or death of lambs at birth. The WAD sires were not associated with dystocia or stillbirths but other sire groups were involved in both. All the difficult parturitions occurred during the rainy season while all stillbirths not associated with dystocia occurred during the dry season. The sires used and the level of feeding the ewes during pregnancy may be associated with the dystocia cases and parturition losses recorded. Eighty per cent of the dystocias involved ram lambs. The mean gestation period of the ewes that lambed during the dry season was significantly (P < 0.01) longer than that of the rainy season group. Application of traction and Caesarean operation were used in the treatment of dystocia cases.

A total of 264 adult sheep comprising WAD and Yankusa rams and ewes traditionally managed in flocks within the south West Nigeria were investigated. Ten geometrical variables were monitored in order to contrast their validity cys racial markers and breed discriminants and identify metric characters which can be valuıuble for population classification within the species. Descriptive statistics showed that the Yankasa generally appear superior to the WAD in all variables measured except for shoulder width where WAD appeared superior giving the breed a blockier look than Yankasa which is relatively narrower. Neck circumference exhibited the highest variability in both sheep studied, c.v. being 18.34 and 20.12% respectively. These were followed by shoulder width in WAD and body length in Yankasa. The cephalic characters (head width and face length) exhibited the lowest variability in both breeds (c.v. being between 3.62 and 5.67%). High environmental sensitivity of neck circumference and shoulder width in the WAD population explains the observed variability although measurement of neck circumference was affected by the neck ruff of the rams. The low variability exhibited by the cephalic characters in both breeds is a reflection of their relative insensitivity to environmental elements resulting from their close association with cranial bone growth. Stepwise discriminant analysis showed that tail length (the most discriminant variable between the breeds) was followed by shoulder width, the cephalic characters, body length and wither height in that order. Other variables did not qualify to enter the model. The small number of variables exhibiting high discriminant power (i.e. tail length, shoulder width, and head width) are explained by the genetic exchange that has existed between the breeds.

SUMMARYObservations were made over a period of 3 years on a total of 331 Nungua Black Head and 104 West African Dwarf sheep. It was shown that ewes of these breeds responded strongly to stimulation occasioned by the sudden introduction of rams which had been separated from them for 10 months. Sudden ram presence apparently altered the normal oestrous cycle of a substantial number of ewes which unlike temperate breeds showed behavioural oestrus soon after being run with the rams resulting in about a quarter of the flock being bred on the first day of association with the ram. This behavioural oestrus must have been accompanied by ovulation as shown by the lambing records 5 months later. The observations also suggested the existence of breed differences in the degree of ewe response to sudden ram presence.