Intrauterine growth rates of the west African dwarf goat and some foetal organs in relation to strategic feed supplementation during pregnancy.

The intrauterine growth rate of West African dwarf (WAD) goats and their foetal brain, heart and liver were studied to provide possible approaches for formulating maternal feeding strategies during pregnancy for minimizing reproductive wastage due to abortion, dystocia and neonatal mortality. Twenty-five pregnant adult WAD does, involving 58 foetuses were studied. The goats were fed a standard farm ration and the foetuses were harvested by caesarean section at 30, 60, 90, 120 and 140 days of gestation. The data were analysed by an exponential growth model subjected to multiple linear regression analysis to obtain the daily growth rate and maximal rate of increase of each variable studied. The results showed that the foetal body, brain, heart and liver weights were significantly related with gestational age (P less than 0.01). The coefficients, b1 and b2, were also significant (P less than 0.01). The variables considered in this study showed different maximum rates of growth and different initial instantaneous growth rates which also decreased at different rates for each day of gestation. The results indicated that feed supplementation in pregnant WAD does should be determined from changes in foetal growth rate in order to minimize reproductive wastage and for economics of animal production, and that high feed supplementation before 70 and after 118 days post-breeding should be avoided.

Crossbreeding in tropical sheep: incidence of dystocia and parturition losses.

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.

Diurnal variations in the concentration, arteriovenous difference, extraction ratio, and uptake of 3-hydroxybutyrate and plasma free fatty acids in the hind limb of lactating sheep.

Four lactating sheep were used to study diurnal variations in the concentration, arteriovenous concentration difference, extraction ratio, and uptake of 3-hydroxybutyrate and plasma free fatty acids by the hind limb of the lactating sheep. The arterial and venous concentrations of 3-hydroxybutyrate showed significant diurnal variations, which appear to be related to the feeding regimen, since values declined after feed withdrawal and rose after refeeding. Throughout the experimental period uptake of 3-hydroxybutyrate by the hind-limb was consistent and none of the small variations in arteriovenous difference, extraction ratio, or uptake of 3-hydroxybutyrate by the hind limb was statistically significant. By contrast, free fatty acid concentrations in arterial blood rose steadily after feed withdrawal. Except at feeding time, there was an output of free fatty acid by the hind limb.

Ovarian activities of the West African dwarf goat (Capra hircus) during oestrus.

Ovarian activity was studied by laparotomy of 9 adult nulliparous goats in which oestrus was synchronized. Ovulation occurred in animals operated on 20-48 h from the onset of sexual receptivity. There was a mean ovulation rate of 1.57 ova per doe and the right and left ovaries had similar follicular activity in relation to sizes of follicles and ovulations.