Factors affecting abortion, stillbirth and kid mortality in the Goat and Yaez (Goat × ibex)

The dry season coupled with large group size may negatively affect reproductive success of group living mammals in semi-arid environments. We determined the reproductive success of goats between seasons and herd sizes in a semi-arid savanna at Msinga, South Africa. To do this, we used 17 herds to count the number of adult females, kid births and mortalities in the wet and dry seasons of 2017–2018. We found that small and large herds had a significantly greater reproductive performance in the wet than dry season, and this was greater in small than large herds. Kid mortalities (44.0%) for both herds across seasons resulted in decreased kidding success. Abortions (7.0%) in both herds across seasons also contributed negatively to kidding success. Ultimately, kidding success was 80.0 and 14.0% in small herds and 65.4 and 39.8% in large herds in the wet and dry seasons, respectively. Our results indicate that goats in semi-arid environments have a poor reproductive performance which may be exacerbated by effects of the dry season. The provision of supplementary feeds may improve the poor survival of kids in semi-arid areas.

Data on the use of transvaginal ultrasonography for pregnancy diagnosis in goats are scarce. The transabdominal and transrectal routes have been repeatedly investigated. The aim of this study was to evaluate the accuracy of real-time transvaginal ultrasound for early pregnancy diagnosis in 50 multiparous Saanen dairy goats. Following estrous synchronization and mating, a B-mode real-time scanner with a 5–7.5 MHz multi-frequency endocavitary probe was used to examine the animals, in a standing position. The value of visualizing at least one gestational sac (with or without any fetal pole) to predict the birth of at least one live kid was monitored at 3–8 weeks post mating. The accuracy (proportion of true positives and true negatives to the overall study population) for predicting a live birth increased gradually from 65% at week 3, to 93% at week 8 post mating. Sensitivity values followed a similar pattern (61% at week 3, increasing to 100% at week 8). Positive and negative predictions at week 8 were 90% and 100%, respectively. However, the relationship between the observed number of fetal sacs and the actual number of live births was only 17% at week 3, increasing to about 60% at week 8. In conclusion, transvaginal ultrasound during early pregnancy in Saanen goats (especially 5–6 weeks post mating) can effectively predict live births, but not multiple pregnancies. Further investigations comparing the use of transrectal and transvaginal routes in pregnant goats should be encouraged.

The effect of environmental factors on preweaning survival rate of Arsi-Bale and Borana kids at the Adami Tulu Agricultural Research Center, was investigated. Data collected on 702 kids born between 1999 and 2003 were used to evaluate the effect of year, parity, breed type, sex, season of birth, litter size and birth weight on survival rate of the goats. All the environmental factors significantly influenced the survival rate of kids. The overall preweaning survival rate of kids averaged 69%. Survival of the Arsi-Bale kids was 75% while it was 57% for the Borana kids. Survival of single (70%) and twin (70%) born kids were high compared to survival rate of triplets (43%). Kids born during the wet season had better survivability than kids born in the other seasons. Kidding occurring in the early dry season (September–November) had the highest mortality rate of 42%. A maximum survival rate was found from kids with 3.1–4.5 kg of live weight at birth. The study indicated that by instituting adequate management improvement actions in addition to selection for larger kids at birth and at weaning, the productivity of goats could be improved.

The reproductive performance following oestrous synchronisation and artificial insemination (AI) was evaluated during the natural breeding season (autumn) in 90 indigenous (Boer and Nguni) South African goats. All does were synchronised for 16 days with medroxyprogesterone acetate (MAP) followed by an IM injection of 300 IU PMSG at progestagen withdrawal. Cervical inseminations were performed at a fixed time (48 h and 60 h) with fresh diluted Boer goat semen. No significant differences between Boer and Nguni goats were recorded with respect to oestrous response (98% and 93%) and the onset of oestrus (29.1 ± 0.9 h and 30.7 ± 0.8 h), respectively. The duration of oestrus in the Nguni goats (29.9 ± 2.0 h) was significantly (P < 0.01) shorter than in Boer goats (37.0 ± 2.1 h). Conception rates were 52% and 53%, litter size averaged 2.2 ± 0.2 and 2.0 ± 0.2 and the gestation period an average of 148.6 ± 0.9 days and 149.1 ± 0.8 days for Boer and Nguni goats, respectively, these differences being non-significant. Does with quadruplets had a significantly (P < 0.05) shorter gestation length (142.7 ± 2.1 days) than does with singles, twins and triplets (150.0 ± 0.9 days, 148.8 ± 1.0 days and 150.0 ± 1.1 days, respectively). The mean kid birth weight was 2.7 ± 0.5 kg with males being (2.8 ± 0.1 kg) significantly (P < 0.05) heavier than females (2.5 ± 0.1 kg) and crossbred kids (2.9 ± 0.1 kg) significantly (P < 0.01) heavier than pure Boer goat kids (2.4 ± 0.1 kg). Kid birth weight decreased with an increase in litter size, resulting in all birth weights for singles, twins, triplets and quadruplets being significantly (P < 0.01) different from each other (3.6 ± 0.4 kg, 3.1 ± 0.5 kg, 2.3 ± 0.6 kg and 1.6 ± 0.3 kg, respectively). The overall neonatal loss rate within 48 h postpartum was 22.2%, which increased significantly with an increase in litter size and was significantly (P < 0.01) higher for Boer goats (34.2%) than for crossbred kids (12.7%). The results indicate that oestrous synchronisation with progestagen is efficient and the duration of the induced oestrus is shorter in Nguni does than in Boer goat does. The conception rates obtained following oestrous synchronisation and AI were, however, very low and this aspect needs more attention. Litter size reduces birth weight and survival rate of indigenous South African goat kids.

In order to assess the effect of controlled seasonal breeding on survival performance of pastoral goat flocks, a systematic breeding programme was initiated in a herd of small East African goats over a period of 4 years in Isiolo District, northern Kenya. This papers presents an analysis of survival rates observed in six different mating seasons. The statistical analysis is based on modelling hazard functions parametrically over time using logistic regression and polynomial spline functions. With respect to kid survival, litter size and parity of dam failed to reach statistical significance after adjustment was made for the effects of birth weight and milk yield until weaning. Highly significant interactions were found between time factors and the effect of mating season, indicating non-proportionality of death risks across mating seasons. Confining mating to the period between June and November is likely to confer a distinctive advantage in terms of young livestock survival. In contrast, joining does during the short dry season leads to kid mortality rates of about 50%, and should therefore be avoided. Doe survival was evaluated in terms of mating season, production cycle, parity, and reproductive status. The ranking of mating season groups with respect to doe survival was similar to that observed in kids, although the differences were much smaller and non-significant. The lowest annual mortality rate was observed when breeding females were mated during the long dry season. It is concluded that confining breeding to the long dry season can be an effective management intervention to reduce mortality rates in pastoral goat flocks.

About 400 Nubian ibex (Capra ibex nubiana) dig many hundreds of temporary night beds, approximately 80 cm × 110 cm and 15 cm deep, on slopes near the edges of the cliffs bordering the Zin valley. The beds are used according to the wind direction and the size of the ibex group, which depends on the ibex social behaviour during the year.

The diggings are gradually abandoned and become important microhabitats for seed accumulation and germination, seedling development and annual plant establishment. These are influenced by soil salinity, slope direction and angle, digging depth, and the time since the diggings were abandoned. A greater variety of plant species and plant density were found in these diggings than upslope from the diggings.