| Popis: |
The aim of this study was to investigate the effect of age at first service (50), breeding season (all the year vs. specific season), housing system (shelter vs. grazing and shelter), manager education level (200), flock size (200) and their interactions on kidding, twining, abortion and stillbirth rates of Ardi goats in Saudi Arabia. Data were collected from 34 goat flocks containing 3700 heads. GLM procedures were used for analysis. The dependent variables in the model were lambing, twining, abortion, and stillbirth rates, while the main effects in the model were age at first service, male/females ratio, breeding season, housing system, manager education level, flock size, and worker/animals ratio. Barren does (n = 104) were examined for the causes of infertility. The results revealed that the means of kidding, twining, abortion and stillbirth rates were 91.5 ± 1.2%, 50.09 ± 5.24%, 3.5 ± 1.4% and 9.47 ± 2.2%, respectively. Does mated by or after 8 months had more twins than those mated before this age (P = 0.006). Flocks with male/females ratio of 1:>50 showed higher stillbirth rate (P = 0.01). Shelter-raised goats had a higher twining rate (P = 0.01) and a lower abortion rate (P = 0.001). Flocks raised in a shelter system with a worker/animal ratio of 1:100 had a higher kidding rate (P = 0.02) and lower abortion rate (P = 0.0001) than those with the same ratio but raised in a mixed grazing and shelter system. Flocks with managers with a ≥ secondary school education had a higher twining rate (P = 0.002). The most common findings in barren goats were pyometra, ovarian inactivity, abnormal vaginal discharges, and hydrometra. In conclusion, management has a profound effect on the reproductive performance of Ardi goats in Saudi Arabia and should be always considered when attempting to improve their production. |
