A study of some economic traits in a herd of Kenana cattle (Northern Sudan Zebu) I. Birth weight in Kenana cattle

The mean birth weight of Kenana calves in the herd under investigation was 24.2±2.8 kg. Male calves were 1.3 kg heavier at birth than female-calves. The difference was attributed, parity at least, to longer gestation length in case of the male-calves. Calves born to cows 2½-5½ years old were significantly lighter than those born to older cows. Likewise calves born to primiparous dams were significantly lighter at birth than those born to multiparous dams

A study of some economic traits in a herd of Kenana cattle. Service period, calving interval and gestation period

The reproduction of the Kenana cattle was studied to establish the service period (SP), calving interval (CI) gestation period (GP), and economic production characteristics. Age of cow had significant effect on SP and highly significant effect on calving interval. The variations in the SP and in the CI were due to non-genetic factors which could be improved through management

A study of some economic traits in a herd of Kenana cattle (North Sudan Zebu). II. Age at first calving and effects of improved nutrition on body development and sexual maturity

The work reported in this paper was initiated to estimate the age at first calving in herd of Kenana cattle with particular reference to the influence of year and season of the birth on age of heifers at calving. It included a feeding trail to elucidate the effects of improved nutrition on body development and sexual maturity of Kenana heifers. The mean age at first calving was found to be 45.2±7.6 months. The study revealed significant (

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

The past 2 years, during which waves of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants swept the globe, have starkly highlighted health disparities across nations. Tegally et al. show how the coordinated efforts of talented African scientists have in a short time made great contributions to pandemic surveillance and data gathering. Their efforts and initiatives have provided early warning that has likely benefited wealthier countries more than their own. Genomic surveillance identified the emergence of the highly transmissible Beta and Omicron variants and now the appearance of Omicron sublineages in Africa. However, it is imperative that technology transfer for diagnostics and vaccines, as well the logistic wherewithal to produce and deploy them, match the data-gathering effort