School of Agricultural, Earth and Environmental Sciences

Professor Ignatius Nsahlai.

Inaugural Lecture Focuses on Ruminant Nutrition

Professor of Animal Science Ignatius Nsahlai shared his decades of experience in assessing ruminant nutrition at his inaugural lecture on the nature of diet intake by ruminants, unpacking useful models to estimate the energy available to livestock from their nutrition.

Deputy Vice-Chancellor and Head of the College of Agriculture, Engineering and Science Professor Albert Modi welcomed guests and said that inaugural lectures that provide official recognition of promotion to full professor present the opportunity to showcase the exciting and ground-breaking research and teaching carried out by professors at UKZN to a wider audience.

Internationally recognised for his research and teaching in livestock production, Nsahlai’s presentation captured significant milestones in his research career, focusing on three studies where he examined Digestible Organic Matter (DOM) intake as a proxy for dietary available energy. With his research team, he developed a model to estimate DOM intake by sheep, that suggests that animals from the hot, humid tropics may have decreased maintenance needs and/or highly efficient usage of metabolisable energy.

‘Scientists want to know what’s happening in the rumen, and the biophysical environment impacts the actual level of production that might not meet desired levels,’ said Nsahlai.

He described the development of a methodology that used urine samples to estimate the DOM intake of grazing livestock with redesigned tools and approaches to capture water intake.

Nsahlai also offered insight into using models to estimate DOM to correct estimations of methane emissions, saying that animals are often blamed for these emissions but that the consequences of diet on emissions needs to be understood. To achieve this, his research group developed a model to estimate methane that is 20% more effective than other leading models.

He examined whether formulated diets would be fully consumed through an empirical model developed by his research group and one developed by other researchers which had a promising structure but required calibration of input parameters.

Nsahlai, who is originally from Cameroon, completed his undergraduate degree in Zoology and a postgraduate diploma in Animal Physiology at the University of Yaoundé. Thanks to a Cameroon Government Scholarship, he was able to complete a postgraduate diploma in Animal Production and a PhD in Animal Science at the University of Reading in the United Kingdom (UK).

He worked as a feed analyst in the UK before being awarded a postdoctoral fellowship at the International Livestock Centre for Africa (ILCA, now the International Livestock Research Institute) in Ethiopia, where he was later appointed Associate Scientist.

Nsahlai joined the then University of Natal’s renowned Department of Animal and Poultry Sciences as a senior lecturer in 1996 and was promoted to associate professor in 2007 and full professor in 2021. While at UKZN he spent a sabbatical at the American Institute of Goat Research in the United States.

In addition to teaching, Nsahlai has served the National Research Foundation (NRF) as an evaluation panel member, selection committee member and reviewer of funding proposals and promotions. He has served as a proposal reviewer for the CGIAR and United States-Israel Binational Agricultural Research and Development Project, a mentor and facilitator of the Sub-Saharan Africa Challenge Programme, a sub-editor of the South African Journal of Animal Science, and a reviewer for various journals.

With a C1 rating from the NRF, Nsahlai has supervised 17 PhD and 30 master’s graduates and has published three manuals, six book chapters, 138 refereed journal articles, and 71 conference proceedings.

The father of five credited his wife Joan’s support for enabling him to reach the point of presenting his inaugural lecture. He thanked God for his success.

Modi praised Nsahlai for his resilience and publishing record, and expressed the University’s gratitude to his family for their contribution through him.

Words: Christine Cuénod

Photograph: Supplied