Beef cow–calf production system integrated with sugarcane production: Simulation model development and application in Japan

The objective of this study was to develop a simulation model for the integration of a beef cow–calf production system and sugarcane production system on Tanegashima Island. A survey was carried out to characterize and identify the role of sugarcane as an alternative feed resource and determine the different interactions within the system. The model was divided into two sub-systems: beef cow–calf and sugarcane and manure production sub-systems. The model is able to simulate the total requirement for energy and protein, and subsequent losses of nitrogen via faeces and urine, throughout the reproductive cycle of a mature cow and the growing stages of her calf. It also estimates the area under sugarcane cultivation for feed and the area on which manure can be applied to complement inorganic fertilizer. A linear programming (LP) approach was used to formulate the least-cost diet and a system simulation method was used to calculate the nitrogen (N) excretion for a cow and her post-weaning calf in the different physiological stages. The model was used to evaluate two scenarios (integrated and specialized scenarios) using production conditions on Tanegashima Island.