Production level, feed conversion efficiency, and nitrogen use efficiency of dairy production systems in China.

A study was conducted in China to evaluate the feed conversion efficiency, nitrogen use efficiency, and the amount of human-edible grains fed under different dairy systems. Three dairy systems were defined and studied: (i) smallholder subsistence farms (SH), (ii) peri-urban farms (PR), and iii) cooperative farms (CO). The PR system had the highest milk yield, better feed conversion efficiency, better nitrogen use efficiency, and used lower proportion of grains in the diet. Within a system, different farms had wide variations in feed conversion efficiency and nitrogen use efficiency, suggesting the need to improve management practices within the system. Among the three systems, SH and CO systems require the most improvements in the management practices.