Strategic grazing management decreases nitrogen excretion intensity of dairy cows

There is limited information regarding both nitrogen (N) and energy partitioning of dairy cows grazing well–managed tropical pastures. The objective this study was to investigate the N mid–lactation on rotationally grazed elephant grass using two pre–grazing targets: 95 % or maximum canopy light interception (LI95% LIMax) during regrowth. used 26 Holstein × Jersey arranged in a randomized complete block design with three 40–day periods sampling. Grazing at LI95% increased organic matter crude protein intake by 20 (p ≤ 0.05) which resulted 9 increase fat corrected milk yield relative LIMax. Cows had greater concentration total volatile fatty acids, butyrate valerate 0.05), smaller acetate than those Intake net for lactation (NEL) NEL secreted were while towards maintenance tended be = 0.07) Milk urea urine fecal excretion but intensity lower LIMax 0.05). Strategic management target increases losses through feces; however, it reduces %.