Citrus aurantium flavonoid extract improves concentrate efficiency, animal behavior, and reduces rumen inflammation of Holstein bulls fed high-concentrate diets

Abstract

Abstract One hundred fourty-four bulls (164.8\u202f±\u202f5.91\u202fkg BW and 135\u202f±\u202f7.2 d of age) were randomly allocated to one of 8 pens and assigned to control (C) or citrus flavonoid (BF) treatments (Citrus aurantium, 0.4\u202fkg per ton of concentrate of Bioflavex CA, > 20% naringin; BF). Each pen had one drinker, one separate five-space straw feeder, and one separate three-space feeder where mash concentrate containing mostly corn, barley, DDG and wheat was offered. Concentrate intake was recorded daily, whilst BW and animal behavior were recorded fortnightly. Animals were slaughtered after 168 d of study (12 periods of 14 d), and HCW and carcass quality were recorded, and rumen papillae samples were collected. Final BW (437.9\u202f±\u202f1.85\u202fkg), HCW (238.7\u202f±\u202f2.02\u202fkg), and concentrate intake (7.1\u202f±\u202f0.13\u202fkg/d) were not affected by treatment. Concentrate feed conversion ratio (kg of concentrate/ kg of BW) tended (P