Partial replacement of corn silage with whole-plant soybean and black oat silages for dairy cows

摘要

This study aimed to evaluate the effects of partiallyreplacing corn silage (CS) with whole-plant soybeansilage (SS) or black oat silage (OS) on nutrient intakeand digestibility, in vitro neutral detergent fiber degradabilityof silages, feeding behavior, rumen fermentation,and performance of dairy cows. Twenty-four lactatingHolstein cows (6 of which were rumen-cannulated) with32.5 ± 4.92 kg/d milk yield, 150 ± 84.8 days in milk,and 644 ± 79.0 kg of body weight were used in a 3 ×3 Latin square design to evaluate the following treatments:(1) corn silage diet (CSD): using corn silage asthe only forage source in the diet [48% dietary dry matter(DM)]; (2) whole-plant soybean silage diet (SSD):SS replacing 16% of corn silage from CSD; and (3)black oat silage diet (OSD): OS replacing 16% of cornsilage from CSD. The inclusion of OS and SS decreasedintakes of DM, organic matter, and crude protein. Cornsilage had the greatest in vivo effective degradabilityof DM, and SS had the least effective degradability ofneutral detergent fiber. The OSD treatment decreasedmilk and protein yields, whereas SSD increased rumenammonia nitrogen concentration compared with theother diets. Cows fed OSD exhibited a greater preferencefor feed with small particles (<4 mm) comparedwith those fed SSD. Cows fed treatments containingeither SS or OS at the expense of CS had increasedrumination and chewing activities. Although replacingCS with OS and SS reduced feed intake, SS had noeffect on productive performance of dairy cows.