Effects of silage type and inclusion level on ruminal characteristics and feeding behavior of feedlot steers

• Published in: Journal of animal science 2016-10, Vol.94, p.725-726
• Main Authors: Campanili, P R B, Sarturi, J O, Trojan, S J, Ballou, M A, Pellarin, L A, Sugg, J D, Ovinge, L A, Alrumaih, A, Hoffman, A A
• Format: Article
• Language: English
• Subjects: Acetic acid; Beef; Corn; Corn silage; Data collection; Data processing; Degradability; Degradation; Diet; Digestibility; Feeding; Feeding behavior; Fermentation; Grain; Medical materials; Propionic acid; Roughage; Silage; Sorghum; Starch; Studies; Tubes
• ISSN: 0021-8812; 1525-3163

Silage type and level of inclusion on beef cattle finishing diets ruminal fermentation and degradability, digestibility, and feeding behavior were evaluated. In Study 1, beef steers (n = 6; BW = 363 ± 23 kg) fitted with ruminal cannula were used (6 x 4 unbalanced Latin square design). Treatments (n = 4) consisted of silage type (corn = BH8895 and sorghum = AF7401) and silage inclusion (10 or 20%, DM basis). Each period consisted of 14 d for adaptation and 7 d for collections. Steers were individually fed ad libitum once daily. Silage degradability was studied by in situ technique. In Study 2, the same technique was used to study the degradability of intact ensiled sorghum grain (n = 10; 18.9-L units; 112 d of storage; 2 sites). Beef steers (n = 3; BW = 547 ± 56 kg) fed a growing diet were used. Data were analyzed using Glimmix procedure of SAS (day as repeated measure). Steers fed 20% sorghum silage had greater DMI (P = 0.03) and total VFA (P = 0.01) but tended (P = 0.07) to the least propionate molar proportion compared with other treatments. Steers fed 10% corn silage had the greatest (P ≥ 0.04) ruminal butyrate and the least (P < 0.01) ruminal pH average compared with other treatments, which reached nadir at 5.62 (P < 0.01) 12 h after feeding. Additionally, the 10% corn silage treatment tended (P = 0.09) to have the least in vitro methane production. Starch digestibility tended (P = 0.08) to peak for steers fed 10 and 20% corn silage (98%) and bottom for steers fed 20% sorghum silage (92%). Steers fed corn silage had greater (P ≥ 0.01) total tract apparent digestibility (11% DM and 32% NDF), lower (P < 0.01) acetate/propionate, and 34% greater (P < 0.01) silage ruminal degradation and tended (P = 0.07) to chew 1.1 h/d less compared with steers fed sorghum silage diets. Steers fed 20% silage chewed and ruminated more (P ≤ 0.04), degraded more (P < 0.01) NDF, and had greater (P < 0.01) acetate/propionate but less DM digestibility than 10% silage-fed steers. Sorghum grain ruminal degradability reached 52% at 96 h. Replacement of corn silage with sorghum silage in beef finishing diets requires adjustments to balance dietary energy. Sorghum material induced a desirable roughage effect in feeding behavior but also offered potential to be improved regarding fiber digestibility and intact grain ruminal degradability.