Dietary buffer comparison and tannins supplementation modulating subacute ruminal acidosis and fermentation in beef cattle.

As the demand of nutrients by the population will continue to grow over the years, efficient practices are required in the food chain to satisfy the demand. This practice involves the intensification of production systems. Moreover, intensification can potentially harm the animal or environment if the resources are used to the limit. The latter, product of pushing to the limit the ruminal environment. Dietary buffers and tannins offer a key role addressing issues related to intensification. This study aimed to evaluate the effects of two dietary buffers and tannins. Ruminal fermentation parameters, in vitro methane production, ruminal pH, in vitro organic matter digestibility were measured. Eight ruminally cannulated steers were used in a duplicated 4 x 4 Latin square design. Steers were fed with a basal diet comprised of 35.5% corn silage, 18.7% protein supplement, 21.5% corn grain, 22% bermuda hay, 1% mineral supplement (DM basis). Four treatments were used: BICARB (Basal diet + 1.2% DM Sodium Bicarbonate), BRIC-050 (Basal diet + 1.2% DM BRIC), BRIC-150 (Basal diet + 1.2% DM BRIC + 0.15 % DM Tannins), TAN (Basal diet + 0.15% DM Tannins). Steers were housed in individual pens and received every morning a TMR and water ad libitum. The experiment consisted of 4 periods with 16 days total, composed by 3 d of covariates, 7 d of treatment adaptation, 1 d of 50% feed restriction, 1 d SARA challenge, 4 d of recovery, and 20 d of washout between periods. Two in vitro batch culture were performed in every period at the last day of covariates and last day of recovery, collecting ruminal fluid from each animal. Treatments with BICARB promoted a higher pH than TAN during the adaptation at 4 h after feeding (P = 0.01). Moreover, BRIC-150 showed similar results with a tendency to increase (P = 0.07) when compared with TAN. During the feed restriction BRIC-150 showed a greater pH (P = 0.01) when compared with TAN. While, for BICARB and BRIC-050 pH tended to be greater (P = 0.06) than TAN. During the SARA challenge and the recovery, treatments with buffer tended to have greater pH (P < 0.1). A significant reduction ammonia nitrogen was observed for BICARB and TAN compared with BRIC-050 and BRIC-150 (P < 0.01). Overall, the three buffers tested showed similar results in terms of maintaining a greater pH than treatment without buffer. [ABSTRACT FROM AUTHOR]