Intake, ruminal fermentation parameters, and apparent total-tract digestibility by beef steers consuming Pensacola bahiagrass hay treated with calcium oxide

Abstract

To determine the effect of CaO treated Pensacola bahiagrass (Paspalum notatum) hay on intake, ruminal fermentation parameters, and apparent total tract digestibility of nutrients, 9 ruminally cannulated Angus-crossbred steers were used in a triplicated 3 × 3 Latin square design. Steers had ad libitum access to either: 1) untreated dry hay (DH; n = 8); 2) hay at 50% DM treated with 8.9% CaCO3 [dry matter (DM) basis; CC; n = 9]; or 3) hay at 50% DM treated with 5% CaO (DM basis; CO; n = 8). Water was added to reach 50% DM in the CC and CO diets. Ruminal fluid and blood samples were collected every 3 h for 24 h. Ruminal fluid was analyzed for pH, volatile fatty acids (VFA), and ammonia-nitrogen (NH3-N). Blood was analyzed for plasma urea nitrogen (PUN). Hay and fecal samples were collected for 4 d, 4 times daily for hay and twice daily for feces, to determine apparent total-tract digestibility of nutrients. The hay provided to steers during the digestibility period was analyzed for in vitro organic matter digestibility (IVOMD) for 48h. Data were analyzed as repeated measures for blood and ruminal fermentation parameters. Total DM intake was not affected (P ≥ 0.674) by treatment. A treatment effect (P < 0.001) was observed for average ruminal pH, where steers consuming CO had the greatest pH (P < 0.001). Ruminal concentration of NH3-N tended (P = 0.059) to be reduced in steers consuming CO. There was a treatment × time interaction (P = 0.023) on concentrations of PUN, where at 3 h DH and CO were lesser than CC (P ≤ 0.050) and at 21 h DH was lesser than CC (P = 0.020). Total VFA, acetate, propionate, butyrate, branched-chain VFA, and valerate concentrations were affected by treatment (P ≤ 0.035), where a reduction (P ≤ 0.034) occurred in steers consuming CO. No treatment differences were observed for total-tract digestibility of DM (P = 0.186), organic matter (P = 0.169), or crude protein (P = 0.152); however, steers consuming DH had greater neutral detergent fiber (P = 0.038) than CC and tended to be greater than CO (P = 0.082). The CO hay had greater (P = 0.005) IVOMD compared with DH and tended (P = 0.100) to be greater than CC. Bahiagrass hay treated with CaO may reduce ruminal fermentation, as indicated by decreased total VFA concentration without altering DM intake. The addition of CaO did not improve the digestibility of bahiagrass hay in vivo; however, in vitro results are contradictory and warrant further elucidation.

A Combination of Novel Microecological Agents and Molasses Role in Digestibility and Fermentation of Rice Straw by Facilitating the Ruminal Microbial Colonization

“…The in vitro culture has become a commonly used technique due to its high correlation with in vivo digestibility and ease of operation. Importantly, in vitro degradation is one of the most direct indicators to evaluate feed quality, which not only reflects the utilization status of nutrients but also evaluates the effect of pretreatment (Ciriaco et al, 2021 ). The chemical composition of forage affects digestibility, and generally high CP and low plant cell wall content are beneficial to improving DM digestibility.…”

Effect of Anaerobic Calcium Oxide Alkalization on the Carbohydrate Molecular Structures, Chemical Profiles, and Ruminal Degradability of Rape Straw

“…However, most of the methods have not been widely accepted by farmers due to their high processing costs, unsatisfying effectiveness, and environmental concerns [7]. According to a published study, CaO compared to other chemical reagents like NaOH presents lesser health risks and is easier to handle [8]. Recent studies have demonstrated the potential of anaerobic CaO alkalization in improving the nutritive value of crop residues and other roughages [9,10].…”