Feed Intake, Digestion and Digesta Characteristics of Cattle Fed Bermudagrass or Orchardgrass Alone or with Ground Barley or Corn

Abstract

Feed intake, digestion and digesta characteristics of cattle fed bermudagrass (BG) or orchardgrass (OG) alone or with supplemental ground corn or barley were determined in two 6 x 6 latin squares with 2 x 3 factorial treatment arrangements. In Exp. 1, beef cows (Hereford, Angus and Hereford-Angus; 452 kg) cannulated in the rumen and duodenum were fed BG (7.9% CP, 79% NDF and 8.7% ADL) or OG (9.8% CP, 79% NDF and 7.2% ADL) hays at 1.2% of BW per day either alone or with added ground barley (.64% BW) or ground corn (.60% BW daily). The increase in microbial OM flow with corn was greater for OG than for BG; corn elevated microbial OM flow more than did barley with OG but less than with BG (forage type x grain source interaction; P less than .10). The increase in total tract OM digestion with grain was greater for BG than for OG (supplementation effect and forage type x supplementation interaction; P less than 05). In Exp. 2, Holstein steers (228 kg) were fed BG and OG hays ad libitum either alone or with addition of either 1.07% of BW per day of barley or 1.00% BW of corn. Total DM intake was 2.19, 3.03 and 2.82% BW for BG and 2.14, 2.80 and 2.52% BW for OG alone or with barley or corn supplements, respectively, being affected by forage type, grain supplementation, grain type and a forage type x grain supplementation interaction (P less than .05). Organic matter digested daily (g/d) was higher for OG than for BG, higher with than without grain and higher for barley than for corn (P less than .05).

Digestion characteristics by beef cattle consuming bermudagrass or bromegrass hay alone or with alfalfa and(or) corn

“…Similar ruminai OM digestibilities for BER and BRO agrees with findings of Brake et al (1989) with a cool season grass of greater maturity than the warm season grass used. In the present study, similar ruminai digestion of OM for both forages and higher NDF digestion for BER than BRO probably related to the higher NDF level of BER, slightly greater potential digestibility of BER NDF and faster ruminai digesta passage rate with BRO.…”

“…Higher particulate passage rate (PPR) and fluid passage rate (FPR) for BRO than BER agree with results of other studies in which ruminai digesta passage rates were faster for cool season grasses than warm season grasses with limited Brake et al, 1989) or ad libitum intake (Lagasse et al 1990;Reid et al, 1990). Typically, both PPR and NDF digestibility are greater for cool season grasses than warm season grasses (Minson, 1990).…”

“…A portion of duodenal digesta was lyophilized and ground to pass a 1-mm screen. Another portion was centrifuged at 10,000 x g for 10 min, and supernatant was later analyzed for ammonia nitrogen concentration (Broderick and Kang, 1980). The DM content of whole duodenal digesta also was measured.…”

Influence of grass source on net flux of nutrients across splanchnic tissues in sheep with restricted intake

“…Organic matter, neutral detergent fibre, energy and N digestibilities for W were similar between these experiments; however, values for C were much higher in our study. Thus, level of feed intake may affect extent of total tract digestion of C relatively more than that of W. Though rate of digesta passage from the rumen was not measured in either experiment, it is typically more rapid with high vs low feed intake (Owens and Goetsch, 1986) and for C than for W with limited (Jones et al, 1987;Brake et al, 1989; and ad libitum intake (Lagasse et al, 1990;Reid et al, 1990). Therefore, it is likely that in our experiment ruminai digesta passage rate for W and C did not differ or did so less compared with the previous study (Patil et al, 1995a).…”

“…At the same relative stage of maturity, cool season grasses are more digestible than warm season grasses (Minson, 1990). Primarily because of the lower nonstructural carbohydrate level in warm than in cool season grasses, acetate:propionate in ruminai fluid is greater for warm season grasses (Minson, 1990 warm and cool season grasses does not appear to differ greatly (Jones et al, 1987Brake et al, 1989;, although intestinal amino acid absorption and ruminai volatile fatty acid production may be lower for warm season grasses because of less fermentable organic matter and lower microbial protein synthesis (Hart and Leibholz, 1985;Doyle, 1987). Because of high metabolic activity of splanchnic tissues, effects of differences between forages on net flux of nutrients across splanchnic tissues may not necessarily coincide with expectations based on feed intake, digestibility and concentrations of digestion endproducts in the gastrointestinal tract if splanchnic tissue metabolism varies.…”