Sites of Digestion in Beef Steers Fed Bermudagrass Hay and Supplemented with High-Nitrogen Feeds alone or Mixed with Tallow

Abstract

Five crossbred beef steers (329 kg) were used in a 5 x 5 Latin square experiment with 14-d periods to determine the effects of supplementation with high-nitrogen (N) feeds alone or mixed with tallow on sites of digestion with a basal diet of bermudagrass hay. Hay was 1.93% nitrogen, 75% neutral detergent fibre and fed at 1.83% of body weight (dry matter; DM). Supplements were basal (B; 105 g DM): 81.8% dried molasses product (DMP) and 18.2% calcium carbonate (CC); soybean meal (S; 942 g DM): 88.0% soybean meal, 9.8% DMP and 2.2% CC; S mixed with 9.8% tallow (SF; 1041 g DM); corn gluten and blood meals (CB; 662 g DM): 62.5% corn gluten meal, 20.8% blood meal, 13.6% DMP and 3.0% CC; CB mixed with 13.2% tallow (CBF; 757 g DM). Total N intake was 117, 185, 187, 174 and 172 g/d, and duodenal N flow was 121, 148, 143, 162 and 169 g/d for B, S, SF, CB and CBF, respectively, being lower for B than for other treatments and higher for supplements with the corn gluten and blood meal mix than for soybean meal (P less than 0.05). Duodenal microbial N flow was 39, 51, 49, 38 and 45 g/d for B, S, SF, CB and CBF, respectively, being greater (P less than 0.05) for supplements with soybean meal than with corn gluten and blood meals. Duodenal flow of feed N was greater (P less than 0.05) with than without high-N feeds and for supplemental corn gluten and blood meals than for soybean meal (78, 90, 86, 117 and 116 g/d for B, S, SF, CB and CBF, respectively). In conclusion, mixing of tallow and high-N feeds did not affect the extent of ruminal N disappearance, and soybean meal supplementation increased duodenal N flow less than did supplementation with corn gluten and blood meals. Increased duodenal N flow with soybean meal was associated with about equal elevations of ruminal outflow of microbial and feed N, whereas the corn gluten-blood meal mix affected the intestinal protein supply by increasing ruminal escape of feed protein.

Digestion and live-weight gain by beef cattle consuming bermudagrass supplemented with grain or different high-protein foodstuffs

“…S LWG was slightly lower than for other Ruminal losses of N for S, GB and M + S were considerable, whereas for other treatments N intake and duodenal flow differed little. N intake and appearance at the duodenum have been similar in other trials with unsupplemented cattle fed bermudagrass (Jones, Goetsch, Stokes and Colberg, 1988;Landis et al, 1989;Hall, Goetsch, Landis, Forster and Brake, 1990). The ruminal loss of N for treatment GB in this study could have been due to the feeding of the supplement once instead of twice per day as indicated by the work of Landis et al (1989).…”

“…In period 1, and pattern of energy liberation from LWG was highest for M + GB, while M + bermudagrass fermentation. The ruminal loss of N for treatment GB in this study could have been due to the feeding of the supplement once instead of twice per day as indicated by the work of Landis et al (1989). Landis, Goetsch, Forster and Brake (1989) also increased ruminal N loss by supplementing beef steers consuming bermudagrass hay with soya-bean meal, but pre-intestinal N disappearance was not markedly affected by providing a mixed maize-gluten-blood meal supplement.…”

“…Heifers have other studies have shown that low-level maize less potential to deposit protein than steers, supplementation of the diets of cattle but a growth stimulant was employed in ingesting bermudagrass increases performance experiment 2 which may have changed the (Brake et al, 1989;Goetsch, 1989; Hardin et potential protein accretion of the trial heifers al., 1989; A. L. Goetsch, unpublished data), to a level similar to untreated steers. Heifers have other studies have shown that low-level maize less potential to deposit protein than steers, supplementation of the diets of cattle but a growth stimulant was employed in ingesting bermudagrass increases performance experiment 2 which may have changed the (Brake et al, 1989;Goetsch, 1989; Hardin et potential protein accretion of the trial heifers al., 1989; A. L. Goetsch, unpublished data), to a level similar to untreated steers.…”

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

“…Numbers of protozoa in the rumen were not estimated, but increases are frequently associated with elevated butyrate production (Ushida et al, 1986), as was observed with corn supplementation in this experiment. Supplementing forage diets with corn has increased the number of protozoa (Hall et al, 1990;Landis et al, 1990), and legumes promote relatively large protozoal populations (Ushida et al, 1986;Ushida and Jouany, 1990). Constant feed intake, restricting ruminai digesta outflow with supplementation, and minimizing protozoal washout (Michalowaski and Muszynski, 1978), could have accentuated substrate-induced increases in numbers of protozoa (Jouany et al, 1988).…”

Ruminal degradation characteristics of corn and corn–sunflower intercropped silages prepared at two stages of maturity

“…The manner of delivery of fat to the animalas a fat supplement (Ikwuegbu and Sutton 1982;Broudiscou et al 1990;Landis et al 1990), as supplementation with a fat-containing product (Davenport et al 1987), or as a fatcoated supplement (Glenn et al 1977) affects the degradability of feed nutrients.…”