Teff grass for continuous stocking in the Southern High Plains by growing beef steers receiving protein supplements

This experiment evaluated forage quality, total nutrient yield, water footprint, and growth performance of beef steers receiving protein supplements while grazing Teff grass ['Tiffany'Eragrostis tef (Zucc.) Trotter] over two consecutive growing seasons. Each year, four 2.66-ha irrigated paddocks (experimental units) were stocked with crossbred beef steers (n = 5 per paddock, initial BW = 289 ± 30 for yr 1; and n = 6, initial BW = 286 ± 23 for yr 2) in a randomized complete block design and stocked continuously for 63 d. Daily supplements [0.45 kg/d of cottonseed meal (Control) enough to avoid a negative ruminal N balance; and 0.50% mean paddock BW animal-daily (approximately 1.65 kg) of sorghum-dried distillers grains plus solubles, (DDGS)] were randomly assigned to two paddocks each. Supplement did not influence forage neutral detergent fiber (NDF), acid detergent fiber, crude protein, or in vitro true digestibility (P ≥ 0.54), except for a tendency (P = 0.08) for a numerical increase in NDF content of paddocks with steers that received DDGS supplementation. Paddock nutrient-yields were similar (P ≥ 0.43) between supplement treatments. Supplementation with DDGS produced greater (P = 0.01) cattle shrunk average daily gain (ADG). Predicted teff dry matter intake (DMI), net energy for maintenance (NE_m), and growth (NE_g) (P ≤ 0.03) were greater with cattle offered Control treatment. Predicted total DMI was similar (P = 0.14) although predicted dietary NE_m, NE_g, gain:feed, and total BW gain were greater (P ≤ 0.02) with DDGS. Predicted forage intake was greater (P ≤ 0.05) for cattle offered Control treatment. Teff nutrients remaining on d 56 were similar (P = 0.33) between treatments. Water footprint for total production of forage nutrient components did not differ (P ≥ 0.12) by treatments. Nutrient yield and water use efficiency of continuously stocked teff grass was not affected by supplemental regimen. Using DDGS as a supplement may increase BW gain through increased nutrient utilization without hindering teff nutrient production on a continuous stocking system.

Ruminal degradation kinetics, intake, digestibility, and feeding behavior of beef steers offered annual or perennial grass-hay with or without supplementation

Effects of dried distillers grains plus solubles (DDGS) on ruminal fermentation, degradation kinetics, and feeding behavior of steers offered annual (Eragrostis tef; TEFF) or perennial (Bothriochloa bladhii; OWB) grass hay were evaluated. Ruminally cannulated Angus crossbred steers (n = 6; body weight [BW] = 304 ± 11 kg) were assigned to a 4 × 6 unbalanced Latin square design with four treatments arranged as a 2 × 2 factorial: hay type (OWB or TEFF) and DDGS supplementation (0% or 0.5% BW [dry matter {DM} basis]). Steers had ad libitum access to hay. Periods consisted of a 14-d adaptation followed by 7 d of collection. Residues from the in situ incubations (0, 3, 6, 12, 24, 36, 48, 72, and 96 h post-feeding) were fitted to a first-order kinetics model using the NLIN procedure of SAS. The DDGS decreased (P < 0.01) TEFF DM intake (DMI) by 11.3%, while not affecting DMI of OWB. The greatest DMI was observed for steers supplemented with DDGS, regardless of forage, and least in steers consuming OWB without DDGS (hay type × DDGS; P = 0.03). Non-supplemented steers spent more (P < 0.01) time eating hay. Digestibility of DM tended (P = 0.06) to increase with DDGS supplementation. A hay type × DDGS interaction was observed (P ≤ 0.05) on ruminal effective degradable fractions. The rate of degradation, soluble fraction, and the potentially degradable fraction of organic matter (OM), neutral detergent fiber, and acid detergent fiber (ADF) increased (P ≤ 0.05), while the undegradable fraction of all components decreased (P ≤ 0.01) when steers were offered TEFF compared to OWB. Ruminal DM, OM, and ADF degradation lag-time increased (P ≤ 0.02) in steers offered OWB. Ruminal degradation kinetics were not (P ≥ 0.17) independently affected by DDGS supplementation. Average ruminal pH of steers offered TEFF (P < 0.01) and those offered DDGS (P < 0.01) were lower than OWB and non-supplemented steers. Total concentration of VFA tended (P = 0.09) to increase when DDGS was provided with OWB, while decreasing when TEFF was offered. The acetate:propionate increased (P < 0.01) with DDGS supplementation due to a decrease (P = 0.03) in propionate. Ruminal NH3-N was greater (P = 0.03) in steers offered TEFF compared to OWB, and those supplemented with DDGS (P = 0.03). An annual, in place of a conventional, perennial hay improved intake and digestion of nutrients, without affecting feeding behavior. The supplementation with DDGS appears to affect forage intake, ruminal degradation, and feeding behavior, although not independent of forage quality.

Comparison of monensin sodium sources for finishing beef cattle

The objective of this study was to evaluate the ruminal fermentation characteristics of ruminally fistulated beef steers consuming a steam-flaked corn (SFC) or dry-rolled corn (DRC) based diet containing either Rumensin 90 (RUM; Elanco, Greenfield, IN), or Monovet 90 (MV; Huvepharma, Peachtree City, GA). Six ruminally fistulated steers (657.7 kg ± 72.6) housed individually were used in a 6 × 6 Latin square design with 2 × 3 factorial treatment arrangement. Each of the 6 periods were 15 d with 14 d for diet adaptation and 1 d of rumen fluid collections. Dietary treatments were DRC without monensin sodium (DRC-C), SFC without monensin sodium (SFC-C), DRC with Rumensin 90 (DRC-R), DRC with Monovet 90 (DRC-MV), SFC with Rumensin 90 (SFC-R), and SFC with Monovet 90 (SFC-MV). Rumen contents and fluid were collected through the fistula of each animal at 0, 3, 6, 12, and 24 h on d 15 of each period. Rumen fluid collected at 6 h post-feeding each period was used for in vitro analyses. Steer was the experimental unit and the model included fixed effects of grain processing, additive, and grain processing × additive. Total gas produced was composited from each in vitro bottle into a gas collection bag for the 48-h determination of methane concentration. No differences were detected for DMI (P = 0.81). Ruminal pH did not differ for the control or additive treatments (P = 0.33). However, ruminal pH was lower (P < 0.01) with SFC compared to DRC. There was a significant difference in acetate to propionate ratio for grain type (P = 0.01) and a tendency for additive inclusion (P = 0.06). Additive inclusion reduced methane proportion of total gas compared to control treatments (P ≤ 0.01). Overall, monensin sodium reduced methane concentration though source had no effect on DMI or ruminal pH.

Ruminal Degradation Kinetics of Beef Steers Fed Annual or Perennial Grass-hay with or Without Supplementation

The effects of dried distillers grains plus solubles (DDGS) supplementation on ruminal degradation kinetics of steers fed annual [‘Tiffany’Eragrostis tef (Zucc.) Trotter; TEFF] or perennial [‘WW-B Dahl’ Old World bluestem, Bothriochloa bladhii (Retz).T. Blake; OWB] grass hay were evaluated. Ruminally cannulated crossbred-Angus steers (n = 6; BW = 304 ± 11 kg) were assigned to a 4 × 6 unbalanced Latin square design with 4 treatments. Treatments were arranged as a 2 × 2 factorial, with factors being hay type (OWB or TEFF) and DDGS supplementation [0 or 0.5% BW (DM basis)]. Steers had ad libitum access to hay and received 110 g of a mineral/vitamin packet daily. Periods consisted of a 14-d adaptation followed by 7 d of collection. Hay types were reverse-incubated at 0, 3, 6, 12, 24, 36, 48, 72, and 96 h post-feeding. Residues from the in situ incubations were fitted to a first-order kinetics model using the non-linear procedure of SAS. The GLIMMIX procedures of SAS were used for the statistical analysis. A hay type × DDGS interaction was observed (P ≤ 0.05) for the estimation of substrate effective degradable fraction of OM, NDF, ADF, and hemicellulose; however, after adjusting with Tukey’s, there were no treatment mean differences (P ≥ 0.08). The rate of digestion, soluble fraction, and the potentially degradable fraction of OM, NDF, ADF, and hemicellulose increased (P ≤ 0.05), while the undegradable fraction decreased (P ≤ 0.01) when steers were fed TEFF, regardless of DDGS supplementation. Ruminal degradation lag-time increased (P ≤ 0.02) by 1.5, 1.45, and 2.6 h for DM, OM, and ADF, respectively in steers fed OWB, regardless of DDGS supplementation. Ruminal degradation kinetics were not (P ≥ 0.17) independently affected by DDGS supplementation. Future investigations should elucidate the interaction between supplementation and forage quality.

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33 Comparison of Monensin Sodium Sources for Finishing Beef Cattle

The objective of this study was to evaluate the digestive characteristics of ruminally cannulated beef steers consuming a steam-flaked corn (SFC) or dry-rolled corn (DRC) based diet containing either Rumensin 90 (R) or Monovet 90 (MV). Six ruminally fistulated steers (657.7 kg ± 72.6) housed individually were used in a 6 × 6 Latin square design with a factorial treatment arrangement. Each of the 6 periods were 15 d with 14 d for diet adaptation and 1 d of rumen fluid collections. Six 15-d periods consisted of 14 d diet adaptation prior to rumen fluid collections. Dietary treatments were DRC without monensin sodium (DRC-C), SFC without monensin sodium (SFC-C), DRC with Rumensin 90 (DRC-R), DRC with Monovet 90 (DRC-MV), SFC with Rumensin 90 (SFC-R), and SFC with Monovet 90 (SFC-MV). Rumen contents and fluid were collected through the fistula of each animal at 0, 3, 6, 12, and 24 h on d 15 of each period. Rumen fluid was collected 6 h postfeeding each period for in vitro analyses. Steer was the experimental unit and the model included fixed effects of grain processing, additive, and grain processing × additive. Total gas produced was composited from each in vitro bottle into a gas collection bag for the 48-h determination of methane concentration. No differences were detected for DMI (P = 0.81). Ruminal pH did not differ for the control or additive treatments (P = 0.33). However, ruminal pH was lower (P &lt; 0.01) with SFC relative to DRC There was a significant difference in acetate to propionate ratio for both additive (P = 0.04) and grain type (P ≤ 0.01). Additive inclusion reduced methane proportion of total gas relative to control treatments (P ≤ 0.01). Monensin sodium reduced methane concentration though source had no effect on DMI or ruminal pH.

PSXIV-41 Warm-season annual or perennial hay fed to growing beef steers with or without dried distillers grains supplementation: ruminal fermentation characteristics, digestion, and feeding behavior

The effects of hay type and protein supplementation on intake, feeding behavior, nutrient digestion, and ruminal digestion characteristics were evaluated. Ruminally cannulated Angus beef steers (n = 6; BW = 304 kg ± 11 kg) were randomly assigned within a sequence of treatments using a 4 × 6 unbalanced Latin square design (6 steers; and 4 diets; fed once-daily). A 2 x 2 factorial treatment arrangement was used as follows: 1) ‘WW-B. Dahl’ Old World bluestem [Bothriochloa bladhii (Retz) S.T. Blake; WWBD or Eragrostis tef (Zucc.) Trotter; TEFF); and 2) dried distillers grain (DDGS) at 0 or 0.5% BW. Each period consisted of a 14-d of adaptation and 7-d collection. Steers were observed (5-min intervals, 24 h) for behavioral assessment; while ruminal pH was continuously measured (wireless pH probe), and ruminal fluid collected at 0, 2, 4, 8, and 16 h after-feeding. Steers fed TEFF hay and those fed DDGS (both, P = 0.04) had greater DMI compared to WWBD and not supplemented. Chewing activity did not differ (P ≥ 0.54). Non-supplemented steers spent more time eating hay (P &lt; 0.01) than supplemented steers. Average ruminal pH of TEFF (6.32) was lower (P &gt; 0.01) than WWBD (6.56). Non-supplemented steers produced less in vitro total gas and methane (both, P = 0.02) per g rumen fluid DM. The VFA profile was not affected (P ≥ 0.45) by treatments. Apparent total-tract digestibility and ruminal degradation (P ≤ 0.01) were greater with TEFF fed steers than WWBD. Hemicellulose digestion was reduced by 6.95% (P = 0.03) with DDGS supplementation. An annual hay in place of a conventional perennial hay improved intake, ruminal digestion of nutrients, without affecting feeding behavior, while supplementation with DDGS reduced forage intake time and quantity, without negatively affecting ruminal fiber digestion.

Effects of silage type and inclusion level on ruminal characteristics and feeding behavior of steers fed finishing diets

Crossbred beef steers fitted with a ruminal cannula were used to study the effects of silage type (BH 8895 corn or AF7401 sorghum) and level of inclusion (10 or 20%) in beef cattle finishing diets on digestibility of nutrients, ruminal kinetics, in vitro methane production, and feeding behavior. A 4 × 6 unbalanced Latin square design was used (6 steers; 363 ± 23 kg; 4 diets: corn silage [CS] or sorghum silage [SS], both at 10 or 20% inclusion, DM basis). Each period consisted of 14 d of adaptation and 7 d of collection. Steers were fed once daily at 1000 h. An additional study evaluated the ruminal degradability of intact ensiled sorghum grain ruminally incubated in 3 steers (547 ± 56 kg BW), using the same hybrids from the main study from 10 laboratory experimental silos. The GLIMMIX procedures of SAS were used for statistical analyses. Steers fed SS had greater NDF intake ( < 0.01) compared with the ones fed CS. The magnitude of the NDF intake change depended on the level of inclusion ( < 0.01), which was 6 and 16% for 10 and 20% inclusion, respectively. Regardless the level of inclusion, CS diets promoted greater ( ≤ 0.01) apparent total tract digestibility of nutrients evaluated (DM, OM, NDF, ADF, hemicellulose, and starch) compared with SS diets. Steers fed SS diets tended to chew 1.1 h/d more ( = 0.07) than steers fed CS diets. The level of inclusion increased ( = 0.02) the chewing time per day by 1.3 h. No major differences were observed in any of the ruminal pH and in vitro gas production variables evaluated for silage type and inclusion level ( ≥ 0.09). The CS-fed steers had 12% greater total VFA concentration and an 18.5% lower ( < 0.01) acetate-to-propionate ratio compared with SS-fed steers. The acetate-to-propionate ratio was 16% greater ( < 0.01) when steers were fed SS compared with when steers were fed CS. The CS samples were more extensively ruminally degraded ( < 0.01) than the SS samples. Greater ( < 0.01) NDF ruminal disappearance was observed in ruminal environments containing 20% silage compared with those containing 10% silage. After 96 h inside the rumen, intact ensiled sorghum grain degradability of DM reached only 51.7%. Replacing CS with SS in beef finishing diets (low roughage inclusion) requires adjustments to balance dietary energy. Sorghum material induced a desirable roughage effect in feeding behavior but also offered the potential for improved regarding fiber digestibility and intact grain ruminal degradability.