Technical Note: Collection and preparation techniques change nutrient composition of masticate collected from esophageally fistulated cattle.

Two experiments determined effects of collection and preparation techniques on nutrient composition of masticate samples from esophageally fistulated cattle. In Exp. 1, 12 esophageally fistulated cattle were maintained on 2 precollection diets, high CP (24% CP; = 6) or low CP (7.7% CP; = 6), for 8 d. On d 9, the esophageal plug was removed, screen bottom bags were attached, and each cow was offered fresh grass. Immediately after fresh grass sample collection was complete, dry grass (hay) was offered and a sample was collected. Blood samples were collected and analyzed for serum urea nitrogen concentration. Masticate samples of both fresh and dry grass were divided and each was either squeezed by hand until no more saliva could be removed or remained unsqueezed. In Exp. 2, 10 esophageally fistulated cattle were fitted with either screen ( = 5) or solid ( = 5) bottom collection bags after removal of the esophageal plug and presented grass hay, fresh grass, alfalfa hay, or fresh alfalfa. In Exp. 1, the precollection diet did not affect ( = 0.49) CP content of masticate even though serum urea nitrogen tended to be greater ( = 0.08) for high- vs. low-CP precollection diets. Forage harvest type offered (fresh vs. hay) interacted ( = 0.01) with preparation technique (squeezed vs. unsqueezed) for CP, where CP decreased in squeezed fresh samples ( < 0.001) but not in squeezed grass hay samples ( = 0.98). In Exp. 2, ingestion greatly increased levels of ash ( < 0.001). Crude protein was greater ( < 0.004) before ingestion for all samples except grass hay ( = 0.43). Levels of NDF were similar before and after ingestion ( > 0.15) for all samples except fresh alfalfa, which was greater after ingestion ( = 0.002). Ingestion status did not affect in vitro OM disappearance (IVOMD; > 0.34) except for grass hay, which was greater after ingestion ( < 0.001). Bag type (screen vs. solid) did not affect ash and NDF ( > 0.31), except for fresh alfalfa, which were greater ( < 0.03) for solid bottom bags. Bag type did not affect alfalfa CP ( = 0.71) but did affect grass CP, which was lower ( = 0.02) for solid bottom bags. Bag type did not affect IVOMD ( > 0.33). More ( = 0.01) fresh forage than hay was recovered through the esophageal opening. Previous diet did not impact masticate samples but squeezing impacted CP levels of high-quality forage and therefore should not be performed. Nutrient values should be reported on an OM basis.

Effects of stocking rate on forage nutrient composition of Nebraska Sandhills upland range when grazed in early summer.

Twelve 2-ha, Nebraska Sandhills upland range paddocks were used in a 2-yr study to determine effects of stocking rate on grazed forage nutrient value in early summer. Paddocks contain a mixture of native cool- and warm-season grasses with forbs as a minor component. Stocking rates were 0 (control), 0.57 (light), and 0.85 (heavy) animal unit months per ha, respectively. Three esophageally fistulated cows collected diet samples on May 14 (d 0), May 21 (d 7), May 28 (d 14), and June 4 (d 21) in 2013 and 2014. Ten quadrats per paddock were clipped and separated into current or previous year growth on each diet sampling date. All samples were analyzed for CP, NDF, and in vitro OM disappearance, which was adjusted to an in vivo OM basis (). For diet samples, treatment interacted ( < 0.001) with sampling date for CP, NDF, and IVOMD. However, treatment and date did not interact ( ≥ 0.32) for clipped samples. Diets collected in control paddocks had greater ( < 0.05) IVOMD and CP and lower NDF compared with light and heavy stocking rate paddocks on d 7, 14, and 21 but light stocking rate paddocks did not differ ( ≥ 0.26) from heavy stocking rate paddocks on any sampling day except d 21 NDF ( = 0.03). In general, previous year growth IVOMD, CP, and NDF were not affected ( ≥ 0.11) by treatment. Generally, current year growth IVOMD and CP were not affected ( ≥ 0.22) by treatment. Current year growth NDF did not differ ( = 0.23) among stocking rates on d 0, but control paddock had lower ( = 0.02) NDF than light and heavy on d 7, 14, and 21. In stocked paddocks, diet samples had greater ( < 0.01) IVOMD and CP and lower NDF than current and previous year growth except IVOMD on d 0 where diet and current year growth did not differ ( = 0.34). Generally, in control paddocks, current year growth and diet samples had greater ( < 0.01) IVOMD and CP than previous year growth. Control paddocks had greater ( < 0.01) forage accumulation than stocked paddocks on d 7, 14, and 21; however, light and heavy stocked paddocks did not differ ( ≥ 0.29). On d 0 it was estimated that 96% of the diet was current year growth and only 4% previous year growth, whereas on d 21, 70% of the diet was current year growth vs. 30% previous year growth. Stocking pastures decrease current year growth forage mass and therefore diet nutritive value by forcing cattle to consume diets containing previous year growth in early summer.

Effects of 35% corn wet distillers grains plus solubles in steam-flaked and dry-rolled corn-based finishing diets on animal performance, carcass characteristics, beef fatty acid composition, and sensory attributes.

Fifty-four individually-fed Hereford-Angus cross steers (initial BW = 308 ± 9 kg) were used in an unbalanced randomized block design with a 2 × 2 factorial treatment arrangement to determine effects of corn processing method and corn wet distillers grains plus solubles (WDGS) inclusion in finishing diets on animal performance, carcass and beef characteristics, and sensory attributes. Dietary treatments included steam-flaked corn- (SFC) and dry-rolled corn (DRC)-based finishing diets containing 0 or 35% WDGS (DM basis; 0SFC and 35SFC, 0DRC and 35DRC, respectively). Yellow grease was used to equilibrate fat content of diets. Steers were fed 174 d, and were harvested on a single date when the mean ultrasound fat thickness was estimated to be 1.30 cm. No interactions between corn processing and WDGS were observed for performance or carcass characteristics (P ≥ 0.11). Final BW (556 ± 14 kg) and ADG (1.43 ± 0.06 kg) were not affected (P ≥ 0.25) by dietary treatment. Steers fed SFC-based diets consumed less feed, and were 10.6% more efficient (P < 0.01) than those fed DRC-based diets. Including WDGS in finishing diets improved feed efficiency of steers consuming both SFC- and DRC-based diets (P ≤ 0.04). Dietary treatment did not affect HCW, dressing percentage, fat thickness, or yield grade (P ≥ 0.27). Including WDGS in finishing diets decreased the concentration of 16:1cis-9, 18:1cis-9, and 18:1cis-11 fatty acids, and tended (P ≤ 0.10) to increase total fat concentration of steaks compared with diets without WDGS. A corn processing method by WDGS interaction was detected for 18:1trans-11 where steaks from 0DRC diets had decreased concentrations compared with other diets. There were no dietary effects on palatability attributes (P > 0.20). Livery-organy aromatics (P = 0.03) and sweet basic tastes (P = 0.01) in steaks from the 35SFC treatment were more intense than in other treatments, but were barely detectable. Thiobarbituric acid reactive substances tended to be greater in steaks from steers fed WDGS after 5 d of storage (P = 0.10), and were greater after 7 d. (P < 0.01). Inclusion of WDGS used in this experiment improved G:F with minimal impacts on carcass characteristics. Both WDGS inclusion and corn processing method impacted fatty acid composition. However, diet had minimal impacts on palatability attributes. When compared with diets fat-equilibrated with yellow grease, the primary concern with incorporating WDGS appears to be decreased shelf-life after 5 d of storage.

Effects of twenty percent corn wet distillers grains plus solubles in steam-flaked and dry-rolled corn-based finishing diets on heifer performance, carcass characteristics, and manure characteristics.

Two hundred sixty-four crossbred heifers (initial BW = 354 kg ± 0.5) were used to determine effects of corn processing method and wet distillers grains plus solubles (WDGS) inclusion in finishing diets on animal performance, carcass characteristics, and manure characteristics. The study was conducted as a randomized complete block with a 2 × 2 factorial arrangement of treatments. Dietary treatments included steam-flaked corn (SFC)- and dry-rolled corn (DRC)-based finishing diets containing 0 or 20% WDGS (0SFC, 20SFC, 0DRC, and 20DRC, respectively). Heifers averaged 154 d on feed and were marketed in 3 groups. There were no interactions between corn processing method and WDGS detected (P ≥ 0.29) for any performance or carcass response variables. Heifers fed diets containing WDGS tended to have greater final BW (P = 0.10) and increased G:F (P = 0.08) compared with heifers fed diets without WDGS. Heifers fed SFC-based diets consumed 7% less feed (P < 0.01) and were 9% more efficient (P < 0.01) than heifers fed DRC-based diets. Carcass characteristics were not affected by corn processing method or WDGS inclusion (P ≥ 0.16). Intakes of OM, N, P, and K were greater (P ≤ 0.05) for heifers fed DRC-based diets than those fed SFC-based diets, which resulted in greater net accumulation of the nutrients in the manure (P ≤ 0.04). Heifers fed diets containing WDGS had greater (P < 0.01) intakes of N, P, and K than heifers fed diets without WDGS. As a result, a greater net accumulation of P and K (P ≤ 0.03) and N (P = 0.10) were present in the manure from cattle fed diets containing WDGS compared with those fed diets without WDGS. There was no interaction (P ≥ 0.16) between corn processing and WDGS on N volatilization losses. Nitrogen volatilization losses from manure (expressed as a percentage of intake and g·heifer(-1)·d(-1)) were greater (P < 0.01) for heifers fed SFC-based diets than heifers fed DRC-based diets. Feeding DRC-based finishing diets to heifers resulted in increased manure production and nutrient excretion and decreased N volatilization. Both corn processing method and WDGS inclusion affected animal performance and manure characteristics.

Use of dried distillers grains throughout a beef production system: effects on stocker and finishing performance, carcass characteristics, and fatty acid composition of beef.

A 2-yr study was conducted using a 3 × 2 factorial arrangement of treatments to evaluate the effects of feeding dried distillers grains throughout a beef production system on performance, carcass characteristics, and fatty acid profile of beef. Factors were wheat pasture supplement [no supplement (CON), dry-rolled corn (DRC), and dried distillers grains (DDG)] fed at 0.5% BW daily and finishing diet [steam-flaked corn based diet containing 0 (SFC) or 35% (35DDG) DDG]. Each year, 60 preconditioned Hereford steers (initial BW = 198 kg ± 3) grazed winter wheat pasture with or without supplement. Body weight gain was 8% greater for steers consuming DDG supplement compared with CON and DRC steers (P < 0.01). After the grazing period, pastures within supplement treatment were randomly assigned to SFC or 35DDG. There was no supplement by finishing diet interaction for any performance or carcass variable of interest (P ≥ 0.41). Previous supplementation on winter wheat affected BW at feedlot entry and adjusted G:F (P ≤ 0.05) but had no effect on finishing ADG or carcass traits (P ≥ 0.12). On a carcass-adjusted basis, steers consuming 35DDG had reduced final BW, ADG, G:F, and total BW gain throughout the system (P ≤ 0.04) compared with SFC. Additionally, steers consuming 35DDG had reduced HCW, dressing percent, and fat thickness (P ≤ 0.03) compared with SFC. There was a supplement by finishing diet interaction (P = 0.02) for 18:0, in which cattle supplemented with DRC and fed the SFC finishing diet had the lowest concentration of 18:0 but DRC supplemented steers fed the 35DDG diet had the greatest concentration. The interaction was not significant (P ≥ 0.18) for other fatty acids. Main effects of supplement and finishing diet affected (P ≤ 0.05) several other fatty acids of interest, particularly 18:2, which is associated with reduced flavor-stability of beef. The use of DDG as a supplement to wheat pasture resulted in greater ADG during wheat grazing and heavier BW at feedlot entry, but final BW was not different from CON or DRC groups. Feeding DDG at 35% DM in steam-flaked corn-based finishing diets reduced ADG, G:F, and HCW, and affected the fatty acid composition of beef.

Wet distillers grains plus solubles concentration in steam-flaked-corn-based diets: Effects on feedlot cattle performance, carcass characteristics, nutrient digestibility, and ruminal fermentation characteristics.

Two experiments were conducted to determine the effects of wet distillers grain plus solubles (WDG; <15% sorghum grain) concentration in steam-flaked corn (SFC) diets on feedlot performance, carcass characteristics, ruminal fermentation, and diet digestibility. In Exp. 1, six hundred crossbred steers (364 ± 35 kg of BW) were used in a randomized complete block design with 8 replications/treatment. Dietary treatments consisted of a dry-rolled corn (DRC) control diet without WDG, a SFC control without WDG, and SFC with 4 WDG concentrations (15, 30, 45, 60% DM basis) replacing SFC, cottonseed meal, urea, and yellow grease. Final BW, ADG, G:F, HCW, and 12th-rib fat depth were greater (P ≤ 0.05) for SFC compared with DRC. Dry matter intake tended (P = 0.06) to be greater for DRC compared with SFC. Final BW, ADG, G:F, HCW, 12th-rib fat depth, and marbling score decreased linearly (P < 0.01) with increasing WDG concentration. In Exp. 2, six ruminally and duodenally cannulated crossbred steers (481 ± 18 kg of BW) were used in a 6 × 6 Latin square design using the same diets as Exp. 1. Ruminal, postruminal, and total tract OM and NDF digestibility were not different (P > 0.14) for DRC compared with SFC. Ruminal and total tract starch digestibility were greater (P < 0.01) for SFC compared with DRC. Dry matter and OM intake were not different (P ≥ 0.43) among WDG treatments. Ruminal and total tract OM digestibility decreased linearly (P < 0.01) with increasing WDG concentration. Intake, ruminal digestibility, and total tract digestibility of NDF increased linearly (P < 0.01) with increasing WDG concentration. Starch intake decreased linearly (P < 0.01) with increasing WDG concentration. Ruminal starch digestibility increased (P = 0.01) with increasing concentration of WDG. Total tract starch digestibility decreased quadratically (P < 0.01) with increasing concentration of WDG. Feeding SFC improved steer performance compared with DRC. The concentration of WDG and corn processing method influences nutrient digestibility and ruminal fermentation. The addition of WDG in SFC-based diets appears to negatively affect animal performance by diluting the energy density of the diet.

Evaluation of performance, carcass characteristics, and sensory attributes of beef from finishing steers fed field peas.

Whole field peas were fed at 0, 10, 20, and 30% of DM to 139 yearling steers (British cross; 409 ± 31 kg of initial BW) for a 119-d finishing period. Carcass data and Choice grade strip loins (n = 98) were collected from a commercial abattoir in Lexington, Nebraska. Consumer sensory and Warner-Bratzler shear force analyses were performed on 2.5-cm strip steaks. No differences (P ≥ 0.17) were observed in final BW, ADG, DMI, and G:F of steers. Likewise, no differences (P ≥ 0.23) were observed for HCW, LM area, fat thickness at the 12th rib, yield grade, and marbling scores. However, KPH responded quadratically to increasing dietary amount of field peas (P = 0.02). Regarding the sensorial analysis, feeding peas linearly increased subjective tenderness (P < 0.01) and led to a quadratic response of overall like ratings (P = 0.01) and flavor like ratings (P = 0.12). Feeding peas did not alter (P ≥ 0.64) juiciness, but decreased shear force values linearly when quantities were increased (P = 0.02). These data suggest that feeding peas does not affect steer performance or carcass characteristics differently from dry-rolled corn, but does improve objective and subjective tenderness, overall desirability, and flavor of beef. Field peas could be fed to cattle and give positive attributes to the quality of the meat up to 30% inclusion in the diet.