Interseeding alfalfa (Medicago sativa L.) into bermudagrass [Cynodon dactylon (L.) Pers.] can be an effective way to improve forage quality and reduce the need for additional supplementation when fed to livestock. The objective of this research was to compare the nutritive value and forage mass of bermudagrass with and without interseeded alfalfa when harvested as baleage. On 19 Feb. 2016, 0.2‐ha plots were assigned in a randomized complete block design to either ‘Tifton 85’ (T85) or T85 interseeded with ‘Bulldog 805’ alfalfa (T85+Alf) in an established field of Tifton 85 bermudagrass at the University of Georgia Tifton Campus, Tifton, GA. The T85 received 84 kg N ha−1 four times throughout the growing season. Plots were harvested at early bloom stage every 28–35 d throughout the growing season, baled at 40–60% moisture, and individually wrapped. At each harvest, plots were evaluated for botanical composition and forage mass, and bales were sampled prior to wrapping for nutritive value analysis. The T85+Alf plots produced additional harvests each season, leading to greater herbage accumulation than T85 plots (P < .01). The T85+Alf treatment had greater crude protein and total digestible nutrients than T85 in each of the 3 yr, suggesting this mixture will need no or less supplementation to meet the nutritional requirements of a lactating beef cow. Therefore, interseeding alfalfa into a bermudagrass system improves forage mass and nutritive value.

The objective of this study was to evaluate the meat quality and shelf life of steaks from steers fed dried distillers grains with solubles (DDGS) or dried corn gluten feed (CGF) compared with soybean meal with corn (SBM) as a protein supplement from weaning to slaughter. Angus cross steers (n = 81; BW = 306 ± 26.1 kg) were randomly assigned to pens (n = 9) and fed a stocker diet of corn silage (75% of DM) with DDGS, CGF, or SBM and ground ear corn. After 84 d of stockering, 12 steers (BW = 397 ± 15.3 kg) were randomly selected from each treatment and finished using the same protein supplement at 25% of DM for 100 d. Carcass data were collected (24 h) and the longissimus lumborum was fabricated into steaks at 48 h postmortem. Steaks were assigned to proximate analysis, Warner-Bratzler shear force (7-, 14-, or 21-d aging), and retail display (1, 3, 6, or 9 d). Protein source did not affect carcass yield, quality, or longissimus lumborum composition (P > 0.05). After 7 d of aging, DDGS and CGF steaks were more tender (P < 0.01) than SBM, but were similar (P = 0.30) after 14 and 21 d of aging. Feeding corn by-products did not influence subjective overall color acceptance (P = 0.17) in this study, but acceptance declined over time (P < 0.01). Subjective redness was similar (P > 0.05) among diets except SBM steaks were more red (P < 0.01) than DDGS after 9 d. On d 3 and 6 of retail display, CGF steaks exhibited more discoloration (P < 0.04) than SBM or DDGS steaks. However, after 9 d DDGS steaks were more discolored (P < 0.01) than CGF or SBM. Objective L* was lighter for CGF (P < 0.04) over 9 d of display, and all treatments became darker (P < 0.01) as time increased. Redness (a*) declined (P < 0.01) over time with SBM steaks maintaining more color in the red spectrum than CGF and DDGS after 6 d of display. Protein source did not affect (P > 0.05) the rate of lipid oxidation. Total SFA concentrations were similar (P > 0.05) among treatments; however, total MUFA were less (P < 0.05) and total PUFA concentrations were greater (P < 0.05) in DDGS steaks compared with SBM or CGF steaks. These data show that DDGS or CGF can be fed as a protein supplement at 25% DM from weaning until slaughter while maintaining meat quality when compared with steers fed soybean meal as a protein supplement.

Abstract The demand for a year-round supply of fresh, locally grown, forage-finished beef products has created a need for forage-finishing strategies during the summer months in the southeast. A 3-yr study was conducted to evaluate four warm-season annual forages in a southeastern forage-finishing beef production system. Treatments were four forage species and included brown-midrib sorghum × sudangrass (Sorghum bicolor var. bicolor*bicolor var. sudanense; BMR), sorghum × sudangrass (SS), pearl millet [Pennisetum glaucum (L.) R. Br.; PM], or pearl millet planted with crabgrass [Digitaria sanguinalis (L.) Scop.; PMCG]. Treatments were distributed in a randomized complete block design with four replicates. Pastures (0.81 ha, experimental unit) were assigned to one of four forage treatments, subdivided, and rotationally stocked with a variable stocking density. British-cross beef steers (n = 32; 3-yr average: 429 ± 22 kg) grazed for 70, 63, and 56 d in 2014, 2015, and 2016, respectively. Put-and-take animals were used to maintain a forage allowance of 116 kg forage dry matter /100 kg body weight. Forage mass was measured by clipping a 4.3-m2 area in triplicate on d 0 and on 14-d intervals. Hand grab samples for forage nutritive value determination and quadrat clippings for species compositions were measured on d 0 and on 34-d intervals until termination of the trial. Forage mass was lowest (P &lt; 0.01) for PMCG at the initiation of the grazing trial, whereas BMR was greater (P &lt; 0.01) than SS at wk 6. Total digestible nutrients in 2014 were greater for SS compared to BMR and PM at the middle harvest (P &lt; 0.01) and BMR, PM, and PMCG at the final harvest (P &lt; 0.01). At the middle and final harvests in both 2015 and 2016, PM and PMCG contained greater (P &lt; 0.01) concentrations of crude protein than SS. These results suggest that BMR, SS, PM, and PMCG may all be used in southeastern forage-finishing beef production systems, as long as the producer strategically accounts for the slight growth and nutritive value differences throughout the season.

Angus×Simmental crossbred heifers (n=150) and steers (n=100) were used to evaluate 1 of 5 growing diets: 1) a corn-based growing diet (CRN); 2) a high-fat, high-protein coproduct blend; 3) a high-fat, low-protein coproduct blend; 4) a low-fat, high-protein coproduct blend; and 5) a low-fat, low-protein coproduct blend in a 2×2+1 factorial arrangement. Low-protein and low-fat diets were formulated to be isonitrogenous and isofat to CRN (16.0% CP and 3.0% fat), and high-protein and high-fat diets were formulated to have 20.0% CP and 5.0% fat, respectively. Calves were weaned at 85±1.2 d, blocked by weight, and allotted to pens (10 calves/pen) within sex (10 pens of steers and 15 pens of heifers). The objective of this experiment was to determine if the concentration of protein or fat or their interaction in coproducts used in growing diets fed to early-weaned calves affects feedlot performance or carcass composition. Starting on d 0, calves (141±1.2 d of age) were fed experimental diets for 112 d and then fed a common feedlot diet for an additional 112 d. Body weight, hip height, and ultrasound data were collected at the end of each 112-d feeding phase. Carcass data included HCW, LM area (LMA), 12th-rib back fat (BF), marbling score (MS), KPH, and USDA quality grade. There was no fat×protein interaction (P≥0.27); therefore, only main effects are discussed. No effects (P≥0.47) of CRN, protein, or fat were detected for BW at d 112 or 224. Increased dietary protein resulted in greater (P=0.04) ADG at d 112 compared to calves fed low protein. Feeding cattle CRN decreased (P=0.04) DMI and increased (P<0.01) G:F during the growing phase compared to coproducts. High-fat diets increased (P=0.05) BF in calves at d 112 compared to low-fat diets. High-protein diets decreased (P=0.02) ultrasound MS at d 112 compared to low-protein diets. Carcasses from cattle fed high-fat diets had greater (P=0.03) MS compared to those from cattle fed low-fat diets. No differences (P≥0.14) were observed for HCW, LMA, BF, KPH, or yield grade. These data indicate that final BW was unaffected by protein and fat content of growing calf diets but that increased dietary fat and low dietary protein increased MS.

Potassium fertilization and harvest timing both influence the stand life and performance of alfalfa (Medicago sativa L.), but many producers do not apply sufficient K fertilizer as recommended by soil test recommendations. The objective of this trial was to determine the impact of reduced rates of K fertilization on cultivar Bulldog 805 alfalfa managed under different harvest regimes on forage yield, stand persistence, and nutritive value when grown in the southern Coastal Plains. Plots were harvested at bud, 10, 30, and 50% bloom growth stages. Potassium was applied three times across the season at total rates of 0, 67, 101, 134, and168 kg K 2 O ha −1 . Aboveground and belowground plant and soil responses were evaluated. Evaluated levels of K were not sufficient to elicit a positive response in aboveground variables, as all treatments exhibited K deficiency as confirmed by tissue analysis at the end of the study. Harvest timing affected many of the aboveground yield components, however no clear trends existed. As expected, material harvested at later growth stages tended to have higher fiber and lower digestibility than alfalfa harvested at less mature stages. Reduced rates of K fertilization helped maintain soil K levels above the final level in the untreated control. Harvesting alfalfa at later (50% bloom) growth stages decreased starch and nonstructural carbohydrate (NSC) content in the roots. To optimize both alfalfa yield and nutritive value, current University recommendations for alfalfa harvest timing and K fertilization should be maintained in the southern Coastal Plains. Abbreviations: ADF, acid detergent fiber; CP, crude protein; DM, dry matter; ESC, ethanol-soluble carbohydrate; IVTDM, in-vitro true dry matter digestibility; NDF, neutral detergent fiber; NFC, nonfibrous carbohydrates; NIRS, near infrared reflectance spectroscopy; NSC, nonstructural carbohydrates; TDN, total digestible nutrients.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.