Warm-season annual forages in forage-finishing beef systems: I. Forage yield and quality.

Autor:	Harmon DD; Department of Crop and Soil Sciences, University of Georgia, Athens, GA., Hancock DW; Department of Crop and Soil Sciences, University of Georgia, Athens, GA., Stewart RL Jr; Department of Animal and Dairy Science, University of Georgia, Athens, GA., Lacey JL; Department of Animal and Dairy Science, University of Georgia, Athens, GA., Mckee RW; Department of Animal and Dairy Science, University of Georgia, Athens, GA., Hale JD; Department of Crop and Soil Sciences, University of Georgia, Athens, GA., Thomas CL; Department of Animal and Dairy Science, University of Georgia, Athens, GA., Ford E; Department of Animal and Dairy Science, University of Georgia, Athens, GA., Segers JR; Department of Animal and Dairy Science, University of Georgia, Tifton, GA., Teutsch CD; Department of Plant and Soil Sciences, University of Kentucky, Princeton, KY., Stelzleni AM; Department of Animal and Dairy Science, University of Georgia, Athens, GA.
Jazyk:	angličtina
Zdroj:	Translational animal science [Transl Anim Sci] 2019 May 18; Vol. 3 (2), pp. 911-926. Date of Electronic Publication: 2019 May 18 (Print Publication: 2019).
DOI:	10.1093/tas/txz075
Abstrakt:	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-m 2 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 < 0.01) for PMCG at the initiation of the grazing trial, whereas BMR was greater ( P < 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 < 0.01) and BMR, PM, and PMCG at the final harvest ( P < 0.01). At the middle and final harvests in both 2015 and 2016, PM and PMCG contained greater ( P < 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. (© The Author(s) 2019. Published by Oxford University Press on behalf of the American Society of Animal Science.)
Databáze:	MEDLINE
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