Identifier

etd-11092016-125412

Degree

Master of Science (MS)

Department

Plant, Environmental Management and Soil Sciences

Document Type

Thesis

Abstract

Cow-calf operations in the southeastern United States (U.S.) are based on warm-season perennial grass pastures. Stored forage feeding during the non-grazing season constitutes more than half of a cattle operation’s annual expenses. Cool-season annuals can extend the grazing season, thereby reducing stored forage feeding. A two-year field trial was conducted to determine the forage potential of a variety of crops commonly used as winter cover crops in the southeastern U.S. The ten cover crop treatments included seven monocultures (annual ryegrass [Lolium multiflorum], rye [Secale cereal], oats [Avena sativa], triticale [Triticale hexaploide], tillage radish [Raphanus sativus], hairy vetch [Vicia villosa], crimson clover [Trifolium incarnatum]) and three mixtures. Harvests were made in late winter and early spring of each year. Spring harvest yielded more than twice as much dry matter (DM) as winter harvest across all treatments. Total dry matter yield per treatment ranged from 2,066 to 3,732 kg ha-1. Neutral and acid detergent fiber concentrations increased about 10% from winter to spring. Crude protein decreased about 8% between harvests, however, overall crude protein concentrations were high enough to meet the nutrient requirements of lactating cows and growing calves, ranging from 17 to 25% in winter, and 11 to 22% in spring. All treatments proved to be highly digestible according to in vitro true digestibility analysis, ranging from 72-90% digestibility. High nutritive value across all treatments indicates feasible usage as winter forages and potential reduction of cattle production cost. Multispecies forage mixtures produced yields similar to monocultures with less risk from environmental impact and potential for a more evenly distributed yield.

Date

2016

Document Availability at the Time of Submission

Secure the entire work for patent and/or proprietary purposes for a period of one year. Student has submitted appropriate documentation which states: During this period the copyright owner also agrees not to exercise her/his ownership rights, including public use in works, without prior authorization from LSU. At the end of the one year period, either we or LSU may request an automatic extension for one additional year. At the end of the one year secure period (or its extension, if such is requested), the work will be released for access worldwide.

Committee Chair

Han, Kun-Jun

Available for download on Saturday, February 23, 2019

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