Liu, Kesi

Newman, Y. C.

Sollenberger, Lynn E.

Vendramini, Joao M. B.

White, U. Renée

English

University of Kentucky

University of Kentucky UKnowledge International Grassland Congress Proceedings XXI International Grassland Congress / VIII International Rangeland Congress Grazing Intensity and Frequency Effects on Herbage Accumulation and Nutritive Value of Tifton 85 Bermudagrass (Cynodon sp.) Kesi Liu University of Florida Lynn E. Sollenberger University of Florida U. Renée White University of Florida Y. C. Newman University of Florida Joao M. B. Vendramini University of Florida Follow this and additional works at: https://uknowledge.uky.edu/igc  Part of the Plant Sciences Commons, and the Soil Science Commons This document is available at https://uknowledge.uky.edu/igc/21/15-2/21 The XXI International Grassland Congress / VIII International Rangeland Congress took place in Hohhot, China from June 29 through July 5, 2008. Proceedings edited by Organizing Committee of 2008 IGC/IRC Conference Published by Guangdong People's Publishing House This Event is brought to you for free and open access by the Plant and Soil Sciences at UKnowledge. It has been accepted for inclusion in International Grassland Congress Proceedings by an authorized administrator of UKnowledge. For more information, please contact UKnowledge@lsv.uky.edu. 瞯 718　 瞯 　 Multifunctional Grasslands in a Changing World 　 Volume Ⅱ 　Grasslands/Rangelands Production Systems ——— Forage Quality ,Conservation and UtilizationGrazing intensity and frequency effects on herbage accumulation and nutritive value of Tifton 85Bermudagrass (Cynodon sp .)Kesi Liu , L .E . Sollenberger 倡 ,U . Renée White , Y .C . Newman , and J .M .B . Vendramini .Department o f Agronomy , University o f Florida , Gainesville FL , 倡 E‐mail : lesollen ＠ u f l .eduKey points : Tifton ８５ bermudagrass ( BG) response to grazing management was studied in northern Florida , USA . Herbageaccumulation ( HA) generally was greatest with short stubble height ( SH ) and long periods between grazings ( GC) or shortGC and taller SH . Herbage crude protein ( CP) and in vitro digestion ( IVDOM) were most affected by GC and were greatestwith shorter GC .Key words : Tifton ８５ , bermudagrass , grazing managementIntroduction Tifton ８５ BG has achieved wide acceptance for a range of livestock uses in warm climates because of high HA andforage quality ( Hill et al . , ２００１ ) . Data assessing the impact of different grazing management practices on Tifton ８５ arelacking . Our objective was to evaluate HA and nutritive value responses of grazed Tifton ８５ BG to grazing intensity ( SH ) andfrequency ( GC) .Materials and methods This study was conducted in ２００６ and ２００７ on Tifton ８５ BG pastures at the University of Florida BeefResearch Unit . Treatments were the nine factorial combinations of three post‐graze SH (８ , １６ , and ２４ cm) and three lengthsof GC (１４ , ２１ , and ２８ days) arranged in two replicates of a randomized complete block design . All the treatments received atotal of ２５０ kg N fertilizer ha‐１ yr‐１ in five equal applications . Pasture size was ４００ m２ , and pastures were rotationally stockedfrom June through October each year .Herbage accumulation was measured using double sampling . Herbage nutritive value was determined using pre‐grazing hand‐plucked samples ; only ２００６ nutritive value data are presented . Data were analyzed using PROC MIXED of SAS .Results and discussionHerbage accumulation There was SH × GC interaction for HA in both years . Increasing GC resulted in greater HA when SHwas ８ cm , but when SH was ２４ cm , HA tended to decrease with increasing GC ( Table １ ) . This response is similar to resultsof Pedreira et al . (１９９９ ) with Florakirk BG .Herbage nutritive value For herbage CP , there was interaction of SH and GC ( Table ２ ) . Greatest CP was achieved with １４‐dayGC and ８‐cm SH and lowest with a ２４‐cm SH and ２８‐day GC . Herbage IVDOM decreased linearly from ６３０ to ６０１ g kg‐１ as GCincreased from １４ to ２８ days . Mandebvu et al . (１９９８ ) found similar digestibility trends for Tifton ８５ .Table 1 Stubble height ( S H ) × graz ing cycle ( GC )interaction f or herbage accumulation ( H A ; Mg ha‐１ ) in２００６ and ２００７ .SH( cm )GC ( d )Year １４ ２１ ２８PC 报８ ２００６ １１ .４ １１ .３ １５ .４ L ,Q２００７ ９ .１ １０ .９ １０ .７ NS１６ ２００６ １３ .１ １１ .０ １４ .５ L ,Q２００７ ９ .９ ８ .１ ７ .９ L２４ ２００６ １４ .２ １２ .８ １１ .９ NS２００７ ９ .１ ７ .６ ６ .４ LPC 报 L ( ２００６ )N S ( ２００７ )L ,Q ( bothyears )L ( bo thyears )报Polynomial contrast : L ＝ linear and Q ＝ quadratic effects ( P ≤ ０ .１０ ) ; NS ＝Not significant ( P ＞ ０ .１０ )Table 2 Stubble height ( S H ) × grazing cycle ( GC )interaction f or herbage crude p rotein (CP ; g kg‐１ ) in ２００６ .SH( cm )GC ( days )１４ ２１ ２８PC 报８ １４９ １２８ １２９ L ,Q１６ １３３ １２５ １１１ L ,２４ １３６ １３３ １０８ L ,QPC 报 L ,Q NS L ,Q报 Polynomial contrast ; L ＝ linear and Q ＝ quadratic effects ( P ≤ ０ .１０ ) ; NS ＝Not significant ( P ＞ ０ .１０ )Conclusions Other than the ２４‐cm SH , Tifton ８５ responded well to grazing across the range of treatments . Greatest HA wasobtained with infrequent grazing to a short SH , while nutritive value was greatest with frequent defoliation .ReferencesHill , G .M . , R .N . Gates , and J .W . West . ２００１ . Advances in bermudagrass research involving new cultivars for beef anddairy production . J . Anim . Sci . ７９ :E４８‐E５８ .Mandebvu , P . , J .W . West , G . M . Hill , R .N . Gates , R .D . Hatfield , B .G . Mullinix , A .H . Parks , and A .B . Caudle .１９９８ . Comparison of Tifton ８５ and Coastal bermudagrasses for yield , nutrient traits , intake , and digestion by growing beefsteers . J . Anim . Sci . ７７ :１５７２‐１５８６ .Pedreira , C .G .S . , L .E . Sollenberger , and P . Mislevy .１９９９ . Productivity and nutritive value of Florakirk bermudagrass asaffected by grazing management . Agron . J . ９１ :７９６‐８０１ .

Grazing Intensity and Frequency Effects on Herbage Accumulation and Nutritive Value of Tifton 85 Bermudagrass (\u3ci\u3eCynodon\u3c/i\u3e sp.)

https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=3615&amp;context=igc

Grazing Intensity and Frequency Effects on Herbage Accumulation and Nutritive Value of Tifton 85 Bermudagrass (\u3ci\u3eCynodon\u3c/i\u3e sp.)

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