Weeds For Pasture And Hay?eeds are a common componentof pastures and hayfields. In latewinter, most bermudagrass and

bahiagrass pastures have large amountsof volunteer cool season annual weeds.Cattle graze them. Likewise, in summerthere are many weed species are found inpastures and hayf ie lds. Weeds aregeneral ly considered undesirable inpastures and sprayed or mowed toeliminate the ungrazed weeds. What isoften not noted is that many weeds areeaten along with the planted pasturegrasses. Many weeds are palatable tolivestock and are eaten. Are they anygood?

A number of years ago, GaleBuchanan and I conducted research onweed quality. We grew a large number ofcool- and warm- season weeds alongwith some cul t ivated forages andanalyzed them for digestible dry matterand crude protein at several stages ofmaturity over a two-year period. Some ofthese results are presented in the tableand should be of interest to cat t leproducers.

DigestibilitySurpr is ingly, we found that

digest ib i l i ty of weed species wasgenerally high. At the vegetative stage( leafy and young), a l l warm-seasonweeds were more digestible than Coastalbermudagrass. Another weed notincluded in this study, johnsongrass, hasbeen found to also be of higher qualitythan bermudagrass or bahiagrass. Cool-season weeds also had high digestibilityat the vegetat ive stage and werecomparable to rye and tal l fescue.Another weed not on this l is t ,chickweed, has very high digestibility.As wi th cul t ivated forage grasses,digestibil i ty of many weeds declinedwith increasing maturity.

Crude proteinBoth weed and forage species at the

vegetative stage had crude protein levelsadequate for maintenance and growth ofhi gh-producing catt!,er^Crude proteinlevels of warm-seasof f i leeds declinedk than grre weeds with maturity.)Yrort ; . , -c"{ ie l { .

2O The Georgia Cattleman / February 1995

Carl S. Hoveland, Crop & Soil Sciences Dept.University of Georgia

Cool-season weeds generally maintainedhigh levels of crude protein.

MineralsBoth warm- and cool-season weeds

contained enough calcium for moderateproducing cattle. Warm-season broadleafweeds were high in calcium. In contrast,sicklepod, tall morningglory, Floridabeggarweed, Carolina geranium, cutleafevening primrose, wild rye, and litt lebar ley were low in phosphorus andsuboptimum for high-producing cattle.

Magnesium content of warm-seasonweeds was adequate. Most cool-seasonweeds tested were low enough inmagnesium to be considered possibleinducers of grass tetany if used as thesole source of feed. Henbit at 0.47o and

primrose al. O.3Vo were unusually high inmagnesium. Potassium levels of bothweeds and cultivated forages were wellabove nutrient requirements.

Value of weeds?It is apparent from these results that

many weed species are as nutritious ascultivated forages and some are evenbetter. Why not just grow weeds andforget about weed control in pastures andhayf ie lds? There are two majorproblems: (l) most weed species are nothigh yielding, and (2) many weeds areunpalatable and would not usually beconsumed by grazing animals.Sicklepod, coffee senna, hemp sesbania,

(Continued on page 23)

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(Continued from page 20 )

pr ickly s ida, j imsonweed, crowfootgrass, pr imrose, cur ly dock, andcheatgrass are examples of unpalatableweeds. However, these weeds couldbecome part of the animal's diet in hayand especially silage.

Some weeds can be useful additionsto a forage program when managedproperly. During late winter and spring,palatable winter weeds such as henbit,chickweed, Carolina geranium, and littlebarley (until heading) can provide high-qual i ty grazing on dormantbermudagrass or bahiagrass sods. Insummer, crabgrass is a highly palatableforage that can furnish excellent qualitygrazing and/or hay if fertilized. Probably,crabgrass iurnishes more grazing insummer than we realize. When f'ertilized,crabgrass can be highly product ive.Other weeds are eaten along with pasturegrasses and add var iety to the diet .Weeds can sometimes be usefuladditions to a forage program br.rt whenunpalrr table weeds increase in a pusture.herbic ide t reatment wi l l be necessary.Problems with persistent, spreading,unpalatable weeds such horsenett le,th ist les, cur ly dock, bi t ter sneezeweed,blackberry, but tercup, dogfennel , andsmutgrass should be dealt with promptlyby appl icat ion of a recommendedherbicide at the proper tirne. An excellentpublication "Forage Weed Management"is available fiom yor.rr county agent.

Helping Youls What

We Do Best.

Ceorgia Farm BureauInsurance Companies

Home Office - Macon, Georgia

The Ceorgiu CattLennn / Februan 1995 23