:
Resumen
Las especies forrajeras constituyen la principal fuente de alimentación de los bovinos en Colombia; en la mayoría de las explotaciones son el único alimento debido a las condiciones climáticas favorables para la producción de forraje a través del año y a lo poco práctico que resulta alimentar rumiantes con granos o subproductos agroindustriales, debido al alto costo y la baja oferta de estos recursos en el mercado nacional. El manejo del pastoreo es el aspecto menos entendido en las explotaciones y ocurren con frecuencia eventos de sobrepastoreo y subpastoreo a lo largo de un mismo año, con reducciones drásticas en la producción animal y en la persistencia del pasto, lo que conduce a una degradación rápida de las praderas. En este artículo se revisan las principales respuestas fisiológicas de las praderas en pastoreo y se incluye un análisis de los efectos del animal sobre las plantas y el suelo. Así mismo, se compendian los mecanismos de respuesta a la defoliación, el papel de las reservas orgánicas, de los meristemos y del área foliar residual, al igual que el manejo del pastoreo, con sus variables de frecuencia e intensidad de la defoliación y su efecto sobre la composición botánica el valor nutritivo y la producción de forraje de la pradera. Finalmente, se analiza brevemente la productividad de las praderas, la producción animal y las variables de respuesta bajo pastoreo.
Pablo Antonio Cuesta Muñoz, Corporación Colombiana de Investigación Agropecuaria (Agrosavia)
Zootecnista, Ph.D. Investigador Principal, Programa de Fisiología y Nutrición Animal. Coordinador Area Temática de Recursos Fonajeros, Plan de Modemización Tecnológica de la Ganadería Bovina Colombiana. C.I Tibaitatá. A. A. 240742 Las Palmas. Bogotá
Arnold G.W. 1981. Grazing behavior. In: F.A.W. Morley (ed.). Grazing animals. p. 79. Elsevier Publishers & Co., New York, NY.
Booysen, P.V., and CJ. Nelson. 1971. Leaf area and carbohydrate reserve in regrowth of tall fescue. Crop Sci. 75:262-266. https://doi.org/10.2135/cropsci1975.0011183X001500020036x
Brown, R.H., and R.E. Blazer. 1965. Relationships between reserve carbohydrate accumulation and growth rate in orchardgrass and tall fescue. Crop Sci. 3:577- 581. https://doi.org/10.2135/cropsci1965.0011183X000500060028x
Bryan W.B., E.C. Prigge, M. Lasat, T. Pasha, D.J. Flaherty and J. Lozier. 2000. Productivity of Kentucky Bluegrass pasture grazed at three heights and two intensities. Agron. J. 92:30-35. https://doi.org/10.2134/agronj2000.92130x
Buwai, M. and M.J. Ttlica,1977, Defoliation effects on root weights and total non-structural carbohydrates of bluegrama and western wheatgrass. Crop. Sci. 77:15-17. https://doi.org/10.2135/cropsci1977.0011183X001700010005x
Davidson, J.L., and F.L. Milthorpe.l966. The effect of defoliation on the carbon balance Dactylis glomerata Ann. Bot. 30:185-198. https://doi.org/10.1093/oxfordjournals.aob.a084066
Davies, A. 1965. Carbohydrates levels and regrowth in perennial ryegrass. J. Agric. Sci. 65:185-221. https://doi.org/10.1017/S0021859600083945
Deregibus, V. A., M.I. Trlica, Jr., y D.A. Jameson. 1982. pp 315. In: M. Rechcigl (ed.) 16. Handbook of Agricultural Productivity. Vol 1. CRC Press, Inc., Boca Ratóry FL.
Donaghy D.I. y W.J. Fulkerson. 1998, Priority for allocation of soluble carbohydrate reserves in Lolium perenne. Grass and Forage Sci. 5:21,1,-278.
Emmick D.L. y D.G. Fox. 1993. Prescribed grazing management to improve pasture productivity in New York. United States Department of Agriculture. Soil conservation Service and Cornell University Department of Animal Science.w ww.css.comell.edu/forage/pasture.1 7 pp.
Fisher, MJ. and D. Thomas. 1997. Environmental and physiological limits to tropical forage production in the Caribean Basin. p 3. In: forage- livestock research for the Caribean Basin. (ed.) J.E. Moore, K.H. Quesenberry M.W. Michaud.
Fulkerson WJ.y K. Slack. 1995. Leaf number as criterion for determining defoliation time for Lolium perenne.2. Effect of defoliation frequency and height. Grass and Forage Sci. 50: 16-20. https://doi.org/10.1111/j.1365-2494.1995.tb02289.x
Fulkerson W.J, K. Slack y E. Havilah. 1999. The effect of defoliation interval on high and growth and herbage quality of Kikuyo grass( Pennísetum clandestinum)T. rop Grassl. Vol. 33 : 138-145.
Gomide, J.A., J.A. Obeid and L.R.A. Rodríguez. 1979. Factores morfofisiológicos de rebrota do capim-coloniao (Panicum maximum) Rev. Soc. Bras. Zoot. 8:352-362.
Hammond A.C. 1987. Chemical. anatomical and other antiquality factors limiting forage utilization. p 59. In: foragelivestock research for the Caribean Basin. (ed.) J.E. Moore, K.H. Quesenberry, M.W. Michaud.
Harris, W. 1978. Defoliation as a determinant of the growth, persistence and composition of pasture. p.67.In: J.R. Wilson (ed.). Plant relations in pastures. CSIRO, Melboume, Australia.
Holt E.C. y B.E, Conrad. 1986. Influence of harvest frequency and season on bermudagrass cultivar yield and forage quality. Agr. J. 7 8:433.
Humphreys, L.R. L966. Pasture defoliation practice: A review. f. Aust. Inst. Agric. Sci. 32:93-705.
Ludlow, M.M. 1985. Photosynthesis and dry matter production in C3 and C4 pasture plants, with special emphasis on tropical C3 legumes and C4 grassesA. ust. J. Plant. Physiol. 12:557-572. https://doi.org/10.1071/PP9850557
Minson D.J. y M.A. Laredo.1972, Influence of leafiness in voluntary intake of tropical grasses by sheep. J. Aust. Inst. Agric. Res. 27:881.
Mislevy, P., F.G. Martin y M.B. Adjei. 1989. Changes in elephantgrass plant components with maturity. II Crude protein and digestibility. p 84I. hr: R. Desroches (ed.) Proc. Int. Grassl. Congress, 16th, Nice, France, 4-11 Oct. 1989. The French Grassl Soc., Versailles Cedex, France.
Monson, W.G. and G.W. Burton. 1982. Harvest frequency and fertilizer effects on yield and persistence of eight Bermuda grasses. Argon. joumal 74 :371- 374. https://doi.org/10.2134/agronj1982.00021962007400020026x
Motazedian, L and S. H. Shanow.1990, Defoliation frequency and intensity effects on pasture forages quality. J. Range Mgt 43: 198 - 201. https://doi.org/10.2307/3898671
Mott, G.O. 1959, Symposium on forage evaluation. IV animal variation and measurement of forage quality. Agr. J. 51,:223. https://doi.org/10.2134/agronj1959.00021962005100040012x
Ourry A., B. Gonzales, J. Bigot, J. Boucaud and J. Salette. 1989. Nitrogen and carbohydrate mobilization during regrowth of defoliated Lolium perenne L . p.513- 514. In R. Desroches (ed.) Proc. Int. Grassl. Congress, 16, Nice France. 4 - 11 Oct. 1989. The French Grassland Societv, Versailles Cedex F rance.
Ourry, A., J. Bigot, and Boucaud. 1988. Protein mobilization from stubble and roots, and proteolitic activities during post-dipping regrowth of perennial ryegrass. Joumal Plant Physic. 134: 298 -303. https://doi.org/10.1016/S0176-1617(89)80246-9
Pérez B.,R,A., A. Rincón C., G. Bueno G. y P.A. Cuesta M.2f[2. Estrategias de manejo para mejorar la productividad de las praderas del Piedemonte y la Altillanura de los Llanos Orientales. En: Manual Técnico-Producción y Utilización de Recursos Forrajeros en Sistemas de Producción Bovina de la Orinoquia y el Piedemonte Caqueteño. Plan de Modernización Tecnológica de la Ganadería Colombiana. Corpoica. pp 334.
Richards, IJI. and M.M. Caldwell.1985. Soluble carbohydrates, concurrent photosynthesis and efficiency in regrowth following defoliation Afield study with Agropyron species. J. Appl. Ecol. 22:. 907 - 9n. https://doi.org/10.2307/2403239
Ryle, G.J.A. and C.E. Powell. 1975. Defolation and regrowth in the graminaceous plant: The role of current assimilate. Ann. Bot. 39:297 -310. https://doi.org/10.1093/oxfordjournals.aob.a084943
Salisbury, F.B. and C.W Ross.1985. Plant physiology.3th. Ed. Wadsworth Publ. Co., Belrnont, CA.
Sheard R.W.1973. Organic reserves and plant regrowth . P. 353-377. In G.W. Blutler and R.W. Bailey (eds.). Chemistry and biochemistry of herbage. Vol. 2. Academic Press, New York.
Smith, D. 7973.The nonstructural carbohydrates. p 105. úr: G.W., Buttler and R.W. Baitey (ed.) Chemistry and biochemistry of herbage. Vol. 1. Academic press, NY.
Vickery, PJ. 1981. Pasture growth under grazing. P.55-57. In F.H.W. Morley (ed.) Grazing animals. Elsevier Scientific Publ. Co., New York.
Ward, C.V., and R.E, Blazen 1961.Carbohydrate food reserves and leaf area in regrowth of orchardgrass. Crop. Sci. 1:366-370. https://doi.org/10.2135/cropsci1961.0011183X000100050021x
Watson, D.l. 7947. Comparative Physiological studies on the growth of field crops. I. Variation in net assimilation ratio and leaf area between species and varieties and within and between years. Ann. Bot. 11:41,-76. https://doi.org/10.1093/oxfordjournals.aob.a083148
Weinmann, H.1961. Total available carbohydrates in grasses and legumes. Herb. Abstr. 31:255-260.
White, L.M. 1973. Carbohydrate reserves of grasses: A review. J. Range Manage.26:13-18. https://doi.org/10.2307/3896873
Woledge, f., and E.L. Leafe. 1976. Single leaf and canopy photosynthesis in a ryegrass sward. Ann Bot. 40:773-783. https://doi.org/10.1093/oxfordjournals.aob.a085191
Descargas
