Yembitkilerinde anatomik yapı ve kimyasal kompozisyonunun besleme değerine etkileri

Her bitkinin besleme değerine etkili olan, kendine has morfolojik ve fizyolojik özellikleri vardır. Bazı genellemeler yapılsa da bitki grupları, türleri ve hatta varyeteleri arasında dahi önemli farklılıklar vardır. Bu farklılıklar yembitkileri arasında baklagillerle buğdaygiller, serin mevsim bitkileri ile sıcak mevsim bitkileri arasında oldukça belirgindir. Genel olarak sıcak mevsim bitkilerinin otunda serin mevsim bitkilerine göre daha fazla yapısal madde bulunmaktadır, Çünkü birçok sıcak mevsim bitkisi hızlı büyüme ve düşük yaprak/sap oranına sahiptir. Bu nedenle sıcak iklimlerde yetişen bitkiler düşük besleme değerine sahiptir. Diğer yandan buğdaygiller baklagillere göre daha fazla hücre duvarı maddelerine ve olgunlaşma ile hızlı bir lignin birikimine sahiptir. Bundan dolayı olgunlaşma ile sindirimlerinde hızlı bir azalma meydana gelir. Bu makalede farklı bitki grupları arasında yem kalitesine etki eden anatomik, morfolojik farklılıklar ve kimyasal kompozisyon tartışılmıştır.

Effects of anatomic structure and chemical composition on forage quality

Each plant has a unique morphology and physiology which gives it specific growth and forage quality characteristics. Although some generalizations can be made, there are the differences in quality that exist among groups of plants, individual species, and even cultivars. These differences are very clear between grass-legume and warm-cool season forage crops. In general, warm season plants almost always have higher levels of structural matter in hay than cool-season plants because of many warm season plants have low leaf/stem and high growth rate. Therefore, forages grown in warm climates have poor quality. On the other hand, grasses have higher cell wall concentrations and a more rapid accumulation of lignin than legumes, and thus a more rapid decline in digestibility with maturity. In this paper, effects of anatomy, morphology and chemical composition on forage quality was discussed in details among forage groups.

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Akin, D.E., 1989. Histological and Physical Factors Affecting Digestibility of Forages. Agron. J., 81:17-25.
Akin, D.E., Robinson, E.L., 1982. Structure of Leaves and Stems of Arrowleaf and Crimson Clovers as Related to in Vitro Digestibility. Crop Sci., 22: 24-29.
Akin, D.E., Wilson, J.R., Windham, W.R., 1983. Site and Rate of Tissue Digestion in Leaves of C3, C4 and C3/C4 Intermediate Panicum Species. Crop Sci., 23: 147-155.
Buxton, D.R., 1990. Cell-Wall Components in Divergent Germplasm of Four Perennial Forage Grass Species. Crop Sci., 30: 402-408.
Buxton, D.R., Casler, M.D., 1993. Environmental and Genetic Effects on Cell Wall Composition and Digestibility. In Forage Cell Wall Structure and Digestibility, H. G. Jung, D. R. Buxton, R. D. Hatfield, J. Ralph (Eds.). American Society of Agronomy, Inc. Madison, Wisconsin, USA, p:685-714.
Buxton, D.R., Anderson, L.C., Hallam, A., 1988. Intercropping Sorghum into Alfalfa and Red Canarygrass to Increase Biomass Yield. J. Prod. Agric, 11: 481-486.
Buxton, D.R.,. Redfearn, D.D., 1996. Plant Limitations to Fiber Digestion and Utilization. 37th Annual Ruminant Nut. Conf., 14 April, 1996, Washington, p: 814-818.
Cherney, D.J.R., Cherney, J.H., Davidson, A.H., 1997. Characterization of Legume and Grass Residues Following in Vitro and in Sacco Ruminal Digestion. Proc. The XVIII International Grassland Cong., June 8-17, 1997, Winnipeg and Saksatoon, Session: 17:17-23.
Deinum, B., Dirven, G.P., 1975. Climate, Nitrogen and Grass. 6. Comparision of Yield and Chemical Composition of Temperate and Tropical Grass Species Grown at Different Temperatures. Neth. J. Agric. Sci., 69-82.
Ehlke, N.J., Casler, M.D., 1985. Anatomical Characteristics of Smoothbrornegrass Clones Selected for in Vitro Dry Matter Digestibility. Crop Sci., 25: 513-517.
Galyean, MX., Goetsch, A.L., 1993. Utilization of Forage Fiber by Ruminants. . In Forage Cell Wall Structure and Digestibility, H. G. Jung, D. R. Buxton, R. D. Hatfıeld, J. Ralph (Eds.). American Society of Agronomy, Inc. Madison, Wisconsin, USA, p: 33-71.
Hanna, W.W., Monson, W.G., Burton, G.W., 1973. Histological Examination of Fresh Forage Leaves After in Vitro Digestion. Crop Sci., 13: 98-102.
Hastert, A. A., Owensby, C.E., Harbers, L.H., 1983. Rumen Microbial Degradation of Indiangrass and Big Bluestem Leaf Blades. J. Anim. Sci., 57: 1626-1636.
Kephart, K.D., Buxton, D.R., 1993. Forage Quality Responses of C3 and C4 Perennial Grasses to Shade. Crop Sci., 33: 831-837.
Merchen, N.R., Bourquin, L.D., 1994. Processes of Digestion and Factors Influencing Digestion of Forage-Based Diets by Ruminants. In Forage Quality, Evaluation, and Utilization, G. C. Fahey (Ed.). American Society of Agronomy, Inc., Madison, Wisconsin, USA, p:564-612.
Minson, D.J., 1990. Forage in Ruminant Nutrition. New York Academic Press.
Minson, D.J., Wilson, J.R., 1980. Comparative Digestibility of Tropical and Temperature Forage - A Contrast Between Grasses. J. Aust. Agric. Sci., 46: 247-249.
Moore K.J., Cherney, J.H., 1986. Digestion Kinetics of Sequentially Extracted Cell Wall Components of Forages. Crop Sci., 26: 1230- 1235.
Nelson, C.J., Moser, L.E., 1994. Plant Factors Affecting Forage Quality. In Forage Quality, Evaluation, and Utilization, G. C. Fahey (Ed.). American Society of Agronomy, Inc., Madison, Wisconsin, USA, p: 115-144.
Sanderson, M.A., Wedin, W.F., 1989. Phenological Stage and Herbage Quality Relationships in Temperate Grasses and Legumes. Agronomy J.s 81: 864-869.
Sleper, D.A., Roughan, P.G., 1984. Histology of Several Cool-Season Forage Grasses Digested by Cellulase. New Zealand Agric. Res., 27: 161-166.
Smith, L.W., Goering, H.K., Gordon, C.H., 1972. Relationships of Forage Compositions with Rates of Cell Digestion and Digestibility of Cell Walls. J. Dairy Sci., 55:1140-1147.
Susmel, P., Stefanon, B., Mills, C.R., Spangher, M., 1990. Rumen Degradability of Organic Matter, Nitrogen and Fibre Fractions in Forages. Animal Prod., 51: 515-526.
Wilson, J.R., 1993. Organization of Forage Plant Tissues. In Forage Cell Wall Structure and Digestibility, H. G. Jung, D. R. Buxton, R. D. Hatfield, J. Ralph (Eds.). American Society of Agronomy, Inc. Madison, Wisconsin, USA, p: 1-32.
Wilson, J.R., Akin, D.E., McLeod, M.N., Minson, D.J., 1989. Particle Size Reduction of the Leaves of a Tropical and a Temperate Grass by Cattle. II. Relation of Anatomical Structure to the Process of leaf Breakdown Through Chewing and Digestion. Grass and Forage Sci., 44: 65-75.
Wilson, J.R., Brown, R.H., Windham, W.R., 1983. Influence of Leaf Anatomy on the Dry Matter Digestibility of C3, C4 and C3/C4 Intermediate Types of Panicum Species. Crop Sci., 23: 141-146.
Wilson, J.R., Hattersley, P.W., 1989. Anatomical and Digestion Characteristics of Leaves of Panicum and other Grass Genera with C3 and C4 PCK, C4 NAD-ME and C4 NADP-ME Photosynthetic Pathways Aust. J. Agric. Sci., 40:125-135.
Wilson, J.R., Minson, D.J., 1980. Prospects for Improving the Digestibility and Intake of Tropical Grasses. Trop. Grassl., 14: 253-257.