نوع مقاله : مقاله پژوهشی

نویسندگان

1 پژوهشگر پسادکتری، گروه علوم دامی، دانشکده کشاورزی،دانشگاه رازی، کرمانشاه، ایران.

2 استاد، گروه علوم دامی، دانشکده کشاورزی، دانشگاه رازی، کرمانشاه، ایران.

چکیده

مطالعه حاضر به منظور بررسی اثر فواصل برداشت در مراحل مختلف رشد بر عملکرد تولید و ارزش غذایی علف نپیر به‌عنوان یک منبع علوفه‌ای جدید در ایران، در قالب طرح بلوک کامل تصادفی با 13 تیمار و سه تکرار انجام شد. چین‌ها در فواصل هر 16 تا 20، 24 تا 28 و 43 روز یا 136 روز پس از کاشت (پایان مرحله رویشی) برداشت شدند که به‌ترتیب در ارتفاع‌های تقریبی 50، 100، 150 و 300 سانتی‌متر بودند. این فواصل برداشت به‌ترتیب منجر به شش، چهار، دو و یک چین برداشت شد. ترکیبات شیمیایی و تخمیر شکمبه‌ای برون‌تنی به‌همراه عملکرد تولید علف نپیر اندازه‌گیری شد. بیشترین عملکرد ماده خشک (25/1 تن در هکتار) فقط با یک برداشت در ارتفاع 300 سانتی‌متر صورت گرفت. قابلیت هضم ماده خشک و ماده آلی در تمام چین‌ها 60 تا 70 درصد بود و بیشترین مقادیر آن در علوفه برداشت شده در ارتفاع 50 سانتی‌متر مشاهده شد. علوفه برداشت شده در ارتفاع 300 سانتی‌متر بیشترین تولید ماده خشک و ماده آلی قابل هضم (به‌ترتیب 15/9 و 14/2 تن در هکتار) را داشت. بیشترین غلظت پروتئین خام و کمترین الیاف نامحلول در شوینده خنثی و لیگنین در ارتفاع 50 سانتی‌متر مشاهده شد. کمترین پتانسیل گاز تولیدی و بیشترین نرخ تخمیر به‌ترتیب در ارتفاع 300 و 50 سانتی‌متر بود. براساس نتایج حاصل، برای دستیابی به حداکثر عملکرد ماده آلی قابل هضم می‌بایست علف نپیر را بدون اعمال چین‌های اضافی و در پایان مرحله رویشی (136 روز پس از کاشت و ارتفاع 300 سانتی‌متر) برداشت نمود.

کلیدواژه‌ها

عنوان مقاله [English]

Effect of harvesting interval in different stages of growth on yield and nutritive value of Napier grass

نویسندگان [English]

  • Leila Taherabadi 1
  • Farokh Kafilzadeh 2

1 Postdoctoral Researcher, Department of Animal Science, Razi University, Kermanshah, Iran.

2 Professor, Department of Animal Science, Faculty of Agriculture, Razi University, Kermanshah, Iran.

چکیده [English]

Introduction: Increased livestock production can be achieved through the cultivation of high-quality forages with high-yielding capacity. Napier grass has been introduced to all tropical and subtropical areas of the world and is used as a forage crop with high potential productivity in terms of annual dry matter yield. However, both dry matter yield and nutritional quality of this grass have been affected by different cutting interval. This grass has been neither grown nor studied as a source of forage for ruminant nutrition in Iran.This research was conducted to identify the appropriate cutting interval for Napier grass to produce the maximum nutritive value and yield.
Material and methods: Napier grass was cultivated in a complete randomised block design with three replicates. During the growth season, the cutting intervals were 16-20, 24-28, 43 d or 136 d after planting to corresponding cutting heights of 50, 100, 150 and 300 cm. Hence, from each plot 6, 4, 2, or 1 cuts were harvested, respectively. Cell wall fractions, organic matter, and crude protein of Napier grass from different cuts were determined. Dry matter and organic matter digestibility and in-vitro ruminal fermentation kinetics of the forages were also determined. Biomass production of Napier grass under different cutting interval programs was also assessed.
Results and Discussion: The highest yield of dry matter of Napier grass (25.1 tons per hectare) was observed when only one cut was harvested at the end of vegetative stage (height of 300 cm). The digestibility of organic matter (OMD) ranged from 60 to 70 % in all treatments and the highest OMD was observed at the height of 50 cm. The maximum dry matter and digestible organic matter per hectare (15.9 and 14.2 tons, respectively) was produced when forage was harvested in one cut at the height of 300 cm. There was no difference in the yield of digestible dry matter and digestible organic matter of the forage harvested at the height of 50 and 100 cm. The concentration of crude protein in forages from different cuts ranged from 7.1 to 14.2 % and neutral detergent fiber ranged 65.7 to 76.2 %. The highest concentration of crude protein and the lowest cell wall components were observed at the height of 50 cm. The lowest and the highest gas production potential and fractional rate of gas production were observed at the cutting height of 300 cm and 50 cm, respectively.
Conclusion: The present study showed that it is possible to obtain higher quality of Napier grass by shortening the harvesting intervals. However, this resulted in a pronounce decrease in the yield of organic matter and digestible dry matter yield per hectare. The highest organic matter and digestible dry matter per hectare was produced when Napier grass was harvested only once (136 d after planting and height of 300 cm) at the end of vegetative stage.
 

کلیدواژه‌ها [English]

  • Chemical composition
  • Cutting interval
  • In vitro fermentation
  • Napier grass
AOAC. (2000). Official Methods of Analysis, 15th Edition. Association of Official Analytical Chemists, Washington, DC, USA.
Cook, B. G., Pengelly, B. C., Brown, S. D., Donnelly, J. L., Eagles, D. A., Franco, M. A., Hanson, J., Mullen, B. F., Partridge, I. J., Peters, M., & Schultze-Kraft, R. (2005). Tropical forages: an interactive selection tool. Tropical Forages: an interactive selection tool.
Huhtanen, P., Seppala, A., Ahvenjarvi, S., & Rinne, M. (2008). Prediction of in vivo neutral detergent fiber digestibility and digestion rate of potentially digestible neutral detergent fiber: Comparison of models. Journal of animal science, 86(10), 2657-2669.
Ishrath, P. K., Thomas, U. C., & Dhanya, G. (2018). Effect of cutting intervals on yield and quality fodder production in hybrid napier. Forage Research44(2), 137-140.
Manyawu, G. J., Chakoma, C., Sibanda, S., Mutisi, C., & Chakoma, I. C. (2003). The effect of harvesting interval on herbage yield and nutritive value of Napier grass and hybrid Pennisetums. Asian-australasian journal of animal sciences16(7), 996-1002.
Magcale-Macandog, D. B., Predo, C. D., Menz, K. M., & Predo, A. D. (1998). Napier grass strips and livestock: a bioeconomic analysis. Agroforestry Systems40, 41-58.
McDonald, I. M. (1981). A revised model for the estimation of protein degradability in the rumen. The Journal of Agricultural Science96(1), 251-252.
McDougall, E. I. (1948). Studies on ruminant saliva. 1. The composition and output of sheep's saliva. Biochemical journal43(1), 99.
Minson, D. J. (1984). Digestibility and voluntary intake by sheep of five Digitaria species. Australian Journal of Experimental Agriculture24(127), 494-500.
Mutimura, M., Ebong, C., Rao, I. M., & Nsahlai, I. V. (2015). Nutritional values of available ruminant feed resources in smallholder dairy farms in Rwanda. Tropical animal health and production47, 1131-1137.
Muia, J. M., Tamminga, S., Mbugua, P. N., & Kariuki, J. N. (1999). Optimal stage of maturity for feeding napier grass (Pennistetum purpureum) to dairy cows in Kenya.
Negawo, A. T., Teshome, A., Kumar, A., Hanson, J., & Jones, C. S. (2017). Opportunities for Napier grass (Pennisetum purpureum) improvement using molecular genetics. Agronomy, 7(2), 28.
Queiroz Filho, J. L. D., Silva, D. S. D., & Nascimento, I. S. D. (2000). Dry matter production and quality of elephantgrass (Pennisetum purpureum Schum.) cultivar Roxo at different cutting ages. Revista Brasileira de Zootecnia29, 69-74.
Rusdy, M. (2016). Elephant grass as forage for ruminant animals. Livestock Research for Rural Development28(4), 1-6.
Rambau, M. D., Fushai, F., & Baloyi, J. J. (2016). Productivity, chemical composition and ruminal degradability of irrigated Napier grass leaves harvested at three stages of maturity. South African Journal of Animal Science46(4), 398-408.
Rengsirikul, K., Ishii, Y., Kangvansaichol, K., Pripanapong, P., Sripichitt, P., Punsuvon, V., Vaithanomsat, P., Nakamanee, G., & Tudsri, S. (2011). Effects of inter‐cutting interval on biomass yield, growth components and chemical composition of napiergrass (Pennisetum purpureum Schumach) cultivars as bioenergy crops in Thailand. Grassland science57(3), 135-141.
Sunusi, A. A., Ito, K., Tanaka, S., Ishii, Y., Ueno, M., & Miyagi, E. (1997). Yield and digestibility of napiergrass (Pennisetum purpureum Schumach) as affected by the level of manure input and the cutting interval. Japanese Journal of Grassland Science43(3), 209-217.
Taherabadi, L., & Kafilzadeh, F. (2023). Nutritive value of Napier grass at different growth stages. Animal Production25(1), 83-91. (In Persian).
Theodorou, M. K., Williams, B. A., Dhanoa, M. S., McAllan, A. B., & France, J. (1994). A simple gas production method using a pressure transducer to determine the fermentation kinetics of ruminant feeds. Animal feed science and technology48(3-4), 185-197.
Tilley, J. M. A., & Terry, D. R. (1963). A two‐stage technique for the in vitro digestion of forage crops. Grass and forage science18(2), 104-111.
Van Soest, P. V., Robertson, J. B., & Lewis, B. A. (1991). Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. Journal of dairy science74(10), 3583-3597.
Wang, S. M., Chen, C. S., Chen, W., Yan, S. F., & Cheng, Y. K. (2003). The contents of crude protein, acid-detergent fiber and neutral-detergent fiber in Napiergrass affected by cutting intervals, seasons and locations. Journal of Taiwan Livestock Research36(4), 357-368.
Wangchuk, K., Rai, K., Nirola, H., Dendup, C., & Mongar, D. (2015). Forage growth, yield and quality responses of Napier hybrid grass cultivars to three cutting intervals in the Himalayan foothills. Tropical Grasslands-Forrajes Tropicales3(3), 142-150.
Zailan, M. Z., Yaakub, H., & Jusoh, S. (2016). Yield and nutritive value of four Napier (Pennisetum purpureum) cultivars at different harvesting ages. Agriculture and Biology Journal of North America7(5), 213-219.
Zewdu, T. (2005). Variation in growth, yield, chemical composition and in vitro dry matter digestibility of Napier grass accessions (Pennisetum purpureum). Tropical Science45(2), 67-73.