کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2454607 1110402 2007 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
CASE STUDY: In Situ Ruminal Nitrogen and Neutral-Detergent Insoluble Nitrogen Disappearance from Bermudagrass Fertilized with Different Nitrogen Rates and Harvested on Two Dates
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم دامی و جانورشناسی
پیش نمایش صفحه اول مقاله
CASE STUDY: In Situ Ruminal Nitrogen and Neutral-Detergent Insoluble Nitrogen Disappearance from Bermudagrass Fertilized with Different Nitrogen Rates and Harvested on Two Dates
چکیده انگلیسی
Fertilizing bermudagrass (Cynodon dactylon L. Pers.) with N can produce large quantities of forage and increase plant N concentrations. Bermudagrass growing on a caged-layer manure-amended site was fertilized with ammonium nitrate at 4 rates (0, 56, 112, and 168 kg N/ha) approximately 1 mo before first and third harvests on May 30 and August 18, 2000, to determine in situ disappearance kinetics of N and neutral detergent insoluble N (NDIN). Five crossbred ruminally cannulated steers (BW = 422 ± 21.0 kg) were used to evaluate in situ disappearance kinetics in a randomized complete block design with a 2 × 4 factorial arrangement. Immediately soluble N (fraction A) and rate of N disappearance increased linearly (P < 0.05) with fertilization rate for both harvests, but N disappearing at a measurable rate (fraction B) decreased linearly (P < 0.01) with fertilization rate for both harvests. A linear N fertilization rate × harvest date interaction (P < 0.05) was detected for the unavailable N fraction (fraction C) and for potential extent of ruminal N disappearance. Effective ruminal N disappearance (% of N) increased quadratically (P < 0.01) with N fertilization rate. The intercept of the regression of effective N disappearance on N fertilization rate was greater (P < 0.05) for bermudagrass harvested in May compared with that harvested in August. For NDIN, quadratic N fertilization rate × harvest date interactions (P < 0.05) were detected for fractions A and C and the potential extent of NDIN disappearance; rate of NDIN disappearance did not differ (P = 0.17) across harvest dates or fertilization rates. Effective NDIN disappearance (% of NDIN) increased linearly (P < 0.01) with N fertilization rate. The pool of total N (% of DM) effectively disappearing was composed largely of neutral-detergent soluble N (NDSN; 75.1 and 66.6%, respectively from May and August harvests). Effective NDSN and NDIN disappearance (% of DM) increased quadratically and linearly (P < 0.01), respectively, with N fertilization rate, and these NDSN and NDIN pools were larger (P < 0.01) from bermudagrass harvested in May. Nitrogen fertilization may enhance the ruminal disappearance of both total N and NDIN from bermudagrass. On a percentage of DM basis, later harvests may have less extensive ruminal disappearance from both NDIN and NDSN pools.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: The Professional Animal Scientist - Volume 23, Issue 5, October 2007, Pages 556-564
نویسندگان
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