Accuracy of two optical chlorophyll meters in predicting chemical composition and in vitro ruminal organic matter degradability of Brachiaria hybrid,Megathyrsus maximus, and Paspalum atratum

作     者：Martin P.Hughes Victor Mlambo Cicero H.O.Lallo Nasreldin A.D.Basha Ignatius V.Nsahlai Paul G.A.Jennings 

作者机构：Department of Food ProductionFaculty of Food and AgricultureUniversity of the West Indies Department of Animal ScienceSchool of Agricultural SciencesFaculty of AgricultureScience and TechnologyNorth-West University Open Tropical Forage-Animal Production LaboratoryDepartment of Food ProductionFaculty of Food and AgricultureUniversity of the West Indies Department of Animal & Poultry ScienceSchool of AgriculturalEarth and Environmental SciencesCollege of AgricultureEngineering and ScienceUniversity of KwaZulu-Natal Department of Animal Nutrition Faculty of Animal Production Shampat CampusUniversity of Khartoum MARJEN Consulting Group 

出 版 物：《Animal Nutrition》 (动物营养（英文版）)

年 卷 期：2017年第3卷第1期

页      面：67-76页

核心收录：

学科分类：090502[农学-动物营养与饲料科学] 0905[农学-畜牧学] 09[农学] 

基　　金：the University of the West Indies and the Jamaica Dairy Development Board for providing financial support to undertake this research 

主　　题：Optical chlorophyll measurements Chemical composition Prediction model Tropical grass 

摘      要：The objective of this study was to determine the accuracy and reliability of 2 optical chlorophyll meters:FieldScout CM 1,000 NDVI and Yara N-Tester, in predicting neutral detergent fibre(NDF), acid detergent fibre(ADF), acid detergent lignin(ADL), acid detergent insoluble nitrogen(ADIN) and in vitro ruminal organic matter degradability(IVOMD) of 3 tropical grasses. Optical chlorophyll measurements were taken at 3 stages(4, 8 and 12 weeks) of regrowth in Brachiaria hybrid, and Megathyrsus maximus and at 6 and 12 weeks of regrowth in Paspalum atratum(cv. Ubon). Optical chlorophyll measurements showed the highest correlation(r = 0.57 to 0.85) with NDF concentration. The FieldScout CM 1,000 NDVI was better than the Yara N-Tester in predicting NDF(R^2 = 0.70) and ADF(R^2 = 0.79) concentrations in Brachiaria hybrid and NDF(R^2 = 0.79) in M. maximus. Similarly, FieldScout CM 1,000 NDVI produced better estimates of 24 h IVOMD(IVOMD_(24 h)) in Brachiaria hybrid(R^2 = 0.81) and IVOMD_(48 h) in Brachiaria hybrid(R^2 = 0.65) and M. maximus(R^2 = 0.75). However, these prediction models had relatively low concordance correlation coefficients, i.e., CCC 0.90, but random errors were the main source of bias. It was,therefore, concluded that both optical chlorophyll meters were poor and unreliable predictors of ADIN and ADL concentrations. Overall, the FieldScout CM 1,000 NDVI shows potential to produce useful estimates of IVOMD_(24h) and ADF in Brachiaria hybrid and IVOMD_(48 h) and NDF concentrations in M. maximus.