The Analysis Of The Nutrition Of Common Roughage In Main Dairy Production Area Of China Using Near-infrared Reflectance Spectroscopy

This experiment aimed to study the nutrition of roughage(Leymus chinensis,Alfalfa and Cron Silage)for dairy cows using Near-infrared reflectance spectroscopy(NIRS)and explored the stability and applicability of the NIRS portable near-infrared instrument(Polispec,EDDF00E4)calibration and verification models.After the model was calibrated,the nutrition of the roughage from different farms of China was analyzed using NIRS.Test I : The Polispec was used to analyze nutrition of roughage(Leymus chinensis,Alfalfa and Cron Silage)for dairy cows.A total of two external validations were performed.The first external validation was used to evaluate the suitability of the NIRS model in the Polispec,and the second external validation was used to analyze the accuracy of the NIRS model after extended detection.Both of the two external validation sets included 15 samples in Leymus chinensis set,15 samples in Alfalfa set and 15 samples in Cron Silage set.The nutrition of samples were analyzed and validated the calibration model of Polispec for the first time.The second enternal vertification was performed based on the first time calibration model.It could conclude that the Coefficient of determination for calibration(RSQcal)was 0.887-0.963 of the first validation,and Coefficient of determination for validation(RSQv)was 0.883-0.955 of the second validation.The model of Polispec is available to the daily analysis.Test II: This study aimed to evaluate the nutrition of Leymus chinensis,Alfalfa,Corn silage in different areas of China(2016.06.08-2017.12.31)using Polispec.The results showed that:(1)Compared with 2017,CP and ADF was decreased by 7.03% and 1.45%,separately.There was no significant difference of DM,CP of Leymus chinensis between the Northeast and North China(P>0.05)and the Ash of Leymus chinensis in North China increased by 7.02% than that in Northeast China(P<0.05)in 2016(2016.6.8~2016.12.31).(2)The quality of Alfalfa above the secondary level both in 2016(2016.6.8~2016.12.31)and 2017.The quality of Alfalfa used in North and northwest China was better than that in other areas in 2016(2016.6.8~2016.12.31)and 2017;(3)The DM of corn silage in Northwest China was significantly higher than that in Northeast China and North China in 2016(2016.6.8~2016.12.31)(P<0.05);The ADF in Northeast China was highest,the second was North China and the third is Northwest China in 2016(2016.6.8~2016.12.31)(P<0.05).The NDF in Northwest China was the lowest,which was significantly lower than that in Northeast China in 2016(2016.6.8~2016.12.31)(P<0.05).