Estimation of Nitrogen Use Efficiency for Ryegrass-Fed Dairy Cows: Model Development Using Diet- and Animal-Based Proxy Measures

This study aimed to identify suitable predictors of nitrogen (N) use efficiency (NUE; milk N/N intake) for cows that differed in breeds and were fed with ryegrass pasture, using existing data from the scientific literature. Data from 16 studies were used to develop models based on the relationships...

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Bibliographic Details
Main Authors: Wumaierjiang Aizimu, Omar Al-Marashdeh, Simon Hodge, Richard J. Dewhurst, Ao Chen, Guangyong Zhao, Saranika Talukder, Grant R. Edwards, Long Cheng
Format: Article
Language:English
Published: MDPI AG 2021-08-01
Series:Dairy
Subjects:
Online Access:https://www.mdpi.com/2624-862X/2/3/35
Description
Summary:This study aimed to identify suitable predictors of nitrogen (N) use efficiency (NUE; milk N/N intake) for cows that differed in breeds and were fed with ryegrass pasture, using existing data from the scientific literature. Data from 16 studies were used to develop models based on the relationships between NUE and dietary and animal-based factors. Data from a further 10 studies were used for model validation. Milk urea N (MUN) and dietary water-soluble carbohydrate-to-crudeprotein ratio (WSC/CP) were the best and most practical animal- and diet-based proxies to predict NUE. The results indicate that it might be necessary to adopt separate models for different breeds when using WSC/CP to predict NUE but not when using MUN.
ISSN:2624-862X