A Meta-Analysis of the Effects of Slow-Release Urea Supplementation on the Performance of Beef Cattle
Solutions Deployment Team, Alltech (UK) Ltd., Stamford PE9 1TZ, UK
Regulatory Affairs Department, Alltech SARL, Rue Charles Amand, 14500 Vire, France
Alltech Biotechnology Centre, Summerhill Road, A86 X006 Dunboyne, Ireland
Author to whom correspondence should be addressed.
Received: 27 February 2020
Revised: 30 March 2020
Accepted: 8 April 2020
Published: 10 April 2020
Plant-based feedstuffs, such as soybean meal and rapeseed meal are utilised to supply rumen degradable protein (RDP) and rumen undegradable protein (RUP) in the diets of ruminant animals (e.g., cattle, buffalo, sheep and goat). The RDP is utilised by rumen microbes for microbial protein synthesis. Microbial protein can contribute up to 80% of the protein requirement of ruminants. However, the use of plant protein sources in ruminant diets can be restricted based on their availability, costs and associated environmental impacts. Slow-release urea (SRU) is a non-protein nitrogen (NPN) source that allows for a partial replacement of vegetable RDP sources in ruminant diets by providing a sustained availability of ammonia for rumen microbial synthesis. Over the past three decades, extensive research has been conducted on the use of SRU in beef cattle diets. The current study analysed a combined dataset obtained from multiple research studies to derive quantitative and research-based evidence on the impact of a commercial SRU (Optigen®) on beef cattle performance. Results revealed that dietary supplementation of SRU improves the performance, profitability and environmental impacts of beef cattle production. Thus, this study demonstrates SRU as an effective NPN solution in beef cattle diets.