@article{a6403b93b23940a883e305506a108821,
title = "New feeds and new feeding systems in intensive and semi-intensive forage-fed ruminant livestock systems",
abstract = "The contributions that ruminant livestock make to greenhouse gas and other pollutant emissions are well documented and of considerable policy and public concern. At the same time, livestock production continues to play an important role in providing nutrient-rich foodstuffs for many people, particularly in less developed countries. They also offer a means by which plants that cannot be digested by humans, e.g. grass, can be converted into human-edible protein. In this review, we consider opportunities to improve nutrient capture by ruminant livestock through new feeds and feeding systems concentrating on intensive and semi-intensive systems, which we define as those in which animals are given diets that are designed and managed to be used as efficiently as possible. We consider alternative metrics for quantifying efficiency, taking into account resource use at a range of scales. Mechanisms for improving the performance and efficiencies of both individual animals and production systems are highlighted. We then go on to map these to potential changes in feeds and feeding systems. Particular attention is given to improving nitrogen use efficiency and reducing enteric methane production. There is significant potential for the use of home-grown crops or novel feedstuffs such as insects and macroalgae to act as alternative sources of key amino acids and reduce reliance on unsustainably grown soybeans. We conclude by highlighting the extent to which climate change could impact forage-based livestock production and the need to begin work on developing appropriate adaptation strategies.",
keywords = "Animal production, Meat, Methane, Milk, Nutrient use efficiency, Animals, Climate Change, Diet, Poaceae, Livestock, Ruminants",
author = "Jon Moorby and Mariecia Fraser",
note = "Funding Information: None. This work was supported with the financial assistance of Biotechnology and Biological Sciences Research Council grants Genomics-assisted breeding for fatty acid content and composition in perennial ryegrass (Lolium perenne L.) (Lipigrass) (BB/K017160/1), Genetic improvement of pea to replace soya bean in the diets of poultry and monogastric livestock (PeaGen) (BB/P017517/1), Advancing sustainable forage-based livestock production systems in Colombia (CoForLife) (BB/S01893X/1), and the BBSRC Core Strategic Programme in Resilient Crops: Upland Grasslands (BBS/E/W/0012843C). This article is part of a supplement entitled {\textquoteleft}Sustainable livestock systems for high-producing animals{\textquoteright}, supported by the European Federation of Animal Science (EAAP) and the World Association for Animal Production (WAAP). Funding Information: This work was supported with the financial assistance of Biotechnology and Biological Sciences Research Council grants Genomics-assisted breeding for fatty acid content and composition in perennial ryegrass (Lolium perenne L.) (Lipigrass) (BB/K017160/1), Genetic improvement of pea to replace soya bean in the diets of poultry and monogastric livestock (PeaGen) (BB/P017517/1), Advancing sustainable forage-based livestock production systems in Colombia (CoForLife) (BB/S01893X/1), and the BBSRC Core Strategic Programme in Resilient Crops: Upland Grasslands (BBS/E/W/0012843C). Publisher Copyright: {\textcopyright} 2021 The Author(s)",
year = "2021",
month = dec,
day = "1",
doi = "10.1016/j.animal.2021.100297",
language = "English",
volume = "15",
journal = "Animal",
issn = "1751-7311",
publisher = "Elsevier",
number = "S1",
}