EQUINE DIET ANALYSIS & CLINICAL NUTRITION in the 21st century

19 Feb

At the end of 2108, Dr Stewart was asked to write an article for the publication, Partners in Practice, from Provet. This magazine is sent to all veterinary clinics Australia wide and it was such a great article we thought we would share it with you. It is slightly long, so the second half will be shared next week. We hope you enjoy….

We are becoming increasingly aware of the strong association between nutrition, diet and the health of ourselves and our companion animals. As veterinarians and veterinary nurses, it is one of our many roles to be across current knowledge and to make it available to our clients and their horses. As well as the part they play in health, welfare and behaviour, diet and nutrition can support recovery from clinical conditions. This article provides an update on the applications and limitations of diet analysis and the importance of equine clinical nutrition.

Nutrition is involved in the pathogenesis, management, treatment and prevention of a wide range of equine performance, behavioural and clinical conditions. In addition to disease prevention, correct nutrition is a necessary adjunct when a combination of both dietary and medical/surgical management are needed for the best outcome.

There has been extensive research, experiences and recommendations for feeding horses. Much is accurate and applicable, some is not. Some must be interpreted or combined with other information for it to be useable. In addition, some experiences, anecdotes and recommendations are proven to be false, or true only under certain circumstances. Never-the-less they are oft repeated by those unaware of current and recent research, studies and findings to the contrary.

Procedures that may or may not be useful in detecting toxicities and nutrient deficiencies, excesses and imbalances include: history and clinical examination; haematology and biochemistry; urine, hair and other tissue testing, and diet analysis and evaluation. Currently available diet analysis programs are based on reference values developed by Germany, France (INRA) and the National Research Council (NRC) Nutrient Requirements of Horses (2007). The NRC calculated minimum requirements through feeding experiments and extrapolation for studies in other species to arrive at minimum feeding standards, and this is what nutritionists use to provide diet and feeding advice.

EQUINE CLINICAL NUTRITION
Jennifer Stewart

The limitations of the NRC feeding standards include that they were established for a population of horses of a given age, weight, reproductive and performance status. No consideration is given for weather, climate or the requirements of an individual horse that may vary considerably from group averages. Second, they were established for healthy horses, but those with veterinary clinical conditions; growth or performance problems; sick or post-surgical, and neonates often have increased or decreased requirements. Breed differences studied by the INRA found ponies require 20% less energy than predicted by weight extrapolation from studies in horses. And, the minimum requirements are just that - calculated according to the amount required to prevent clinical signs of deficiencies and excess. Equine clinical nutrition goes beyond minimum recommended intakes and standard feeding guides.

Over the last decade, ongoing research has provided valuable and practical information on various clinical conditions and how diseases affect nutrient requirements, such that many of the NRC (2007) values are no longer accurate. The NRC feeding standards are a useful guide for nutritionists to estimate requirements, but they lack precision and do not include more recent veterinary and scientific studies on genetics and epigenetics, the effects of growth and performance problems, and equine clinical nutrition.