Energy systems for horses

Because horses cannot ruminate, they spend twice as long as ruminants chewing their food, with a consequent energy cost, which depends on the physical form and nature of the food consumed. The NE system also takes into account the energy cost of eating in assessing kj.  

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Energy systems for horses, based on either DE or NE, produce similar results. The NE system provides a sound theoretical framework but is complex to use. The DE system is relatively simple and easily understood by nutritionists, veterinarians and horse owners. 

In the French net energy system for horses, the gross energy of milk is assumed to be 2.3 MJ/kg and the net requirement for milk production is 2.3 YMJ. 

Martin-Rosset W.,Vermorel M.,2002. Evaluation and expression of energy allowances and energy value of feeds in the UFC system for the performance horse. In I" European Workshop on Equine Nutrition. Dijon. January 17-18, France, p. 19- 58... 

In the French net energy system, the requirement for maintenance is calculated as 0.351 MJ/kg with factors used to allow for activity that depend upon the type of horse and whether the animal is at work. Thus, for a riding horse at work, the factor would be 1.05 at rest and 1.10 at work for a draft animal at work, the factors would be 1.0 and 1.05. 

The ammonia-oxidizing bacteria biosynthesizes the cellular materials from carbon dioxide. For this purpose, they need NAD(P)H. Electrons to reduce NAD(P)+ seem to come from ferrocytochrome c-552 by the supply of energy, because Aleem (1966) reported that he had demonstrated that NAD(P)+ was anaerobically reduced with horse ferrocytochrome c on addition of ATP using the cell-free extracts of N. europaea, though the enzymatic system participating in the reduction of NAD(P)+ has not been known. However, every attempt by the author and his colleagues to reproduce his results has been unsuccessful to date. 

Martin-Rosset W.,Vermorel M., Doreau M.,Tisserand J. L., Andrieu J., 1994. The French horse feed evaluation systems and recommended allowances for energy and protein. Livest Prod. Sci., 40,37-56. 

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