The development of a metabolizable energy system for horses

Abstract

Summary The development of a metabolizable energy (ME) system for horses is described. Predictive equations for gross energy and digestible energy (DE) are revisited. The relationship between feed protein content and renal energy losses and the relationship between feed fibre content and methane energy losses were analysed in a literature review to develop predictive equations for ME. In horses, renal energy losses are much higher than losses by methane energy. Renal energy losses were correlated more strictly to protein intake than to digestible protein intake. The reason probably is that per gram of digestible crude protein energy losses are higher for roughage than for concentrates presumably because phenolic acids of forage cell walls contribute to higher urinary energy losses. However, digestibility of protein is lower in forages than in concentrates. The net result is a rather constant urinary energy loss of 0.008 MJ/g of crude protein in the feed. Methane losses in horses are smaller than in ruminants, presumably because of reductive acidogenesis in hind gut fermentation. Methane energy losses in equines are closely related to crude fibre intake. The mean methane energy losses amount to 0.002 MJ ME/g of crude fibre which can be used to correct for methane losses. Both corrections can be made for any predictive equation for DE. Metabolizable energy is then calculated as follows: ME MJ/kg = DE MJ/kg – 0.008 MJ/g crude protein – 0.002 MJ/g crude fibre. The equation of Zeyner and Kienzle (2002) to predict DE was adapted as mentioned above to predict ME: ME (MJ/kg dry matter) = −3.54 + 0.0129 crude protein+0.0420 crude fat−0.0019 crude fibre+0.0185 N‐free extract (crude nutrients in g/kg dry matter).

Effects of Different Oral Doses of Sodium Chloride on the Basal Acid-Base and Mineral Status of Exercising Horses Fed Low Amounts of Hay

“…The diet had been calculated to provide 1.4-fold the maintenance level of metabolizable energy (metabolizable energy in the feed according to Kienzle and Zeyner [34] and GfE [1]; energy requirement for maintenance according to Kienzle et al [35] and GfE [1]: 0.52 MJ ME/kg dry matter, DM) which corresponds to the requirements for medium work according to NRC [2]. The feedstuffs were given in two equal per day (07:30 AM and 4:30 PM) consisting of 24.75 g/kg bwt 0.75 (5.0 g/kg bwt) meadow hay and 15.80 g/kg bwt 0.75 (3.2 g/kg bwt) of the mix of oats and barley grains each as fed.…”

Comparative selective retention of particle size classes in the gastrointestinal tract of ponies and goats

“… Metabolizable energy ME estimated and for goats according to GfE () and for ponies according to Kienzle and Zeyner (). …”

Horse-meat for human consumption — Current research and future opportunities

“…Moreover, hindgut fermentation is characterized by a much higher reductive acidogenesis than in the rumen fermentation, which results in lower methanogenesis (Demeyer, Graeve, Durand, & Stevani, 1989;Franz et al, 2010;Kienzle & Zeyner, 2010). The environmental part is not the only benefit of horse production versus other traditional productions (i.e., bovine, ovine, caprine).…”