For example, can you compare the ME contents of soybean meal (as an example of cake) and corn grain (sa an example of grain) for ruminants and monogastrics?
Yes, as energy losses through urine and methane are much higher in ruminants tan in monogastrics (ME = GE-Energy in faeces- energy in urine and methane). Actually, tables of feeding value give different values of ME for ruminants, poultry, horses, pigs, rabbits, etc.
I think so because these two animals have different digestive physiology, and moreover, ME of animal depends in number factors which includes stage of production, breed, and as well as age of the animal.
The ME value of any feed will vary with the type of animal to which it is fed. It should also be noted that Me value is a general guide as even within a class of animals the metabolic efficiency of individual animals will vary. This makes it extremely difficult to mathematically reconcile actual energy output with input for the individual animal.
Additionally within the individual animal life cycle stage will also influence the efficiency with which the feed ME is utilized.
Monogastric animals generally are more efficient in energy use (fewer metabolic steps in digestion). That is why in the tables, the metabolizable energy is higher for monogastric animals. However, there are differences on the efficiency of energy use among animals of this group (monogastric)
The hierarchy of ME values accross animals depends on two opposite trends:
- for highly digestible compounds (starch, fat ...) the monogastric are much more efficient than ruminants
- for lower digestible compounds (fibre) ruminants are more efficient, except for some monogastric categories as adult swine (sows) which can digest fibre to a higher extent.
This leads to a unconstant ratio of ME value with roughly
for low ME feedstuffs (6-7 MJ/kgDM) : adult swine > ruminants > young swine = rabbits >>> poultry
for intermediate ME feedstuffs (10-11 MJ/kgDM) : Adult swine >> young swine >> ruminants = rabbits >> poultry
for high ME feedstuffs (14-15 MJ/kgDM) : Adult swine > young swine >> poultry = rabbits > ruminants
For the raw materials you mention (soybean, corn), monogastrics use their energy much more efficiently than ruminants. Attached is a paper (in french-sorry) with some discussion on the relative value of feedstuffs in different animals.
Article Ressources tropicales : disponibilité et valeur alimentaire
NRC 2001 (Nutrient Requirements of Dairy Cattle) give very high values for soybean meal ME ( 3.3- 3.6 Mcal/kg or 3300 to 3600 Kcal/kg) for dairy cows and if you compare this value with that of ME (NRC, 1994) in poultry (2450 Kcal/kg), It is concluded ME for soybean meal is much higher in ruminants than poultry, but corn ME value for poultry is 3350 Kcal/kg while for ruminants is 3.1 Mcal or 3100 Mcal/kg. however energy values for poultry must be 10% higher if we want to compare it with ruminants since their feed composition analysis is based as-fed,
yes, energy losses through rumen fermentation , urine and methane are much higher in ruminants than in monogastric animal . for example, In general, CH4
production in cattle constitutes about 8-12 % of gross energy intake.