434 PRINCIPLES OF ANIMAL NUTRITION. 
his.own experiments and from those of Grandeau and LeClere, 
with the following results per 500 kgs. live weight: 
Total Digestible Nutrients,* 
Grms. 
On hay alone aoc ees eee teteeeeeeesanns 4586 
About equal parts hay and grain ........... 4190 
About ? grain and + hay (Grandeau)........ 3626 
Zuntz & Hagemann, from the results of a respiration experi- 
ment with the horse, make a still lower estimate of the maintenance 
requirement, viz., 3265 grams total nutrients per 500 kgs. live 
weight on a ration of which about four sevenths was grain, but 
after allowing for the differences in crude fiber content compute a 
satisfactory agreement between their results and Wolff’s. Since 
their estimate for the work of digestion of crude fiber is really ' 
based on the difference in digestive work required by coarse fodder 
and by grain this is equivalent to showing that the latter is more 
valuable for maintenance than the former. 
On the other hand, Grandeau and LeClerc { in later experiments 
on exclusive hay feeding found that the live weight was almost 
exactly maintained for a month on 8 kgs. of hay per day, the total 
digested nutrients being as follows: 
Total Digestible Nutrients. 
Animal. le a 
Per Head, Per 500 Kgs., 
Grms. Grms. 
ING: eta ieee < 395 2892 3660 
Be Ds hated eeaee-s)s 419 3036 3622 
Se SO aeuasisis Pore 413 3058 3701 
These figures do not materially exceed the average computed by 
Wolff from their previous experiments on heavy grain rations. The 
horses had a half-hour’s walking exercise daily, so that the ration 
seems to have been amply sufficient for maintenance, and no reason 
for the divergent result is obvious. 
While none of these comparisons have the conclusiveness of 
* Including fat x 2.4. 
t Loc. cit., pp. 422-4. 
} L’alimentation du Cheval du Trait, 3d memoir, pp. 23-31. 
