52 FEEDS AND FEEDING 



It is shown in later chapters that as the grasses and legumes mature 

 their content of fiber materially increases, and as a consequence the feed 

 becomes less digestible and usually of lower value. However, the large 

 accumulation of starch which occurs in the corn plant as it ripens gives 

 the more mature form of that plant a greater total feeding value. (27) 



If green forage is cured without waste and in a manner to prevent 

 fermentation, the mere drying does not appreciably lower its digesti- 

 bility. Ordinarily, however, in curing forage much of the finer and 

 more nutritious parts is wasted, and dews, rain, and fermentations effect 

 changes which lower digestibility. Also more energy is required in 

 masticating dry forage and passing it thru the digestive tract than 

 in the case of green fodder. These facts explain why green forage 

 commonly gives better results than dry forage. The long storage of 

 fodders, even under favorable conditions, decreases both their digesti- 

 bility and palatability. Hay browned by heating shows increased 

 digestibility of fiber but decreased digestibility of crude protein and 

 nitrogen-free extract. 



82. Influence on digestibility of amount of feed eaten. Animals tend 

 to digest their food somewhat more completely when given a maintenance 

 ration than when on full feed. This may be due to the more rapid move- 

 ment of the food thru the digestive tract or to a less complete absorption 

 of the digested nutrients when present in large amount. Jordan 11 found 

 that sheep digested 4.7 per ct. more of the dry matter when given a half 

 ration than when fed a full ration. Mumford, Grindley, Hall, and 

 Emmett 12 of the Illinois Station, on feeding steers clover hay and corn 

 in varying proportions, found that those fed a maintenance ration 

 digested 75.4 per ct. of the dry matter; those fed one-half more, 71.6 

 per ct. ; those fed twice the maintenance ration, 69.4 per ct. ; and others 

 on full feed, consuming two and one-fourth times as much as the first 

 lot, 65.9 per ct. of the dry matter of the ration. The difference in digest- 

 ibility was greatest in the case of the carbohydrates. The steers on full 

 feed digested the crude protein and fat nearly as well as those getting 

 the maintenance ration. When a large proportion of roughage and 

 concentrates was fed, there was little difference between the digestibility 

 of a liberal and a scant ration. 



Eckles 13 of the Missouri Station found that the dairy cow digests a 

 maintenance ration somewhat better than a heavy ration. Under normal 

 conditions, in feeding farm animals for the production of meat, milk, 

 or work, other economic factors, which will be treated in later chapters, 

 more than offset the slightly better utilization of feed when a scant 

 ration is fed. 



83. Influence of preparation of feed on digestibility. Grinding, crack- 

 ing, and rolling grain increase digestibility only in the case of hard 

 seeds which would otherwise pass thru the digestive tract unbroken, or 

 with animals unable to chew their food properly. The saving thru 



"N. Y. (Geneva) Bui. 141. "111. Bui. 172. "Mo. Res. Bui. 7. 



