240 KEPORT OK NUTRITIVE VALUE OP CERTAIN AUSTRALIAN GRASSES, 



III the examination of American grasses and of feeding stuffs generally, 

 the chemists are working in conjunction with the botanists (Gi'itRths, 1915; 

 Knight, 1905, 1906, 1908, 1911). The advantages accruing from team 

 work of this kind must be apparent to every thinking person, and it is to ba 

 hoped more of it may be done in Australia than has been tlie case so far. 



ii. Material. 



Through the courtesy of the Director of Agriculture, for which I am very 

 grateful, the material has, for the most part, been sent in from the various State 

 Experiment Farms. Any slight abnormalities which may exist as a result of 

 cultivation on the Farms should be more than compensated for by obtaining the 

 material in a pure state, which would be almost impossible if it were taken from 

 the grass paddocks of an ordinary farm or station. 



In every case a sample of the grass analysed has been kept, so that its 

 identification can be verified at any time. 



Stages of Growth. — On beginning this work it was found advisable, if any 

 systematic research was to be conducted, to obtain the material in certain -well- 

 defined stages of growth. Each grass has, therefore, been procured as far as 

 possible in — 



(a) what is known as the medium stage, or about half-way between the 

 time when it begins to shoot and the early flowering period. Grasses are often 

 fed off to stock at this stage, which is said to contain the largest amount of mois- 

 ture and crude protein, — the latter, however, being largely composed of amino 

 acids and other so-called immature proteins (Armsby, 1911; Vipond, 1914), and 

 the smallest amount of crude fibre, the percentage of which appears to increase 

 rapidly as the grass grows older (Pummel, 1901, p. 411). 



(b) The second stage chosen for analysis is the early flowering period. For 

 most of the analytical work on grasses which has been done in the United States, 

 this stage and the third stage, mentioned later, have been used (Griffiths, 1915; 

 Knight, 1906). 



(c) The third stage being used for analysis is that at which the seed is 

 quite set. 



Condition of Material. — Most of the analytical work has been done on the 

 air dried material. In the firet place it was found impossible to get material, 

 which had to come any great distance, in a perfectly fresh condition. In one 

 case, which will be referred to later, a grass arrived from Glen Innes in ai 

 wilted condition, and on being dried and analysed showed a different protein 

 c(mtent from another sample of the same grass in the same stage, which had 

 been dried on the Farm. 



Tlie material is weighed at the Farm as soon as cut, dried and then re- 

 weighed, the difference in weight rejiresenting the moisture content otlier tlian 

 hygroscopic moisture. Unfortunately, none of the Farms, except Hawkesbury 

 Agricultural College, jiossess oven a rough chemical balance, so that inaccuracies 

 will be found in the percentages of total moisture. At present these seem un- 

 avoidable. Tile material must be weighed immediately after being cut, as it 

 begins to lose water at once. 



For analytical purjjoses (lie material is grouiid uji until it is line enough to 

 pass through a 1 mm. sieve (Hruiinich and Sniitli, 1907, j). SA'.i). It is then 

 stored in airtight bottles and kept in the dark until re(|uired (Knight, 1906, p. 

 5). 



