H. E. Woodman 149 



the storm, but whicli lia,d been cut at the same time as the forage on the 

 experimental f>lot. It came from a neighbouring part of the field, but, 

 as will be seen later, this circumstance detracted somewhat from the 

 strictly comparative nature of the trials. The hay sample was finally 

 packed tightly into a meadow haystack standing in a Dutch barn and 

 a thick layer of straw was pressed compactly on top, so that the water 

 vapour generated by the hea.ting in the stack should pass into the straw 

 and not condense in the upper portions of the hay, thus causing it to 

 mould. 



The experimental procedure in the trials was, in the main, identical 

 with that adopted in the earlier work on oat and tare silage digestibility. 

 The Hainan harness was again employed with success, and there can be 

 little doubt that, from the point of view of convenience, safety and com- 

 fort for the sheep, it is distinctly superior to the orthodox " funnel and 

 bag" harness. 



The analytical period in all three cases consisted of fourteen days, 

 this being preceded by a preliminary period of seven days. Bi-weekly 

 composites of urine and faeces were made, nitrogen estimations being 

 carried out on these samples. Determinations of dry matter were made 

 on aliquot portions of the faeces samples, the dried residues being pre- 

 served in air-tight bottles to be utilised in the making up of the period 

 composite samples for complete analysis. Separate period urine com- 

 posites were kept for dry matter estimations and the determination of 

 the energy content by means of the bomb calorimeter. They were pre- 

 served by the addition of chloroform. 



In the hay period, the daily rations for the whole period were weighed 

 out previously into paper bags from the bulk of chaffed hay, the samples 

 for complete analysis and moisture determinations being drawn at the 

 same time. In the silage period, as in the green forage period, moisture 

 determinations were made on representative samples every two days, 

 the dried material being made up into the composite samples for com- 

 plete analysis. It was not considered necessary to carry out determina- 

 tions of nitrogen on the fresh silage samples, since in the earlier work 

 with oat and tare silage, it was noted that no measurable loss of nitrogen 

 occurred during the drying down of silage. 



In order to gain a trustworthy comparison of the digestion coefficients 

 of the protein constituents of the three foodstuft's, it was essential to 

 take into account the well-established fact that the faeces do not con- 

 sist solely of undigested food residues, but that the latter are largely 

 contaminated by nitrogenous metabohc products which have been 



