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Three degress of consolidation and air exclusion were imposed by vacuum compression during the making of three 60 tonne stacks of silage from a common source of mixed pasture grasses. Maximum air exclusion resulted in a silage having lowest pH and butyric acid and highest lactic acid content. When the three silages were fed as sole diets to lactating dairy cows intake was about 12% lower and butterfat yield about 14% lower on the silage from which air had been most effectively removed.

Silages made from direct-cut pasture herbage ensiled in stacks (i), bunkers (ii), and by vacuum compression (iii) have been evaluated as sole feedstuffs for milking cows in two series of experiments. Total nitrogen, ammonia-nitrogen, and pH were highest in (i), from which significantly more dry matter (D.M.) was consumed, and more milk of significantly higher fat percentage was produced, than from (ii) or (iii)|but these differences were too small to influence appreciably choice of the method of ensiling. Voluntary intakes of silage D.M. ranged between 2.2 and 3.0% of live weight. Feed requirements for maintenance and lactation have been calculated and are discussed relative to others previously obtained for pasture herbage.

Two sets of twin cows were used to compare the following methods of measuring the volume of water in the reticulo-rumen (fluid volume) :— 1. (i) directly, by removing the digesta from the reticulo-rumen; 2. (ii) indirectly, by dosing with polyethylene glycol (PEG) and following its disappearance curve from the reticulo-rumen; 3. (iii) indirectly, from body weight, by using information gained from (i) above on variations in empty body weight (i.e., weight after removing the digesta). The direct measurements were simple, rapid. and presumably accurate. During experiment I, PEG measurements showed no significant bias when compared with direct measurements, but standard errors of mean differences between PEG and direct measurements were relatively large. During experiment II, a modified technique gave PEG measurements which were more consistent (standard errors were smaller), but in two cows PEG measurements were significantly lower than direct measurements. The differences between fluid volumes obta...

Attention has been drawn to problems associated witb separating and collecting dung and urine from milking cows when on metabolism trials. The limitations of apparatus currently used for this purpose are outlined. Alternative equipment is described which has been designed specifically for collecting the excreta from Jersey cattle fed exclusively on fresh pasture herbage. This consists of four items; a special harness, a hinged metal separator, and dung and urine chutes. Faeces and urine are delivered into separate containers on the floor. All items are readily constructed by local tradesmen. Methods of assembly and fitting are outlined and an estimate of the total cost is provided.