The growth of young cattle fed on dried grass alone and with barley 1. Feed intake, digestibility and body gains

Abstract

SUMMARY1. The primary growth of a sward of S24 perennial ryegrass was harvested between 23 April and 9 May 1968, artificially dried and either chopped or coarsely milled. The two physical forms of grass were wafered either alone or together with 50% by dry weight of rolled, anaerobically stored barley, and given to 7-month-old, Hereford × British Friesian steers in an experiment of 2 × 2 factorial design.2. A representative group of animals was slaughtered at the beginning of the experiment, and the remainder were individually fed ad libitum for 70 days, after which they also were slaughtered. During the feeding period digestibility was determined by total faecal collection from all the animals individually on two occasions.3. Dry-matter intake and live-weight gain were similar on all feeds. The weight of gut contents as a percentage of final live weight was significantly lower and the carcass-weight gain was significantly higher for animals given wafers containing barley compared with those for animals given wafers of grass alone.4. Coarse milling compared with chopping reduced the apparent digestibility of dry matter, organic matter, cellulose and energy; the addition of barley increased the digestibility of organic matter but further reduced that of cellulose.5. The efficiency of conversion of digested energy to empty-weight or carcass gain was similar for wafers containing the two forms of forage, but the digested energy of wafers containing barley was converted to carcass weight with significantly greater efficiency than that of wafers consisting solely of grass.6. Physical separation of the tissues of sample joints failed to show any significant differences in the proportion of fat, muscle and bone as a result of either differences in physical form or the inclusion of barley.7. The results indicate that live-weight gain is an insufficiently sensitive measurement by which to assess the true productive potential of feeds given to ruminants in short-term experiments.

Effect of Feeding Hay versus Silage with and without Barley on Digestibility and Nitrogen Utilization in Growing Bulls

“…Only the digestion coefficients of organic matter and nitrogen free extract were, however, found significantly higher in this trial. The results are in support of Putnam & Loosli (1959) and Lonsdale et al (1971). Digestibility of crude protein, crude fibre and ether extract was higher in silage plus barley than in hay plus barley, but the digestibility of nitrogen free extract was highest in hay plus barley.…”

The efficiency of energy utilization in growing cattle consuming fresh perennial ryegrass (Lolium perenne cv. Melle) or white clover (Trifolium repens cv. Blanca)

“…Evidence of seasonal differences in k, have been reported by Corbett et al (I 966) and Lonsdale & Tayler (1971). Forage season effects were not specifically examined in the present study but owing to the extended feeding period required for the comparative slaughter technique, the forages could be considered as M-and L-season crops.…”

The performance of fattening cattle offered barley and grass silage in various proportions either as discrete feeds or as a complete diet

“…These calculated ME values will be an over-estimate of the energy intake as increasing levels of barley depress the digestibility of the cellulose in silage (Lonsdale et al, 1971;Tayler and Wilkins, 1976). There are highly significant differences between the methods of cereal presentation and between the proportions of barley :silage for DMI (P<001).…”