Published online by Cambridge University Press: 02 September 2010
The performance of Israeli-Friesian male calves on six rations, including two levels (15% and 30%) of ground wheat straw and oatvetch hay in pelleted mixtures, and the same two levels of ground straw in non-pelleted mixtures, was examined.
Daily live-weight and carcass gain were higher on the lower level of both roughages. The differences in performance on hay and straw were insignificant. Feed intake was higher on the 15% level of both roughages when pelleted but the energy conversion ratio was higher on pelleted rations of both levels of straw.
The dressing percentage was higher for animals on pelleted rations. There was no significant difference in percentage fat trim, percentage bone or percentage saleable meat in the carcasses. There was 20% more kidney, pelvic and cod fat on the lower level of roughage.
The digestibility of organic matter was higher on rations with the lower level of roughage, and on the pelleted rations compared with the non-pelleted at equal level of roughage. This was not the case for the digestibility of crude fibre. Nitrogen retention was significantly higher on the lower levels of straw and on the pelleted rations of a similar level, and was higher on hay rations than on straw rations. Ration differences in the molar proportions of volatile fatty acids in the rumen liquor were detected.
Pelleting appeared to improve the nutritive value of straw.