Utilising the maize crop in various forms for beef production

Abstract

Whole crop maize silage is well suited to the fattening of bulls when supplemented with concentrates (850 – 950 g total crude protein per day for dairy breed bulls between 270 and 650 kg), minerals and vitamins. Supplements of hay are not essential but 1 kg good lucerne or grass hay could slightly improve growth rate. Urea can supply all the nitrogen supplement for animals over 200 kg: in this case, animal performance decreases (by 9 – 10%); it is wiser to add 4 – 500 g to the maize silage plus urea, to limit the decline in performance. For early maturing breeds, cereal supplements are not necessary, except during the last 2 or 3 months to improve the carcass and are mainly needed with low dry matter silages. For late maturing breeds, energy supplementation of maize silage is followed by slight improvement in growth rate, feed efficiency and carcass quality. The rate of substitution of silage by concentrate was found to be higher with moist cereals than with dried cereals and with high dry matter silage than with low dry matter silage. There was no difference in feed efficiency between ground dried grain and moist grain (either crushed and ensiled, or stored after propionic acid treatment and rolled) when maize grain amounted to 35 or 40% of DM intake. On the other hand, dried or moist maize grain had a much better utilisation when crushed before being fed to the animals. Maize ears dried or ensiled can replace maize grain as supplements to whole crop silage. Maize ears of grain can be fed as the basis of a diet, to which grain, some straw (0.5 to 1 kg per day) or hay (1 – 2 kg per day) is added. The growth rate is higher with ensiled ears and grain diets than with whole crop diets; feed efficiency is better for diets of ensiled ears (by 16% on average) and for moist grain diets (by 18.5% on average) than for the whole crop diets. Storage method for maize grain when grain is given ad libitum did not seem to have an effect on the growth rate, but feed efficiency is better with moist grain (by 10– 12%) than with dried grain and with ground grain than with whole grain (especially in the case of propionic acid treated grain for heavy animals). In France, the development of maize cultivation has certainly allowed an acceleration in the organisation of young bull production in such a way that maize and maize silage are synonymous with modern cattle feeding. Over the last few years many studies have been carried out on maize utilisation (whole plant, ears, grains or associations of these different parts). We are going to present here the main conclusions of the results obtained in France by INRA, ITCF or ITEB, for diets of whole crop maize silage and ears or grains ensiled or dried. A more complete review of this subject with a full list of references is given by Malterre (1976).