Molasses-Urea Blocks as a Multinutrient Supplement for Ruminants

Ruminant diets in most developing countries are based on fibrous feeds: mainly mature pastures (particularly at the end of the dry season) and crop residues (e.g. wheat and rice straw, maize and sorghum stovers). These feeds are imbalanced as they are deficient in protein, minerals and vitamins and since they are highly lignified their digestibility is low. Both these characteristics keep intake and productivity low.

Mixtures of liquid molasses and urea, which provide fermentable nitrogen and are a good source of minerals, have been used for many years by ranchers in Australia and Southern Africa. Mineral licks (sometimes including urea) have also been extensively used in various parts of the world. However, small farmers have rarely benefitted from these supplements usually because of difficulties of handling these in small quantities. Molasses in the liquid form is difficult to transport (requiring expensive tanker trucks), to store (requiring tanks), to handle (it is highly viscous) and to distribute to animals (troughs or other receptacles being needed). Mineral licks which are usually imported are highly expensive and their cost/benefit ratio is often questionable.

By-pass nutrients, with the exception of legume leaves, come generally from rather expensive feeds which are either in demand for human nutrition (cereals) or exported for foreign exchange (oil cakes). However, because recent research has generally shown that their inclusion at a low rate in the diets is efficient, they should be economical to use in many situations.

--- FAO