Supplement strategies for ruminants and management of feeding to maximize utilization of roughages.

Principles of supplementation are discussed in respect of both, their positive and negative effects on roughage digestion and utilization by ruminants. It is pointed out that negative effects mainly occur when excessively processed concentrate is given in large quantities two times per day. This lowers rumen pH which in turn depresses cellulose digestion and intake of cellulosic feeds, leading to problems of acidosis and secondary ketosis due to off-feed conditions. To a large extent, such problems can be overcome by limited processing and feeding the concentrate mixed with the roughage. Supplements can also have positive effects by alleviating deficiencies such as nitrogen or by providing easily fermentable fiber to increase microbes for attachment to roughages. Supplements can increase microbial protein production and undegraded protein supply. It is emphasized that proper use and management of supplements can make the difference between profit and loss for small farmers.