LIQUID SUPPLEMENTATION FOR RUMINANTS FED LOW-QUALITY FORAGE DIETS - AREVIEW

Forty-three studies involving liquid supplementation of cattle and she ep consuming low-quality forages were identified, summarized in tabula r form and reviewed. All studies that could be found containing animal gain, forage intake and (or) supplement consumption with molasses-ure a supplements under grazing conditions were reviewed. Seven studies we re found which compared forage intake or animal performance by animals fed hay or straw and molasses-urea supplements with unsupplemented an imals. Molasses-urea supplements did not increase forage intake or ani mal per formance compared with unsupplemented animals in five of the s even studies. Thirteen studies were identified which evaluated perform ance of grazing animals receiving molasses-urea supplements compared w ith unsupplemented animals. Seven of these 13 grazing studies reported improved live weight change when animals received molasses-urea suppl ements. Only two grazing studies were found which evaluated forage int ake by animals consuming molasses-urea supplements and compared it wit h unsupplemented animals. Both studies found no effect. Five of six st udies identified that compared molasses-urea supplements with dry supp lements, forage intake or animal live weight change were not increased by molasses-urea supplements over dry supplements. Most authors concl uded that feeding molasses-urea supplements to grazing ruminants was n ot as profitable as feeding dry supplements; however, few studies repo rted economic data. Studies demonstrated that level of molasses and ni trogen influenced animal performance. Asynchrony between molasses and nitrogen resulted in animal weight loss. Most positive animal response s were seen with a combination of high levels of molasses and nitrogen . However, these results may have been influenced by supplement formul ation. Performance and intake results were confounded by pasture condi tion, forage quality, animal variation and supplement delivery system. In four studies that measured supplement intake by individual animals , between 1 and 20% of experimental animals refused to consume any mol asses-urea supplement. Quantification of supplement intake and animal feeding behavior has not been adequately addressed in the literature.