Submitted to: Delicias Internacional Ganadero Lechero Conference
Publication Type: Proceedings
Publication Acceptance Date: 7/15/2003
Publication Date: 9/11/2003
Citation: Broderick, G.A. 2003. Optimal utilization of forage protein by high producing cows. Delicias Internacional Ganadero Lechero Conference. September 11-12, 2003. Interpretive Summary:
Technical Abstract: Inefficient utilization of CP in hay-crop forages, particularly the high amounts of NPN in AS, and the feeding of large amounts of protein supplements that this inefficiency necessitates, leads to excessive costs and N losses to the environment from dairy farms. Lowering protein breakdown to NPN in the silo will improve utilization of CP in hay-crop silages. However, practical, cost-effective methods for reducing NPN in AS currently are still lacking. Certain forages such as red clover give rise to silage with reduced NPN; although promising, red clover silage has not yet proven to be an effective substitute for alfalfa. Genetic engineering approaches may prove effective for producing an alfalfa that produces silage with reduced NPN. Feeding more finely ground concentrate, if adequate effective fiber is maintained in the diet, will help maximize utilization of silage NPN for microbial protein formation in the rumen. Replacing some of the dietary NFC with sugars and pectins may be advantageous for improving rumen capture of degraded forage CP. The lower NPN content of alfalfa hay, and possibly its slower rate of protein degradation in the rumen, increases the efficiency of microbial protein formation in the rumen compared to AS. Ionophores such as monensin may be helpful for reducing excess ammonia formation in the rumen. Dairy farmers often overfeed CP; reducing dietary CP so it is more in line with requirements is an effective way to improve protein efficiency and reduce excess N excretion.