Sunflower Meal as a Protein Supplement for Growing Ruminants

Nutritional value of sunflower meal (SFM) as a protein supplement for growing cattle and sheep was determined by the evaluation of treatment effects on in vivo digestibility, N retention, average daily gain, feed efficiency and wool growth. Three experiments—two steer digestion and metabolism studies and one lamb feedlot study—were conducted. No differences (P>.05) were found in total diet digestibility of N retention of steers fed Coastal bermudagrass hay and urea diets in which 0, 5, 10 or 20% SFM was added to replace hay on an air-dry basis. In Exp. 2, SFM was substituted for cottonseed meal (CSM) in a growing-finishing feedlot diet at levels of 0, 5.5, 11 and 22%. No differences (P>.05) in digestibility were detected at the 0, 5.5 and 11% levels, indicating that solvent-extracted SFM, when fed on an equal crude protein and crude fiber basis, was similar to solvent-processed CSM. Dry matter and organic matter digestibilities of the complete diets were highest (P<.05) in steers fed the 22% SFM diet. No differences (P>.05) in N retention were observed. In the third experiment, 120 feedlot lambs were fed SFM, CSM or a combination of SFM and CSM in 8 and 12% crude protein growing-finishing diets. Lambs fed the 12% crude protein diets had similar (P>.05) gains. However, gains with the 12% CSM diet were not different (P>.05) from those with the 8% SFM diet but were greater (P<.05) than those with the 8% CSM diet. No differences (P>.05) in feed efficiency were observed at similar crude protein levels; however, efficiency with the 12% diets was superior (P<.05) to that with both 8% diets.