By Loretta Sorensen
**Extended comments highlighted in blue.
Sunflowers, cottonseed possible options
Dairy producers using soybean meal in feed rations may want to consider using some alternate meal sources such as sunflower or cottonseed, as long as those meals remain at a lower cost per ton than soybeans.
The nutrient value of both sunflower and cottonseed meal is comparable to soybean meal. Each producer must evaluate the actual cost of the energy and protein content of his dairy ration and determine which option is most economic for his operation.
To pinpoint the cost of a ration, producers can identify the ration’s energy, metabolizable protein and fiber content, and calculate the quantity of each of those elements that a cow would need to meet her nutrient requirements.
Mike Hutjens, a University of Illi-nois Extension dairy specialist, says the amount of oil meals to be added to a dairy ration depends on the level of supplemental protein needed (for forage quality, milk yield, etc.).
"With sunflower meal, we suggest combining two-thirds sunflower and
one-third soybean meal in the ration," Hutjens says. "That combination maintains the proper amino acid balance and enhances palatability. If a dairy producer uses cottonseed meal at a favorable price, it’s possible to use 100% cotton-seed meal. Otherwise, the same two-to-one ratio is recommended."
Soybean meal aids amino acid balance in dairy cows. Numerous studies have demonstrated that an insufficient supply of total amino acids or individual essential amino acids (EAA) will cause a decrease in milk protein synthesis and secretion (for example, Guinard and Rulquin 1994).
"Soybean meal could also provide peptides, although that is a controversial theory," Hutjens says.
When purchasing optional meals, producers need to obtain information about meal quality. For sunflowers, hull inclusion reduces overall energy levels and nutrient quality. The oil extraction process—whether solvent or expeller—also affects meal quality.
"Before producers purchase any type of protein meal, they should be aware of cost per ton, palatability, amino acid profile, rumen undegraded protein [RUP] fraction and nutrient content [oil, fiber and minerals]," Hutjens says.
Based on dry-matter content values, soybean meal has the highest percentage of crude protein at 55.1%. Dehulled sunflower meal has the next highest at 49.8%, with cottonseed meal at 45.6% and sunflower meal with hulls at 25.9%. In terms of neutral detergent fiber (NDF)--the bulk or fill that increases as forages mature--sunflower meal with hulls ranks at 40 NDF, dehulled sunflower meal is 25 NDF, cottonseed meal is 26 NDF and soybean meal is 8 NDF.
Sunflower meal with hulls has an acid detergent fiber (ADF) level of 33. Soy ADF is 6, cottonseed is 19 and dehulled sunflower meal is 15 NDF.
Storing sunflower or cottonseed meal in a covered, dry area preserves quality, Hutjens says.
"Cottonseed meal users must be aware of gossypol [a toxic, crystalline compound present in cottonseed], especially if they’re feeding fuzzy cottonseed and cottonseed meal," he adds. "Aflatoxin levels should also be verified."