Written by: Dr. Jacquie Jacob, University of Kentucky
Safflower seed is a productive crop under semiarid or rain-fed conditions. Most of the US safflower crop is grown in California, primarily for the bird-feed industry. Safflower was originally grown for its flowers. The flowers were used to create red and yellow dyes for clothing and coloring for foods. Today safflower is grown primarily for its oil, which is used for food and industrial purposes.
Safflower meal is made from the seeds that remain after oil extraction. The quality of the safflower meal is variable and depends on the amount of hulls and the extent of the oil extraction. Safflower oil can be obtained from the seeds by cold-pressing, expeller pressing, or solvent extraction. Solvent extraction is more effective at oil removal than mechanical extraction. Dehulling improves crushing efficiency, but the removal of hulls is expensive. In safflower seed meals in which the seeds have not been dehulled (undecorticated), the protein content of the meal varies from 20% to 25%. In meals produced from dehulled (decorticated) safflower seeds, the protein content can be over 40%. The hull is the main source of fiber in the seed, so the level of crude fiber in safflower seed meal varies depending on the level of hulls remaining. Fiber can be 30% to 40% in undecorticated meals and as low as 10% in decorticated meals.
The quality of safflower seed meal for use in poultry diets is considered poor because the meal is deficient in the essential amino acids lysine, methionine, and isoleucine. Safflower meal is an excellent source of phosphorus and a good source of zinc and iron. In general, the vitamin content of safflower meal is low, but when compared to soybean meal, safflower meal is a good source of biotin, riboflavin, and niacin.
Even partial decortication improves the feeding value of safflower meal. Decorticated safflower meal is high in protein and low fiber and is a suitable ingredient for poultry feed, but removal of the hulls makes it a costly feed ingredient. Decorticated full-fat safflower seed can be fed to broiler chickens at up to 8% of the diet with no adverse effects on performance. The levels of decorticated full-fat safflower seed can be higher in older broilers and laying hens—up to 10% of the diet. When formulating diets with safflower meal, it is important to ensure that the lysine and methionine requirements of the poultry are met. Dehulled, extruded safflower meal can replace up to 60% of the soybean meal in a practical broiler diet without adversely affecting broiler performance.