It is known that the content of unsaturated fatty acid in beef fat is associated with quality of beef, such as the beef taste and texture. Generally, if the content of unsaturated fatty acid is high with low melting point, the beef is considered to have good quality, which gives good taste and texture.
However, in order to judge whether the beef has such quality, there was no other way but to depend on the subjective (sensuous) method, in which the beef was actually eaten and evaluated. In other words, there was no conventional method, which was more objective, simple and efficient, like the judgment approach of predicting quality of beef, simply based on the genotype of a specific bovine gene.
By the way, stearoyl-CoA desaturase (SCD) is known as an enzyme which desaturates beef fat. This enzyme desaturates stearoyl-CoA which plays an important role for in vivo biosynthesis of lipids and their degradation. Amino acid sequence and cDNA sequence of bovine stearoyl-CoA (derived from Bos taurus) are shown in DDBJ/EMBL/GenBank databases; Accession number “AB075020”. Information of these sequences was provided by inventors of the present invention.
As mentioned above, the content of unsaturated fatty acid in beef fat (in other words, the amount of the unsaturated fatty acid content) is associated with quality of beef, such as the beef taste and texture. If the amount of the unsaturated fatty acid content can be predicted on the basis of the genotype of a specific bovine gene, then it provides a new method which enables simple examination as to quality of beef, such as the beef taste and texture.
Such method based on the genotype is useful not only for evaluation and selection of cattle (beef cattle) with good quality of beef, but also for breeding and reproduction of cattle.
Furthermore, the content of unsaturated fatty acid in beef fat is associated with the cholesterol accumulation caused by beef intake, and it is considered one of important features of the cattle, especially in the countries where beef is eaten very often, such as the Europe and the United States of America. Therefore, the above-mentioned method for evaluating the unsaturated fatty acid content based on the genotype, is also useful from the view point of health care.
In addition, the content of unsaturated fatty acid in milk fat of the dairy cattle is considered to affect the taste and mouthfeel of dairy products, such as butter. For example, when the content of unsaturated fatty acid in milk fat is higher and the melting point is lower, then the butter produced by using the milk as raw material is softer with good mouth-melt. Therefore, the above-mentioned method for predicting the unsaturated fatty acid content based on the genotype, is also useful for dairy products and dairy cattle breeding.