Iodine value and packer concerns
Posted on February 17, 2012 in Swine Performance
By Spencer Jones
Some pork packers have recently placed increased emphasis on pork carcass composition, specifically fat quality. Iodine value (IV) is a measurement that estimates the amount of unsatuation present in the fatty acids found in carcass fat. Unsaturated fats are softer at room temperature. That means a carcass with higher unsaturated fat content – and thus higher IV – has softer fat. This softer fat may cause processing problems for the packers. For example, it may be more difficult to slice bacon. It may also negatively impact shelf life and acceptance by export markets. IV can be determined by measuring the amount of iodine that binds to unsaturated fatty acid double-bonds within a sample. However, it is more often calculated using an equation based on fatty acid composition of the fat. (This method is easier, faster and less expensive than the direct iodine method.) Fat samples are usually taken from the jowl or belly (note that jowl samples typically have IV values 2 to 3 points higher than belly samples). It is important that these samples are taken from a consistent location and that the location is specified in packer reports. IV is reported as grams of unsaturated fat per 100-gram sample. Again, higher IV values indicate more unsaturated (softer) fat. That means that a lower value (with more saturated fat) is more desirable. The acceptable range varies among packers, but most will accept a carcass IV range of 70 to 75. Some do not set a maximum level, but instead give specific recommendations for ingredient inclusions. For example, a packer may set a maximum level of DDGS that can be fed in late finishing diets. Does that mean you should stop feeding DDGS? No, feeding high levels of DDGS is almost a necessity in today’s economic environment. However, a step-down program for reducing the DDGS inclusion in the late finishing stage can producer harder fat and decrease IV. Contact your Vita Plus consultant
for more information about managing carcass IV in your system. About the author: Spencer Jones joined the Vita Plus team in 2011 as the swine business manager. He received both his bachelor’s and master’s degrees in nutrition from Kansas State University. Jones grew up showing hogs and steers for 4-H and working on a beef feedlot. He is a member of ASAS, American Angus Association, Iowa Angus Association and Iowa Cattleman’s Association. Jones lives in Iowa with his wife of four years, Cassie, and their son, Ty.