The effect of grapeseed oil on performance, rumen fermentation, antioxidant status and subcutaneous adipose fatty acid profile in lambs
In 2013, Iran produced more than two million metric tons of grapes (FAOSTAT, 2013). As grapeseeds consist approximately 5% of the fruit weight (Choi and Lee, 2009), so around 100 kton of grapeseeds is discarded annually in Iran.
Grapeseed oil is produced from the seeds in the pomace left over from juice and wine production by cold pressing method and thus adds value to the industry. This agricultural by product contain 10–20% oil (Crews et al., 2006), so annual production of GSO is approximately 10–20 kton in Iran and its nutritive value can be similar to other oil sources such as sunflower, flax and fish oils. An important characteristic of GSO is having very high amount of linoleic acid and presence of tocopherols and tocotrienols which exhibit strong antioxidant activity (Beveridge et al., 2005; Choi and Lee, 2009). In addition, grapeseed has higher level of polyphenol compounds such as proanthocyanidins, mainly composed of catechin, epicatechin, gallic acid and polymeric and oligomeric procyanidins, which can be recovered by extraction (Monagas et al., 2003). So GSO can consider an alternative for other oil sources in the diet of ruminants to improve meat and milk quality. Jerónimo et al. (2012) found that adding grapeseed extract had no effect on lamb muscle FAs but reduces oxidation of meat lipids by lowering concentration of malondialdehyde (MDA). Therefore, it seems that GSO due to having high levels of linoleic acid, in addition to its capability to increase PUFA, it can also act as a natural antioxidant. According to our information, while a few studies have been conducted on grape by‐products in ruminant, there is no study about using GSO in ruminant nutrition. This study was carried out to evaluate the effect of GSO on performance, rumen fermentation, antioxidant status and adipose FA profile in lambs.