The use of genetic engineering techniques to improve the lipid composition in meat, milk and fish products: a review

Abstract

The health-promoting properties of dietary long-chain n-3 polyunsaturated fatty acids (n-3 LCPUFAs) for humans are well-known. Products of animal-origin enriched with n-3 LCPUFAs can be a good example of functional food, that is food that besides traditionally understood nutritional value may have a beneficial influence on the metabolism and health of consumers, thus reducing the risk of various lifestyle diseases such as atherosclerosis and coronary artery disease. The traditional method of enriching meat, milk or eggs with n-3 LCPUFA is the manipulation of the composition of animal diets. Huge progress in the development of genetic engineering techniques, for example transgenesis, has enabled the generation of many kinds of genetically modified animals. In recent years, one of the aims of animal transgenesis has been the modification of the lipid composition of meat and milk in order to improve the dietetic value of animal-origin products. This article reviews and discusses the data in the literature concerning studies where techniques of genetic engineering were used to create animal-origin products modified to contain health-promoting lipids. These studies are still at the laboratory stage, but their results have demonstrated that the transgenesis of pigs, cows, goats and fishes can be used in the future as efficient methods of production of healthy animal-origin food of high dietetic value. However, due to high costs and a low level of public acceptance, the introduction of this technology to commercial animal production and markets seems to be a distant prospect.

Supplementation of organic acid blends in water improves growth, meat yield, dressing parameters and bone development of broilers

“…Similarly, use of citric acid found to increase retention of phosphorus (Brenes et al, 2003), tibia ash (Rafacz-Livingston et al, 2005;Martinez-Amezcua et al, 2006;Moghadam et al2006), and toe ash (Atapattu and Nelligaswatta, 2005) in broiler chicks. In a recent study, Świątkiewicz and Arczewska-Wlosek (2012) reported that organic acids have no effects on increases the solubility and absorption of phosphorus and calcium in the small intestine (Overland et al, 2002), thereby improving retention of phosphorus and calcium.…”

Effects of dietary Clostridium butyricum and fructooligosaccharides, alone or in combination, on performance, egg quality, amino acid digestibility, jejunal morphology, immune function, and antioxidant capacity of laying hens

“…This is in line with other reports in laying hens, that CB enhanced feed efficiency (Xiang et al, 2019;Wang et al, 2020), while synbiotics enhanced feed intake (Tang et al, 2017). The positive effects of diets on laying performance, egg mass and feed efficiency could be attributable to availability of nutrients necessary for metabolism, maintenance and egg production (Markowiak and Śliżewska, 2018), probably because probiotics and prebiotics modulate gut structure for efficient nutrient absorption (Swiatkiewicz et al, 2015;Tang et al, 2017;Xiang et al, 2019). Also, gut fermentation effects are linked with production of short-chain fatty acids which nourish the enterocytes, protect the villi from pathogen invasion and invariably increase microvilli structures for nutrient absorption (Hajiaghapour and Rezaeipour, 2018;Liu et al, 2018).…”