Investigating Feeding Omega-3 Polyunsaturated Fatty Acids and/or Soy Protein Isolate to Female pck Rats on Polycystic Kidney Disease and Related Complications

Polycystic kidney disease (PKD) is a genetic disorder characterized by multiple benign cysts along the epithelial lining of the kidneys. As PKD progresses, cyst growth increases kidney volume, decreases renal function, and may eventually lead to end stage renal disease. In addition to renal manifestations, PKD patients are at risk of complications that include bone loss and polycystic liver disease (PLD). Currently, no genetic therapy or effective pharmacological treatments exist. Therefore, dietary intervention offers a potentially efficacious, cost-effective, and safe therapeutic option for PKD and PKD-related complications. Offering dietary treatment to attenuate PKD disease progression has the potential to improve renal function, preserve bone health, and to prevent PLD. Dietary soy protein has been shown to reduce cyst proliferation and growth and to enhance bone mass. Dietary omega-3 polyunsaturated fatty acids (n-3 PUFA\u27s) have anti-inflammatory properties. Dietary n-3 PUFAs have been shown to reduce PKD severity and may attenuate bone loss and PLD severity. Therefore, the objectives of this thesis was to investigate the role of dietary soy protein and/or n-3 PUFAs on PKD progression and severity and related complications of bone loss, and PLD using a pck rat model. Young (age 28 d) female pck rats were randomly assigned (n=12/group) to diets consisting of casein + corn oil (Casein + CO), casein + soybean oil (Casein + SO), SPI + soybean oil (SPI + SO) or SPI + 1:1 soybean/salmon oil (SPI + SB) for 12-weeks. Histological evaluation showed that all rats had renal and hepatic cysts regardless of the dietary group. Rats fed SPI+ SB diet had the highest (P = 0.03) renal and hepatic cortical cyst obstruction. Although, rats fed SPI+SB diet had the highest (P\u3c 0.001) renal docosahexaenoic acid (DHA) and highest (P\u3c0.001) hepatic eicosapentaenoic acid (EPA) and DHA content, this did not reduce inflammation. Gene expression of various transcription factors and inflammatory genes in the kidneys and liver was not significantly different among the dietary treatment groups. Histological evaluation of hepatic and renal fibrosis and gene expression of fibrosis were also not significantly different among the dietary treatment groups. However, rats fed SPI + SB diet had the highest (P \u3c 0.01) serum blood urea nitrogen levels indicating reduced renal function. Rats fed SPI + SB diet also had the highest liver total lipid (P \u3c 0.001) and steatosis (P = 0.003) suggesting disordered lipid metabolism. Rats fed SPI+SB diet had higher (P=0.01) calcium (Ca) and phosphorus (P) retention, but there were no significant differences in bone Ca, P, bone mass, bone microarchitecture or strength among the diet groups. Based on the results, dietary soy protein and/or n-3 PUFAs did not attenuate PKD progression and severity or related complications of bone loss and PLD in the female pck rat model of PKD. Furthermore, feeding SPI + SB diet was potentially detrimental on kidney function and liver metabolism in female pck rats

The effect of dietary inclusion of conjugated linoleic acid in finishing hog feed on sensory characteristics and storage quality indicators of pork loin

Marbling in meat occurs when fat is distributed throughout the skeletal muscle and is visually apparent by light streaks of fat that look like a marble pattern. It is associated with increased quality, tenderness, and likeability. Incorporating dietary conjugated linoleic acid (CLA) into finishing hog feed increases intramuscular fat and decrease backfat in harvested pigs; therefore, the purpose of this study was to determine if inclusion of CLA in pig feed would increase intramuscular marbling and consumer likeability without compromising storage stability. Twenty pigs were housed in ten pens (2 pigs per pen) and fed either 1% Soybean oil or 1% CLA diet for a period of six weeks. After slaughter, pork loins were cut and divided into cranial and caudal ends, vacuum packed and stored at -8°C until evaluations were conducted. Quality indicators of pork were measured on both raw and cooked samples over a 7-d storage period. Measurements included color (L*, a*, b*), muscle pH, texture, and lipid oxidation by thiobarbituric acid reactive test (TBARS). Sensory panelists evaluated tenderness, juiciness, flavor, aroma, off-flavor, and likeability of each sample on an 8-point hedonic scale. Raw and cooked color scores, texture, TBARS, and raw and cooked muscle pH changed over time (p\u3c0.05); however, these changes were independent of diet. Differences in quality indicators between diets were seen numerically but did not reach significance (p\u3e0.05). Sensory evaluation by 20 panelists showed a trend that CLA loins presented with better flavor and juiciness (p0.05). Results of this study indicate that the inclusion of CLA in pig feed provides a meat product similar to soybean pig feed. The similar storage stability and sensory results of this study indicate limited, if any, benefits of feeding a CLA-diet over a traditional one.;Keywords. Linoleic acid; marbling; pork