Growth, heart weight, cardiac lipid, and pathology of chickens fed soybean oil or oil extracted from different rapeseed cultivars

High Levels of Erucic Acid Cause Lipid Deposition, Decreased Antioxidant and Immune Abilities via Inhibiting Lipid Catabolism and Increasing Lipogenesis in Black Carp (Mylopharyngodon piceus)

This study investigated the effects of dietary erucic acid (EA) on growth, lipid accumulation, antioxidant and immune abilities, and lipid metabolism in black carp fed six diets containing varying levels of EA (0.00%, 0.44%, 0.81%, 1.83%, 2.74%, and 3.49%), for 8 weeks. Results showed that fish fed the 3.49% EA diet exhibited lower weight gain, compared to those fed the 0.81% EA diet. In a dose-dependent manner, the serum triglycerides and total cholesterol were significantly elevated in the EA groups. The 1.83%, 2.74%, and 3.49% levels of EA increased alanine aminotransferase and aspartate aminotransferase activities, as well as decreased acid phosphatase and alkaline phosphatase values compared to the EA-deficient group. The hepatic catalase activity and transcriptional level were notably reduced, accompanied by increased hydrogen peroxide contents in the EA groups. Furthermore, dietary EA primarily increased the C22:1n-9 and C20:1n-9 levels, while decreasing the C18:0 and C18:1n-9 contents. In the EA groups, expressions of genes, including hsl, cpt1a, cpt1b, and ppara were downregulated, whereas the fas and gpat expressions were enhanced. Additionally, dietary EA elevated the mRNA level of il-1β and reduced the expression of il-10. Collectively, high levels of EA (2.74% and 3.49%) induced lipid accumulation, reduced antioxidative and immune abilities in black carp by inhibiting lipid catabolism and increasing lipogenesis. These findings provide valuable insights for optimizing the use of rapeseed oil rich in EA for black carp and other carnivorous fish species.

[Rapeseed and rapeseed meal as components in diets of laying hens]

In an experiment with 405 Hisex white hens rations with 5-20% low glucosinolate rapeseed (RS) or rapeseed meal (RSM) of 00 quality were used. Feed intake, egg production, individual egg weight and live weight gain were reduced in hens fed 5-20% RS and 10-20% RSM. There was a positive correlation between the RS proportion in the ration and the thyroid weight as well as the iodine content of the thyroid. The relation between the iodine content related to one gram of thyroid and the RS proportion was not significant. There were not any significant differences between the RSM groups and the iodine content of the thyroid. The T3 and T4 concentrations in the blood plasma was independent of the RS- or RSM-proportion in the diet. The outward egg quality was not influenced by feeding. The Haugh units were lower when RS or RSM were offered. The fatty acid pattern of the yolk was changed by RS or RSM feeding, particularly the proportion of oleic acid increased. We concluded from the results, RS cannot be recommended for feeding white hens and only a maximum of 5% RSM should be administered.

Pathological changes associated with the feeding of soybean oil or oil extracted from different rapeseed cultivars to single comb white Leghorn cockerels

A total of 384 Single Comb White Leghorn cockerels of the Hyline strain were fed either a basal (control) diet containing no added oil or a diet supplemented with 20% by weight of soybean oil, rapeseed oil from cultivars Tower, Candle, a mixture of Echo and Arlo high erucic acid rapeseed (HEAR), or R-500. Levels of erucic acid (22:1) in the rapeseed diets varied from .03 to 10.31%. Three birds from each unit were killed at 28, 56, 84, and 112 days and a wide range of tissues were examined histologically. A number of birds in all dietary groups had healed lesions of avian encephalomalacia. Two cockerels fed HEAR oil and 12 fed R-500 developed marked ascites, firm shrunken livers, hydropericardium, and cachectic muscular atrophy. Marked periacinar necrosis was present in birds dying with ascites. A significantly higher number of birds fed the rapeseed oils developed hepatic sinusoidal distention than birds fed the basal or soybean oil diets. Degenerative myocardial changes were seen only in R-500 and HEAR oil-fed birds. This, coupled with hepatic changes, producing shrunken firm livers, led to development of ascites, cachectic muscular atrophy, and periacinar hepatic necrosis. These changes were probably produced by the high erucic acid content of the HEAR and R-500 oils and the resultant grossly imbalanced diet.

Some aspects of the composition of avian ascitic fluid

Ascitic fluid from male Single Comb White Leghorn chickens fed a diet containing 20% by weight rapeseed oil rich (51.6 weight percent) in erucic (22:1n9) acid contained 2.84 +/- .09 g/dl protein and 2.55 +/- .22 micrograms/ml DNA. A characteristic feature of ascitic fluid as compared to liver and plasma was its high polyunsaturates, low saturates, and low saturate to unsaturate ratio. In general, the fatty acid profile of ascitic fluid is more comparable to the fatty acid profile of plasma lipids than to that of liver lipids. These data suggest that there is no direct absorption of fat and transfer to the ascitic fluid.