Beef, canned factors

The transfer of PBBs from soil to plants is so low, e.g., Table III and References (6,29), that the only important issue In the agricultural scenario appears to be soli ingestion (and possibly ingestion of groundwater) by cattle. Based on an estimated half-life, tj/2> in beef of 120 days (30) an estimated mass of fat per animal, M, of 67 kg and a soil Ingestion rate, Mg, of 0.72 kg/day (31), a reasonably conservative soll-to-fat bioconcentration factor can be obtained ... 

Several U.S. researchers speculate that the authors of the French report mistakenly drew their conclusion from published studies analyzing naturally occurring creatine found in protein-rich animal products such as beef and pork. When these creatine-containing foods are heated and cooked, the creatine and amino acids interact to form compounds known as heterocyclic amines (HCAs), which have been shown to cause cancer in animal studies. The level of HCAs can vary with cooking method and other factors. Creatine monohydrate does not contain HCAs, and as of early 2002, no published or reported clinical research existed to demonstrate that creatine monohydrate taken in supplement form causes cancer. 

The effectiveness of pectin in lowering cholesterol in tissues can be influenced by many factors (1) The type of pectin - that with methoxy groups and with high viscosity (35, 36) was reported to be more effective. The results from a comparative study of several types of pectin by Mokady (36) are shown in Table IV. Neither a high degree of methylation nor high-viscosity alone was very effective (2) the level of dietary fat - with a high-fat diet (2% corn oil plus 18% beef tallow), pectin has no effect on serum cholesterol level (57). Tsai et al. also reported that with... 

Among the many systems Racker used, one is a particulate system prepared by exposing beef mitochondria to sonic oscillation. The system can oxidize succinate and NADH but cannot couple the oxidation of the substrate to the phosphorylation of ADP. Coupling can be achieved by adding to the system two soluble proteins referred to by Racker as factor 1 (FJ and factor 4 (F4). F is a protein with ATPase activity obtained by sonic disintegration of mitochondria. F4 is prepared by alkaline extraction of the mitochondria. Fi, which has been extensively purified, is a decamer with a molecular weight of 284,000, each monomer weighing 26,000. 

The system can be used in two ways, either to predict the performance of animals given a specific ration or to formulate a ration for a desired level of performance. Operation of the system is illustrated for beef cattle in Boxes 12.1 and 12.2 and an example of ration formulation for dairy cows is presented in Box 12.3. Ration formulation is often more difficult than prediction of performance because the ME concentration of the ration cannot be calculated until the ration has been formulated. This means that for factors that are dependent on q, provisional data must be used initially, and the calculations have to be repeated until the factors and diet match each other. The repetition of calculations (known as iteration) is easily carried out by a computer, but if a computer is not available the approximate method illustrated in Box 12.2 can be used. For convenience, the example in Box 12.2 starts at the end point of the example in Box 12.1. 

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