Cattle estimation

Following administration to rat, dog, rabbit, and cow, clenbuterol was rapidly eliminated, being largely excreted in urine in the form of the parent drug (15). Following a 4 day treatment of cattle at the therapeutic dosage (0.8 g/kg bw) and a 7 day withdrawal, concentrations of clenbuterol in liver were at the level of 0.35 ppb or below, whereas concentrations in urine were approximately one-tenth of the levels in liver (16). Administration, on the other hand, of a single oral dose of radiolabeled clenbuterol to cattle showed that 40% of the urinary radioactivity was due to the parent compound. The urinary half-life of clenbuterol in cattle, estimated from the urinary excretion of the parent compound, was approximately 36 h (17). 

Economics. Estimates of anaboHc steroids in growing cattle indicate that savings associated with reduced feed costs are approximately 50.00 per animal. Increased value of the carcass resulting from the increased amount of saleable lean meat produced is estimated to range from 15.00 to 30.00 per animal. 

Anticoccidial Activity. The 1968 report that claimed monensin has activity against Eimeria sp., particularly E. tenella E. macdma., and E. acervulina greatly altered the prevention and control of coccidiosis in poultry (172). It is estimated that the polyether ionophores presently constitute more than 80% of the total worldwide usage of anticoccidials (173). Lasalocid and monensin have been approved for use in control of coccidiosis in cattle. 

Poisoning by ergot still occurs occasionally in countries where rye is extensively used as a food grain or where ergotised grain is liable to be fed to cattle and methods for its detection have been devised, but interest in the analysis of ergot centres chiefly on the estimation of the active alkaloids in the crude drug or its preparations. The methods used may... 

Matsumoto et al. developed an immunoassay for the determination of clenbuterol in bovine and equine tissues and in bovine milk. The LOD of clenbuterol in milk, muscle, liver, kidney, small intestine, and adipose tissues was 0.1 qgkg Bovine tissue samples fortified wifh 1 qg kg of clenbuterol had recoveries that varied from 75 to 96%, but recoveries from milk samples were 99%. The authors utilized this method to estimate the clenbuterol withdrawal periods for cattle and horses. Cattle were treated with a bolus dose of either 0.3 or 0.6 qg kg body weight, by intravenous injection, and three animals were slaughtered at days 1, 6, and 9. Tissue clenbuterol levels were detectable only on day 1. Clenbuterol in milk was not detectable after a 2.5-day withdrawal period. Liver contained the highest clenbuterol concentration of the tissues measured, but this group did not measure eye tissues. 

The production of livestock and livestock products has been greatly increased through the effective application of agricultural chemicals, as evidenced in the control of insects and diseases on and around dairy cattle, which has resulted in many instances of increased milk production ranging between 15 and 20%. It has been reliably estimated that the treatment of beef cattle for insect pests has resulted in additional gains of 50 pounds per head of beef animals treated. The dollar value of these increases in both beef and milk has been estimated at 54,000,000 per year. 

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 ... 

One can estimate that there is a fair good correlation between N produced in animal manure and the ammonia emission. As the production of cattle slurry is linked with grassland and in many regions the main part of the manure from pigs and poultry is spread on arable land, there is a risk for underestimating the ammonia emissions from cattle slurry. In table II an estimate is made of the total production of mineral N in animal manure in the Netherlands. 

Approximately 80% of the poultry. 75% of the swine. 60% of the beef cattle and 75% of the dairy calves marketed are estimated to have received antibiotics at some time in their life (CAST. i). Of the antibiotics produced each year in the U.S.. 45 to 55% are... 

The main source of E. coli 0157 H7 is from the manure of ruminants (cattle, sheep) and sewage (Chase-Topping et al., 2008). Other livestock and wildlife have lower frequency of carriage. Although the estimates of STEC vary seasonally, and between herds, approximately 2-100% of cattle harbor E. coli 0157 H7 (Hancock et al, 1997). In a 12-month abattoir study in Great Britain, Milnes et al. (2008) determined the fecal carriage of STEC 0157 to be 4.7% in cattle, 0.7% in sheep, and 0.3% in swine. Conversely, in another British study, Hutchison et al. (2005) isolated... 

Food and feed additives, also known as dietary supplements, are minor ingredients added to improve the product quality. Most commonly, the effects desired relate to color, flavor, nutritive value, taste, or stability in storage. The market sizes are estimated to be 20 billion each for food and for feed additives, respectively. The major customers for the food additives are the big food companies Ajinomoto, Danone, Kraft, and Nestle, mentioned at the beginning of the chapter. With the exception of Ajinomoto, these companies are rarely backward-integrated. As they prefer to use natural ingredients rather than synthetic ones, they are not very important customers of the fine-chemical industry. Premixers, that is, enterprises that prepare ready-to-use mixtures of nutrients for the farmers who raise cattle, pigs, and chicken, are the main users of feed additives. 

In 1986, the animal drug market was estimated to be worth over 9000 million, with feed additives and therapeutics each contributing 45% of the total (6). The United States shared 28% of the market, and Western Europe 24.5%. A breakdown by animal usage showed that cattle formed 32%, with poultry making up 24%, swine 21%, sheep 10% and horses 4%. 

In the gut lumen of the target animals, thiophanate undergoes cyclization, forming 2-ethoxycarbonylamino-benzimidazole, which is also known as lobenda-zole. The extent of thiophanate metabolism to lobendazole in cattle has been estimated at approximately 57%. 

Following subcutaneous administration of 0.3 mg radiolabeled abamectin/ kg bw to cattle, a mean peak plasma radioactivity level of 0.09 ppm equivalents was detected. Depletion half-life rates for liver, kidney, muscle, fat, and plasma were estimated at 4.6, 5.7, 5.6, 8.1, and 4.7 days, respectively. About 70% of radioactivity was detected in feces, and 1-2% in the urine, within 7 days of treatment. 

---