Cows and hens

At steady state the excretion of a persistent compound equals the uptake. In cows and hens, feed/soil is the only relevant source of PCDD/F uptake, and there are two forms of excretion faeces and milk/eggs. If, for a given PCDD/F uptake, the flux in the faeces can be determined, then the net transfer of PCDD/Fs from the feed to the food product (often referred to as carryover) can be easily calculated. Or, in other words, at steady state all of the persistent PCDD/Fs that are absorbed by the animal are transferred to the milk/eggs. Hence, we need to understand absorption in order to understand carryover. 

The upper limit (UL) for human daily iodine intake recommended by the German, Austrian and Swiss Societies of Nutrition (D-A-CH, 2000) is 500 pg/day. Consumption of only 250 ml of the milk produced during period 4 of the study would result in ingestion of more than 500 pg iodine. As a result of this experiment, the European Food Safety Authority reduced the maximum allowed iodine intake of cows and hens in the EU from lOmg/kg feed to 5mg/kg grain dry matter equivalent (EU, 2003, 2005 EFSA, 2005). 

Baldwin MK, Crayford JV, Hutson DH, et al. 1976. The metabolism and residues of [14C] endrin in lactating cows and laying hens. Pestic Sci 7 575-594. 

Parade magazine, the following question was cows and how many hens were in the barnyard ... 

Monensin plays a dual role in veterinary practice because it is used both as a coccidiostat in poultry and as a growth promotant in cattle. It is also efficacious in the control of coccidiosis in lambs and calves, can treat ketosis in dairy cows, and can control bloat in pastured dairy cattle. It is administered incorporated in poultry feeds as a coccidiostat at a dose up to 120 ppm, and in cattle and sheep feeds at a dose of 11-33 ppm. Monensin is not recommended for administration to laying hens, while a 3 day withdrawal period is required for chicken meat. 

A steady state exists when the uptake, storage and excretion of a substance does not change with time. Given that the concentrations of PCDD/Fs in feed are relatively constant, milk cows and egg laying hens are in an approximate PCDD/F steady state. The one exception is the cow that has calved for the first time. In this case the PCDD/Fs that it has accumulated as a heifer are initially... 

Milk and eggs of acceptable animal species are permitted. Acceptable species are sheep, goats, lambs, cows, chickens, hens, quails, turkeys. Pork and any porcine derived ingredients are absolutely forbidden. 

Fettman et al. 1984 Cl requirement for milking cows and Feed of hens should contain < 1-7 g... 

Zinc deficiency includes depressed feed intake, stunted growth, skin lesions, and reproductive difficulties. Zinc is a component of enzymes which catalyze more than fifty different biochemical reactions, as well as a component of proteins involved in gene expression. The recommendation for zinc intake amounts to 30 mg kg for calves, heifers and lambs, 40 mg kg for dairy cows, piglets, pigs, sows and hens, and 50 mg kg feed DM for broilers. 

Shek, L.P.C., Soderstrom, L., Ahlstedt, S., Beyer, K., and Sampson, H.A., Determination of food specific IgE levels over time can predict the development of tolerance in cow s milk and hen s egg allergy, J. Allergy Clin. Immunol, 114,387-391, 2004. 

In addition to the Aotoisomerization of deltamethrin, its metabolic pathway was also studied by means of TLC. C-deltamethrin labeled on the acid or benzyl part of the molecule was used in metabolism studies on eggs, yolks, and albumen or liver and kidney samples of laying hens (113) and on enzyme preparations of cow and chicken livers (114) (Table 9). The main metabolites were assigned and characterized by the / y values given in Table 9. 

The above listed carotenoids are also added to the feed of dairy cows and poultry to ensure desirable pigmentation of milk, dairy products, eggs and meat. All these carotenoids are added to feed for laying hens and broilers (to provide pigmentation of eggs and meat), with the exception of P-carotene, and also synthetic citranaxanthin (E161i, 9-194) and carotenoids obtained from different plant materials. The reason why the feed for laying hens and broilers does not contain added P-carotene is its quick conversion into retinol, which has almost no effect on the yolk and... 

Hypotaurine could also be shown in the Fallopian tube of cow, horse and rabbit, but it could not be detected in the rat, turkey and hen. Curiously in these species of animals hypotaurine was also... 

The concentration of iodine in cow s milk was 27-28 ug/1. At the end of the 70 s the concentration of iodine in the milk had increased to 160-170 ug/1 . The total intake exceeded 300 ug/d of which close to 200 ug/d derived from milk, milk products and hen s eggs. Still only 20% came from iodized salt because the salt consumption had decreased during two decades from 7-8 g/day in the early 60 s to 4 g or less. ... 

Knippels, L.M.J., van der Kleij, H.P.M., Koppelman, S.J., Houben, G.F., Penninks, A.H., Felius, A.A., Comparison of antibody responses to hens egg and cows milk proteins in orally sensitized rats and food-allergic patients. Allergy, 55, 251, 2000. 

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