Selenium nutrition in the cow and calf

مرکز و کتابخانه مطالعات اسلامی به زبان های اروپایی

منو

" Selenium nutrition in the cow and calf "
M. M. Abdelrahman R. L. Kincaid

Document Type	:	Latin Dissertation
Language of Document	:	English
Record Number	:	1112821
Doc. No	:	TLpq304227982
Main Entry	:	M. M. Abdelrahman
	:	R. L. Kincaid
Title & Author	:	Selenium nutrition in the cow and calf\ M. M. AbdelrahmanR. L. Kincaid
College	:	Washington State University
Date	:	1995
student score	:	1995
Degree	:	Ph.D.
Page No	:	152
Abstract	:	The physiological status of cattle and associated dietary factors affect the dietary requirement for Se. To partially quantify these effects, a trial was conducted in which fetuses were collected from pregnant heifers at slaughter. Concentrations of Se in fetal liver decreased significantly (2.03 vs 1.68 mug/g of DM; P <.05) during the final trimester of pregnancy, thus emphasizing the importance of Se supplementation of the dam during late gestation. A second trial was conducted to determine the effects of maternal Se supplementation on Se transfer to the fetus. Cows were randomly assigned at dry-off to receive either no supplemental Se or a bolus designed to deliver 3 mg of Se/day. Blood Se in the dam was significantly increased by the supplemental Se. Likewise, calves of Se supplemented cows had higher blood (.08 vs.11 mug/ml; P <.001) and liver Se (1.11 vs 2.34 mug/g; P <.001) at birth. Colostral Se concentrations were increased (.04 vs.06 mug/ml; P <.10) by maternal Se supplementation. Concentrations of Se in calf liver at d 42 were closely correlated to the liver Se concentrations at birth. A third study was conducted to determine how supplemental Se was distributed among plasma selenoproteins in growing calves. Calves were randomly assigned to adequate (0.56 mg/kg) or high (1.06 mg/kg) dietary Se and concentrations of Se in serum, and serum protein fractions were determined. Selenoprotein P appeared to be present in cattle serum and to have the highest percentage of Se among serum proteins. A final trial was conducted in western Sudan to investigate possible seasonal deficiencies of Se and other minerals in grazing dairy cattle. Selenium and Cu were deficient in serum of dairy cattle throughout the year. Phosphorus, Ca, and Na were deficient only during the late dry season. In summary, Se is an essential nutrient and mechanisms exist for its transfer from the dam to calf. If the dam's blood Se exceeds.12 mug/ml, enough Se will accumulate in fetal liver to prevent white muscle disease in the neonate. Also, Se supplementation of the dam leads to greater Se concentrations in colostrum. Selenoprotein P appears to be present in serum of cattle and probably functions as a Se transport protein. Deficiencies of Se in cattle are likely to exist in Sudan. Programs to supplement diets with Se would benefit cattle production in Sudan and improve Se intakes in local human population consuming meat and dairy products.
Subject	:	Biological sciences
	:	Livestock