Effect of Dietary Potassium on Absorption of Magnesium and other Macroelements in Sheep Fed Different Levels of Magnesium

Abstract

Two metabolism trials were conducted with 24 crossbred wether lambs. Two levels of Mg (.1 and .2%) and four levels of K (.6, 1.2, 2.4 and 4.8%) were fed in a 2 x 4 factorial arrangement of treatments. Each trial consisted of a 10-d preliminary period followed by a 10-d collection of feed, feces and urine. Increasing levels of dietary K resulted in a linear increase in fecal Mg excretion and a linear decrease in Mg absorption. A large depression in Mg absorption occurred when K was increased from 1.2 to 2.4% with a further decrease when K was increased to 4.8%. Lambs fed the high level of Mg (.2%) absorbed and retained more (P less than .05) total Mg (g/d, but not percentage of intake) compared with the low magnesium level (.1%). Dietary Mg did not affect the amount of K excreted, absorbed or retained. Increasing the level of dietary K resulted in a linear increase in urinary, fecal and total K excreted, absorbed and retained (P less than .05).

Influence of varying dietary cation anion difference on serum minerals, mineral balance and hypocalcemia in Nili Ravi buffaloes

“…The probable explanation of this act might be the high K content of higher DCAD diets. It is documented that high K inhibits the absorption of Mg in ruminants (Greene et al, 1983;Schonewille et al, 1997). The kidneys are responsible for plasma Mg concentration because there is no specific Mg regulating hormone and high urinary Mg reflects higher intake (Capen and Rosol, 1989).…”

Perdas endógenas e coeficientes de absorção aparente e real do magnésio em caprinos

“…Houve efeito significativo dos níveis de Mg na dieta somente para excreção fecal de Mg, resultando em valores de 7,0; 20,8; e 34,4 mg Mg/kg PV 0,75 /dia, para os níveis 0,05; 0,20; e 0,35% Mg, respectivamente. GREENE et al (1983a), quando utilizaram ovinos recebendo dietas com 0,20% Mg, encontraram maior excreção de Mg nas fezes que os animais alimentados com dietas contendo 0,10%. GREENE et al (1983b) mostraram que a excreção fecal de Mg aumentou de 0,77 para 1,08 g/dia, quando a dieta foi suplementada com Mg, representando 43% de aumento.…”

“…GREENE et al (1983a) observaram que a excreção urinária de Mg aumentou com os níveis de Mg na dieta, 0,10 e 0,20%, constatando que o aumento ocorreu, provavelmente, em virtude do incremento da absorção. O efeito dos níveis de Mg sobre a diminuição da excreção de Ca na urina pode estar relacionado à diminuição na absorção aparente de Ca, devido ao aumento dos níveis de Mg na ração.…”

Effects of Calcium Loss and High Dietary Calcium and Potassium on Calcium Kinetics and Magnesium Balance in Sheep Fed Low Magnesium Diets

“…Elowever, others (Newton etal. 1912;Greene et al 1983a;Grings and Males 1987) have olbserved no change in or elevated absorption of Ca when diets contained high levels c,f K.…”