Magnesium Utilization in Wethers Fed Diets with Varying Ratios of Nitrogen to Readily Fermentable Carbohydrates

House, W.A. and Mayland, H.F. (1976) Magnesium Utilization in Wethers Fed Diets with Varying Ratios of Nitrogen to Readily Fermentable Carbohydrates. Journal of Animal Science. 43(4):842-849.

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Abstract

Two experiments were conducted to study
magnesium utilization in wether lambs fed diets
with varying ratios of nitrogen to readily
fermentable carbohydrate (N:RFC). Semipurified
diets fed to the lambs contained about
4.1% nitrogen (25.6% crude protein), .08%
magnesium, .4% calcium, 2.4% potassium and
varied amounts of readily fermentable carbohydrate
provided mainly as either starch (experiment
1) or sucrose (experiment 2). Dietary
ratios of N:RFC were .2, .4, .7 and .9 in
experiment 1 (five lambs/treatment), and .2
and 1.6 in experiment 2 (nine lambs/treatment).

In experiment 1, ruminal fluid ammonia-nitrogen
levels increased as starch intake decreased,
but differences between treatments
were not significant (P>.05). Apparent absorption,
retention and plasma concentration of
magnesium were not affected (P>.05) by decreased
starch intake. In experiment 2, ruminal
ammonia levels increased (P<.05) as sucrose
intake decreased. Urinary excretion (P<.05)
and apparent absorption (P<.1) of magnesium
were higher in lambs fed supplementary sucrose
than in those fed the diet without added
sucrose; plasma magnesium levels were similar
in both groups. Results of experiment 2 support
the hypothesis that supplemental energy
may enhance the availability of dietary magnesium
to ruminants.

Item Type:	Article
NWISRL Publication Number:	0355
Subjects:	Animal > Animal health Mass Import - autoclassified (may be erroneous)
Depositing User:	Dan Stieneke
Date Deposited:	20 Nov 2010 21:51
Last Modified:	15 Feb 2017 18:10
Item ID:	305
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/305