The effect of different proportions of Leucaena leucocephala in the diet of cattle on growth, feed intake, thyroid function and urinary excretion of 3-hydroxy-4(1H)-pyridone

Author:

Jones RJ,Hegarty MP

Abstract

Steers were fed in pens on diets containing 0, 10, 20, 40, 67 and 100% Leucaena for 112 days. The remainder of the diet was a good quality sorghum hay. Liveweight change, feed intake, mimosine intake, urinary output of 3-hydroxy-4(1H)-pyridone (DHP), serum thyroxine (T4), serum triiodothyronine (T3) and effective thyroxine ratio (ETR) were measured. Steers on the 67 and 100% Leucaena diets had low feed intakes (40-50 g (kg LW)-a 75), lost weight and were severely hypothyroid. Steers on the 0, 10 and 20% Leucaena had intakes of 80-90 g (kg LW)-a 75, gained liveweight at 0.3-0.5 kg day-' and showed normal thyroid function. Steers on the 40% Leucaena diet had high feed intakes and grew well initially, but subsequently their feed intakes and rates of liveweighr gain declined. Reduced feed intake was associated with serum T3 levels below 1.0 nmol l-1. DHP excretion in the urine was linearly related to Leucaena and mimosine intake (P < 0.01). Recoveries of mimosine eaten, as DHP in the urine, varied from 33% with the 10% Leucaena diet to 55% with full Leucaena feeding. Feed intake declined as the proportion of Leucaena in the diet increased, but recovery of appetite was rapid when steers were transferred to an all sorghum hay ration. It is concluded that diets containing less than 1 % mimosine on a DM basis have little adverse effect on thyroid function or feed intake, whereas above this level hypothyroidism and low feed intakes may occur. Under Australian conditions Leucaena can only safely be used as a supplement (<30%) to roughage diets, rather than as a major dietary component, until some solution to the toxicity problem is found.

Publisher

CSIRO Publishing

Subject

General Agricultural and Biological Sciences

Cited by 56 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3