Bakalli R I, Pesti G M, Ragland W L
Department of Poultry Science, College of Agricultural and Environmental Sciences, University of Georgia, Athens 30602, USA.
Vet Hum Toxicol. 1995 Feb;37(1):15-9.
Four experiments were conducted to study the toxic effects of supplemental dietary lead (Pb) on broiler chickens from hatching to 42 d of age. Dietary variables were 0, 0.1, 0.5 or 1.0 mg Pb/kg feed as lead sulfate in Experiment 1, and 0, 0.5 or 1 mg Pb/kg feed as lead sulfate and lead acetate in Experiment 2. Experiments 3 and 4 were 2 x 4 factorial designs with 2 levels of calcium (0.65% or 1.30%) and 4 levels of Pb (0, 1, 10 or 100 mg Pb as lead sulfate/kg feed). Lead supplementation caused linear decreases in body weight gain in all experiments. In Experiments 1, 2 and 4, even 1 mg added Pb/kg feed caused significantly depressed body gains. Significant negative effects of added Pb on feed conversion ratios were found at 10 mg Pb/kg feed. Supplemental Pb caused a linear decrease in delta-aminolevulinic acid dehydratase (ALAD) activity. The higher level of calcium (1.30%) in the feed significantly reduced the negative effects of Pb on ALAD inhibition. Lead additions to the diet resulted in a dose-related increase of Pb in blood, kidney, liver and tibia. Higher dietary calcium caused reduced Pb in blood and liver. Lead is toxic to chickens at much lower levels than previously recognized.
进行了四项实验，以研究日粮中添加铅（Pb）对从孵化到42日龄肉鸡的毒性作用。在实验1中，日粮变量为0、0.1、0.5或1.0毫克铅/千克饲料（以硫酸铅形式），在实验2中，日粮变量为0、0.5或1毫克铅/千克饲料（以硫酸铅和醋酸铅形式）。实验3和4采用2×4析因设计，有2个钙水平（0.65%或1.30%）和4个铅水平（0、1、10或100毫克铅/千克饲料，以硫酸铅形式）。在所有实验中，添加铅均导致体重增加呈线性下降。在实验1、2和4中，即使每千克饲料添加1毫克铅也会导致体重显著下降。在每千克饲料添加10毫克铅时，发现添加铅对饲料转化率有显著负面影响。添加铅导致δ-氨基乙酰丙酸脱水酶（ALAD）活性呈线性下降。饲料中较高水平的钙（1.30%）显著降低了铅对ALAD抑制的负面影响。日粮中添加铅导致血液、肾脏、肝脏和胫骨中的铅含量呈剂量相关增加。较高的日粮钙导致血液和肝脏中的铅含量降低。铅对鸡的毒性比以前认为的要低得多。
