THE EFFECTS OF ENDOPHYTE-INFECTED TALL FESCUE CONSUMPTION AND USE OF A DOPAMINE ANTAGONIST ON INTAKE, DIGESTIBILITY, BODY-TEMPERATURE, AND BLOOD-CONSTITUENTS IN SHEEP
THE EFFECTS OF ENDOPHYTE-INFECTED TALL FESCUE CONSUMPTION AND USE OF A DOPAMINE ANTAGONIST ON INTAKE, DIGESTIBILITY, BODY-TEMPERATURE, AND BLOOD-CONSTITUENTS IN SHEEP
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DOI：
10.2527/1993.711158x
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发表时间：
1993-01-01
影响因子：
3.3
通讯作者：
PATERSON, JA
中科院分区：
文献类型：
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作者：
ALDRICH, CG;RHODES, MT;PATERSON, JA
在升高的温度和湿度下，用食用内生菌感染的（多穗枝顶孢）高羊茅饮食并补充有多巴胺拮抗剂甲氧氯普胺（M）的羔羊进行两个实验。在Exp.将1，12只经瘤胃插管的公羊（平均体重49 kg）按重量分配至无内生菌饮食（E-）或内生菌感染饮食（E+; 1，170 ppb麦角缬氨酸）或补充有M的E+（15 mg/kg羔羊BW; E+M）。E+组的自由采食量和消化率显著低于E-组（P <0.05）.补充E+和M使DM摄入量增加27.6%（P <0.05），但不改变DM消化率。当羔羊食用E+时，体温升高（P <0.05），当补充M时，体温进一步升高。用于实验将2，19只公绵羊羔羊（平均体重24 kg）分配至处理组以评估内生菌消耗（0 vs 2，430 ppb麦角缬氨酸）和补充M（0 vs 20 mg/kg BW）的效果。测量了DM摄入量的主效应的相互作用（P <0.05）。羔羊消耗E+M消耗更多的DM比羔羊只喂E+，但羔羊提供E-饮食和补充M没有增加DM的消费。日粮干物质消化率在各处理间无显著差异。由于E+消耗和M补充，皮肤汽化减少（P <0.05）。血浆中催乳素的浓度通过消耗E+（8 ng/mL对136 ng/mL）而降低（P <0.05），并且没有由于M补充而增加。结果表明，补充E+饮食与多巴胺拮抗剂M导致DM消费增加，但没有减轻羔羊的无法消散身体热量通过皮肤汽化。
Two experiments were conducted with lambs that consumed endophyte-infected (Acremonium coenophialum) tall fescue diets under elevated temperature and humidity and supplemented with the dopamine antagonist metoclopramide (M). In Exp. 1, 12 ruminally cannulated wethers (average weight 49 kg) were allotted by weight to either an endophyte-free diet (E-) or endophyte-infected diet (E+; 1,170 ppb of ergovaline), or E+ supplemented with M (15 mg/kg of lamb BW; E+M). Ad libitum DM intake and digestibility were lower (P < .05) for E+ than for E- diet. Supplementation of E+ with M increased (P < .05) DM intake by 27.6% but did not change DM digestibility. Body temperature increased (P < .05) when lambs consumed E+ and was further increased when M was supplemented. For Exp. 2, 19 wether lambs (average weight 24 kg) were allotted to treatments to evaluate the effects of endophyte consumption (0 vs 2,430 ppb of ergovaline) and supplementation with M (0 vs 20 mg/kg BW). An interaction (P < .05) of main effects was measured for DM intake. Lambs that consumed E+M consumed more DM than did lambs fed only E+, but lambs offered the E- diet and supplemented with M did not increase DM consumption. Diet DM digestibility was not different among treatments. Skin vaporization decreased (P < .05) due to E+ consumption and M supplementation. The concentration of prolactin in plasma was decreased (P < .05) by consumption of E+ (8 vs 136 ng/mL) and did not increase due to M supplementation. Results suggest that supplementing E+ diets with the dopamine antagonist M resulted in increased DM consumption but did not alleviate the lambs' inability to dissipate body heat through skin vaporization.