然后，科学家们开始改变它们的饮食，限制其能量的摄入，低脂饮食。

The scientists then switched them to a calorie-controlled, low-fat diet.

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在性成熟阶段之前，对于那些生长过快很可能显著超过目标体重的后备母猪品种，有必要限制它们的能量摄入。

For genotypes whose growth rate is so rapid that they are likely to be significantly over the target weight before reaching puberty, it may be necessary to restrict energy intake.

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限制摄入高能量、缺乏微量营养素的食品（例如袋装零食）；

restrict intake of energy-dense, micronutrient-poor foods (e.g. packaged snacks);

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