The first two examples are the most correct. The last example has somewhat childish connotations. You could also say:
"What does a piglet's diet consist of?"
最初の2つの例文が最も適切だと思います。3番目の例文はどこか子供っぽい響きになります。また次のようにも言えます。
"What does a piglet's diet consist of?"
（子豚の食べ物は何でできていますか？）
A baby pig is known as a piglet. Usually piglets will eat only their mother's milk until old enough to manage solids. To ask a knowledgeable person, so that you can get a definite answer as to what piglets eat, simply say any of the above.
"What do piglets normally eat?" This asks the person to explain to you what food piglets eat on a normal diet.
"What do piglets eat?" This asks the person to tell you what they eat.
例文
"What do piglets normally eat?"
こぶたは通常何を食べますか？
こぶたが、通常の食事にどんな食べ物を食べるのかを説明するように頼んでいます。
例文
"What do piglets eat?"
こぶたは何を食べますか？
こぶたが何を食べるかを教えてくれるように頼んでいます。
*What does piglets eat?- A piglet is a young one of a pig. Meat from pigs is called pork. Due to different religious background some people don't eat pork.
Example Sentences:
The pig gave birth to 5 piglets.
The piglets were all muddy and dirty.
例文
*What does piglets eat?
子豚は何を食べますか？
A pigletは子豚です。豚の肉は porkと呼ばれています。宗教事情により、豚肉を食べない人もいます。
例文
The pig gave birth to 5 piglets.
その豚は子豚を5匹生んだ
The piglets were all muddy and dirty.
その子豚は全て泥だらけで汚い
Explanation:- 'Usually' means normally or generally.
Example sentence:- "Piglets usually drink their mother's milk but later will start to eat small pieces of almost any food."
解説：'Usually' は「通常」、「普段は」という意味です。
例文：
"Piglets usually drink their mother's milk but later will start to eat small pieces of almost any food."
子豚は普段は母豚のお乳を飲みますが、その後は小さいサイズのものであればほとんどなんでも食べるようになります。
A young pig or baby pig is referred to as a 'piglet' so if you want to know what they normally eat then you would ask
'what do piglets eat?' , 'what do young pigs eat?' or 'what do baby pigs eat?'
こぶたのことを 'piglet'と言います。以下は、こぶたが何を食べるのか知りたいときのフレーズです。
'what do piglets eat?'
'what do young pigs eat?'
'what do baby pigs eat?'
これらは全て、こぶたは何を食べるの？という意味です。
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