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From Farm to Fork, how grass can be made into milk and cheese.


Teagasc Staff; Marion Beecher, Emer Kennedy, Eimear Ferguson and Margie Egan, are together addressing the questions you have about cows for Science Week. Why grass is green or how grass grows? Why cows can eat grass but humans cannot? How much does a cow eat and drink in a day? Find out more..

Have you ever wondered why grass is green or how grass grows?

Grass grows by taking up water and nutrients from the soil. The nutrients are the food the plant uses to grow. Grass is green because it contains chlorophyll, which is used to trap energy from the sun to help it grow. This is called photosynthesis.  

Why can cows eat grass but humans cannot?

Unlike humans, cows can eat grass because they are ruminants. This means that cows have one stomach with four compartments. The four compartments are called the rumen, reticulum, omasum and abomasum. The rumen is the largest compartment and can vary in size but holds up to 250 litres. Cows have special microbes that live in their rumen and start the digestive process. In Ireland, grass or grass silage is the main part of a cow’s diet but they like to snack on concentrates.

How much does a cow eat and drink in a day?

The amount of grass a cow eats in a day depends on a number of different things like how old she is, how much milk she produces, whether she is just after calving or a long time after calving and what size she is. Bigger and older cows eat more grass than younger and smaller cows. A cow can eat 18kg dry matter of grass or about 120kg of fresh grass per day. A cow will spend up to eight hours a day eating grass. The amount of water a cow drinks in a day depends on how hot the day is or how much milk she is producing. A cow will typically drink 40-60 litres of water per day.

How much milk does a cow produce and what is the milk used for?

A cow can produce up to 30 litres of milk in a day. From 30 litres of milk, you can make 3 kg of cheese. Milk is important for humans because it contains calcium and vitamin D, which is needed to make healthy and strong bones. Milk contains whey and casein proteins, which are easy for humans to digest and is used in our bodies to grow strong muscles and bones.

Join Teagasc for a series of exciting virtual events for Science Week (November 8-15) as part of ‘The Festival of Farming and Food – SFI Science Week at Teagasc’. The core theme for Science Week 2020 is ‘Science Week - Choosing our Future’ focusing on how science can improve our lives in the future, and in the present. This will explore how science can help us to make positive choices that will impact the environment, our health, and our quality of life. Changes based in scientific evidence that we make today can hugely improve our future life, but also right now. Join our events on Zoom and get a chance to put your questions to our scientists in our live Q&As.

Click here to register.

We’d love to hear from you. Be part of The Festival of Farming and Food journey on Social Media:

@Teagasc @ScienceWeek #FestFarmFood #BelieveInScience #ScienceWeek