Ceist Eile

Ceist Eile is in development. Features, questions and prices may change while we refine it.

Subjects · Leaving Cert Agricultural Science

Leaving Cert Agricultural Science: Silage & hay

How often Silage & hay comes up on the Agricultural Science papers, every year it was asked, and questions to try.

HL Asked on 3 of the last 5 Higher Level papers, most recently in 2025. most years

OL Asked on 5 of the last 5 Ordinary Level papers, most recently in 2025. banker

Silage & hay, Higher Level(8 marks)

Quick ones on Silage & hay.

(a)Which bacteria produce lactic acid in well-made silage?
  1. Clostridium
  2. Lactobacillus
  3. Rhizobium
(b)Why must a silage pit be well rolled and sealed quickly?
  1. To keep the pH high so moulds cannot grow
  2. To let oxygen in to feed the good lactic bacteria
  3. To exclude air so fermentation is anaerobic
(c)200 g of fresh grass dries to 50 g. What is its dry matter %?
  1. 25%
  2. 4%
  3. 75%
Show the answers

(a) Lactobacillus

(b) To exclude air so fermentation is anaerobic

(c) 25%

Your turn: Higher Level questions on Silage & hay.

Higher Level

Asked on 3 of the last 5 Higher Level papers, most recently in 2025. most years

Every paper, year by year

YearWhere it came up
2025Q16
2024Q14, Q14c
2023Not asked
2022Q12a, Q12b
2021Not asked

Links open the State Examinations Commission’s paper for that year.

More Silage & hay questions

Silage & hay, 3 marks

Why is hay baled before it is dry enough a risk?

  1. It ferments into silage
  2. It loses all its protein
  3. It can heat and even catch fire
Show the answer

It can heat and even catch fire

Damp hay heats as microbes respire. It goes mouldy and can heat enough to self-ignite, a fire risk in sheds.

Ordinary Level

Asked on 5 of the last 5 Ordinary Level papers, most recently in 2025. banker

Every paper, year by year

YearWhere it came up
2025Q16
2024Q14
2023Q6a, Q6b
2022Q10, Q16
2021Q15

Links open the State Examinations Commission’s paper for that year.

More Silage & hay questions

Silage & hay, 2 marks

Which bacteria produce good silage by fermenting grass sugars?

  1. Butyric acid bacteria
  2. Nitrogen-fixing bacteria
  3. Lactic acid bacteria
Show the answer

Lactic acid bacteria

Lactic acid bacteria turn sugars into lactic acid, and the pH falls to about 4, preserving the grass. Butyric bacteria make smelly, poor silage.

Silage & hay, 2 marks

Why is a silage pit sealed tightly with plastic?

  1. To keep the grass growing
  2. To keep air out
  3. To let rain soak in
Show the answer

To keep air out

Fermentation must be anaerobic. Air lets moulds and yeasts spoil the silage and waste feed. Tyres or bales keep the cover tight.

Silage & hay, 3 marks

Fresh grass weighs 200 g and 50 g after oven drying. What is its DM %?

  1. 25%
  2. 75%
  3. 4%
Show the answer

25%

DM % = dry mass ÷ fresh mass × 100 = 50 ÷ 200 × 100 = 25%. The other 75% was water.

Other Agricultural Science topics

All of Leaving Cert Agricultural Science