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a) (i) List two grasses commonly used for silage production - Leaving Cert Agricultural Science - Question 15 - 2021
Question 15
a) (i) List two grasses commonly used for silage production. 1. PRG / IRG / hybrid rye grass 2. Other grasses (ii) Outline one reason for using any one of the gras... show full transcript
Worked Solution & Example Answer:a) (i) List two grasses commonly used for silage production - Leaving Cert Agricultural Science - Question 15 - 2021
Step 1
Step 2
Step 3
State at what stage of the grass growth cycle the grass should be cut for good quality silage and justify your answer.
Answer
Stage: Vegetative stage or leafy stage.
Justification: most digestible / leafy stage / high sugar content / high protein content / stem remains compact at base of stem / plant tillers (constant number of leaves on plant).
Step 4
Step 5
Advise a beef farmer of the different steps involved in making good quality first cut silage under the following headings: Fertiliser requirements.
Answer
Soil test for nutrient requirement / apply (compound) fertilizer (18-6-12 or urea (protected urea) or 10-10-20) / spread manure or slurry / 6-8 weeks prior to cutting.
Step 6
Advise a beef farmer of the different steps involved in making good quality first cut silage under the following headings: Harvesting & storage.
Answer
Do not cut during or after rainfall / cut in the afternoon (conditioner or precision chop mower / wilt for 24 hours / ensile (bale) - harvester (baler) / pit - pack to remove air (anaerobic conditions) / use additives / cover pit (wrap bales) / stack bales.
Step 7
Step 8
Based on the silage quality analysis results above, outline two reasons why the farmer should feed concentrates to his finishing beef steers.
Answer
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DMD not high enough (67%), will need to feed concentrates / concentrates with high protein (14 - 16%) as silage protein low / poor preservation, not enough lactic acid produced as pH too high.
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To ensure sufficient energy intake to meet the growth needs of finishing beef steers.
Step 9
Outline two ways the farmer could have achieved the target pH during the production of the silage in line with the target analysis.
Answer
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Cut at leafy stage to increase sugar for fermentation / do not cut during or after rainfall as water dilutes the sugar content / cut in the afternoon as photosynthesis produces more sugar.
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Use additives (microbial) / allow grass to wilt to increase sugar content / use additive (molasses or acid) to correct pH.
Step 10