Question 1

How much dry matter does a dairy cow need per day?

Accepted Answer

A high-yielding dairy cow in peak lactation typically needs 22–28 kg DM per day — approximately 3.5–4.0% of bodyweight for a 600–650 kg cow. Mid-lactation cows need 18–22 kg DM/day (3.0–3.5% of bodyweight). Dry cows and late-lactation cows need less — typically 12–16 kg DM/day or 1.8–2.5% of bodyweight. These figures depend on milk yield, body condition score, and stage of lactation. High-yielding cows have a physical limit on how much feed they can consume — maximising diet quality (ME and CP) is as important as the DM quantity.

Question 2

How much dry matter does a beef cow or steer need per day?

Accepted Answer

A beef cow at maintenance (not growing) needs approximately 2.0–2.5% of bodyweight in DM per day. A 600 kg cow at maintenance needs 12–15 kg DM/day. Growing beef cattle targeting 1.0–1.5 kg/day liveweight gain need 2.5–3.0% of bodyweight — a 450 kg store bullock targeting growth needs approximately 11–14 kg DM/day. Suckler cows in late pregnancy or early lactation need more — 2.5–3.0% of bodyweight. Always allow ad-lib access to silage in the weeks before calving to prepare the rumen for the lactation diet.

Question 3

What is the difference between DM (dry matter) and fresh weight?

Accepted Answer

Dry matter is the nutrient-rich portion of feed remaining after all water is removed. Fresh weight is the total weight including water. Silage is typically 25–45% DM — meaning 25–45% of what you physically weigh is actual nutrients; the rest is water. To convert: fresh weight × (DM% ÷ 100) = DM content. For example, 30 kg fresh grass silage at 30% DM contains 9 kg DM. When comparing rations or calculating feeding rates, always use DM — it is the only meaningful measure for nutrient intake.

Question 4

What is the DM content of different types of silage?

Accepted Answer

DM content varies significantly by silage type and conditions: Grass pit silage (first cut, wilted) typically 28–35% DM. Grass pit silage (second cut, less wilted) typically 20–28% DM. Maize silage typically 28–35% DM. Big bale grass silage typically 35–50% DM — dry bales can be 50%+. Wholecrop cereal silage typically 35–55% DM. Fresh grazed grass typically 15–25% DM. Always use your own silage analysis rather than these averages — DM content directly affects how much fresh silage you need to feed, so inaccurate DM figures lead to either under-feeding or wasted feed.

Question 5

How do I measure the dry matter content of my silage?

Accepted Answer

There are two main approaches. Laboratory analysis: send a representative sample (minimum 1 kg from multiple points across the clamp face) to a forage analysis laboratory. This gives DM%, ME, CP, NDF, and other key nutrient values. Results take 1–5 days. Near-infrared (NIR) on-farm meters: handheld devices that estimate DM% instantly by shining infrared light through the sample. Less accurate than lab analysis but useful for day-to-day management and checking within-clamp variation. For a new clamp or bale batch, always start with a lab analysis — then use an on-farm meter to track variation as you work through it.

Question 6

Can I use this calculator for sheep?

Accepted Answer

Yes — the formula (DM required = bodyweight × intake percentage) applies to all ruminants. For ewes in mid-pregnancy use approximately 1.8–2.0% of bodyweight. Late pregnancy (last 6 weeks before lambing) increases to 2.0–2.5%. Lactating ewes with twin lambs may need 2.5–3.0% of bodyweight. Multiply the DM required by (100 ÷ silage DM%) to get the fresh silage weight. A 70 kg ewe at 2% DM intake needs 1.4 kg DM/day — at 30% DM silage that is 4.7 kg fresh silage per ewe per day.

Question 7

How does silage quality affect how much I need to feed?

Accepted Answer

Higher quality silage (higher ME, higher DM, lower NDF) allows animals to eat more DM per unit of gut fill, and each kg DM provides more energy. This means you can meet the animal's energy requirements with less fresh silage. Poor quality silage (low ME, high NDF, low DM) fills the rumen faster and limits intake before nutritional requirements are met — leading to reduced milk yield, poor body condition, or reduced growth rate. A 1 MJ/kg DM improvement in silage ME is roughly equivalent to 1–2 kg/day less concentrate needed in a dairy cow ration. Getting a silage analysis every cut is one of the best investments in winter feeding management.

Question 8

What is the formula for calculating fresh silage requirements?

Accepted Answer

Step 1 — DM required: Liveweight (kg) × DM intake percentage ÷ 100 = DM required (kg/day). Example: 650 kg × 3.0% ÷ 100 = 19.5 kg DM/day. Step 2 — Fresh silage weight: DM required ÷ silage DM percentage × 100 = fresh silage weight (kg/day). Example: 19.5 ÷ 30 × 100 = 65 kg fresh silage per head per day. This calculator performs both steps automatically — enter your liveweight, DM intake percentage, and silage DM% for the instant result.

Livestock DM Required Calculator

1Daily Dry Matter Requirement

2Fresh Silage Equivalent

3Download PDF Report

Typical Intake Rates

Silage DM Guide

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