Halm som grovfoder – faglige overvejelser og foderplanmodeller

Straw as roughage – professional considerations and feeding plan models

September 9, 2025Ingeborg Rahbek Pedersen

🔬 Nutritional properties of straw

Property	Value / Note
Energy content	Low (about 0.25–0.35 FE per kg TS)
Sugar	Very low (<1%)
Starch	Almost zero
Crude protein	Typically 2–4%
Fiber content	Very high – primarily cellulose and lignin
Fermentability	Low – limited production of VFA

Straw may be relevant for horses where energy intake and sugar intake are desired to be reduced, without reducing chewing time and fiber amount.

📈 Evidence of use

Several studies (including Jansson et al., 2018; Muhonen et al., 2019) indicate that:

Up to 50% of the roughage dry matter can be made up of straw without negative effects on gastrointestinal health in healthy horses
Straw increases chewing time and supports satiety and calm behavior
In the case of energy-rich or sugary roughage portions, straw can dilute the overall ration.

🌍 Climate change and unstable forage profiles

Climate change and regulations affect the growth conditions of grass and thus the nutrient content of the harvested forage:

Factor	Effect on WSC	Effect on crude protein	Comment
Elevated CO₂	+15–30%	–5–10%	Increased C fixation, lower CP
High solar radiation	+20–40%	Neutral/slight decline	Especially on clear nights
Drought stress	+10–25%	–5–15%	Especially in ryegrass and timothy
Low N fertilization	Up to +15%	–20–50%	Low N → higher sugar, lower CP
Frequent mowing	Lower	Higher	Shorter time for sugar accumulation

The trend is:

Higher sugar and lower protein in wrap and hay
Greater risk of imbalance with simple roughage strategy
Increased relevance for using straw strategically

⚖️ When do roughage recommendations apply – and when do they not?

The classic recommendations of 1.5–2.5% DM/kg body weight/day only apply when the roughage has the following composition:

TS content 65–75%
Crude protein >7.5%
WSC <10%
FE approx. 0.6–0.75 per kg

When wraps are low in protein and high in sugar, you typically see:

Protein deficiency (reduced ability to maintain normal performance)
Excess sugar (risk of obesity and imbalance in blood sugar regulation)
Increased feed intake → weight gain and low metabolic efficiency

📊 Feed rations without hay – focus on weight loss and fiber balance

Assumptions for calculation : 500 kg horse, requiring 1.4–1.5 g/kg crude protein (700–750 g), maintaining 5 FE. Sugar, starch and soluble fiber calculated. Always feed 65 g/100 kg horse of EDH / Peak Performance or 20 g/100 kg Supreme Minerals, to have vitamin-mineral coverage when combined feeding.

- For straw-only ration (model g) with 1.2 kg of soybean meal and 75–80 g/100 kg EDH or PP, or 25 g/100 kg Supreme Minerals. Can be used in emergency situations – not recommended for daily feeding (too little soluble fiber, also called green fiber).

Model	Composition	Dry matter (kg)	Energy / FE	Crude protein (g)	Sugar (g)	Starch (g)	Soluble fiber	Vitamin/mineral supplements
a	Average wrap, 70% DM, 6.7% sugar; 8.2% protein: 11 kg	7.7	4.9	906	732	0	~230 g (pectin)	EDH/PP 65 g/100 kg or SM 20 g/100 kg
b	Wrap, 70% DM, 13.7% sugar; 3.7% protein: 11 kg	7.7	5.2	407	1507	0	~230 g (pectin)	EDH/PP 65 g/100 kg or SM 20 g/100 kg
c	Only spring barley straw, 10 kg	9.0	0.7	113	0	0	~160–175g	EDH/PP 65 g/100 kg or SM 20 g/100 kg
d	Spring barley straw 6 kg + Lucerne 4.5 kg or green pellets 4.5 kg (14% protein)	9.0	2.6 (Alfalfa) 2.9 (Green pills)	702 (Lucerne) 744 (Green Pills)	171 (Lucerne) 328 (Green Pills)	0	~500–530 g (Alfalfa) ~330–350 g (Green pellets)	EDH/PP 65 g/100 kg or SM 20 g/100 kg
e	Low-energy, high diversity: 6.5 kg straw, 1 kg beet pellets, 1.5 kg green pellets, 1 kg +Fiber Mash, 500 g soybean meal	10.5	3.4	733	291	0	~420–540g	EDH/PP 65 g/100 kg or SM 20 g/100 kg
f	High energy, good diversity: 6.5 kg straw, 2 kg Energy Fiber Mash, 1 kg green pellets, 300 g soy meal	9.8	5.2	719	263	362	~350–390 g (high β-glucan)	EDH/PP 65 g/100 kg or SM 20 g/100 kg
g	Only spring barley straw 10 kg + 1.2 kg soybean meal	10.3	~4.2	~730	0	0	~380–400g	EDH/PP 80 g/100 kg or S M 25 g/100

🧠 Academic key points

Model c is suitable for frugal and metabolically sensitive horses without a need for energy - but requires targeted supplementary protein and fermentable fiber.
Models d–f show how to create balanced, low-sugar feeding plans with high protein coverage – even without wrap or hay.
Model g (straw + 1.2 kg of soy meal) is the simplest solution, which covers the protein requirement with soy meal alone. However, it does not provide any variation in fiber and no additional fermentable fiber, so it can be one-sided for the intestinal environment . Therefore, the model is primarily recommended as a short-term or emergency solution - or with the addition of e.g. beet pellets, +Fiber Mash or green pellets for better fiber diversity.
The use of pectin- and arabinoxylan-rich fibers (e.g. citrus, beet pulp, +Fiber Mash, bran) is recommended over high doses of yeast-based β-glucan for frugal horses.
When choosing Every Day Happy or Supreme Minerals , RC O3 Algae Oil (2.5–5 ml/100 kg) can supplement omega-3 supply and contribute to normal metabolic and intestinal functions.

📌 Conclusion

Straw is not just an emergency feed, but a strategic feed material for modern feed planning – especially by:

High sugar content in wrap
Low protein levels in roughage
Weight loss goals or metabolic challenges
Focus on chewing time, satiety and intestinal balance

When used correctly, straw can be included as a main ingredient in balanced rations, provided that protein, fermentable fiber, vitamins and minerals are supplemented in a targeted manner.

If you want to see how this knowledge is translated into a concrete feeding plan for frugal and metabolically challenged horses , read the light version here:

➡️ Straw as horse feed - is it even a good idea?