Straw as an Alternative Roughage Source for Wintering Beef Cows

Overview
When hay supplies are limited, straw can serve as a major roughage source for wintering beef cows. However, straw is nutrient‑deficient and must be supplemented with energy, protein, minerals, and vitamins to meet cow requirements for health, body condition, reproduction, and calf performance. Rations must be balanced according to the animal’s production stage.
 
Nutritional Requirements of the Breeding Herd
Cow nutrient needs increase during late gestation and lactation. The following table summarizes approximate requirements.
Table 1. Nutritional Requirements of the Breeding Herd
Class
TDN (%)
Crude Protein (%)
Ca (%)
P (%)
Mid‑Gestation
50–53
7
0.20
0.20
Late Gestation
58
9
0.28
0.23
Lactating
60–65
11–12
0.30
0.26
Replacement Heifers
60–65
8–10
0.30
0.22
Breeding Bulls
48–50
7–8
0.26
0.20
Yearling Bulls
55–60
7–8
0.23
0.23
Nutrient requirements vary with body weight, frame size, expected rate of gain, and stage of production.
 
Nutrient Content of Straw
Straw is low in protein and energy, and nutrient values vary by crop type.
Table 2. Average Nutrient Values of Straw (100% DM basis)
Straw Type
CP (%)
TDN (%)
Ca (%)
P (%)
Wheat
3.9
44
0.18
0.11
Barley
4.9
46
0.13
0.08
Oat
4.5
48
0.26
0.10
Flax
5.4
43
0.26
0.08
Pea
6.4
48
0.60
0.19
It is clear that straw alone cannot meet cow requirements, especially for protein, energy, and phosphorus.
 
Feeding Challenges
1. Physical Intake Limitations
  • Cattle typically consume ~1.25% of body weight in straw (DM/day).
  • Straw’s high fibre content slows rumen passage.
  • Risk of rumen compaction increases if no energy or protein is supplied to support rumen microbes.
2. Increased Nutrient Needs
  • Energy requirements increase by 15–20% when temperatures drop to –20 to –25°C.
  • Late gestation significantly increases nutrient demands, requiring higher‑quality supplements.
 
Key Considerations When Feeding Straw
  • Feed test all straw—nutrient levels and digestibility vary widely.
  • Balance rations for energy, protein, minerals, and vitamins.
  • Cattle often prefer one‑year‑old straw to fresh straw.
  • Ammoniation improves palatability, protein content, and intake.
  • Grinding or chopping straw increases consumption and allows better mixing in total mixed rations.
  • Provide appropriate minerals:
    • A 2:1 or 3:1 mineral is typically required.
    • Limestone may be needed if no other forage is fed.
  • Check for:
    • Nitrates
    • Pesticide residues
  • Always ensure a readily available energy supplement (grain or silage) and adequate protein supplementation.
  • Ensure a clean water supply is available at all times.
 
Example Ration Options
The following rations illustrate combinations of straw, silage, grain, and supplements suitable for 1400 lb gestating cows.
Table 3. Example Winter Rations (lbs/day, 1400 lb cow)
(Add 5–15% for waste depending on feeding method)
Ration #
Key Feed Components (lbs/day)
Supplements
1
35 lb alfalfa‑grass hay
0.12 lb 1:1 mineral, 0.07 lb salt
2
17 lb barley straw, 48 lb barley silage
0.5 lb 32% supplement, 0.06 lb 2:1 mineral, 0.07 lb salt
3
19 lb barley straw, 47 lb corn silage
0.5 lb 32% supplement, 0.06 lb 2:1 mineral, 0.07 lb salt
4
23 lb barley straw, 11 lb barley grain
1 lb 32% supplement, 0.06 lb 2:1 mineral, 0.07 lb salt
5
16 lb alfalfa‑grass hay, 19 lb greenfeed
0.12 lb 2:1 mineral, 0.07 lb salt
6
23 lb barley straw, 2.9 lb liquid supplement
0.2 lb 2:1 mineral, 0.2 lb limestone, 0.07 lb salt
7
10 lb alfalfa‑grass hay, 15 lb barley straw, 32 lb corn silage
0.2 lb 2:1 mineral, 0.07 lb salt
8
23 lb barley straw, 14 lb 20% grain pellets
0.06 lb 2:1 mineral, 0.2 lb limestone, 0.07 lb salt
 
Summary
Straw can be an effective winter feed resource when properly supplemented. Key management points include:
  • Always feed test and balance rations.
  • Provide sufficient energy, protein, minerals, and vitamins.
  • Consider ammoniation, grinding, or TMR feeding to improve intake.
  • Watch for nutrient deficiencies, cold‑weather increases in energy needs, nitrates, and pesticide residues.
With good ration formulation and management, straw can help stretch forage supplies while maintaining cow performance through winter.