2. How much to feed?
• The simple answer is to feed as much good-quality feed as the animal
can eat –and the best quality feeds are fresh leafy grass and legumes.
• Feed quality has the greatest impact on intake as it influences the rate
of passage of the feed through the rumen. Since different feeds have
different moisture content, intake is usually expressed as the amount
of dry matter consumed daily (dry matter being the weight of the
feed after all the water is removed).
3. • Feed intake depends on the size of the animal, its condition, stage of
production, milk production level, environmental conditions, and the
amount and type of forage or feed offered, and its water content.
• Table 2.3 shows some approximate relations between feed quality
and the animal’s weight, and is followed by worked examples
estimating feed intake
4. Table 2.3. How much can an animal eat?
Forage quality Example Forage Intake DM (% of body
weight)
Low Mature grass, crop residues 1.5
Average to good Leafy grass (few seed heads 2.5
High Young leafy grass, legume 3.0
5. Example
• 1. A 400 kg animal fed low-quality feed (60% moisture, 7% crude
protein)
• The animal can eat only 1.5% of its bodyweight as DM
• Amount of DM the animal can eat = 1.5/100 x 400 = 6.0 kg
• Amount of green feed it can eat = 6 x 100/40 = 15 kg
• Amount of CP it can eat = 7/100 x 6 = 0.4 kg CP
• 2. A 400 kg animal fed good-quality feed (75% moisture, 12% crude
protein)
• Amount of DM the animal can eat = 2.5/100 x 400 = 10 kg
• Amount of green feed it can eat = 10 x 100/25 = 40 kg
• Amount of CP it can eat = 12/100 x 10 = 1.2 kg CP
6. • These two examples show the amount of crude protein in the
animal’s diet can be more than doubled simply by feeding better
quality forage.
• Generally, if crude protein is adequate in unsupplemented forage,
most of the other essential nutrients will also be in adequate supply.
• However, some minerals, particularly extra phosphorus, may be
needed. The crude protein value of cut grass can be increased by
adding legume.
7. Answer this!
• A 450 kg cattle fed high-quality feed (50% moisture,
15% crude protein)
Note: Put in a ½ sheet of yellow paper and submit it in
google classroom.
