Feed Tables - Ruminants

On this page you can find the equations for calculating feed values for ruminant feeds, and feeding recommendations. The Feed Table is a list of typical compositional and feed value data for commonly used feeds, i.e., a list of the so-called reference feeds.

In the planning of feeding of ruminants, Feed Table values may generally be used for common concentrates (e.g. cereal grains). However, the composition of forages vary widely depending on the cultivation, harvesting and preservation techniques applied and prevailing weather conditions. Due to the high proportion of forage in ruminant diets, the analysis of different forage batches used for feeding is of paramount importance.

If the composition of a feed batch has been analysed, feed values can be calculated using the equations described in Basis of calculation and the digestibility coefficients of the reference feed, but using the compositional data of the feed batch concerned in the equations.

An example of energy requirement for a cow that weighs 650 kg and produces 40 kg energy corrected milk (ECM) per day:
Energy requirement (MJ ME/day) = 650^0.75kg × 0.515 MJ/kg + 5.15 MJ/kg ECM × 40 kg ECM/d = 272 MJ ME/d

An example of energy requirement for a cow that weighs 550 kg and produces 20 kg energy corrected milk (ECM) per day:
Energy requirement (MJ ME/day) = 550^0.75kg × 0.515 MJ/kg + 5.15 MJ/kg ECM × 20 kg ECM/d = 161 MJ ME/d

The effects of housing type (tied-up or loose-housed), grazing or temperature are not taken into account in energy requirements of dairy cows.

Correction equation for energy intake

The feed evaluation system uses constant feed values irrespective of the feeding situation. The feeds do however have important associative effects, which can be taken into account by using correction equations. The following correction equation was taken into use in year 2010 and is based on a large data set of production experiments:

Corrected ME-intake (MJ/day) = Uncorrected ME-intake (MJ/pv) – (-56.7 + 6.99 × MEm + 1.621 × DMI – 0.44595 × CP + 0.00112 × CP²)

DMI = Dry matter intake, kg/day
MEm = Uncorrected ME concentration of the diet, MJ/kg DM
CP = Crude protein concentration of the diet, g/kg DM

The correction equation indicates that ME intake is reduced, when:

• Dry matter intake increases
• Diet has a high energy value
• Diet has a low crude protein concentration (the effect is curvilinear so that the benefits from increased crude protein concentration become smaller at higher concentrations)

In some cases (particularly for dry cows with low feed intake energy concentration in the diet), the correction term produces negative values. In that case, the energy intake will increase compared to the calculated values. The increase will be taken into account up to 2 MJ/day.

The energy corrected milk (ECM) yield can be calculated according to Sjaunja et al. (1990) based on milk yield and fat, protein and lactose concentrations (g/kg):
ECM (kg) = Milk production (kg) × (38.3 × fat + 24.2 × protein + 16.54 × lactose + 20.7) / 3140

If lactose concentration has not been determined, the following equation can be used:
ECM (kg) = Milk production (kg) × (38.3 × fat + 24.2 × protein + 783.2) / 3140

Example: calculations of  MP requirement

An example of MP requirements for a dairy cow, that weighs 650 kg, consumes 25.3 kg DM/day, produces 40 kg energy corrected milk (ECM) and 1240 g milk protein per day:
MP requirement (g/day) = 1.8 × 650^0.75 kg + 14 × 25.3 kg DM/d + (1.47 – 0.0017 × 40 kg ECM/d) × 1240 g milk protein/d = 2324 g MP/d

An example of MP requirements for a dairy cow, that weighs 550 kg, consumes 14.9 kg DM/day, produces 20 kg energy corrected milk (ECM) and 620 g milk protein per day:
MP requirement (g/day) = 1.8 × 550^0.75 kg + 14 × 14.9 kg DM/d + (1.47 – 0.0017 × 20 kg ECM/d) × 620 g milk protein/d = 1303 g MP/d

Dry matter intake estimation

If the dry matter intake of the cow is not known, it can roughly be estimated using the energy requirement and an average diet energy concentration (i.e. 11.5 MJ ME/kg DM). This method assumes that the cow is in energy balance (not using or building body energy reserves).

Example: A cow weighs 650 kg and produces 30 kg ECM/day, so that her energy requirement is 221 MJ ME/d.
Dry matter intake (kg/day) = 221 MJ ME/day / 11.5 MJ ME/kg DM = 19.2 kg DM/day

Protein balance in the rumen

The rumen is in protein balance when the average diet PBV value is close to zero. In ration formulation, negative diet PB values should not be accepted for dairy cows. The adequacy of nitrogen for rumen microbes can also be judged from milk urea concentration, which should be over 17-18 mg/dl.

The energy and protein requirements of suckler cows are based on the needs for maintenance of body functions, milk production, pregnancy and changes in live weight (condition score). Feeding recommendations for suckler cows are mainly based on those for dairy cows. 

The energy and protein requirements of dairy cows are calculated using energy corrected milk yields. For suckler cows, the calculation of energy corrected milk yields is unnecessary due to many uncertainties. It is most practical to use the estimated milk yield as the basis for the calculation. The average milk protein content of 31 g/kg milk from Finnish studies can be used to calculate protein yields for suckler cows (Manninen 2007). 

Example:  An example of maintenance energy requirement for a suckler cow that weighs 700 kg and is in a
body condition score 3.0. No conditioning requirement: :

Energy requirement (MJ ME/d) = 700^0,75 × 0,515 = 70 MJ/d

Effect of body condition score on energy requirements

The weight of one condition score unit is 45-60 kg. The weight of condition score unit and the amount of energy vary by the animal breed type and size. Body condition score change can be calculated by using liveweight change if known how many kilograms increasing/decreasing the condition score requires.

Example: A suckler cow weighs 700 kg and is in a body condition score 2.0. The conditioning requirement is one condition score unit (2.0 ->3.0). 

Increasing the condition score 2.0 →2.5:

Energy requirement (ME MJ/d) = 700^0,75 kg × 0,515 MJ/kg × 1,19 = 83 

Increasing the condition score 2.5 →3.0:

Energy requirement (MJ ME/d) = 700^0,75 kg × 0,515 MJ/kg × 1,09 = 76 

Improving the condition score should be done before the last two months of pregnancy. 

Example: A suckler cow weighs 700 kg and is in a body condition score 4.0.
Decreasing the condition score 4.0 → 3.5:

Energy requirement (MJ ME/d) = 700^0,75 kg × 0,515 MJ/kg × 0,84 = 59 

Effect of pregnancy on energy requirements

Example: An example of energy requirement during the last two months of pregnancy for a suckler cow
that weighs 700 kg and is in a body condition score 3.0.
8^th pregnancy month:

Energy requirement (MJ ME/d) = 700^0,75 × 0,515 + 19 = 89

9^th pregnancy month:

Energy requirement (MJ ME/d) = 700^0,75 × 0,515 + 34 = 104

Example: An example of energy requirement during the lactation period for a  suckler cow of Hereford breed that weighs 700 kg and is in a body condition score 3.0. Moderate milk production. No conditioning requirement:

Energy requirement (MJ/day) = (700^0.75 kg× 0.515 MJ/kg) + (5.15 MJ/kg × 8 kg/d) = 111

Example: An example of energy requirement during the lactation period for a  suckler cow of Simmental breed that weighs 850 kg and is in a body condition score 3.0. Very high milk production. No conditioning requirement:

Energy requirement (MJ/day) = (850^0.75 kg × 0.515 MJ/kg) + (5.15 MJ/kg × 14 kg/d) = 153 

Example: An example of energy requirement during the lactation period for a  suckler cow of Hereford breed that weighs 700 kg and is in a body condition score 2.5. Moderate milk production. Conditioning requirement: 0.5 condition score:

Energy requirement (MJ/day) = (700^0.75 kg × 0.515 MJ/kg × 1.09) + (5.15 MJ/kg × 8 kg/d) = 118 

Example: An example of energy requirement during the lactation period for a  suckler cow of Simmental breed that weighs 850 kg and is in a body condition score 2.0. Very high milk production. Conditioning requirement: one condition score:
Increasing the condition score 2.0 → 2.5:

Energy requirement (MJ/day) = (850^0.75 kg × 0.515 MJ/kg × 1.19) + (5.15 MJ/kg × 14 kg/d) = 169 

Increasing the condition score 2.5 → 3.0:

Energy requirement (MJ/day) = (850^0.75 kg × 0.515 MJ/kg × 1.09) + (5.15 MJ/kg × 14 kg/d) = 161 

Protein balance in the rumen (PB) recommendation

The rumen is in protein balance when the average diet PB value is close to zero.  During the maintenance period the PB value can be -20 g/kg dry matter intake. During the lactation period the PBV value should not be negative.

Dry matter intake of suckler cows

If the dry matter intake of the suckler cow is not known, it can be roughly estimated using the body weight and forage digestibility (D-value) when the suckler cows are fed ad libitum.

Example: Maintenance period, body weight 700 kg, forage D-value 630 g/kg DM.

Dry matter intake (kg DM/d) = 700 kg × 0.022 = 15.4 kg DM/d

Example: Lactation period, body weight 700 kg, forage D-value 650 g/kg DM.

Dry matter intake (kg DM/d) = 700 kg × 0.025 = 17.5 kg DM/d
 

Effect of pregnancy to intake

During the last month of pregnancy dry matter intake decreases 0.2 percent of body weight when forage D-value is over 600 g/kg DM.

Example: Dry matter intake during the last month of pregnancy. Body weight 700 kg. Forage D-value 630 g/kg DM.

Dry matter intake (kg DM/d) = 700 kg × (0.022-0.002) = 14 kg DM/d 

During the last month of pregnancy dry matter intake decreases 1.2 percent of body weight when forage D-value is below 600 g/kg DM.

Example: Dry matter intake during the last month of pregnancy. Body weight 700 kg. Forage D-value less than 600 g/kg DM.

Dry matter intake (kg DM/day) = 700 kg × 0.012 = 8.4 kg DM/d 

Effect of breed type

Dry matter intake of Limousin and Blonde d’Aquitaine suckler cows is 2.0 kg DM/day less during the maintenance period and 1.7 kg DM/day less during the lactation period compared to other breeds.

Example: Dry matter intake of a Limousin suckler cow during the maintenance period. Body weight 800 kg. Forage D-value 630 g/kg DM.

Dry matter intake (kg DM/d) = 800 kg × 0.022 – 2 = 15.6 kg DM/d
 

Effect of body condition score

If body condition score is below 3.0 dry matter intake increases 10 %.

 Example: Dry matter intake during the maintenance period. Body weight 700 kg. Body condition score 2.0. Forage D-value 630 g/kg DM.

Dry matter intake (kg DM/d) = 700 kg × 0.022 × 1.1 = 16.9 kg DM/d 

If body condition score is over 4.0 dry matter intake decreases 10 %.

Example: Dry matter intake during the maintenance period. Body weight 700 kg. Body condition score 4.0. Forage D-value 630 g/kg DM.

Dry matter intake (kg DM/d) = 700 kg × 0.022 x 0.9 = 13.9 kg DM/d 

Model calculations for MP requirements during different production periods

Maintenance period

Body weight 700 kg. Body condition score 3.0. Forage D-value 600 g/kg DM. Ad libitum feeding.

MP requirement (g/d) = 1.8 × 700^0.75 kg + 14 × (700 kg × 0.018) = 421 g/d 

Pregnancy

Body weight 700 kg. Body condition score 3.0. Forage D-value 630 g/kg DM. 9th pregnancy month. Ad libitum feeding.

MP requirement (g/d) = 1.8 × 700^0.75 kg + 14 × (700 kg × (0.022–0.02)) + 205 = 646 g/d 

Lactation period

Body weight 700 kg. Body condition score 3.0. Moderate milk production, 8 kg/day. Forage D-value 650 g/kg DM. Ad libitum feeding.

MP requirement (g/d) = 1.8 × 700^0.75 kg + 14 × (700 kg × 0.025) + (1.47 – 0.0017 × 8) × (8 × 31) = 851 g/d 

Feeding recommendations for growing animals are calculated on the basis of live weight and daily growth rate. Growth rate affects the animal's nutritional requirements and, on the other hand, feeding can influence growth. The breed, sex and purpose of the bovine animal influence feeding, for example dairy replacement heifers are fed differently from bulls of beef breed. Nutritional requirements vary at different stages of growth.

The recommendations are given for free growing animals. The energy requirements of growing beef breed cattle are about 10% lower than those of dairy breed cattle. All energy recommendations are expressed in MJ of metabolizable energy.

Calves

Growing bulls

The requirements are based on the equation of AFRC (1990), and the coefficients have been modified according to Finnish research results. The requirements are presented for dairy breed animals. For beef breeds and mixtures, the energy requirement is approximately 10 % lower. The requirements are presented for animals in a loose-house environment. The growth rate indicates the growth at that time point, not averaged over the whole growing period.

Growing heifers

Energy requirements for growing heifers are calculated on the basis of live weight and daily growth rate. The pregnancy addition is calculated in the same way than for lactating cows (tables 1 and 2).  

Protein requirements of growing cattle

The metabolizable protein (MP) requirements are presented only for cattle smaller than 200 kg live weight. For animals over 200 kg, the protein intake is adequate if the protein balance in the rumen (PB) of the total diet is not lower than -10 g per kg feed intake. If an animal eats 8 kg DM per day, the daily dietary PB value may thus be -80 g/day. The microbial protein synthesized in the rumen and the by-pass protein of the feeds provide enough amino acids for the needs of growing cattle.

Mineral requirements of dairy cows