|Each extra day at grass can reduce milk production costs by 0.16c/l 1 and is worth €1.54 per suckler cow/day 2|
|Feeding good quality grazed grass is almost four times cheaper than concentrates.|
|Table 1: Cost of Feedstuff Types 3|
|Feedstuff||Cost (c/kg utilisable Dry Matter)|
|2nd cut silage||17.4|
|1st cut silage||16.5|
Grass growth and use is largely dictated by prevailing weather conditions, therefore cost savings will vary with soil conditions and rainfall. However, in general feeding good quality grazed grass is almost four times cheaper than concentrates.
Suitable soil conditions may allow you to consider extended grazing.
|Reseeding 10% of the farm each year will increase net profit by 1.2c/l 4.|
Perennial ryegrass delivers highest yields across all soil types. Aim for 65% perennial ryegrass in swards. Grass breed selection and yields are impacted by soil conditions. Correct soil fertility and pH levels are essential for good sward establishment. The optimum range for soil pH levels for perennial ryegrass is 6.2 to 6.7.
|Concentrate feed costs for in-lamb ewes increases by 8% for each 1% fall in silage DMD 6|
|Concentrate feed requirements for dairy cows increase by 4% for each 1% decline in silage DMD.|
Increased DMD increases the amount of energy available from silage and leads to improved animal performance in terms of milk yield and body weight gain.
|Comparison of the value per tonne of DM of silages of varying quality|
|Silage||Dry matter digestibility %||Net energy value per kg dry matter (UFL) 7||Value per tonne DM|
|Adapted from S. Kavanagh 8|
to approximately 95 kg of concentrates 9. Poor silage quality is characterised by low DMD. Delayed harvesting has a major influence on silage quality. While there will be increased yield it will result in more of the silage passing through the animal undigested. Each 1 unit increase in silage dry matter digestibility will increase carcass gain by 24g per day in finishing beef cattle 10. For example, increasing your silage DMD from 60% to 70% will increase carcass gain by 250g/day
|High protein does not mean high energy.|
|The protein value of any feedstuff is best measured by the quantity of protein that is absorbed by the animal, not what the animal consumes.|
Rations should be bought firstly on the basis of their energy content, next protein, then minerals and finally fibre. If livestock are not performing well, (losing body condition or low milk proteins), then the problem is usually a lack of energy. This is generally the most limiting nutrient in grass based livestock diets.
Ingredients in rations are listed in order of decreasing inclusion level although the quantities included are not listed. Anything listed below molasses is making a minimal contribution to the ration.
Top quality energy sources include barley, wheat, distillers grains, maize and beet pulp.
Know the energy value in feedstuff by looking at the net energy value which is expressed in terms of feed units (UF). In most feeding systems the net energy value is known as UFL, for intensive finishing cattle it is UFV. Barley is the standard feed in this system and all other feeds are given values relative to barley, which has UFL of 1.0 on a fresh weight basis. 11
Top quality protein ingredients include soyabean meal (the best protein source) distillers, rapeseed meal and more limited availability ingredients like peas and beans.
The protein value of any feedstuff is best measured by the quantity of protein that is absorbed by the animal, not what the animal consumes. Protein that is absorbed into the animal comes from bacterial protein in the rumen and protein that passes through the rumen undegraded. Each feed you purchase will have two protein values PDIN and PDIE.12 The lower of the two values is the actual protein value of the feed.
|Energy and Protein values of Dry Feeds|
|Dry Feeds||UFL (per kg DM)||CP g/kg||PDIN g/kg||PDIE g/kg|
Buying rations containing feedstuffs with the highest UFL represents better value per tonne. You are buying more energy. Ask your feed merchant for a list of the feedstuffs and the quantity of each per tonne.
Remember the cheapest ration does not always represent the best value.
|Severe mineral deficiency will reduce animal performance.
Reduced fertility and increased disease incidence can also occur.
While the identification of a mineral deficiency can be quite difficult and often symptoms overlap between different minerals, items to consider include:
The second step is to decide the best supplementation option for your farm?
When developing a mineral supplementation programme, obtain independent expert advice and consider the cost, ease of use and uniformity of supplementation.
A feed budget is an essential management tool on livestock farms.
During the grazing season budgets can change on a weekly basis due to the dynamic nature of grass growth. Weekly grass measurements and grass budgets should be considered in order to assess the quantity of feed available on the farm. This will allow you to make decisions in advance of periods of deficit or surplus.
Download, print and fill in the tables below to calculate your feed requirements
STEP 1 – Calculate winter fodder required
|Stock type||No. of animals (a)||No. of winter months (b)||Pit silage needed t/month (c)||Total tonnes (a x b x c)|
|Dairy Cows (dry)||1.3 - 1.4|
|Dairy cows (milking)||1.6|
|Dairy in-calf heifers||1.3|
|A = tonnes of pit silage required|
|Stock type||No. of animals (a)||No. of winter months (b)||No. of bales /month (c)||Total no. of bales (a x b x c)|
|Total no. of bales|
|B = tonnes of bale silage required = no. of bales x 0.6|
Total fodder required (tonnes) = A + B
STEP 2 – Assess the quantity of fodder available
This requires calculating the quantity of silage in the pits and in bales. Remember to include bales of hay, straw and any other fodder you have on the farm.
Measure all silage pits in metres – multiply the length X breadth X average settled height = volume of silage in m3 . To convert from volume in m3 to tonnes apply the conversion factors in the table below.
|No. of silage pits||Length (metres) (a)||Breadth (metres) (b)||Average height (metres) (c)||Volume m3 to tonnes|
x by 0.77 @ 20% DM
x by 0.69 @ 22% DM
x by 0.68 @25% DM
x by 0.61 @30% DM
|Tonnes corrected to tonnes of grass silage at 20% DM|
|Silage Pit 1||2|
|Silage Pit 2||1.7|
|Silage Pit 3||1.9|
|C = Total tonnes of pit silage (corrected to tonnes of silage equivalent at 20% DM) =|
Other fodders such as hay and straw can be converted from bales to tonnes of silage equivalent (@20% DM) to determine your total fodder supply in tonnes.
|Bales 4 x 4||No. of bales (a)||Weight per bale tonnes (b)||Factor used to convert to the equivalent tonnes of grass silage at 20% DM (c)||Total feed supply (equivalent to grass silage at 20% DM) = (a x b x c)|
|Grass silage @ 30% DM||0.6||1.5|
|Grass silage @ 25% DM||0.7||1.35|
|Grass silage @ 82% DM||0.24||4.1|
|Hay bales @ 88% DM||0.15||4.4|
|D = Total tonnes of bales corrected to tonnes of silage equivalent @ 20% DM =|
STEP 3 – Calculate fodder surplus or deficit
To determine if you have a surplus of deficit of fodder, subtract your tonnes of fodder required calculated in STEP 1 from your tonnes of fodder available calculated in STEP 2.
Deficit / Surplus = (A+B) – (C+D) =
Download, print and fill in the tables above to calculate your feed requirements