Calculating nutrient units for livestock and poultry
Learn how to calculate the nutrient units on your livestock farm. This technical information is for Ontario livestock producers.
Overview
Most farmers will encounter the term “nutrient unit” when they are planning to build or expand their livestock barn or manure storage facility.
Depending on the livestock or poultry numbers that are housed on the farm upon completion, you may be required to have an approved nutrient management strategy (NMS) prior to starting their project and possibly a nutrient management plan (NMP), under the Nutrient Management Act, 2002 (NMA) and Ontario Regulation 267/03.
This page explains the calculations used to determine the number of nutrient units on farms and provides some examples.
About nutrient units
The nutrient unit (NU) calculation allows for an “apples-to-apples” comparison of different livestock and poultry manures based on the nutrient values of their manure.
A nutrient unit is defined in Ontario Regulation 267/03 as “the amount of nutrients that give the fertilizer replacement value of the lower of 43 kilograms of nitrogen or 55 kilograms of phosphate as nutrient as established by reference to the Nutrient Management Protocol”.
The NU conversion factors for most livestock and poultry types are summarized in Table 1, column C, and are also found in 2023 Table 1 Nutrient Unit Livestock Information in the Nutrient Management Tables for Ontario Regulation 267/03, made under the Nutrient Management Act, 2002.
How to calculate NUs
To calculate the number of nutrient units associated with a given livestock or poultry, divide the number of that given animal type and subclass on the farm by the corresponding NU conversion factor in column C of Table 1. If the result is not a whole number, round up to the next whole number.
For example, a beef cattle farm with 10 backgrounders has the equivalent of 4 NU since 10 divided by 3 NU per beef backgrounder equals 3.33.
If there is more than one livestock and poultry type on the farm, calculate the NU for each type and subclass of livestock and sum the various NU values together to determine the total NU value for the farm.
If the total NU capacity for all livestock and poultry types on the farm is greater than 5 NU, then an approved NMS is required prior to building or expanding a livestock barn or manure storage facility. The strategy shows how the manure, runoff and other farm generated wash water will be properly managed. If the total number of NU is 300 or greater, then a NMP is also required. Additional information about nutrient management strategies is found in OMAFRA fact sheet, When Farms Require an NMS, NMP or NASM Plan.
Examples
The following are two scenarios showing NU calculations and the need for an NMS and in some cases an NMP.
Scenario 1
A farmer is planning to build a barn to house up to 50 adult alpacas on a property. The farmer is unsure whether this number of adult alpacas will require an NMS to obtain the building permit.
To calculate the nutrient units, look at Column A and B to find the corresponding livestock and subclass. In this example, Alpaca is the livestock type and the subclass is “Adult” including unweaned animals and replacements. Look across this row at the corresponding NU factor for this type of livestock and subclass in column C. It indicates that 8 alpaca (adults) is equivalent to one NU. To calculate the NU for 50 adult alpacas, divide by the NU factor from column C which is 8 adult alpacas per NU and the result for this farm is 6.25 NU, which means an approved NMS is required to obtain the building permit. A NMP is not usually required in this situation because the number of NU is less than 300 NU, unless there is a municipal well within 100 m of the property.
Scenario 2
A dairy farmer recently purchased additional milk quota to fill the existing free stall barn that was constructed in 2016. The current livestock numbers on the farm are 200 Holstein cows and the farmer is planning to increase the herd to 220 Holstein cows with the additional quota. How many NU does the farm have currently and how many NU will the farm have if the herd increases in size to 220 cows? The dairy heifers and calves are housed on a different property that is not included in this NU calculation
To calculate the nutrient units, look at Column A and B to find the corresponding livestock and subclass. In this example, “dairy” is the livestock type and the subclass is “large farm - adult”. Look across this row at the corresponding NU factor for this type of livestock and subclass in column C. It indicates that 0.7 Holstein cows (adults) is equivalent to one NU. To calculate the NU, 200 Holstein cows (current herd size) divided by the NU factor from column C (0.7/NU) is equal to 286 NU. With expansion of the herd to 220 cows, then 220 cows divided by 0.7 animals/NU = 314 NU and a NMP would be required. The farm operator was required to have an NMS since 2016 when the barn was built.
Alpaca
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Alpaca | Adults (includes unweaned animals and replacements) | 8 | 41 | 2,400 |
| Alpaca | Feeders 23-48 kg (50-105 lb) | 26 | 131 | 7,800 |
Beef
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Beef | Cow calf (includes calves to weaning) | 1 | 6 | 300 |
| Beef | Backgrounders | 3 | 16 | 900 |
| Beef | Feeders | 3 | 16 | 900 |
| Beef | Short keep | 2 | 11 | 600 |
Bison
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Bison | Adults (includes unweaned replacements) | 1.3 | 7 | 390 |
| Bison | Feeders 170 - 477 kg (375 - 1050 lb) | 4 | 21 | 1,200 |
Chicken
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Chicken | Broiler breeder grower (females and males transferred out) | 300 | 1501 | 90,000 |
| Chicken | Broiler breeder layer (females and males transferred in) | 100 | 501 | 30,000 |
| Chicken | Broilers – 8-week cycle | 351 | 1756 | 105,300 |
| Chicken | Broilers – 9-week cycle | 300 | 1501 | 90,000 |
| Chicken | Broilers – 10-week cycle | 250 | 1250 | 75,000 |
| Chicken | Broilers – 12-week cycle | 199 | 996 | 59,700 |
| Chicken | Layer pullets (day-olds) | 500 | 2501 | 150,000 |
| Chicken | Laying hens | 150 | 751 | 45,000 |
Chinchilla
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Chinchilla | Breeding females (including males/rep/market animals) | 320 | 1601 | 96,000 |
Dairy
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Dairy | Calves – small framed (Jersey) | 8.5 | 43 | 2,550 |
| Dairy | Heifers – small framed (Jersey) | 2.9 | 15 | 870 |
| Dairy | Cows – small framed (Jersey) | 1 | 6 | 300 |
| Dairy | Calves – medium framed (Guersney) | 7 | 36 | 2,100 |
| Dairy | Heifers - medium framed (Guersney) | 2.4 | 13 | 720 |
| Dairy | Cows - medium framed (Guersney) | .85 | 6 | 255 |
| Dairy | Calves – large framed (Holstein) | 6 | 31 | 1,800 |
| Dairy | Heifers – large framed (Holstein) | 2 | 11 | 600 |
| Dairy | Cows – large framed (Holstein) | 0.7 | 4 | 210 |
Deer/elk
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Deer/elk | Elk adults (> 24 months includes unweaned offspring) | 2 | 11 | 600 |
| Deer/elk | Elk feeders 91-162 kg (225-400 lb) | 6 | 31 | 1,800 |
| Deer/elk | Hybrid adults** (24 months and older) | 4 | 21 | 1,200 |
| Deer/elk | Elk/red deer hybrid feeders 65-155 kg (160-340 lb) | 10 | 51 | 3,000 |
| Deer/elk | Fallow deer adults (> 24 months includes unweaned offspring) | 13 | 66 | 3,900 |
| Deer/elk | Fallow deer feeders | 23 | 116 | 6,900 |
| Deer/elk | Red Deer adults (> 24 months includes unweaned offspring) | 7 | 36 | 2,100 |
| Deer/elk | Red Deer feeders | 14 | 71 | 4,200 |
| Deer/elk | White Tailed Deer adults (> 24 months includes unweaned offspring) | 11 | 56 | 3,300 |
| Deer/elk | White Tailed Deer feeders | 21 | 106 | 6,300 |
Ducks
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Ducks | Peking | 105 | 526 | 31,500 |
Emu
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Emu | Adults (includes unweaned offspring) | 12 | 61 | 3,600 |
Fox
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Fox | Breeding females (includes replacement and market animals and males) | 25 | 126 | 7,500 |
Goats
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Goats | Dairy does | 8 | 41 | 2,400 |
| Goats | Dairy kids | 32 | 161 | 9,600 |
| Goats | Feeder kids (>20 kg) | 32 | 161 | 9,600 |
| Goats | Mature meat goats | 8 | 41 | 2,400 |
Horses
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Horses | Small framed | 2 | 11 | 600 |
| Horses | Medium framed | 1 | 6 | 300 |
| Horses | Large framed | 0.7 | 4 | 210 |
Llama
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Llama | Adults (includes unweaned animals and replacements) | 5 | 26 | 1,500 |
| Llama | Feeders 45-86 kg (100-190 lb) | 16 | 81 | 4,800 |
Mink
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Mink | Breeding females (includes replacement and market animals and males) | 60 | 301 | 1,800 |
Ostrich
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Ostrich | Adults (includes offspring to market size) | 4 | 21 | 1,200 |
Rabbit
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Rabbit | Breeding does (includes bucks, replacements and market animals) | 40 | 201 | 12,000 |
Rhea
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Rhea | Breeding adults (includes replacements and market birds) | 13 | 66 | 3,900 |
Sheep
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Sheep | Dairy ewes and rams (includes unweaned offspring and replacements) | 6 | 31 | 1,800 |
| Sheep | Dairy and feeder lambs | 20 | 101 | 6,000 |
| Sheep | Meat ewes and rams | 8 | 41 | 2,400 |
Swine
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Swine | Feeders | 5.25 | 27 | 1,575 |
| Swine | Gilts | 5 | 26 | 1,500 |
| Swine | Sows (dry) and boars – non-SEW) | 3.5 | 18 | 1,050 |
| Swine | Sows (dry) and boars – SEW | 3.33 | 17 | 990 |
| Swine | Sows with litters – non-SEW) | 3.5 | 18 | 1,050 |
| Swine | Sows with litters – SEW | 3.33 | 17 | 990 |
| Swine | Weaners | 20 | 101 | 6,000 |
Turkey
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Turkey | Breeder toms | 45 | 226 | 13,500 |
| Turkey | Broilers (less than 6.2 kg) | 133 | 666 | 39,900 |
| Turkey | Hens (6.2 to 10.8 kgs) | 110 | 551 | 33,000 |
| Turkey | Toms (greater than 10.8 kg) | 75 | 376 | 22,500 |
| Turkey | Turkey breeder layer | 67 | 336 | 20,100 |
| Turkey | Turkey pullet (0-6 week) | 267 | 1336 | 80,100 |
Veal
| Column A | Column B | Column C | Column D | Column E |
|---|---|---|---|---|
| Livestock/poultry type | Subclass | Number of animals per NU | Number of animals required to be greater than 5 NU | Number of animals required to be equivalent to 300 NU |
| Veal | Grain fed | 6 | 31 | 1,800 |
| Veal | Milk fed | 6 | 31 | 1,800 |
Disclaimer
The information in this document is provided for informational purposes only and should not be relied upon to determine legal obligations. To determine your legal obligations, consult the relevant law. If legal advice is required, consult a lawyer. In the event of a conflict between the information in this fact sheet and any applicable law, the law prevails.