Lambing Calculator | Beef + Lamb New Zealand

Lambing Calculator

The lambing percentage distributions displayed in the lambing calculator are sourced from the Beef + Lamb New Zealand Economic Service Sheep and Beef farm survey.

Compare Lambing Percentage

Add your number of lambs tailed from ewes to compare your ewe Lambing Percentage.

The lambing percentage distributions displayed in the lambing calculator are sourced from the Beef + Lamb New Zealand Economic Service Sheep and Beef farm survey.

The lambing percentage is calculated as follows.

The number of lambs tailed from ewes on hand at 1 July that have been run with a ram. However note:

  1. Where ewes run with a ram are diagnosed as dry through scanning and sold, these are included in the ewes to ram tally. If these were excluded it would not be measuring the true ewe flock fertility. It would be including an element of management practice and overstate the lambing percentage and true flock fertility.
  2. Bought in in-lamb ewes are included in the ewes to ram tally.
  3. Sold in-lamb ewes are excluded from the ewes to ram tally.
  4. Lambs from hoggets are recorded separately in the Survey and are not included in the lambs tailed from ewes lambing percentage calculation.

The lambing percentage distributions displayed in the lambing calculator are sourced from the Beef + Lamb New Zealand Economic Service Sheep and Beef farm survey.

Data up to the spring of 2019 are actual lambing percentages from surveyed farms and are provisional for the spring of 2020 and estimated for 2021.

The All Classes distributions are 'weighted averages' of individual Farm Class data to correctly portray a whole region or the New Zealand lambing percentage distribution. These allow you to evaluate where your lambing percentage result sits nationally, within your region and within a particular Farm Class. If there are insufficient observations within a Class and Region you will need to compare your farm with its whole Farm Class or your All Classes Region distribution.

The Farm Class descriptions are noted below and Table 1 shows the estimated number of commercial sheep and beef farms in each Class.

Table 1: Sheep and Beef Farm Survey 2019-20
  Sheep and beef farm survey 2019-20 farm class Estimated farms
South Island High country 200
South Island Hill country 620
North Island Hard hill country 920
North Island Hill country 3,055
North Island finishing 1,045
South Island Finishing breeding 1,820
South Island finishing 1,040
South Island Mixed finishing 465
  Total all classes 9,165

The eight farm classes are defined as follows.

  1. South Island High Country

    Extensive run country located at high altitude. These farms run a diverse mix of operations which include breeding sheep, often fine wooled, breeding cows and deer. Stocking rate is typically up to three stock units per hectare. Located mainly in Marlborough, Canterbury and Otago.
  2. South Island Hill Country

    Traditionally store stock producers with a proportion sold prime in good seasons. Carrying between two and seven stock units per hectare, they usually have a significant proportion of beef cattle.
  3. North Island Hard Hill Country

    Steep hill country or low fertility soils with most farms carrying 6 to 10 stock units per hectare. While some stock are finished a significant proportion are sold in store condition.
  4. North Island Hill Country

    Easier hill country or higher fertility soils than Class 3. Mostly carrying between 7 and 13 stock units per hectare. A high proportion of sale stock sold is in forward store or prime condition.
  5. North Island Finishing Farms

    Easy contour farmland with the potential for high production. Mostly carrying between 8 and 15 stock units per hectare. A high proportion of stock is sent to slaughter and replacements are often bought in.
  6. South Island Finishing-Breeding Farms

    Farms which breed or trade finishing stock, and may do some cash cropping. A proportion of stock may be sold store, especially from dryland farms. Carrying capacity ranges from 6 to 11 stock units per hectare on dryland farms and over 12 stock units per hectare on wetter or irrigated farms. Mainly in Canterbury and Otago, this is the dominant farm class in the South Island.
  7. South Island Finishing Farms

    High producing grassland farms carrying about 9 to 14 stock units per hectare, with some cash crop. Located in Southland, South and West Otago.
  8. South Island Mixed Finishing Farms

    Located mainly on the Canterbury Plains. A high proportion of their revenue is derived from grain and small seed production, as well as stock finishing or grazing.