Animal health programme
A planned schedule of vaccinations, drenching, and preventative treatments administered to a sheep flock throughout the year to maintain health and productivity.
Anoestrus
The non-breeding season in ewes when they do not cycle, typically during longer days (late spring and summer) in New Zealand. Anoestrus timing varies by breed.
Artificial insemination (AI)
The placement of semen into the reproductive tract of a ewe by human intervention, used to introduce high-value genetics.
Back-fencing
Temporary fencing placed behind a mob of sheep to prevent them from returning to already-grazed pasture and to protect pasture recovery.
Birth weight
The weight of a lamb recorded within 24 hours of birth. An important indicator of lamb survival, particularly in cold or wet conditions.
Body condition score (BCS)
A standardised numerical assessment of a ewe’s body fat reserves, scored on a 1 to 5 scale by palpating the loin area. Used to guide nutrition management around mating, lambing, and weaning.
Breeding ewe
A mature female sheep used for reproduction within the flock, typically from 2 years of age onwards.
Broken mouth
A sheep that has lost one or more permanent incisor teeth, reducing its ability to graze efficiently. Broken-mouthed sheep are commonly culled or moved to easier country.
Cast for age (CFA)
Sheep that are sold or culled from the breeding flock based on age rather than condition or productivity, typically at 5–7 years of age depending on breed and farm policy.
Classing
The process of visually assessing and sorting sheep within a flock to select superior animals for breeding and cull those below standard.
Condition scoring
See Body condition score.
Crutching (dagging)
The removal of wool and faeces from around the tail and breech area to reduce the risk of flystrike and to improve hygiene. Often carried out before lambing and in summer.
Culling
The planned removal of sheep from the flock due to poor reproductive performance, wool production, structural faults, lameness, age, or disease.
Dagging
See Crutching. The trimming of soiled wool from the breech and dock region of sheep.
Dag score
A numerical score assessing the degree of faecal soiling (dags) around the breech, used to select for breech strike resistance in breeding programmes.
Docking
The removal of the distal portion of the tail in lambs, typically carried out within 2 weeks of birth using a rubber ring, hot iron, or surgical method, to reduce the risk of flystrike.
Drenching
The oral administration of anthelmintic products to control internal parasites (worms) in sheep. Drench resistance is an increasing challenge in New Zealand flocks.
Drench resistance
The ability of a worm population to survive treatment with an anthelmintic at the recommended dose. A significant and growing concern in New Zealand sheep farming.
Early weaning
The separation of lambs from ewes before the normal weaning age, used during drought or poor feed conditions to allow ewes to recover body condition before the next mating.
Estimated breeding value (EBV)
A statistical estimate of a sheep’s genetic merit for a specific trait, used to make selection decisions within Sheep Improvement Ltd (SIL) recorded flocks.
Ewe
An adult female sheep.
Ewe hogget
A young female sheep, typically between 6 and 18 months of age, that has not yet lambed.
Flushing
The practice of feeding ewes a rising plane of nutrition (increased feed allowance) for 3–4 weeks before mating to stimulate ovulation rate and improve multiple birth rates.
Flystrike (myiasis)
A condition caused by blowfly larvae (maggots) feeding on the living tissue of sheep, resulting in tissue damage and rapid deterioration. Preventable by crutching, chemical treatments, and Numnuts/ring docking.
Gestation length
The period from conception to lambing in sheep, averaging approximately 147 days (21 weeks), with minor variation between breeds.
Gummy
A sheep that has lost all permanent incisor teeth. Gummy sheep have limited grazing ability and are typically culled.
Hogget
A young sheep between weaning and first shearing, typically 6–18 months of age. Hogget ewe lambs may be mated in their first year in some breeding systems.
Joining
The period during which rams are run with ewes for natural mating. In New Zealand, joining typically begins in late autumn (April–May) and lasts 6–8 weeks.
Lamb marking
A collective term for the procedures carried out on young lambs, typically including docking, castration of male lambs, ear tagging, and drenching.
Lambing percentage
The number of lambs weaned per 100 ewes mated, a key production KPI for sheep flocks. National average in New Zealand is approximately 125–130%; high-performing flocks achieve 150%+.
Lambing spread
The distribution of lambings over the lambing season, influenced by ewe cycling activity, joining length, and ram management. A tighter lambing spread allows more uniform management.
Liveweight (LW)
The total body weight of a live animal measured on a scale, used to guide management, drenching decisions, and slaughter timing.
Mob
A defined group of sheep managed together as a unit for grazing, feeding, movement, or husbandry purposes.
Mob stocking
A management system where sheep graze at high density for a short period before being moved, allowing extended pasture recovery.
Mules operation
A surgical procedure removing skin folds around the breech area to create bare, wrinkle-free skin that is resistant to flystrike. Less commonly used in New Zealand than Australia.
Muster
The gathering and moving of sheep from pasture into yards for management purposes.
NAIT (National Animal Identification and Tracing)
New Zealand’s mandatory livestock traceability system requiring sheep farmers to register their property and record animal movements.
Oestrus
The period of sexual receptivity in a ewe during which she will stand to be mated by a ram. Oestrus recurs every 16–17 days if the ewe does not conceive.
Ovulation rate
The number of eggs released by a ewe’s ovaries during a single oestrous cycle, directly influencing the potential for multiple births (twins and triplets).
Pasture dry matter (DM)
The weight of pasture excluding water, measured in kg DM/ha, used to quantify feed supply and plan grazing management.
Planned start of mating
The date on which rams are first introduced to the ewe flock, or AI begins, chosen to align lambing with optimal seasonal feed and weather conditions.
Polled
An animal that is naturally without horns.
Pre-lamb shearing
The shearing of ewes 6–8 weeks before lambing to improve shelter-seeking behaviour, lamb survival (ewes seek shelter earlier), and ease of lambing observation.
Ram
An intact (uncastrated) adult male sheep used for breeding.
Ram joining ratio
The number of ewes assigned per ram during mating. Typical ratios are 1 ram per 50–60 ewes for paddock mating, and higher for AI programmes.
Replacement ewe
A young ewe (often a two-tooth or four-tooth) selected to join the breeding flock as a replacement for culled animals.
Reproduction rate
See Lambing percentage.
Scanning
Ultrasound pregnancy scanning of ewes to determine pregnancy status and the number of foetuses present (singles, twins, triplets). Used to allocate ewes to different nutritional management groups.
Scour (diarrhoea)
Profuse diarrhoea in lambs caused by bacterial, viral, or nutritional factors, leading to dehydration and high mortality if untreated. Also used to describe adult sheep scouring due to parasitism or poor nutrition.
Shearing
The removal of a sheep’s fleece using mechanical handpieces or blade shears, typically carried out once or twice annually.
Shedding breeds
Sheep breeds that naturally shed their fleece without shearing, such as the Wiltshire Horn and East Friesian crosses, used to reduce shearing costs.
SIL (Sheep Improvement Limited)
New Zealand’s national sheep genetic recording system, providing EBVs and indexes to assist with selection decisions.
Staple length
The length of wool fibre grown between shearings, measured in millimetres. Along with fibre diameter, it determines the processing value of the fleece.
Stocking rate
The number of stock units (SU) per hectare of effective pasture, a key driver of pasture utilisation and farm profitability.
Stock unit (SU)
A standard unit of livestock feed requirement used in New Zealand. One stock unit is equivalent to the annual feed requirements of a 55 kg Romney ewe plus her lambs.
Tagging
The application of ear tags for individual identification and traceability. NAIT-compliant visual and RFID tags are compulsory in New Zealand sheep operations.
Terminal sire
A ram selected for its ability to produce fast-growing, well-muscled offspring intended for meat production rather than breeding.
Tooth aging
The assessment of a sheep’s age based on the number and wear of its permanent incisor teeth. Sheep are classified as lambs (milk teeth), two-tooths, four-tooths, six-tooths, and full-mouthed.
Two-tooth
A sheep with two permanent incisors, typically 12–24 months of age. Two-tooth ewes are commonly mated for the first time at this stage.
Tupping
The act of a ram mating a ewe. The term is widely used in New Zealand and the United Kingdom to describe natural service during the breeding season. The mating period is commonly referred to as the tupping season, and rams are sometimes called tups.
Ute
A utility vehicle commonly used in New Zealand farming, similar to a small pick-up truck and typically fitted with an open rear tray.
Weaning
The separation of lambs from ewes, typically carried out at 10–16 weeks of age in New Zealand. Weaning weight is a key production benchmark.
Withholding period
The minimum time that must pass after an animal is treated with a veterinary product before its meat or wool can be supplied for human consumption or processing.
Wool cut
The total weight of greasy wool shorn per sheep per year, a key production KPI in Merino and dual-purpose breeds.
Works (meatworks)
A colloquial New Zealand term for an abattoir or slaughterhouse where sheep are processed for lamb and mutton.
Yearling
A sheep approximately 12 months of age. Yearling weights and fleece weights are commonly recorded as production benchmarks.
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