age classes


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age classes

the classification of animals according to age is an important part of animal farming but is difficult to carry out and has limited value because of varying interpretations of the terms used. Some of the classifications, based on average farming practices, are:
Calf, birth to 1 year, yearling 1 to 2 years, heifer to first calf born. Calf and yearling may be classified as bull or heifer. Cow is female after first calf: bull is entire male over 2 years old. Castrated males: steer calf to 1 year, steer or bullock—over 1 year, stag—adult, castrated when mature.
Lamb, birth to weaning (average 4 months), weaner—4 months to 2-tooth. 2-tooth to 15 months. 4-tooth to 2 years. 6-tooth to 3 years. Full mouth to 4 years. All groups may be subdivided into ram and ewe groups. Females are ewe lambs, 2-tooth ewes, etc. Ewes at first lambing. Gimmer is ewe that has not borne a lamb. Adult entire males are rams or tups. Castrated males are wethers or hoggets or hoggs; these may also be subdivided into age groups, e.g. 2-tooth hoggets.
Piglet—birth to undetermined period, probably synonymous with suckler. Suckler—birth to weaning. Weaner—after weaning to attainment of approximately 30 kg, or 65 pounds, bodyweight. Boar—entire male over 6 months old, usually for breeding but not necessarily so. Maiden gilt—female in the breeding herd, over 6 months old but not yet mated. Gilt—female in breeding herd but not yet farrowed for first time. Sow—female that has farrowed. First litter sow—from first fertile mating to second. Barrow—castrated male in fattening herd.
Foal—birth to one year, filly or colt foal. Yearling—1 to 2 years, filly or colt. Then, 2 year old, 3 year old and so on. Filly—under 4 years. Mare—4 years and over. Then, classified on a use basis—e.g. brood mare. Colt—2 to 4 years. Stallion—entire male 4 years and over. Gelding—castrated male any age.
Show classes for pups have different age limits in different places. Males and females graduate from puppydom at sexual maturity when about 6 months old.
Kittens until sexual maturity at 5 to 6 months for females, slightly older for males.
Chicken, hatching to 4 weeks. Pullet—4 weeks to 5 months. Cockerel—4 weeks to 5 months. Rooster and hen—over 5 months. Turkeys—as for fowls except that young birds are poults and adult males are toms. Ducks similarly, with young birds called ducklings, the adult females are ducks and the males are drakes. In all species the dividing line between adult and young birds is not age but sexual maturity as evidenced by commencing egg laying or, in the case of males, mating females.
References in periodicals archive ?
The Honda Youth RIB (Rigid Inflatable Boat) Championship is split into two age classes - eight to 12 years and 13 to 16 years.
She said the school had spoken to parents to reassure them that for some children it can be "an advantage" to have mixed age classes.
Based on tooth wear, we assigned animals to the following age classes (Grau et al.
Return rates were significantly different between age classes in each region ([X.
Clear-cuts were separated into 4 age classes (3-5, 6-10, 11-15 and 16-20 years old) in order to assess temporal changes during both the period of typical browsing (0-10 years) and at least 10 years post-browsing (11-20 years).
In January 2011, replicated soil samples (0-10 cm) were taken along a chronosequence of 14 forested plots of four age classes within Mount Vernon, Virginia.
tenuis infection prevalence is often high (>80%) and does not differ greatly among age classes of deer because most deer are infected at an early age (3, 4).
high mortality of the first two age classes, low mortality of the last three age classes) (Figure 3).
This suggests that males disperse more frequently and farther than females, dispersal farther from the birthplace continues even in older age classes, and increased dispersal during dry years diffuses lineages that were observed during shorter-term studies in wet periods.
In addition, age classes 0-II for opaleye were determined from length frequency analysis of preserved specimens.
The 13-year-old (pictured) from Denby Dale is a member of the Huddersfield Falcon Motorcycle Club - established for 70 years - and has rocketed through the five age classes of motor cycle trials.