Farm Tech
In The Paddock
Seasonal sheep flock management tips April 2002
Potential benefits from hogget mating but high management requirements
Key Points
- Hogget mating has high management requirements. It should be attempted
only if these requirements can be met.
- Ewes that lambed as hoggets have improved lambing performance as 2-tooths
and for the rest of their lives.
- Breed and/or strain of sheep has a significant impact.
- Hoggets should be mated at around 40 kg at a condition score of 3
or better, using 2 rams per 100 hoggets.
- Good growth rates after weaning are essential in order to achieve
these targets.
- Vaccinate hoggets for toxoplasmosis and campylobacter before joining
teasers or entire rams.
- Aim for growth rates of 80100 g/day from mating until mid-pregnancy
and for a target weight of about 52 kg at lambing.
Successful hogget lambing requires high standards of management. It should
only be attempted if the farm and management system can meet these requirements.
The opportunity cost of the additional feed consumed must also be outweighed
by the benefits of mating and lambing hoggets.
Trials have shown that ewes that lambed as hoggets may be lighter and
clip less wool as 2-tooths. However, these differences do not persist
past the 2-tooth season.
Two-tooths that lamb as hoggets have lower barrenness and higher lambing
and weaning rates. This appears to be due to improved mothering ability.
Ewes that lambed as hoggets produced 20 per cent more lambs in their
lifetime than those that didn't lamb as hoggets.
Romney, Coopworth and Perendales have hogget lambing rates of 2070
per cent, with the higher rates being achieved only by very highly fertile/fecund
strains of these breeds. Some new breeds such as the Finn and East Friesian
have more oestrous cycles and begin cycling earlier, resulting in higher
hogget lambing rates.
With better feeding, hoggets' lambs can wean at similar weights to the
ewe mob's lambs. This means they can be kept as replacements, thereby
shortening the generation interval and improving the rate of genetic gain.
To further speed up the rate of genetic gain, ram hoggets can also be
used with care.
Target liveweights and feeding
Hoggets that show oestrous are more productive over their lifetimes
even if they are not lambed as hoggets.
Breed aside, mating weight is the key to achieving oestrous and consistently
high lambing rates from hoggets.
Many farmers and consultants now use a liveweight of 40 kg and a condition
score of 3 or better on 1 May as the minimum target for hogget lambing.
To achieve this, good ewe lamb growth rates are essential. After weaning,
ewe lambs should be offered 15002000 kg/ha of high quality pasture.
This means not grazing below 45 cm.
If these pasture conditions cannot be met, a high quality specialist
forage crop or pasture should be used.
There is some debate on the merits of shearing hoggets before mating.
While hogget shearing can stimulate ovulation, it appears that the key
to getting this response is to have plenty of high quality feed on offer
after shearing.
Because shearing stimulates appetite and increases maintenance requirements,
animals will lose weight if feed is short. This is exactly the opposite
to what is intended.
To maximise conception rates, ewe hoggets should be on a rising plane
of nutrition at mating.
Aim to reach the 40 kg target about a month before mating, then reduce
the rate of gain to about 50 g/day until the rams are withdrawn. This
will ease the pressure on feed supplies at a time when the main ewe mob
also needs to be gaining weight and condition.
Mating management
Hoggets should be given Toxovax at least one month before mating or the
introduction of teaser rams, preferably by 1 March. Campylovexin should
be administered twice before mating, with a four week interval between
vaccinations. The last vaccination can be given as the ram goes out.
Hoggets start cycling about a month later than ewes. To bring them into
oestrous earlier, some farmers run them with teaser rams for the month
before mating. Others graze their hoggets next to the main ewe mating
mob, where the presence of rams and mating activity has the same effect.
Many farmers join entire rams with ewe hoggets on 1 May and mate for
two cycles. With well-grown hoggets the choice of sire breed is not as
critical as frame size at lambing. Use a ram:ewe ratio of 1:50.
Because hoggets aren't on heat for as long as mature ewes, it's best
to mate in small, easy contour paddocks. When mating with ram hoggets,
give the ram hoggets sexual experience by running them with a small group
of older ewes, before putting them with the ewe hoggets.
Feeding in early- and mid-pregnancy should aim to achieve growth rates
of 80 g/day, or about a 12 kg gain in liveweight over winter. The industry
average is considerably less than this, so liveweight gains over winter
will need to be higher than at present if mating hoggets is to succeed.
More information
- Schick, G. 2001. Hogget mating. Will you follow the trend?, Wool
Grower Summer 2001:Pp 25-26.
- Willoughby, L.; Gavigan, R. 2001. Hogget mating and lambing
A discussion paper. WoolPro internal paper: 11pp.
Northern North Island: Sally
Hobson tel 07-823 3321 or 025-924 751
Hawkes Bay/East Coast: Lew
Willougby tel 06-835 1888 or 025-434 417
Southern North Island: Richard
Gavigan tel 06-376 0006 or 025-499 851
Nelson/Marlborough/Canterbury: Alan
Marshall tel 03-343 7913 025 329 399
South Canterbury: Julia
Mackenzie, tel 03-680 6782 or 025-782 353
Otago: Robert
Pattison, tel 03-489 9021 or 025-323 094
Southland: Aaron
Meikle, tel 03-203 9071 or 025-846 377
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