January 4, 2009

Sheep Farm Husbandry - Reproduction: Hoggets; Mating & lambing

Sheep, farming, husbandry, hoggets, yearlings, mating, advantages, disadvantages, points for success, liveweight, feeding, liveweight, target levels of performance

By Dr Clive Dalton

Practice in New Zealand
About 20% of New Zealand farmers now put their hoggets to the ram at 8-9 months of age to lamb when they are about a year old. They normally lamb them first as two-tooths at two years old to give the hogget time to grow and mature. But to get more production out of the flock, mating hoggets is a very simple concept and has been in and out of fashion over the years. A lot of research has been done on it. Currently it’s in fashion again, and there are plenty of reports of successful farming operations where hoggets are mated and lambed.

You often hear the comment that mating hoggets will provide “bonus” lambs. This is a dangerous statement as they are no such thing as bonus lambs – there’s always a cost involved. So before you do anything – consider the points below:

Points for hogget mating
  • More lambs can be sold from the flock.
  • Hoggets that lamb are more productive ewes.
  • Having more lambs allows greater scope for selection and flock improvement.
  • More sheep with greater nutritional needs, means that you get better utilisation of surplus spring feed. The feed is going into more productive sheep.
  • Hoggets that lamb are better mothers at their subsequent lambings.
Points against hogget mating
  • Extra feed needs to be provided to get hoggets up to a good weight for mating, and to feed them well right through pregnancy and lactation.
  • Deaths are higher in hoggets that lamb.
  • Wool production at hogget shearing will be lower.
  • Lambing will be extended.
  • Lambs from hoggets are generally smaller at weaning and will be slower to reach market weights.
  • More rams are needed. One ram for every 30-50 hoggets is recommended.
  • Performance measured by lambs weaned/100 hoggets joined can be very variable and values from 4-46% have been published
How to ensure success
  • Be realistic and don’t expect a successful operation every year as season and feed supply has the main effect on the result.
  • If you do the job well and it’s a good season for weather and pasture growth, consider these performance levels to be good.
  • 70-90% to take the ram
  • 50-70% to lamb
  • 40-50% lambs weaned/100 hoggets joined
  • Be prepared to expect enormous variation from year to year e.g. 4-46% in LW/HJ
Liveweight is critical. Here are some target weights. Remember these are minimum weights that all animals should reach – they are not average weights:
  • 40kg at mating (4 months old(
  • 55kg at weaning their lambs (11 months old)
  • 60-65kg at two-tooth mating (15 months old)
Feeding is critical. Hoggets should be well fed, but not to grow more than 100 g/head/day immediately after mating, as high feeding levels at this time have been show to cause pregnancy losses. But feed them well after that.
  • Expect hoggets to cycle one month later than the main flock.
  • Give the rams a maximum of two cycles with hoggets. Some farmers only give them one cycle.
  • Run teasers with the hoggets before the rams go out to try and compact lambing.
  • Feed offered hoggets at lambing should be at least 1300kg DM/ha and 1500kg DM/ha for lactation. This must be high quality leafy green feed.
  • Try to avoid as much disturbance at lambing as possible. Keep an eye on things from afar.
  • The hoggets are “priority stock” so keep pasture levels high right through lactation and up to weaning of the hoggets’ lambs. Hoggets need to grow themselves as well as produce plenty of milk for the lambs suckling them so plan to achieve growth of at least 100g/head/day while they are suckling lambs.
  • The hoggets’ lambs then become even higher priority stock to get them up to good commercial weights. This is a real challenge.
  • If you carry on mating hoggets, expecting the lambs born from hoggets to take the ram as hoggets is too much. Their “maternal environment” of having a hogget as a mother is often too much of a burden, and they cannot get to a suitable mating weight.
  • So sell all the lambs bred from hoggets unless you have some important genetic reason for speeding up generation interval.
  • If you can get the hoggets out of hoggets to lamb, you can certainly improve the productivity of your flock genetically – but don’t bank on achieving it.
Final comments
  • You don’t get anything for nothing – you certainly don’t get “bonus” lambs from hoggets.
  • If you cannot grow good feed on the farm and consistently grow good stock, and consistently achieve the target weights, forget about hogget mating.
  • If the hoggets become priority stock, something else in the farm’s management has to change. Sort out what it will have to be before you start.
  • If you go to farmer’s meeting promoting hogget mating and lambing, ask the speakers to tell you the names of farmers who have given the practice away and why, and not just the successful operators. They never do this! The farming press always highlights success stories and never failures.
This material is provided in good faith for information purposes only, and the author does not accept any liability to any person for actions taken as a result of the information or advice (or the use of such information or advice) provided in these pages.

No comments:

Post a Comment