November 22, 2008

Animal behaviour and welfare: Rabbits Part 2


Reproduction: Sexing: Mating: Pregnancy: Birth: Fostering

By Dr Clive Dalton

  • Do this at 6-8 weeks so males and females can be cages separately.
  • Hold the rabbit upside down in your left hand with your fingers holding the legs to prevent struggling.
  • Use your right hand to press gently on the side of the vent area.
  • In the male (buck) a small tubular protrusion (sheath) can be seen, and in a doe there is a minute slit.
  • Seek experienced help to confirm your diagnosis.

Sexual maturity (puberty).
  • Most breeds are sexually mature at 5.5 to 6 months old. So a doe mated at 5.5 months will have her first litter at 6.5 months. Bucks are best used first at 6 months old.
  • The Angora is ready for breeding at 5-6 month's of age, but many producers wait till the third shearing at 8 months to evaluate its fibre production before using it as a parent to improve the stock.
  • A good production routine is as follows:
Week 1 Mate, shear, dose, cut nails.
Week 3 Put next boxes in dam's cage
Week 4 Kits born
Week 5 Kits removed from dam, sexed and shorn.
Week 12 Shear the doe and re-mate her.

Oestrus (heat)
  • Rabbits come on heat all the year round but do not have a regular cycle like larger farm animals. But high temperatures in summer (above 30°C) will reduce oestrus.
  • Follicles mature in 18 days, remain for about 7 days and regress in the next 9 days unless ovulation occurs.
  • The ovaries contain sufficient follicles on the 2nd and 3rd after kindling, and then again on the 17th to 20th day to allow successful pregnancy. So rabbits can be mated the day after the kits are born. So pet owners should be warned! This is why the rabbit can become a major environmental pest.
  • The event of mounting stimulates ovulation and they are prone to false (phantom or pseudo) pregnancies by this event. So for example females mounting females in a communal cage can stimulate false pregnancy.

  • In general mate young bucks to old does, and young does with an old buck. But this advice should not be set in concrete.
  • For mating - Make sure the doe is ready before taking her to the buck's cage. Her vulva will be slightly swollen and a bit red or purplish in colour. When not on heat it will be pale pink or white. Watch out for fighting and possible injury if the doe is not on heat.
  • Does are often taken to the buck in the morning and then 6-8 hours later in the same day. If the doe ovulates and conceives separately to each mating, both litters will be born close to the same time and there will be no size variation.
  • Mating may be a noisy affair (maybe pain or ecstasy) and the buck will fall sideways or backwards after the event. Don't leave the two together for long after mating as their attitudes can change quickly and end up with a fight.
  • Females can be held and supported from below if necessary to make the buck's job easier. But make sure she is properly on heat or false pregnancy and wasted time will be the result.
  • A doe can be bred the day after her kits are born, provided she is healthy.
  • If she is skinny as a result of her large litter and high milk production, then she must be built up with full feeding for a few days before mating.
  • Sometimes a sluggish buck can be stimulated by a back massage or a tickle of his sides and thighs. This may not always work so beware incase he doesn't like it.
  • Bucks that have become obese may need to be put on a strict diet to lose weight to boost their libido.

  • Pregnancy in rabbits averages around 31 days.
  • Does can be palpated to determine pregnancy but it needs experience. The doe is held by one hand and the other is used to palpate the belly in front of the pelvis to feel for the small developing embryos. But be careful as injury can result if not done properly.
Preparation for birth
  • Nest building. Does are nest builders so some form of nesting material (hay, straw or clean shavings) must be provided to put in the next box in the cage. Do this a few days before she is due.
  • The doe will also pluck her belly a few days before birth to line the nest. This will also remove long hair to expose her nipples for the kits.
  • You may have to pluck the belly hair if the doe neglects to do it.

  • Kits are born naked and blind and stay confined to the nest for 2-3 weeks.
  • Leave the doe alone during birth and avoid any disturbance. Severe trauma at birth may result in her eating the young.
  • Give her a "feed treat" the next day so when she's out of the box you can count the litter. Examples are some leaves of comfrey, plantain, dandelion, or clover.
  • Litter sizes will vary greatly. An average litter is about 7 but this can range from 2 to 24 kits per litter.
  • Larger litters tend to have more losses up to weaning. Mortality of 6-8% is usual immediately after birth.
  • High death rates will occur if the kits are not suckled on the three consecutive days after birth.
  • Check for kits that get dragged over the edge of the box when the doe comes out.
  • Check the kits every day until they are ready to come out of the box on their own.
  • High temperatures may cause problems and often it's a good idea to put nesting boxes on the cool ground in a safe place.
  • Kit's eyes should open by 12-14 days. If any are delayed they may need bathing and some gentle encouragement by applying gentle pressure on each side of the eyelid.
  • Suckling takes place once a day, usually in the morning

  • Offspring (kits) can be fostered from one doe to another provided they are within one week of birth of the foster mother. This is a useful practice to give kits from does with large litters to does with small litters - provided they have a good milk supply to rear them.

Rearing orphans
  • This is generally not worthwhile unless you want to preserve some special blood line. It's vital that the kits have their mother's colostrum immediately after birth. Talk to your vet about a suitable milk substitute for young kits.

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