Lambs are born 142 to 152 days after the rams have access to ewes in oestrus. This varies slightly among breeds. Rambouillets have a longer gestation period than Dorsets.
The lamb's survival depends on proper bonding between the ewe and lamb: the first week is vital. Approximately 90 per cent of mortality cases are caused by poor mothering, exposure to cold and starvation.
Provide each ewe with its own lambing jug--individual pen--to properly monitor the bonding between ewe and lamb and prevent mismothering. The pen also makes it easy to catch the lamb for procedures such as tail docking, vaccinations and castration. The pen should be 5' X 5' or larger, clean, well bedded and dry with a separate section to provide the lamb a safe area from the ewe. Water buckets and feed troughs should be high enough that the lamb cannot reach them. The lamb and ewe can be placed with other ewes and lambs in a large pen once the lamb is strong and has received all required treatments.
There is a variety of options for feeding lambs, each has pros and cons. Geographic location, type of production system, marketing options and cost and availability of feed are factors which need to be considered when choosing a feeding program. A mother's milk is the only nourishment a lamb needs for the first several weeks. Within a week or two lambs will begin to nibble on solid food. By the time lambs are 4 to 6 weeks old, they will be receiving 50 per cent of their nutrient intake from sources other than their mother's milk. Fresh, clean grain should be slowly introduced into the lambs' diet until the lambs are on full feed.
Vaccinating and deforming lambs is a vital part of proper sheep husbandry, which provides extra protection from parasites and diseases that the ewe cannot prevent. It is important to consult your veterinarian concerning the correct amount, type and route before administering any medication to your lamb.
The navel of the newborn lamb needs to be disinfected as soon after birth as possible. An untreated navel is a susceptible route for bacteria to enter the lamb; therefore, the navel should be disinfected with an antiseptic solution shortly after birth. Disinfecting solutions such as 1% iodine can be sprayed onto the navel or the navel can be dipped into a small container filled with the solution. If the navel is longer than 2 inches, clip it to be closer to the body before dipping or spraying with the solution.
Various predator management strategies, which reduce the risk of predation, are livestock guardians, good fences and lethal control methods--trapping, shooting, or toxic collars. Lambs raised in confinement are less susceptible to predators than those grazing in open pastures are.
According to the Code of Practice for Sheep, the tail needs to be docked before the lamb is seven days old. A good guide to properly docking the tail is to remove it at the joint in the tailbones. It should cover the anus of the ram or the vuvla of the ewe. It can be removed using an electric or gas heated docker, a rubber ring or a crush and cut device.
Market lambs kept beyond three months of age need to be castrated. There are several methods of castration, which range from surgical to elastic band castration. Castrating sheep at a young age is easier for the operator, less stressful on the sheep and more compliant to the Code of Practice for Sheep.