Sheep 2 Sheep Production

Outline of the year in Lowland sheep production Jan/Feb Lambing takes place   Mar/Apr/May Lamb suckles its mother Creep feeding and creep grazing are introduced Lamb is weaned at 14 weeks or sold as early lamb Jun/Jul/Aug Lamb grazes good quality grass Lamb is sold as it reaches slaughter weight Ewe is put on poor quality pasture prior to flushing Sep/Oct Ewe put on good quality pasture for flushing Mating occurs Ewe remains on good quality pasture after mating Nov/Dec Ewe is fed for maintenance only Dec/Jan Steaming up occurs prior to lambing

Gestation (don’t write) Seasonally Polyoestrous Oestrous Sept-Feb Length 17 days Duration 36 hours Gestation Period 149 days (5 Months)

Oestrous cycle Sheep are seasonally polyoestrous. This means they come into oestrous repeatedly but only over a certain period or season of the year. This period is from early September to February The length of oestrous is 17 days The average duration of oestrous is 36 hours Gestation period is 149 days or 5 months

Oestrous cycle The declining light levels in September act on pituitary gland. This stimulates Follicle stimulating hormone (FSH) This in turn stimulates the ovaries to produce oestrogen This begins the oestrous cycle.

Preparing Stock For Mating Ewes should be in good condition – Condition Score = 3.5-4.0 High Conception rate results Technique = Flushing

Flushing This involves placing ewes on a low plane of nutrition after weaning followed immediately by a high plane of nutrition 3 – 4 weeks before mating Advantages More eggs released at ovulation (twins) More regular heat periods Higher conception rates Better attachment to uterus

Before Mating Two weeks before mating the sheep should receive their winter dip (not before 15th September) Otherwise the sheep can receive the dip a few weeks after mating. The whole flock should be dosed for intestinal parasites (worms). The wool around the tail should be trimmed to facilitate service and avoid injury to the ram.

Care of ram before mating Extra feed supplied eight weeks before mating to increase sperm reserves Shear ram two months before mating to reduce body temperature

Mating Normal breeding: ram:ewe ratio is 1:40 During synchronised breeding ram: ewe 1:10 Rams must be kept away as they will fight Dates kept = lambing date Marker dye or a raddle is used every 17 days Ear tagged if paint is on ewe 6-8 wks- all should be in lamb Suspect ram-cull

Breeding out of season This is a technique used to induce ewes to lamb early enough for the lambs to be ready for the Easter market Prices are highest at this time Lambs born from September/October matings will not be ready for the easter market. Ewes must be brought into oestrous out of season, in July or August.

Breeding out of season This involves placement of the progesterone-impregnated sponges into birth canal of ewe for 12 – 16 days. When the sponge is removed a single intramuscular injection of pregnant mares serum gonadotrophin (PMSG) is administered to the sheep. Two days later, all ewes come into heat

Sponging Ewes are introduced to the ram in early Sept. for 8 weeks Heat & served at different times- lambing protracted Oestrous can be synchronised. Sponges are impregnated with progesterone into the ewes vagina & left their for 12 –16 days. The progesterone blocks the oestrous cycle If sponges are removed simultaneously all ewes come in oestrus 2 days later & are all mated together All lambs born same time (not protracted)

Raddling Harness Detects mating behaviour in rams. Helps predict lambing date. Aids in detecting infertile ewes which is therefore useful for culling. Also identifies infertile ram. (if all ewes show 3 different colours). Colour changes every 17 days.

Learning Check.... Explain the following terms: Synchronisation. Flushing Sponging Breeding out of season. Outline the steps involved in preparing the flock for mating. What is a raddling harness?

Management of ram after mating Ram removed from flock Fed 0.25Kg of concentrates as well as grass to build up his body condition During the winter, ram is fed 0.5Kg of concentrates with silage or hay ad lib.

Management of ewe during gestation Flushing should continue for 4 weeks after mating to ensure the embryos develop properly After this fed for maintenance and BCS can drop back to 3 70% of foetal growth takes place in the last six weeks of pregnancy and ewes should be steamed up this involves placing the ewe on an increased plane of nutrition, e.g. 0.5 – 1 kg of concentrates should be fed Concentrates should contain 15% protein for essential growth, vitamins and minerals

Scanning ewes This is required for determining how much feed is required by ewe (more required if twins or triplets) Allows farmers to separate ewes carrying singles from ewes carrying twins/triplets Identifies barren ewes and these can be culled

Lambing Ewes should have BCS of 2.5 – 3.5 Ensure experienced person on hand if difficulty arises Hygiene must be maintained if lambing indoors Lambs weigh from 3 – 5 Kg when born Allow ewe to lick lamb, this stimulates the lamb’s circulatory system and allows the ewe to bond to lamb Lamb must receive colostrum Dip the navel in iodine to prevent navel and joint ill

After lambing Ewes are kept on a high plane of nutrition to ensure good milk production. Once there is adequate grass, lambs and ewes should be rotationally grazed. Provide mineral lick to prevent grass tetany. Creep feed lambs destined for early lamb or Easter market. Creep feeding is where lambs are allowed to feed on a concentrate ration while the ewes are restricted

Creep feeding

After lambing continued Tail docking is carried out in the first week of the lamb’s life. This involves removing the lamb’s tail. All lowland sheep have their tails docked / removed but some farmers just remove the ewe’s tails only. In addition, all ram lambs not intended for breeding are CASTRATED. Castration and tail docking are performed with the same tool – the “elastrator”.

Weaning Usually takes place in the months of June and July when the lambs are 16 – 18 weeks. Lambs are slaughtered at weights of 35 – 40kgs Ewes are put on low plane of nutrition in preparation for flushing.

Shearing & Summer Dip Lowland sheep are shorn before the end of May. If wool production is important to the farmer, then particular attention is given to the date of shearing and the shearing is done when the wool rises (weather dependant) Sheep should not be sheared if their stomachs are over full or when they are in heat.

Wool Production & Quality Wool fibres are modified epidermal cells. Wool fleece yields vary between 2kg and 4kg each year and contains hairs (kemps) and wool fibres. Wool fibres are solid while kemps are hollow. Ewes, hoggets and withers (castrated males) are shorn whereas lambs destined for slaughter are not. Shearing normally takes place in June. Wool Quality is determined by how fine the wool fibre is. Most wool fibres in Britain and Ireland are between 40 – 50 μm. Merino Wool is only 15 μm.

The Bradford Scale The Bradford Scale is used to measure wool quality. It is defined as: The number of hanks of yarn, each 510m long, that can be spun from 450g of wool prepared for spinning! Don’t worry about it. Know that anything over a Bradford Scaleof 60 is defined as Merino, between 40 & 58 is Crossbred and below 40 is Carpet! Merino wool is used for top quality wool products. Crossbred wool is used for tweed and carpet, well for carpet!

Summer Dip Two weeks after shearing the sheep receive their summer dip. This is to prevent “fly strike”. This refers to the blowfly or the green bottle fly, which lays its eggs in the fleece and maggots grow quickly. Six months after lambing the booster injection against clostridial diseases is administered.

Learning Check.. Outline the key stages in the management of the lamb from birth to weaning. What is the purpose of sheep dip and shearning?

Mixed Grazing of Cattle & Sheep Growth rates increase by 10-15% Tillering- a denser sward & increased DM production Flush of grass around dung is ate by sheep. This is unpalatable to cattle. Even recycling of nutrients

Learning Check... State the length and duration of the oestrous cycle. What is length of gestation? Name the phylum that sheep belong to. State the dental formula for a sheep. What is mixed farming? Give the advantages of mixed grazing.