Sheep Management Plan for Roseworthy Lamb Enterprise
Created 2010

Source: Orrie Cowie Merio and Poll Merino Stud (2010)
Project goals: * Mate Merino ewes with Poll Dorset rams to produce 900 --24kg export lamb carcass * Maximise profit on wool and lamb export carcass * Aim to produce at least 900 Merino x Poll Dorset lambs for export
Key performance Indicators from Roseworthy feed demand calculator (2010) * Liveweight produced , sheep =140 tonnes * Liveweight produced per hectare allocated to sheep =281 kg/ hectare/ year * Pasture demand as % of pasture growth =55% * Pasture deficit, using freshly grown supply= 1000 tonnes / year * Pasture deficit, using supply with carryover = 353 tonnes / year
Scope of Plan * Part 1: Manage pasture growth at Roseworthy * Part 2 : Manage reproduction of Merino ewes with Poll Dorset rams * Part 3: Lamb finishing strategy * Part 4: Manage wool quality of Merino ewes
Abbreviations
Merino ewe: ME
Poll Doset ram:PDR
Merino X Poll Dorset lamb: MxPDL
Prediction calculations : * 900 Merino ewe (each around 50-60kg; average 55 kg liveweight)=55x900=49500 kg * 900 Poll Dorset ram (each around 60-70kg; average 65kg liveweight )=65x900=58500 kg * Predicted at least 900 lambs produced , each will be slaughtered at 21 weeks of age at 50kg= 900x50= 45000kg * Hectare of land needed per year : = 545 hectare of land /year

Part 1. Management of pasture growth at Roseworthy
Pasture management is important to produce food for ME , PDR and MxPDL. A high fertility pasture farming approach is chosen in order to meet the key target total sheep live weight 140tonnes (140,000kg). It is recommended that

per hectare allocated for sheep is 281 kg/hectare/ year (Figure 1.2). Pasture from Roseworthy provides enough feed supply from April to November (Figure1.1), stocking rate could be increased during this period of time. However, during summer in December, January, February and March, the sheep would not have enough pasture to consume unless supplement such as lupin grain is fed. The high fertility pasture decreases the pasture demand. The average pasture utilization is 55%, good enough to maintain the weight of Merino ewe and Poll Dorset rams before mating (Robertson, 2005). To maximize profitability, all weaned young lambs should be sold at October.

Figure 1.1 High Fertility system in Roseworthy, the light green line shows the pasture supply if you graze it as fast as it grows. Dark green shows the pasture supply if you can forward surplus pasture to the next month.
Source: Roseworthy Feed demand calculator (2010)

To maximize profitability, pasture should be kept in phase 2 (rapid growth due to high leaf area, 3-5 cm in height, digestibility 1100-1800 kg/hectare of dry matter) (refer to Figure 1.3) whilst green (May-October) (Prance, 2010), pasture should be ration during summer (Prance, 2010)

Figure 1.3 Phases of pasture growth Source: Prance (2010) A 70% ground cover should be maintained for fertilizer and grazing (Prance, 2010). During winter,
20-30% pasture should be grown with simple rotations, grow extra feed to store up hay for summer (Prance, 2010). Establishing a simple 4 paddock system speeds up pasture growth and minimizes management, time, lambing, water, shelter, cost problems (Prance, 2010). A way to reduce supplementary feeding cost is to establish saltland pastures in Roseworthy as it contains an off season feed supply high in crude protein and micronutrients which can absorb summer and autumn rain (Thomas et al, 2009). Saltland pasture maximizes the flexibility for feeding sheep during summer when little pasture is available (Figure 1.1) (Thomas et al, 2009).On highest yielding pasture, the metabolisable energy (ME) is $360/ hectare according to the replacement plan of purchasing lupin grain as supplement (Thomas et al, 2009).

Table 1.1 Quantity of live medic pasture (kg dry matter /ha) at different heights needed to maintain the weight of different class of sheep. Quantities refer to the quantity harvested at ground level using blade shears, and assumed to be accessible for grazing. Estimated using GrazFeed , assumes 80% digestibility. Assume 1000kg DM/ha of dead cereal stubble, 2cm high, 35% digestible, is also present. | Pasture height | Pasture height | Pasture height | | 1cm | 2cm | 4cm | Unmated ewe (60kg) | 550 | <100 | <100 | Ewe 130 days pregnant | 1250 | 700 | <100 | Ewe peak lactation | 2100 | 1550 | <100 | Prime lamb weaner (growing at 200g/day) | 1300 | 700 | <100 |
Source : Robertson (2005)
It should be aware that there is a minimum quantity of live pasture (harvested using blade shears) at different heights to keep sheep of different age in good shape throughout the year (Table 1.1). Our company target to raises Merino ewes mated to Poll Dorset rams to produce 24kg export carcass. Therefore, the pasture height should be kept between 1-4 cm, our company should pay attention to Table 1.1.
The type of pasture grown affects digestibility of feed by sheep. As digestibility declines, the energy content of the feed eaten and the quality of feed sheep can eat decreases, causing slower growth rate (Robertson, 2005). It is recommended our company should keep sheep in pasture with high percentage of legume (Robertson, 2005) as sheep growth rate would be faster (Robertson, 2005). The pods produced by legumes such as medic are valuable for sheep when annual pastures are dead during summer (Robertson, 2005). The company should not provide cereal stubble to sheep when live pasture is available, cereal stubble has less than 50% digestibility which is even lower than dead leaf at harvest (Robertson, 2005). Before autumn, sheep rely on the quantity of grain and live weeds, rather than dead cereal (Robertson, 2005). During pregnancy of Merino ewes, weight loss should be prevented as it can cause factors that reduce profit such as pregnancy toxaemia, reduced stable strength, low milk production, death (Robertson, 2005). Our company should also take into account the example of things could be done to improve conversion of current pastures into wool or meat, increase the productivity of existing pastures, and improve pasture productivity by introducing more productive species (Table 1.2) (Prance, 2010).

Table 1.2 increasing feed utilization Priority | Cost | Example | 1. Improve conversion of current pastures into wool or meat | Low cost $1-$10/ha | Pasture AssessmentTime of lambingWeaner managementGenetics Sheep sale times Flock structure | 2.Increase the productivity of existing pastures | Moderate cost $20-$50/ha | Weed controlRotational grazingFencing and water Fertilizer | 3.Improve pasture productivity by introducing more productive species | High cost $150-$250/ha | Sowing newPasture varieties or renovating existing pastures |
Source: Prance (2010) 2. Management of reproduction –timing of mating, lambing and weaning (500 words)
The reproduction efficiency of the flock is determined by its fertility , fecundity and lamb survival rate. (Cottle ,1991).
Higher reproduction rates on wool producing properties allow higher culling rates and more rapid genetic improvement, and increase the number of surplus animals available for sale. (Cottle, 1991)
Reproduction rate for Merino flock in Australia is low (Lindsay, 1988)
Reperductive performance in ewes are defined by lamb marking and lamb weaning percentages ( the number born alive at lambing per ewe joined); fertility ( the proportion of ewes in a flock that actually lamb), the fecundity of polificacy (the average litter size among ewes that do lamb).
Time of mating (150 words )
Merino flocks drift gradually towards anoestrus in October –December, some Merino strains continue to cycle all year round (Cottle, 1991). During June to February, Merinos can be stimulated to ovulate by the ram (Cottle, 1991). Merino reproductive performance is superior after autumn (Cottle, 1991). Poll Dorset has a less rigid defined breeding season (Cottle, 1991).
Before mating, joining occurs. Joining is the act of putting rams out with the ewes (Elliott , 1996) . Mating is the act of copulation. Mating take place during joining.
Before breeding, the poll Dorset rams should be inspected frequently to ensure the condition of tossle , testes, teeth, toes are healthy (cottle, 1991). The poll Dorset Rams should beshorn twice a year and dipped at the shearing furthest away from joining (Cottle, 1991).

The reproductive organs of ewe function in (oestrous cycle) repetitive cycles of 15-18 days duration (Cottle, 1991) . When the ewe is in heat or in oestrus during the 20-35 hours, each oestrous cycle of the ewe will accept and actively seek out the ram (Cottle, 1991). At oestrus, there is an increase blood flow and capillary permeability, the uterus becomes pinker and more turgid or less flaccid (Cottle, 1991). The ewe only shows sign of oestrus when the ram is present (Cottle, 1991). Ovulation occurs about 30 hours after the onset of oestrus (Cottle, 1991). The Merino usually sheds one ovum(Cottle, 1991). Ovulation rate peak at autumn equinox, but may remain near maximal for some 2 months thereafter (Cottle, 1991). In South Australia, ovulation rate of ewe is usually highest in summer and falls until April with declining body weight and “net nutritional status” (Cottle, 1991).
Ewes are seasonally polyoestrous, they only exhibit oestrous cycle from February to June in Australia (Cottle, 1991). Merino ewes in this case often bred in spring and early summer in Australia (Cottle , 1991).
Pregnancy is 5 months. The sheep is called a short day breeder , the stimulus control the onset of breeding activity is the decrease in the ratio of hours light to hours dark (Cottle, 1991). It takes 6-10 weeks of decreasing light : dark ratio to stimulate breeding , and breeding activity often ceases within 1-3 months after winter solstice (Cottle ,1991). Most breeding activity occurs in March to April (Cottle, 1991). The successful pregnancy rate is 90% (Cottle , 1991).
Puberty is reached usually in late summer-autumn (Cottle, 1991).
Poll Dorset rams do not have a defined breeding season (Cottle, 1991). Rams have a constant gonadal hormone secretion after puberty, since they do not exhibit similar cyclical breeding activity.
If possible , selection for twining can maximise profit , often twin born ewes have superior reproduction rate , fewer fertility and fecundity (Piper and McGuirk, 1976).
Merinos have a low lamb marking percentage, less than 1.3 % (Cottle, 1991).
Merino ewes within the range of body weight of 35-50kg, increases about 2-4% in ovulation rate and twin lamb born per 100 ewes joined occur for each additional kilogram of liveweight at joining (Cottle, 1991).
Ovulation rate and litter size in Merinos increase with age , being lowest in maidens and highest at 6-7 years (Cottle, 1991), therefore selecting Merino at 6-7 years old can maximise profit.
Before mating, it should be aware that raised testicular temperature causes serious, deleterious effects on spermatogenesis (Fowler , 1976). The poll Dorset rams should be kept under shade and leave undisturbed (Cottle, 1991).
If Artificial insemination(AI) is used, the ewe should be inseminated about 10-20 hours after the onset of oestrus (Cottle, 1991). It is recommended AI to be used as possible, as AI maximises the number of lambs born compare to natural Mating (Maxwell, 1984). Natural mating allows an average of 22 lambs born in a year by 33 ewe/ram ; AI can allow 12000 lambs born per year by 25000 ewes / ram (Maxwell, 1984).

Lambing(150 words)
The length of pregnancy in the Poll Dorset x Merino cross bred last for 147 days (Cottle, 1991). Usually the lamb is expelled head first with nostrils and feet of the forelimbs first appearing together through the cervix and then the vulva (Cottle, 1991). After the the birth of lamb, it is essential to make sure it does not suffer from anoxia or oxygen deprivation , associated with transition from placental to pulmonary respiration (Cottle, 1991). After 0.5 – 8 hours , the foetal membrane and placenta are expelled (Cottle , 1991). Most ewes empty the placenta between 2 to 4 hours after birth (Cottle, 1991). Lambing is a long process that is usually spread throughout day and night, partition occurs in 3-6 hours. After lambing, the uterus undergoes rapid shrinkage, to return to the size of a non-pregnant uterus within 30 days (Cottle, 1991).
Lambing ewes should be inspected every 24 hour or 12 hour , new lambs are caught and tagged . Lamb borned as twins may be identified with less interference by spraying a solution of dye onto them from a distance .
Before lambing, it is essential to manage adequate nutrient for the pregnant Merino ewe so that it is not underweight or overweight. Ewes with high fat levels would have a greater incidence of damaging lambs, having stillborn lambs, lamb dying in less than 12 hours to 72 hours (Holst et al, 2002). Ewes that are underweight would have a higher risk of lesion (Holst et al, 2002). To prevent this, luprin grains (high in protein and energy levels) should be fed to the Merino ewe for 2 weeks before and during joining (Cottle, 1991). (Kleemann et al, 1984).
Spring lambings produced 15% more wet ewes, 25% more twins mothered and 33% more lambs weaned (Dun et al, 1960).
During lambing, supervision should be carried out. The producer should inspect lamb ewes once or twice a day , provide assistance to and take note of ewes that are having difficulty(Cottle, 1991). Producer should constantly return to check out of the ewe needs further assistance (Cottle, 1991). The ewe should be approached quietly and the position of lamb within the vagina, cervix and uterus has to be determined(Cottle, 1991). The producer’s hand should be washed, examination should be done with ewe lying on her side. Provide assistance by applying gentle traction to the portion of the foetus protruding through either the cervix or vulva to complete its expulsion from the ewe or reposition a malpresented foetus within the uterus so delivery can occur. Reposition the lanb so that the muzzle and two forelegs are present ed or rtwo hindfeet and tail are presented ( foetus is drawn out tail- first). Carry a bottle of vegetable oil or liquid paraffin to provide extra lubrication .

Weaning (150 words) Weaning is the process of separation of young from mother, accustoming lamb to green material, losing its need to suckle mother’s milk. Merino x Poll Dorset ram lambs need to be weaned before 5 months old; otherwise there is a risk that the Merino ewes become pregnant to their sons which would cause genetic disease (Cottle, 1991). To achieve a 24kg lamb export carcass, lambs should be weaned when they are 3 months old (Elliot, 1996).
During weaning, all lambs should be drafted from the ewes and transferred to separated paddocks (Elliot, 1996). It should take place at shearing to save trouble (Elliot, 1996). Lambs should be assembled in the paddock they were used to . This minimise stress and gets the lambs ready to the abattoir for slaughter.

Production goals need to be achieved: * No periods of undernutrition in early life so serve as to depress production in adult life * Post weaning survival not less than 95% * Supplementary feeding kept to a minimum
Pre-weaning nutrient needs to be adequate (Cottle, 1991).
Time of lambing, season birth, stocking rate (cottle, 1991)
After 6 weeks of age, lamb growth rate depend on green material, feeding lamb 40% clover would have higher growth rate and wool production (Reed 1972; Ulyatt 1971).
Weaners should also be fed grass and medic dominance(Elliot, 1991). They should have plenty of room to move around.
Sheeps should be weighted to ensure they are over 24 kg.

3. Lamb finishing strategy (500 words) * Finishing is defined as the growth and fattening required to prepare lambs for market (Ross, 1989). Lambs require some fat on the carcass and within the carcass and within tissues in order for the meat to have flavour and eating qualities required by consumers (Ross, 1989). * The 24kg export lamb carcass is exported; it must have covering fat to yield a satisfactory carcass (Ross, 1989). * After 1890, 97% of lambs slaughtered are under 1 year old. *

* Slaughtered lambs must weigh between 48-52kg , have minimum 1.3mm fat over loin (Ross , 1989). * If they have creep fed and are suckling a good ewe, they should reach the weight and finish by the time they are 5 months old. * 40-60% of the lamb go directly to slaughter * “Feeders” are the remaining lamb must be grown, developed and finished before they can be marketed. These lambs are called feeders, because most of them will be put in the feedlot or on the excellent pasture before they are marketed and subsequently slaughtered. * Some lambs were classified as too small and thin for slaughter, these are sold at low price. * Large quantities of waste production call screening, small grains of wheat are screened out; the process is inexpensive and profitable.

Lamb finishing * Lamb finishing varies from year to year * Depends on weather conditions during grazing season * Summer pasture condition is favorable , lamb may come off pasture later in higher condition * High percentage are sent directly to slaughter * Reduces the number of feeder lambs

Lamb finishing characteristics 1. Lamb finishing is seasonal , most feeders put feedlots in September, October, November. 2. Lambs are fed for a short time 50-70 days 3. Lambs gain faster relative to body weights , more efficiently than cattles 4. Narrow spread between price per hundred as feeders and finished lambs 5. Lambs are sensitive feeders, skill is required to finish them 6. Death loss are higher than cattle 7. The market discriminates against under finished or overweight carcasses. Ram lambs and undocked lambs are penalized . 8. Live lambs , carcass , cuts may be transported great distance from feedlot to retail markets.

* Lamb feeding can be used to change thin, light lambs to animals suitable to slaughter .

4. Management of wool quality of ewes (including timing of shearing)(500 words)
Shearing should not take place before mating, since some fleece protects rams fro radiant heat (Cottle, 1991). However , a heavy fleece would reduce mating activity and impair sweating and cooling of scrotum (Cottle, 1991). It is best to shear when rams are first mated and are carrying 3-4 months’ wool , the scrotum should not be shorn (Cottle, 1991).

Botkin et al , 1988)
Diameter or fitness –important, governs the minimum thickness ( spinning limit ) of yarns that can be spun . A minimum number of fibres is required in a cross section of yarn for it to be strong enough for knitting or weaving . the finer grades of wool can be spun into finer yarns than coarser grades .
Blood system – used to describe the proportion of fine wool (Merino or Rambouillet) breeding represented in a given fleece, clip or lot
Wool from pure breed Merino or Rambouillets were called “fine”.
Micron system –describe average fiber of wool, derived by common usage from micrometer (10 -3 mm or 1/25400 of an inch).
Advantage : objective measure , describes wool fiber diameter on a continuous scale rather by categories
Objective measures of wool fibre diameter ae considered accurate to no more tha +0.4 µ and spinning count grade breaks are described at 0.01 µ level

Fine wool breeds: Marino, Rambouillet, Debouillet
Medium wool: Columbia, Corriedale, Panama, Targhee, Montadale, Suffolk, Hampshire, Dorset, Oxford, Southdown, Cheviot, Finn, Polypay, Clun Forest, Ryeland, Tunis
Coarse or long wool: Lincoln, Cotswold, Leicester, Romney, Black-faced Highland, Barbados
Merinos (Botkin et al , 1988) * Produce heavy shearing fleeces that grade 64’s spinning count of finer * Wool attractive in appearance * Unsurpassed in quality for use in the manufacturing of clothing materials * Can live and produce in climatic extremes and under relatively poor feed conditions * Gregarious , will breed at nearly any time of the year

Shearing and timing
Danger of shearing
Shearing is a risk for sheep.
Cuts made in skin by shearing equipment may be severe enough to require surgical stitches.
If cuts are close to leg tendons, the sheep may become permanently unable to walk properly.
Deep cuts in neck can cause excessive bleeding or death.
Cutting of teats and vulva of ewes or the sheath of rams, these sheep become non-productive , they have to be removed. Small cuts or nicks in skin leaves sheep vulnerable to fly strike or maggot infestation or local and secondary infection.
Second cuts –the cuts where the sheep moved or the shearer was out of position , are usually the cuts that cause pain in sheep,
Stuff need to be aware when shearing: holding the sheep in position that insure the skin of animal being stretch tight on the part of the body being shorn, making each stroke with the shearing hand piece as long as possible , keeping ends of the teeth of the shearing comb on the skin of the sheep throughout every stroke .
Other management issues need to be aware: * Keeping shearing equipment in good condition * Providing a clean , smooth surface on which to work * Penning the unshorn sheep close to the shearing space * Good technique of holding a sheep * Making the strokes with the shearing handpieces * Shearer use right hand to shear, left hand aids in tightening the skin on the area * Left elbow and forearm supplement the legs , feet and knees of the shearer in maintaining sheep’s body in correct position. * Sheep’s legs cannot be held forcibly in a cramp position beyond a limited time without causing the sheep to struggle * Front feet kept from touching the floor

Good management: * Tagging ewes before breeding and lambing * Correcting wool blindness—winter wool growth on faces of sheep blocks sheep eye sight causing sheep to be blind. Blind sheep are less alert, do not get their share * Tagging feeder lambs , tagged lambs are cleaner , healthier and more attractive at the close of the feeding period * TIMING----Summer shearing –ewe lambs should be sheared in early summer , sheared lambs do better during hot weather , develop faster than unshorn ones. * Shear only when sheep are dry * Shear on clean floor * Keep shear fleeces clean * Roll and tie fleeces with flesh side out * Use only paper fleece ties * Pack off fleeces or parts of fleece (those exceedingly different from bulk of clip ) separately . These include black fleeces , fleeces from black faced sheep , fleece from dead sheep , crutchings , dung locks, sweepings * Mark bags to identify type of wool in each * Store in dry place

References
Botkin, MP, Field , RA & Johnson , CL 1988, Sheep and Wool Science Production and Management, Prentice Hall, Englewood Cliffs, New Jersey
Coop, IE, Neimann-SØrensen ,A, Tribe ,DE (eds) 1982, World Animal Science C Production System approach 1 Sheep and Goat Production , Elsevier Scientific Publishing Company , Amsterdam -Oxford -New York
Cottle, DJ 1991,Australian Sheep and Wool Handbook, Inkata Press, Melbourne
Dun , RB ., Ahmed , W., and Morrant, AJ (1960) Annual reproductive rhythm in Merino sheep related to choice of a mating time at Triangle , central western New South Wales. Australian Journal of Agricultural Research, 11, 805-826
Elliott , M 1996, Sheep production , Richard Lee Publishing
Finn,J 1990 Sheep production guide, NSW Agriculture Home study program production series , New South Wales Education and training foundation PTY Limited , NSW Farmers
Fowler , DG (1984) Reproductive behaviour of rams. In “Reproduction in Sheep” edited by DR Lindsay and DT Peare , 39-46 (Australian Academy of Science: Canberra)
Holst PJ, Fogarty NM, Stanley DF (2002) Birth Weights, meningeal lesions, and survival of diverse genotypes of lambs from Merino and crossbred ewes, Journal of Agricultural Research, 53, 175-181
Kleemann DO, Dolling HS, Ponzoni RW (1984), Effect of breed of dam , type of birth and sex of lamb on efficiency of conversion of food to lamb and wool in Merino, Poll Dorset X Merino and Border Leicester x Merino Ewes , Australian Journal of Agricultural Research, 35, 579-594
Lindsay DR (1988) Breeding the Flock , Inkata Press: Melbourne
Maxwell, WMC (1984) Current problems and future potential of artificial insemination programs . In “Reproduction in Sheep” , edited by DR Lindsay and DT Pearce, 291-298 (Australian Academy of Science :Canberra)
Orrie Cowie Merio and Poll Merino Stud (2010), Sire of Influence, retrieved 26th October,2010, from http://orriecowie.com.au/sires.htm
Piper , LR and McGuirk BJ (1976), Age effects on the difference in reproductive performance between twin and single-born Merino ewes , Proceedings of the Australian Society of Animal Production, 11: 105-108
Prance, T 2010, Lecture notes for Livestock production, Pasture Slide 1 2010, pasture slide 2 2010, Senior consultant , pastures and grazing management, Victor Habor, Rural solutions
Robertson, S 2005, A photographic guide to annual pastures for low –rainfall sheep production , Primary Industries Research Victoria, Department of Primary Industries
Ross ,CV 1989 , Sheep production and Management , Prentice Hall, Englewood Cliffs, New Jersey
Speedy, AW (1980) Sheep production Science into practice , Longman Handbooks in Agriculture , Longman, London and New York
Thomas DT, White CL, Hardy J, Collins JP, Norman HC (2009), An on-farm evaluation of the capacity of saline land for livestock production in Southern Australia, Animal Production Science, 49: 79-83