Sheep Production
The cycle for breeding sheep for meat begins in the autumn (Sept – Dec) so that lambs are born when grass is available (Spedding 2007) is the spring. Early lambing from Dec-Mar has advantages such as more rapid weight gain, fewer problems with hot weather and parasites and lambs can be sold without being put to pasture. Later lambing (late March) advantages include fewer building requirements, lower feed costs, higher lamb survival due to better weather and lambs can make the maximum use of the available pasture (Ricketts et al 1993). Some farmers use Creep grazing for their lambs, which is when lambs are allowed to graze fresh, unsoiled areas of younger grass which the ewes don’t have access to (Spedding 2007).
Some farmers time their lambing for autumn (Sept-Dec) which has advantages such as favourable weather, lower feed and labour requirements, good prices for lambs and the possibility of accelerated breeding. Accelerated breeding is when ewes produce lambs 3 times in 2 years. So they have lambs every 8 months and lambs are weaned by 60 days at the latest so ewe’s can re-breed in 30 days (Ricketts et al 1993).This does mean, however, that ewe’s require additional supplementary feeding as they may be pregnant during times of bad pasture.
Another method of breeding is oestrus synchronisation. Ewes usually come into heat when the daylight hours become shorter (Sept, Oct, Nov). Their oestrus cycles can be synchronised by introducing them to progesterone hormone treatment for 14 days. Withdrawal of the treatment results in the ewes coming into oestrus within 1-3 days. Ovulation rate and lamb production can change with the seasons.
Table 1. Performance of Rambouillet Ewes Bred During Four Different Seasons in Texas (taken from Ricketts et al 1993)
| Breeding Intervals | ||||
| | Mar 21 – May 2 | Jun 21 – Aug 2 | Sept 21 – Nov 2 | Dec 21 – Jan 1 |
| Percentage | ||||
| Ovulation rate | 106 | 141 | 175 | 152 |
| Lamb production | 84 | 97 | 127 | 135* |
*Higher lamb production in December is believed to be due to better embryo survival at cooler temperatures.
Lambs are weaned at 12-16 weeks old. The best females are selected for future breeding and the rest are finished for slaughter. A profitable lamb flocks needs to meet carcase weights. In Britain these range from 12kg to 20kg+ depending on the breed (Anderson Unknown). The farmer needs to assess different selling options such as auction, private sale, direct consignment to the abattoir and auction plus internet based sale. They also need to consider transport costs and compare live weight price (£/head) with carcase weight price (£/kg dressed and skin price). Market specifications are often narrow so lambs sold outside the ideal weight and fat score can lose money (Court et al 2010).
Dairy Cattle Production
Dairy cattle can be bred in a few ways. 1. The bull can be in with the cows and detect when they are on heat and mate with them unaided by the farmer, 2. The bull can be kept nearby. The farmer detects when the cows are on heat and introduces the bull to them, 3. Artificial insemination. Cows are checked regularly for when they are on heat and are inseminated as soon as possible (Bonnier 2004). In modern dairy farms, cows can be fitted with an electronic tag around one leg. When they enter the milking parlour, a computer detects how far the cow has walked since she was last milked. If she has been walking a lot, then she could be on heat. If her movement has been limited, she could be injured or sick.
Cows calving in the summer months generally produce less milk compared to calving at other times of year. Calves are removed from the mother after a few hours and continue to be fed colostrums for 2-3 days (Gillespie & Flanders 2010). Females are raised for milk production and as replacements for existing stock. Bulls and dairy cows with low milk yields or cows that fail to conceive are fattened up for slaughter (Phillips 2010).
Prices for milk varies seasonally, usually with lower prices in May and June and higher prices in October to December. There is increase competition from imitation and substitute dairy products such as margarine. There is an increased demand for fluid, low-fat milk, fresh cream, ice-cream and butter. Demand is affected by population, price of dairy products and the price of competing products (Gillespie & Flanders 2010).
Beef Production
The cow-calf system of beef production is when cows are bred to produce calves, which are sold to cattle feeders who feed them to slaughter weights. Beef cows can be maintained on roughage so can go on land that crops cannot utilise. Cows generally calve in spring to coincide with the best available pasture. The oestrus cycles of the cows can be managed using hormone treatments so they call come in heat at a similar time (Jarrige & Beranger 1992). Artificial insemination is only used in about 3-5% of beef cows in the UK. Famers use the bull to detect oestrus in the cows and breed with them (Ball & Peters 2004). Calves are weaned in autumn and sold, or fed roughage through winter and sold as yearlings. Feeder calves are sold for further growth, yearling feeders are sold for finishing and slaughter. The aim of cattle feeders is to produce slaughter weight cattle in the shortest time possible (Gillespie & Flanders 2010).
Suckler herds are cows bred to produce calves which suckle all their milk up to weaning at 6-10 months. 30% of cows in the UK are suckler cows, 90% of which are beef-dairy (Jarrige & Beranger 1992) so females are often used to milk production.
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Slaughter calves are between 3 and 8 months and sold as veal. Beef cattle are usually marketed through terminal markets, auction markets and direct selling. When being taken to market, cattle can shrink so careful management and handling is needed to reduce shrinkage and damage (Gillespie & Flanders 2010).
Summary
Many farmers need to manage their animals according to seasons, such as in sheep farming as it is best for lambs to be born in spring when fresh grass arrives and weather conditions are more favourable. This is not such a problem in beef and dairy cattle, as beef cattle can be fed on roughage and on fairly unfertile land. Dairy cattle can be turned out to pasture when there is good grass.
Oestrus cycles in cattle and sheep need to be careful managed. Sheep oestrus can be synchronised using progesterone treatment, so the ram can be introduced and mate with all females at a similar time, therefore lambs are all to be born around the same time. Cattle oestrus cycles can be monitored using an electronic tag which records how far the animal walks between each visit to the milking parlour. The bull can then be introduced or the cows can be artificially inseminated. Beef cattle oestrus cycles can also be controlled using hormone treatments. Artificial insemination in beef cows is rare, the bull is usually left to detect when the cows are on heat and mate with them.
Market requirements for meat vary throughout the year depending on seasons. Meat will reach higher prices at market if it reaches a favourable carcass weight and fat score. Dairy products are in less demand due to imitation products at more favourable prices for the public. Beef can be sold live at market to cattle feeders, who buy calves to feed them and fatten them up to slaughter weight. The main methods of meat sale are auctions and direct sales to other farmers or abattoirs.
References
Anderson J (unknown) Sheep Management Matters No. 8. Planned carcase production. Meat and Livestock Commission.
Ball P.J.H. & Peters A.R. (2004) Reproduction in Cattle 3rd Edition. Blackwell Publishing Ltd.
Bonnier P, Maas A & Rijks J (2004) Agrodok 14. Dairy Cattle Husbandry. Agromisa Foundation, Wageningen.
Court J, Webb Ware J & Hides S (2010) Sheep Farming for Meat and Wool. CSIRO Publishing.
Gillespie J.R. & Flanders F.B. (2010) Modern Livestock and Poultry Production 8th Edition. Cengage Learning, Inc.
Jarrige R & Beranger C (1992) World Animal Science .C. Production-system Approach: 5. Beef Cattle Production. Elsevier Science Publishers B.V.
Phillips C.J.C. (2010) Principle of Cattle Production 2nd Edition. CAB International.
Ricketts G.E, Scoggins R.D, Thomas D.L, Thompson L.H. & Carr T.R. (1993) North Central Regional Extension Publication 240. Management Guidelines for Efficient Sheep Production.
Spedding A (2007) Discovering sheep farming factsheet. Source:www.face-online.orh.uk/resources/factsheets/discovering/sheep.doc
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