Livestock enews is derived from SAC Sheep Beef Notes. Please credit SAC with copyright if articles are reproduced in newsletters substantially unchanged. The views expressed are not necessarily those of Intervet UK ltd.
It is a sobering thought that in Scotland the biggest killer of young lambs is not infectious disease but chilling – accounting for around half of all deaths in that age group. If the weather takes a turn for the worse during lambing, shepherds may be faced with many weak and cold lambs whose temperatures have fallen below the normal range of 39 to 40°C. Thankfully research work carried out at the Moredun Institute has provided us with an effective check-list for dealing with chilled lambs.
When any lamb is suspected of being chilled it should be caught, examined and dried with a towel if wet. Subsequent decisions then depend on three things:
| the lamb’s age, |
| its ability to swallow |
| its rectal temperature as taken with either a mercury or electronic thermometer. |
Lambs of any age with body temperatures in the range of 37-39°C are generally capable of raising their body temperature to the normal level if they are dried and given a feed. These lambs should still retain the basic swallowing reflex and so can be safely fed via a stomach tube (bottle feeding is never recommended in chilled lambs due to the risk of milk passing into the lungs). Once given a meal the lambs may then be returned to their mothers in a sheltered spot where they can be easily examined later. However, if a lamb does not appear fully revived it may need to be brought indoors with the ewe for closer attention and possibly additional feeds.
Lambs with temperatures of less than 37°C present shepherd with a greater challenge and generally require a period within a lamb warming box. If less than 5 hours old the lamb can safely be placed in the warming box and checked regularly until its temperature has increased to 37 or 38°C. It should then be given a colostrum feed by stomach tube and returned to its mother, or if not fully revived retained for longer in an indoor aftercare unit.
Lambs which are older than 5 hours should never be placed directly into the warmer since they will generally have low blood sugar in addition to being chilled. If they do not receive energy in the form of carbohydrate, warming may actually produce a fatal hypoglycaemic fit. If such a lamb can hold its head up it is likely to retain the swallow reflex and can be safely fed by stomach tube. If collapsed and unable to lift its head the lamb must be given an injection of glucose solution into the abdomen. These lambs can then be safely warmed back up to 37°C before being given a feed by stomach tube and returned to mother or the aftercare unit. Those shepherds who use the glucose injection technique know how well it works and how many lambs they have saved with it. If you are not familiar with this method ask your vet the show you how its done – it will be time well spent.
Shelter is one of the most important considerations at lambing time. A variety of different methods have been used around the country ranging from straw bales to tattie boxes. Another novel alternative seen during a farm visit last year was old tyres, cut in half, which offered good shelter to ewes and young lambs. Advantages are that they are portable and can be easily moved to prevent poaching and turned to provide shelter from the prevailing wind. The bigger the tyre, the better the shelter.
Control of scab should be assisted by the reintroduction of OP dips now provided in containers with a safety tap. Note if the flow of dip concentrate stops due to an airlock, stand the can upright to let the air back in through the tap then start again. OP dips are the cheapest option where facilities are already available and the waste can be disposed of according to the groundwater regulations. The cost of injectable endectodcides is coming down as new products appear but these products are not effective against lice.
Sheep scab continues to be a problem mainly due to:
| Poor dipping technique – in the face of an outbreak plunge dipping should ensure thorough wetting of all parts. Keep the sheep in the dipper for one minute and duck the head under. |
| Missed sheep in a gather. |
| Farmers ignoring the need for treatment. |
| Misdiagnosis. Scratching can also be caused by lice which are not killed by injectible endectocides. They require a pour-on. |
| Contractors using sheep showers which are ineffective in the case of a scab outbreak. |
In-feed medication of ewe and lamb diets can be used to reduce the risk of coccidiosis
Coccidiosis
Coccidiosis occurs due to high levels of challenge in the environment and low levels of immunity. Housed lambs aged three to ten weeks are most at risk. Prevention is better than cure, so pay attention to leaking water bowls, dung contamination of feed troughs, overstocking and insufficient bedding as all these can increase the incidence of coccidiosis. Where these have been ineffective at preventing disease outbreaks it is sensible to look at the options of in-feed medication or direct medication of lambs. In-feed medication of ewe diets with Deccox to provide 50 mg/kg costs around £11/tonne of feed, for a ewe fed concentrates at 0.75 kg/day prelambing. The total cost could thus be around 22p/ewe, assuming a total pre-lambing concentrate feed of 20 kg. Medicated feed for lambs or access to feed blocks containing Deccox may also be required.
Whether lambs succumb to coccidiosis or not depends on the number of infectious oocysts they ingest in their first few days of life. Lambs pick up these oocysts from the teats and udders of ewes lying on sparse, wet, soiled bedding or from concentrates which are contaminated with faeces or from water troughs. Stress is a major contributor to the incidence of coccidiosis. Usually it occurs after a severe spell of cold wet weather where immunity is reduced due to reduced intake of feed and weather stress. Where lambs receive adequate colostrum and a good milk supply then the risk of coccidiosis is lower. An alternative to in-feed supplementation with Deccox is to treat lambs at the first signs of coccidiosis with Veccoxin at a cost of around £1/shot when the lambs are around three weeks of age. Generally a second shot will also be required.
Sheep can be stressed by dipping in cold weather and when heavily pregnant. If it is too cold or close to lambing to dip, then use an injectible endectocide to treat sheep scab. Act fast as soon as scratching is seen. The problem builds up quickly in winter and the severe reaction can cause lamb losses. Check your diagnosis; lice can be mistaken for scab and scab for lice infestation. Remember treatment does not immediately remove the itching as it is caused by an allergic reaction to the mites’ faeces which persist for some time. Don’t delay treatment.
Newly-born lambs can be humanely slaughtered on welfare grounds where they are not considered viable. Very young lambs up to 5 kg can be dispatched by a sharp firm blow to the top or back of the head. The preferred method is to hold the lambs by the back legs and hit the back of the head off a solid surface, eg wall or stanchion, using a blow delivered firmly and determinedly.
If the Foot and Mouth outbreak continues or spreads, farmers with finishing sheep will have to make decisions on whether to sell lambs on a depressed home market or hold lambs back hoping the export ban will be lifted.
Concentrate fed lambs
These cost the most to keep, gain weight the fastest and can soon get overfat. Sell when finished. If silage is available, feeding it ad lib should maintain weight and finish for about 3-4 weeks at reasonable cost. 40 kg lambs will eat about a kilo of silage dry matter/day.
Lambs on roots
Teeth generally last 6-8 weeks on roots. Lambs on roots can be stored by cutting off supplementary concentrate, particularly protein supply, but if lambs start losing teeth they may need extra concentrates to finish. In practice, the finish date can easily be extended by 3-4 weeks but longer periods than this may reduce quality.
On all systems it is important not to let lambs get overfat so that the product is spoiled. If you see a profit in lambs, take it rather than hanging on to sell overfat lambs later.
The important aspects to maximise the performance of grazing cattle are:
| grass intakes will be reduced ie the cattle will not be ad lib |
| energy intakes will fall |
| liveweight gains will reduce rapidly |
On taller swards the cattle will be eating ad lib grass but as grass heights approach 10 cm the cattle will begin to selectively graze. The ungrazed patches will then rapidly shoot, go to seed and as a consequence its feed value will fall rapidly. When this occurs in late June/July the cattle will still be ad lib but eating a medium – low quality feed – almost like feeding cattle on ad lib straw! The final results will again be a rapid reduction in growth rates.
| animals which will finish out of the house this winter. These can be kept on their current ration or, if necessary the level of supplementary concentrates even increased slightly to ensure they do all finish. |
| animals which will not finish this winter. These can be further split into possibly three groups based on when they are likely to be finished eg mid summer, late summer, or out of the house next winter. The later the target slaughter date the leaner the cattle should be at turnout. |
| significantly improved growth rates compared with cattle which remained housed on ad lib silage diets |
| does slightly reduce first cut silage yields but improves silage quality |
| improves regrowth of first cut aftermaths, increasing yields where a second cut is taken |
| the reduction in silage yield is less than the additional silage required to keep the cattle in |
In short an early turnout improves performance and reduces costs.
Potential output from grazed grass
With reasonable management it is possible to grow
1 tonne beef/hectare
over the summer. The crucial point to achieve this is to ensure the cattle always have high quality grass available ad lib.
Outbreaks of calf scour can have a devastating effect on your profitability. Obvious costs are calf deaths and treatment costs, but the unseen costs can be significant too. A study done in the North of Scotland by SAC showed that in addition to the above, labour costs to treat sick calves and subsequent poor growth rates added up to give a cost in the average outbreak of £33 per calf at risk or £3300 per 100 cow unit. Prevention is therefore vital, but problems will occur and you have to deal with them quickly and effectively to prevent losses of this size.
Prevention: This comes down to hygiene, a tight calving pattern and nutrition.
| Keep calves in groups by calving date to minimise the age range of calves in the group. |
| Provide a well-bedded creep area to give calves a warm comfortable area away from the cows. |
| Cows should receive a ration that is supplemented with the appropriate suckler cow mineral for the ration. |
| Vaccinate if you have had a problem in previous years. Discuss this with your vet. |
Treatment: Early detection and fluid therapy is essential.
| Supplement calves with an oral fluid designed for the purpose. Again your vet can advise. |
| Collapsed calves and those too weak to look after themselves should be removed from the group until they recover. |
| Intra veinous fluids by drip are vital for collapsed calves. The sooner you call the vet for this the less fluids will be required and the more rapid the recovery will be. |
Control: Identify the source of the problem and correct for next year.
| Where you have an outbreak get your vet to sample the calves to find out the cause. There may be offers available to allow lab fees to be covered. Sample 4 early cases to get the answer. The results of this will allow you to make a decision on vaccination for next year. |
| Review other factors such as hygiene, calving spread, cow nutrition and formulate a plan to correct or manage these. |
| Colostrum is essential for a healthy start. It contains a high concentration of antibody. These are proteins which give protection against some of the common infections the calf will contact in the first few weeks of it life. |
| Colostrum is also rich in vitamin A and vitamin E. Calves are born deficient in both these vitamins and must have good quality colostrum or they will continue to be deficient and as a result be more susceptible to infections and are also at risk of white muscle disease. |
| Colostrum is a vital energy source. Calves which do not get a good feed of colostrum will be energy deficient and at risk of developing hypothermia. This becomes critical if calves are born outside in wet conditions. |
| Calves need 10% of their body weight in colostrum in the first 12 hours of life. This translates as three feeds of 1.5 litres. |
| The goodness of colostrum declines rapidly after 12 hours. Therefore if you want to store colostrum you should only take colostrum from the first milking after calving. |
| Frozen colostrum maintains its goodness provided it is not over heated when thawed. Once the temperature exceeds .........°C the 1/3rd or the antibody content will be destroyed. |
| Artificial colostrum products compare poorly with the real thing. They should only be used as a top up. |
| Calves which have had a difficult calving may not suck. Be prepared to milk the cow and feed the calf by esophageal probe if necessary. |
Many factors combine to reduce conception rates, extend mating and calving periods, and increase the number of barren cows within the suckler herd. Choice of calving date, breed or crossbreed and other less specific aspects of husbandry, such as general handling and stress, all combine to influence fertility. The factor that has the greatest effect on cow fertility, however, is the presence of her suckling calf. The beef cow can be induced to ovulate very soon after calving (around 4 to 5 weeks) by simply restricting calf access to 10-15 minutes once or twice daily. First heat is invariably silent and, in around three-quarters of cows, followed by a short cycle of around 2 weeks. Subsequent and successive heats are normally overt and conception rates improve with each successive heat cycle (Table 1). Using this strategy there is no reason why all cows shouldn’t become pregnant within the 12-week period following calving needed to maintain a tight calving pattern. Calf performance does not suffer provided creep feed is made available.
Table 1. Conception rates in relation to oestrous cycle number from calving
Oestrus number |
Conception rate (%) |
1st |
35 |
2nd |
50 |
3rd |
73 |
4th |
72 |
5th |
100 |
Although this concept is supported by a number of studies, responses to restricted calf access between studies have been quite variable. Recently, we at SAC Aberdeen tested the theory that one factor contributing to this variability was the nutritional wellbeing of the cow. Sixty-four beef cows were placed on different levels of feeding both before and after calving, and subsequently categorized as being of low, moderate or good nutritional status, based on certain metabolic parameters measured from blood samples collected at weekly intervals following calving. Results indicated that the interval from calving to first ovulation decreased as the nutritional status of cows improved (Table 2). This interval was also dramatically shorter for cows that were suckled once daily than for cows that had free association with their calves. The response to and the benefit from calf restriction, however, were dependent on the nutritional wellbeing of the cow. Poorly nourished cows had most to gain from restricted calf access, but relatively few responded to the technique. In contrast, well nourished cows responded positively to the technique, but gained little benefit from it due to the fact that most well nourished cows with free calf access to their calves also ovulated early. Only moderately well fed cows (around half of those on trial) could be categorized as both having responded to and benefited from restricted calf access.
We conclude from this study that acute calf isolation and restricted suckling from around week 4 after calving offers a non-pharmacological means of inducing beef cows to ovulate early and regain cyclical activity at the optimum time after calving for increased herd fertility. To respond to this technique cows need to be in moderate to good nutritional status. This is best achieved by ensuring that cows are in moderate body condition at calving (2.5 to 3.0 units) and fed to appetite during the first few weeks after calving.
Table 2. Days from calving to first ovulation
Nutritional status |
|||
Calf access |
Poor |
Moderate |
Good |
Free association |
83.1 |
64.0 |
44.2 |
1 x daily suckling |
67.9 |
38.0 |
33.2 |
Difference |
15.2 |
26.0 |
11.0 |
French research workers have recently produced information showing the effect of cow age on the milk yield and liveweight for pure Saler cows.
Change in liveweight and milk yield with age for Saler cows (INRA)
As would be expected liveweight, measured post calving in the spring, continued to increase through to nine years of age. However the increase was relatively small from 3rd calving onwards at only around +5 kg per year.
In comparison, maximum milk yields were reached with 4th calvers which produced around 25% more milk compared with first calved heifers. Interestingly milk yield declined from 4th to 7th calvers by around 10%. This suggests that calf weaning weight will peak for 4th calvers and thereafter continually decline by around 5 kg per year. This trend quantifies one of the hidden costs of retaining very old cows rather than replacing them.
Currently there is renewed interest in recording the performance of beef enterprises, including suckler herds. A typical comment would be “how can we improve if we don’t know what we are doing at the moment?”
Why record?
In the UK there are two reasons for recording beef cattle:
Records which do not fulfil one or both of these requirements should not be kept.
Using records to improve profitability
Simply keeping records will not improve profitability. This will only be achieved if records are analysed and appropriate management changes made.
The problem with beef records is that a lot of the useful information has to be calculated from the original records – a good example being daily liveweight gains. The second problem is that often the same records need to be examined in different ways. A good example would be individual dates of calving for a suckler herd. Some of the comparisons between groups we would need to make in their average date of calving in any year could be:
| homebred cows versus purchased cows |
| cows mated last year to bull A compared with cows mated with bull B |
| first calved heifers compared with mature cows |
| fat cows compared with thinner cows |
| cows which had a difficult calving last year |
Such calculations and grouping of figures in different ways is of course what computers do accurately and instantaneously.
What records do I need to keep?
A considerable amount of valuable information can be produced using the records we all already collect for either legal, subsidy or tax purposes. To me it is therefore sensible to concentrate on getting the maximum use from this data before going out and collecting even more. As an example we can use the information needed to fill in an application for a calf passport.
Records available from registering a calf
The date of birth of the calf is the date the cow calved and from this we can calculate the calving interval ie number of days since she last calved, her calving order ie whether she calved early or late in the calving period, her parity, whether she is a fourth or eighth calver and obviously if she has no calf then we can assume she is barren.
For the calf itself we will obviously know when it was born and hence in the future we can calculate its age exactly. In addition of course we will also know its sex and which bull sired the calf. If the calf is a future heifer replacement then the same data will provide us with information on the exact age of the cow throughout her lifetime in the herd as well as knowing the exact breeding of her dam and sire.
Next month we will look at the information which can be calculated from normal disposal or cattle sale records.
The BCMS went on-line on 19 February 2001. Farmers with access to the internet will be able to apply for cattle passports on-line and be able to access and update their Cattle Traceability System. To do this they need to use their user ID sent out in a letter on 15 February from BCMS.
Not got a computer?
Even if you do not own a computer now, do not throw away the letter with the ID number. You may get a computer in future or need to use a third party to order passports or check the database. They will need the ID number, so it is important to keep it in a safe place.
As at March 8th, day 17 of the UK foot & mouth outbreak, the total number of confirmed cases stood at 106. Chief Veterinary Officer, Jim Scudamore, warned the industry that "we will not see the disease disappearing at the end of this week and this outbreak is going to last for a long time. If, over a period of weeks, the daily figures start to go down then that might be an indication of a peak". Although this statement contradicts an earlier announcement made by the Deputy Chief Veterinary Officer, Richard Cawthorne, to the European Commission at the start of the week that there were signs that the disease had peaked, it is made in the light of 15 new cases being confirmed on Wednesday, the highest daily count so far. Farm Minister Nick Brown, is reported to be "disappointed" at the continued spread of the disease but remains confident that keeping the right measures in place will eventually reap rewards. The NFU continues to lobby for an easing of movement restrictions that would allow farmers to muster outlying sheep on welfare grounds for assistance with lambing.
Licensed movement of stock direct from farm to abattoir has started in an effort to maintain supplies of UK fresh meat in the supply chain. Expectations of improved prices in the light of restricted supplies were rapidly dashed when prices below those prior to the outbreak were quoted as processors sought to offset their increased veterinary and hygiene costs.
Average finished cattle prices started the month of February at around 87p/kg/lw.
Pressure mounted on the government to ban imports of beef from Germany in the light of further discoveries of meat destined for processing in the UK that was found to be contaminated with spinal cord residues. Nick Brown has insisted that any ban can only be implemented in response to a request from the Food Standards Agency. There are concerns that fragile consumer confidence will be undermined by news of potentially infected meat entering the food chain.
Movements in GB Finished Cattle Prices
Medium steers (465-555kg live-weight)
Auction Market Throughput of Cattle
(via MLC monitored markets)
Average finished lamb prices started the month of February at around 114.9p/kg/lw.
The results of a survey of lowland lamb production undertaken by Exeter University revealed significant variation between the top-performing flocks and others in the survey - the conclusions being that there was scope for improvement in both the technical performance and the marketing of many flocks.
Publication of MAFF's December 2000 census data is expected to reveal a contraction in the UK national flock as marginal producers have taken advantage of strong cull-ewe prices to exit the industry.
Movements in GB Finished Lamb Prices
Standard weight (32.1-39kg live-weight)
Auction Market Throughput of Sheep
(via MLC monitored markets)
Average finished pig prices started the month of February at around 95.9p/kg/dw (eurospec average).
EU pigmeat prices were widely expected to improve as consumers seek alternatives to beef. With confidence returning to the German sausage market, cull sow prices were expected to improve.
The MLC's controversial advertising campaign promoting the unique welfare attributes of British meat were judged to be misleading and untruthful in a ruling from the Advertising Standards Authority - the MLC has been asked to withdraw the campaign and to avoid misleading consumers in the future. In response, the MLC stood by the claims of the campaign and explained that the promotion had run its course and it was not intended to run the advertisements again.
Movements in GB Finished Pig Prices
Eurospec average
Auction Market Throughput of Pigs
(via MLC monitored markets)
© The Scottish Agricultural College 2000 ISSN 0956 1900
Produced by The Scottish Agricultural College, Farm & Rural Business Division, Greycrook, St Boswells,
TD6 0EU
SAC receives financial support from the Scottish Executive Rural Affairs Department