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Management of the dairy cow

 

There are thousands of dairy farms around the world with different farm plans and management strategies. Climate, market conditions, traditions, breeds etc. affect the running and planning of the business. If we try to categorise and generalise the world wide dairy operations, we relatively easily find three main "types" (see picture below). The American type (North and South America) is characterised by large loose-housing operations, total mixed ration feeding (TMR) and relatively many employees. However, dairy farms in Northeast US and parts of Canada differ from the typical American operation. There you find many smaller family farms with either loose-housing or stanchion barns. These operations are quite similar to the European type, which is characterised by relatively small operations where each cow is fed and treated individually.

Management types in different parts of the world.

 

The third type is mainly found in New Zealand and Australia. The dairy operations in this area are usually run in a very extensive way, relying to a great extent on grazing. Due to the climate and local restrictions, New Zealand and Australian dairy farmers do not rely on concentrate use so much. On top of that, the milk market is deregulated and the prices follow the world market price (WMP).

When you look closely at all these farm types, they share many underlying principles. Regardless of management strategy, farm size or local climate, the cow has to calf, produce milk, eat, be kept in good health status etc. The goal for any dairy farm should be to maximise profit per unit of milk within farm constraints and, in some parts of the world, within milk quotas. To be able to do so, we need to know how to manage the cow and how different production aspects interact with each other.

 

Feeding .

As the dairy cow.s genetic potential is increasing, feeds and feeding strategies are becoming more and more important. It is well known that the amount of milk to be produced is highly influenced by the amount and quality of the feed given to the cow.

It is also possible to influence the milk composition through the feeding. As the cow normally experiences a shortage of nutrients in early lactation, it is of importance to feed the cow a well balanced diet in order to maximise the dry matter intake. An unbalanced diet increases the risk for metabolic disturbances and weight loss, which have a negative effect on the milk yield. Healthy cows will also make the transition from dry to peak easier.

The cow's largest compartment is the rumen (see picture below). Together with the reticulum, it has a total volume of approx. 150.200 litres. In these two compartments, there are billions of micro-organisms. They help the cow to digest and utilise the nutrients in the feed. To reach a good feed utilisation, and in the end a high milk yield, the micro-organisms have to have optimal conditions. (For more detailed information about feeding and nutrition, please see Efficient Feeding and Efficient Calf Management.)

The digestive tract of the dairy cow.

 

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Managing feeding

One of the primary keys to a successful dairy operation is a good nutrition program. Not only is nutrition one of the highest input costs (about 50% of the total costs), but it also controls theresults of milk production, reproduction and health.The basis in all feeding programs is the roughage and a common

recommendation is that this shall account for 40.60 percent of the total dry matter intake. A cow.s intake per day is limited, and it is therefore important to know the dry matter and nutritional content of both the roughage and concentrate. However, the cow.s daily dry matter intake is dependent on her stage of lactation. The intake will gradually increase after calving, to reach its peak approx. 6.12 weeks after calving.

When all the feedstuffs (including roughage) have been analysed, we have to make sure that each cow gets what she need in terms of energy, protein, minerals, vitamins and water. To do so there are a number of feeding strategies and systems to choose between. Their common trait is that the roughage intake is controlled through the distribution of concentrates. The more concentrates that are supplied, either separately or in a mix with the roughage, the less roughage the cow will eat.

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Feeding strategies

Ad libitum feeding

Ad libitum feeding simply means that the animals have free access to the feed and are allowed to eat as much as they want. The roughage is often fed ad libitum regardless of the strategy used for feeding the concentrates (flat rate feeding, challenge feeding and feeding to yield). However, by mixing roughage and concentrates and feeding it ad libitum, the total feed intake for a group of cows can be regulated by means of the degree of concentration of the feed. This strategy is common when using a mixer wagon (see TMR). A disadvantage with ad libitum feeding is that it is not possible to control each cow.s individual feed intake, which increases the risk of both over- and underfeeding.

Flat rate feeding

Flat rate feeding is a strategy in which all cows are fed the same quantity of concentrates during the entire (or part of) lactation. The concentrate is restricted on a certain level, while the roughage is fed either ad libitum or in a mix. As described earlier, the cow.s energy and nutrient demand varies depending on the stage of lactation. Because of the fixed concentrate ratio, flat rate relies on fat mobilisation. The disadvantages with this strategy are the risk for metabolic disturbances (Ketosis) and the difficulty to reach high peak yields. However, the technique is simple and therefore the investment cost can be relatively low.

Challenge feeding

While flat rate feeding relies on fat mobilisation, challenge feeding and feeding to yield (see below) aims to supply the cow with nutrients that are needed for the actual lactation stage.

Challenge feeding of concentrates takes place in the early lactation, when there is a risk of underfeeding. Every cow is given the maximum ration of concentrates that she can consume, without reducing her roughage intake below approx. 40.60 % of total dry matter intake. This is continued until she reaches peak, four to ten weeks after calving. By using this strategy, each individual cow is given the possibility to .show. her production potential.

Feeding to yield

When the peak production is reached and the production starts to decline, there is a risk of overfeeding. By feeding the cow to yield, which means that each cow is fed concentrates individually according to her actual milk yield, the cow.s body condition is maintained and the feed is used as efficiently as possible. A successful implementation of this strategy means increased milk production with the feed cost well under control.

Feeding strategy

+

-

Ad libitium

- High risk of over / underfeeding

 

- Waste of feed

 

- Difficult to reach high peak production

Flat rate feeding - Simple ration

- Risk of overweight cows

 

- Risk of underfed cows wich may cause Ketosis

 

- Difficult to reach high peak production

Challange feeding /

Feeding to yield

- Potential to reach a high production

 

- The cow is fed due to its demand

 

- Reduced risk for overweight cows

- Risk of pH-variation if the feeding is not spread over the whole day

Advantages and disadvantages with different feeding strategies.

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Feeding systems

The layout of the feeding system and the equipment involved differs depending on the type of barn, stanchion or loose-housing, and the management strategy used on the farm. However, the principles of the feeding systems are generally the same and can be divided into the following four categories: Manual Concentrate Feeding, Computerised Concentrate Feeding, Total Mixed Ration (TMR) and Partly Mixed Ration (PMR).

Manual concentrate feeding.

Manual concentrate feeding

This system is common in stanchion barns but it is also found in loose-housing barns using manually operated in-parlour feeding. In a stanchion barn, the system makes individual feeding of both roughage and concentrate possible. However, in both loose-housing and stanchion barns, the roughage is usually fed ad libitum and the concentrate is fed individually.

Suitable feeding strategies depend on the barn layout. In a stanchion barn it is possible, with a varying grade of precision, to implement challenge feeding and feeding to yield strategies. A loose-housing barn with manual in-parlour feeding is more or less only suitable for flat rate feeding.

A drawback with manual systems is the risk of low accuracy. Practical experience has shown that there often are great differences between the intended ration and actual ration. The diagram below shows that, for example, if an animal should have 4.5 kg, the actual ration could range from 3 kg to 8 kg. This may not only result in costly feed waste and overweight cows, but will also have a negative effect on the milk production. A manual system is also labour demanding and requires more time to implement new feed rations, compared to a computerised system. All this means high feed and labour costs and lost milk revenue opportunities.

Ration given when concentrates are dispensed manually.

Computerised out-of-parlour feeding.

 

Computerised concentrate feeding

Instead of feeding the concentrates manually, they can be dispensed and controlled by a computer. In stanchion barns, a rail suspended feed wagon is normally used.

For loose-housing systems, there are two systems to choose from: in-parlour feeding or out-of-parlour feeding (or a combination of both).

The in-parlour feeding is simply a dispenser that can be operated by manual or automatic identification. Out-of-parlour feeders requires automatic identification (transponders). Farms with a long grazing period sometimes prefer to feed all concentrates in the parlour. A disadvantage with this is that large rations cause long eating times and are unhealthy for the rumen. An alternative to this is to use out-of-parlour feeders all year round and keep the cows housed for a couple of hours before letting them out on pasture again.

When out-of-parlour feeding or a rail suspended feed wagon (stanchion barns) is used, challenge feeding and feeding to yield can successfully be used as the feeding strategies. Each cow.s individual ration is programmed in a computer and when the cow enters the feed station, she is identified and the correct amount of feed is dispensed. The computer decreases the demand for labour and facilitates the implementation of new feed rations and the record keeping for each cow.

Total Mixed Ration (TMR)

In the Total Mixed Ration feeding system, the concentrates and roughage are mixed in a mixer wagon and usually fed ad libitum. The mix is often dispensed to the cow directly from the mixer wagon, but can also be distributed by band conveyors or with rail suspended feed wagons.

The TMR system is most common in large loose-housing herds, but can also be used in stanchion barns.

TMR feeding.

There are mainly two ways to feed the cows with TMR: either feed the same ration to the whole herd (no grouping) or different rations to different groups. In non-grouping systems, only one mix is made and dispensed. The mix is usually composed to suit the high yielding cows, which makes the balance of the ration very important to avoid overweight cows.

A way to improve the precision of the feeding is to use a grouping system. The cows can be grouped according to many criteria: yield, stage of lactation, first calf heifers etc. The drawback with grouping is that much of the rationality of the system is lost compared to the non-grouping system.

Much time must be spent moving the cows from one group to another as the production changes. Group changes also result in milk loss due to social adjustment. In addition, several mixes have to be prepared and dispensed to suit each group. However, if the herd is large enough, it should be possible to run an efficient and convenient TMR system with grouping. Disadvantages with all TMR systems are the relatively high amounts of feed waste and the fact that it is not possible to monitor the individual consumption of concentrates. The cost of feeding and storage equipment is also relatively high.

The main advantage is good rumen health, which results in few metabolic disturbances and possible effects on the milk production. To obtain a well working TMR system and a high dry-matter intake, the ration requires much attention.

Partly Mixed Ration (PMR)

Partly Mixed Ration (PMR) is a feeding regime that combines TMR and individual feeding of concentrates. A mixer wagon is used to mix roughage and some of the concentrates. The concentrate level in the mix is adjusted to fit the lower yielding cows.

The high yielding cows are then fed extra concentrates by out-of-parlour feeders, in-parlour feeders or from a rail suspended feed wagon. The PMR system gives you the possibility to combine the advantages of a mixed ration with computerised feeding.

In-parlour

 feeding

Out-of-parlour

feeding

TMR

PMR

Advantages

Possible to use with manual identification

 

Better milk "let down"

 

Often only solution for grazing periods

The conc. feeding can be spread over the day

=> Good rumen health

 

Potential to reach high peak yields

 

Good control over cow's eating performance

If well balanced

=> Good rumen health

 

Possibility to use a wide range of feedstuffs

If well balanced

=> Good rumen health

 

Possibility to use a wide range of feedstuffs

 

Possibility to feed each cow individually

 

Disadvantages

High rations may generate waiting time and therfore slow down milking

 

Restless cows during milking

 

Risk of hygiene problems in the parlour

Sometimes difficult during grazing periods

No possibility for individual feeding

 

High investment cost

High investment cost

Advantages and disadvantages with different feeding systems.

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Milking .

To illustrate an individual cow.s milk production, we normally plot the yields against time, which gives us the lactation curve illustrated in the picture below. As the diagram shows, the milk yield will rise during the first months after calving, which then is followed by a long period of continuous decline. The shape of the lactation curve will differ from individual to individual and from breed to breed. Feeding and management will also influence the shape and have a significant impact on the total amount of milk produced. Lactation is ideally 305 days, but in practice it is usually more, followed by a two-month dry period prior to the next calving. A cow.s milk yield is influenced by many factors, which are described more in detail in the DeLaval booklet Efficient Milking.

A dairy cow's lactation curve.

 

Peak yield

Peak yield is the point where the cow reaches the highest milk production level during the entire lactation. Heifers peak at 70.75% of mature cows and second lactation cows peak at 90% of mature cows. Normally the peak is reached four to ten weeks after calving. The time it takes to reach peak yield varies with many factors, for example breed, nutrition and yield potential. Higher producing animals tend to peak later than low producing ones. A high peak yield normally means a higher total yield. Research shows that each one kilogram increase in peak yield usually means an additional 100.200 kg of milk produced during the actual lactation. Reaching high peak yields requires a very well managed and balanced feeding programme.

 

Persistency

After the peak, milk production starts to decline by approximately 7.10% per month. The rate of decline is normally measured as the cow.s persistency. If a cow.s milk production falls by 7% per month after peak, it is more persistent than a cow that loses 10% per month. A general rule of thumb is that higher peak production leads to lower persistency. As for peak yield, the persistency is dependent on feeding and is therefore, to some extent, possible to influence. Persistency differs between cows, but a first lactating cow is normally more persistent than a second or third lactating cow.

 

Total and daily milk yield

Close monitoring and evaluation of each cow or group are important ingredients when trying to reach a high level of total milk production (high peak and long persistency). However, it is important to remember that a dairy cow is not a stable milk producer. The milk yield differs from day to day and the relative variation can be as high as 6.8 % from one day to another. Cows milked three times or more a day usually have a lower variation than cows milked twice a day.

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Managing milk yield recording

The total milk yield is a good indicator of gross income from milk sales, which has a direct effect on the dairy farm.s income. With milk yield recording, the dairy farmer can monitor his day to day output and use it to control and monitor the production. Milk yields are also the most interesting variable when calculating the feed rations. Common methods for measuring milk yield are: bulk tank monitoring, monthly milk yield recording, recorder jars/stand alone meters and electronic milk yield registration. The milk yield records can then be used for:

- Calculating and follow-up of the nutrient intake
- Monitoring long-term production changes
- Indicating overall health disturbances

Bulk tank monitoring.

Bulk tank monitoring

Bulk tank monitoring does not enable you to monitor the cows individually, but it can be used as an indicator of the overall herd management. To get the correct total yield, you have to account for the number of fresh, treated and dry cows plus the milk used for own consumption and calves.

Monthly milk yield recording

Monthly recording is usually carried out by a milk yield recording organisation and was originally introduced for breeding purposes. Due to the fact that the recording normally takes place once a month, and each cow.s milk production varies day to day, it is not recommended to use this information to manage feeding. When receiving the data, it will be historical and not reflect the current situation.

Recording with Milkoskope (TM).

However, the information can be used for trend analysis and give an idea of the peak and persistency for individual cows, which can be used for culling, breeding and general feeding decisions. As for bulk tank monitoring, the monthly milk yield recording does not give the dairy farmer an early indication of health problems.

Daily milk yield recording

Recording jar.

Daily milk yield recording can be considered as one of the most important decision aids for fine tuning the high producing herd. The milk yield can be measured at every milking by using either recorder jars or milk meters. If using recorder jars, all data has to be recorded manually (e.g. on paper or typed into a computer).

With milk meters connected to a processor or computer, you will have an automatic collection of data and a memory capacity that is much more accurate and efficient than the milkers. The processor contains a database where all individual milk yields and other relevant data are stored on a daily basis. This data provides the manager with exact and timely information of a cow.s or group.s production on a day to day basis, which can be used to:

- Calculate and evaluate feed rations for individual cows or groups to maximise the milk production and avoid over and/or under feeding.
- Identify cows in heat. Research shows that decline in morning milk might indicate oestrus.
- Identify cows with potential health problems early. For example, ketosis is related to a gradual decrease in milk production before it can be diagnosed.
- Calculate the actual lactation curve instead of estimating.
- Group cows by yield, which results in faster milking.
- Evaluate long-term milk production for individual cows to plan breeding and culling.

DeLaval Milk Meter MM15.

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Reproduction .

Reproduction is a necessary and important part of milk production. Without regular calvings in the long run, there will be difficulties in producing the desired amount of milk. It is also important to produce sufficient heifer calves as replacement animals and allow herd size to be maintained or expanded.

Today it is most common to use artificial insemination (AI) instead of a bull. AI increases the control over the breeding and enables the dairy farmer to use sperm from all over the world, which increases the genetic gain. However, at the same time, it increases the need for good planning and well structured working routines.

Another way to get a cow pregnant is to use the embryo transfer technique. So far this is relatively uncommon, but it is expected to increase in importance. The main advantage with embryo transfer is that it is possible to generate more calves from a good cow than it is with AI.

 

The oestrus cycle

As long as a cow or heifer is not pregnant she will normally have a 21-day oestrus cycle. The length of the oestrus cycle may vary but it usually ranges from about 17 to 24 days. A heifer.s oestrus cycle is normally slightly shorter than a cow.s. The cycle will continue until the cow is pregnant. After calving, cows normally undergo a 20 to 30-day period when oestrus cycles do not occur.

The oestrus cycle is controlled by a complex system involving different hormones produced in the brain and ovary. The picture below shows a simplified picture of how two of these hormones, oestrogen and progesterone vary depending on where in the cycle the cow is.

The oestrus cycle.

Some cows do not follow the normal oestrus cycle. For example, a cow can be unoestrus, which means her ovaries do not function with the regular 17 to 24-day cycle and are therefore not observed in heat. Other cows may suffer from ovarian cysts. These cows will show heat at very short intervals and the period that they are in heat will last three to four days.

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Reproductive management

Research has shown that suboptimal calving interval causes large economic losses to dairy farmers, second in importance only to mastitis. Milking cows in late lactation are less profitable due to the decline in production. A long calving interval means milking less profitable cows due to the decline in production, fewer calves and too many cows with low feed conversion efficiencies. Therefore, successful reproductive management has a significant impact on the herd.s overall performance and the net income.

Average Calving Interval (Days)

Production Level (kg milk/cow)

-4499

4 500-5 499

5 500-6 499

6 500-7 499

7 500-

<365

365-377

378-392

393-408

>409

6%

18%

23%

18%

35%

7%

20%

28%

22%

23%

7%

28%

34%

19%

12%

9%

36%

36%

14%

5%

11%

43%

33%

10%

3%

Distribution of controlled Swedish herds in relation to calving interval and production level (Source: SHS, Swedish Association for livestock, breeding and production).

Well managed reproduction also reduces the risk of expensive involuntary culling. Information from UK and USA shows that the cost for a one day extended calving interval ranges from £1.5 to £3 per cow.

The time of the calving interval that is possible to influence by management is the open days, which are determined by the voluntary waiting period (VWP) and the breeding window (BW). A very common reason for undesired long calving intervals are missed heats. With improved heat detection rate (HDR) and conception rate (CR), through better management and improved timing of inseminations, it is possible to obtain a significantly shorter calving interval.

Factors affecting the calving interval.

 

Detecting heat

The most sexually intensive period of the oestrus cycle is during standing heat, which lasts for approximately 18 hours. In loose-housing herds, this period is indicated by the cow in heat standing immobile when mounted by another cow or bull. Other signs of heat are:

- Bellowing
- Increased activity
- Walking the fence line
- Licking/Sniffing
- Swelling and reddening of the vulva
- Mounting other cows
- Lower milk yield
- Reduced feed intake

The sexually intensive period.

The duration of heat varies from animal to animal, but approximately 10 to 12 hours after the end of standing heat, the egg is released (ovulation) and the heat ends.

Manual heat detection

Manual heat detection relies on manual observations in the barn. The cows and heifers shall be observed for oestrus two to three times per day and all observed heats be recorded whether the animal is bred or not. The records provide the manager with information to anticipate future heats, which will make it easier to distinguish if a cow is in heat or not. Most mounting occurs between 6 p.m. and 6 a.m., and it is therefore worth trying to check for heat during these hours. To facilitate the planning and record keeping, a cow calendar is often used. This can be either manual or computerised.

The disadvantage with manual detection is that it is very time demanding and requires people with the ability to observe the right signs. This is particularly important when there are no distinct signs of heat. By using progesterone testing or other tools on the market, the detection rate can be improved.

Automatic heat detection

Another way to identify cows in heat is to monitor their activity. During heat the activity can increase up to 8 times compared to the normal level.

The activity can automatically be recorded by using activity meters attached to the neck or leg.

By comparing the activity with the last observed heat, actual milk yield and feed consumption, a reliable indicator of heat is obtained. The automation will generate a significant time saving and improved calving interval through better heat detection.

Timing of insemination

With artificial insemination, the timing of the insemination becomes important. The optimum time for insemination depends on when the ovulation occurs in relation to the heat and for how long the sperm is viable. Most sperm remain viable for about 24 hours. The ovum.s .life. is only about four hours and is the most critical. It is therefore preferable that viable sperm is present in the salpin during ovulation. As illustrated in figure 18 below, ovulation normally occurs about 30 hours after the start of standing heat.

There are mainly two rules for the timing of insemination. Traditionally the a.m.-p.m. rule was the one dairy producers followed. This rule dictates that cows and heifers first observed in heat in the morning should be bred late in the afternoon. Likewise, cows and heifers first observed in heat in the afternoon should be bred the following morning.

Timing of insemination.

 

This is still a good rule, but many producers have now successfully gone to once-a-day insemination. This rule dictates that cows and heifers first observed in oestrus in the afternoon or the following morning, should be bred late that morning.

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Herd health

Disturbances and diseases will always occur in a herd, but in order to limit the economic loss, it is important to keep them under control. Good health and health management have a significant effect on a dairy farm.s net result.

As the number of different disturbances is great, only the most common ones will be covered here.

 

Common diseases and disturbances

Retained placenta: This is a condition where the foetal membranes are not completely expelled. Retained placenta increases the risk for a whole host of other health problems (e.g., uterus infection, ketosis, and displaced abomasum). Usually a retained placenta is associated with difficult calving, a mineral imbalance (e.g., potassium, calcium) prior to calving, or overconditioning.

Milk fever: Milk fever occurs when there is a shortage of calcium in the blood. This also usually results from a mineral imbalance (e.g., potassium, calcium) prior to calving. The effect of milk fever normally starts with reduced feed intake, followed by difficulties for the cow to move. Eventually the cow becomes paralysed and, if not treated, may die within a couple of hours. However, treatment with calcium usually has a good effect and in most cases, the cow will survive.

Ketosis: Ketosis occurs when cows begin to milk but have a shortage of energy. These cows will use fat to support milk production, but their liver cannot convert the fat to energy fast enough. Ketone bodies accumulate in the blood causing ketosis. Treatments generally consist of rapidly digested sources of glucose such as propylene glycol or molasses.

Left-Side Displacement of Abomasum (LDA): This may occur in relation to calving. The fourth stomach (abomasum) migrates from the right side of the cow to the left side. It is thought that this occurs with low fibre levels in the diet, physical stress such as slippery floors, and secondarily to other problems such as ketosis.

Acidosis: There are a few health problems directly associated with feeding, but high levels of concentrates might cause acidosis. The rumen pH drops below 6.0 for a long period of time causing numerous problems. One result of acidosis is hoof problems. Cows that have acidosis may experience hoof ulcers and a form of founder.

Mastitis: Mastitis is the most common and costly disease in dairy herds. It is an inflammation in the mammary gland which can be caused by bacterial infections or trauma. Cows with clinical mastitis are relatively easy to detect for the farmer. The symptoms are clotting and discoloration of the milk, and the gland becomes hard, red or swollen and in severe cases the cow has fever and loss of appetite. Cows with subclinical mastitis will have no outward signs of mastitis but their mammary gland will still be infected and the somatic cell count will be high.

Lameness: Hoof problems or lameness is characterised by damage to sensitive laminae of the hooves and it is reported to be the third most common cause of culling behind reproduction and mastitis. Hard and slippery floors, decreased exercise and metabolic disturbances (especially acidosis) negatively affect the occurrence of hoof problems. Estimates are that cattle that become lame and are not tended to, can experience a 20% loss in milk production. 

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Managing herd health

The economic losses due to health disturbances can be attributed to one or more of the following factors:

- Less efficient production and higher veterinary costs
- Reduced slaughter value and idle production factors
- Lost future income

Lost future income occurs when the cows have to be replaced (culled) before reaching their economically optimal age. This varies from individual to individual, but it is basically the time when it is more profitable to replace a cow than to keep her. Culling is usually the eventual outcome of health problems and culling rates are normally found to be between 25.35%. Cows that die on the farm are part of this culling rate and should represent less than 3% of the total herd.

The reduction of losses attributed to diseases and the promotion of positive welfare and health should be one of the main goals in dairy herd management. A helpful tool for maintaining healthy cows is body condition scoring (BCS). Other important aspects that might affect health, if not looked after and maintained, are barn environment, milking routines and milking equipment.

Body condition scoring

Body condition scoring (BCS) can be used to troubleshoot problems and improve the health and productivity of the dairy herd. Overweight cows (overconditioned) are more susceptible to metabolic problems, infections and noninfectious health problems. Research shows that overweight cows are more likely to be affected by, for example, mastitis, retained placenta, ketosis and lameness. They are also more likely to have difficulties at calving. Thinness (underconditioning) can lower the milk production and fat content because of insufficient energy and protein reserves.

Body conditioning scoring scale.

The body condition scoring system uses a .one to five. scale with one representing very thin cows and five very overweight cows (see image above). An .ideal. cow has a body condition score of about 3.5, but the system is designed to have cows at certain stages of lactation at certain body conditions (see table below). Important parts to look at when scoring are: chine, loin, rump, hip, tail head and pin bones.

Score

Condition

1

Skin and bones

2-2.5

Severe negative energy balance on cow in early lactation. Risk of production loss.

2.5-3

High producer in early lactation.

3-3.5

Milking cow in good nutrient balance.

3.5-4

Late lactation and dry cow in good condition.

4

Overconditioned. Potential calving problems if dry.

5

Severely overconditioned. Risk of fat cow syndrome.

Body conditioning scores for cows (Source: Heinrichs & Ishler, 1989).

Dry cows should neither gain nor lose weight and their body condition score should be around 3.5. If they have too much fat (>4.0) they tend to have many problems after calving. The reason is that all of this body fat must move through the liver before it can be used for milk production. This is not bad if they use the fat slowly, but if they begin to lose weight quickly, fat will accumulate in the liver and a condition known as .fatty liver. develops. These cows usually perform poorly and are more prone to die. After calving, cows should lose less than one point before they begin to gain weight again. Cows that lose more than one point tend to have more reproductive problems.

From peak milk production to dry off, cows should gain back the body condition that was lost before the peak was reached. It is common for cows that have problems (e.g., ketosis, hoof problems, mastitis etc.) to lose one body condition score within the first two weeks of lactation. Ideally, the body condition score of a cow should be taken whenever she is handled. At least body condition scores should be taken at freshening, breeding and dry off. If over- or underconditioning occurs, the feeding strategy for an individual cow or group has to be evaluated and feed rations may have to be recalculated and corrected to satisfy the cow’s demand.

Preventing and controlling mastitis

Mastitis needs extra attention, as it is the most common disease among dairy herds. It is not unusual that up to 40% of the herd is infected by clinical (with visible symptoms) or subclinical (often without symptoms) mastitis. All these cases are associated with many costs, which is illustrated in the figure below. In the worst cases, the eventual outcome is culling.

Distribution of cost associated with mastitis in an average dairy herd (Source: SHS, 1996).

With good management routines, there are great opportunities to reduce the number of cases. This has a direct effect on production levels and costs. For example, if a farm is able to reduce the somatic cell count from 200 000 to 100 000, it means an increased average production of 0.7 kg per cow and day (see table 5). In a 100 cow herd, this gives an additional milk production of 0.7 X 365 X 100 = 25 550 kg of milk per year.

Somatic Cell Count (SCC)

Milk Loss (kg per cow/day

50 000
100 000
200 000
400 000
800 000
1 600 000

0.0
0.7
1.4
2.0
2.7
3.4

Somatic cell count and the effect on milk production (Source: Hopards Dairyman, May 1997).

The management must focus on actions that prevent new infections and reduces the duration of each infection. This includes proper maintenance of bedding and stalls, hygiene procedures during milking and frequent checking of the milking equipment. Dairy cows require a comfortable, clean, dry and draft-free environment. Comfort can include everything from feed space and walking surfaces to air and resting areas. However, even if the physical facilities are well planned, the daily work routines are of great importance to prevent as many health problems as possible. This includes not only mastitis, but also hoof problems (lameness). The way to avoid many of these cases is to regularly trim the hoofs and make sure that the surfaces in the barn are dry and free from mud.

Bedding & stalls

Milking routines

Milking equipment

• Scrape cubicle house, yards and passageways daily
• Ensure adequate ventilation to prevent humidity
• Keep cubicle bedding dry and fresh
• Use plenty of dry straw for bedding
• Always clean teats with single-use paper or towels washed between milkings
• Dry the teats
• Always foremilk the cows and inspect for clots etc.
• Use post milking teat dipping
• Milk infected cows last
• Change liners and tubes regulary
• Pulsator, pipelines, vacuum regulators and pumps have to be checked and maintained so that large cyclic and/or irregular fluctuations are avoided

Important routines for preventing mastitis.

With good milking routines and adequate milking equipment, the number of new mastitis cases will be significantly lowered. But even so, there will still be cases that need treatment. To avoid excessive costs associated with these cases, the duration of each case has to be reduced through:

• Prompt treatment of clinical cases; early detection, appropriate therapy and recording of clinical cases.

• Culling cows with chronic mastitis.

• Regularly checking the somatic cell count on all cows (High SCC indicates subclinical mastitis).

• Culling persistent offenders, e.g. cows having three cases in one quarter or five cases in mixed quarters in one lactation.

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Milk quality

Milk consumers require healthy and safe milk that is free from contamination, unpleasant smell etc. Processing also demands for milk to meet certain standards. For example, cheese making is very sensitive to spores and antibiotics. The requirements on the quality has increased over the time and will continue to do so. To meet this, more and more dairies put pressure on the milk producers. This is normally reflected in the payment scheme, where producers that deliver milk that does not meet the required standards have to pay penalties. There are also examples of processors paying bonuses to producers that meet the highest standards. As this makes the quality of the milk a determinant of the producer.s final price, it has to be considered in the daily routines.

The dairies use different parameters to check the quality of the milk. The exact level for each parameter varies from company to company. Therefore it is worth taking a closer look at the demands and standards you have to meet. Examples of tests carried out on delivered milk are:

• Fat and protein content
• Bacteria count (Bactoscan)
• Smell and taste
• Residues from antibiotics and other Medicines
• Freezing point (detects water content)
• Somatic Cell Count
• Spores (especially important for cheese making)

 

Milk consumers require healthy and safe milk.

 

Managing milk quality

There are many factors that affect milk quality and some are easier to control than others. With well structured daily routines and an awareness among the personnel, it is possible to control and improve the situation considerably. Below you find a list of actions that all will have a positive effect on the overall quality and the final price of the milk:

• High quality water in sufficient amounts
• Feeds with high hygienic quality
• A well balanced ration with suitable ingredients
• Good overall hygiene
• A good and well maintained barn and parlour environment
• Prompt treatment of diseases
• Do not deliver colostrum milk
• Avoid delivering milk from cows with high cell count
• Do not deliver milk containing residues of antibiotics, sulpha etc.
• Do not add any water to the milk
• Make sure no detergent and/or other chemical residues get into the milk
• Ensure good ventilation to avoid undesired smell
• Make sure the milking equipment is cleaned properly
• Cool the milk directly after milking (Avoid freezing!)

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Headlines

 

Feeding

Managing feeding

Feeding strategies

Feeding systems

 

Milking

Peak yield

Persistency

Total and daily milk yield

Managing milk yield recording

 

Reproduction

The oestrus cycle

Reproductive management

 

Herd health

Common diseases and disturbances

Managing herd health

 

Milk quality

Managing milk quality