The increasing use of water trough treatment as a means of administering soluble salts and trace elements, as well as anti-foaming agents for bloat control, suggest that more information on the technique would be helpful.
This bulletin therefore compares the different available methods of water treatment, summarises some of the recent work on the subject, and suggests the most suitable alternatives.
Drinking Water Treatment
Supplementation through the drinking water (if it is to be useful) must meet the following requirements:
a) It must provide a supplement based on a predetermined dose rate per animal which is relatively consistent when averaged over a period of two to three days.
b) It should not result in intake variation of 4-5 times from day to day.
c) It should not permit excessive over-dosing or under-dosing over a period of several days.
d) The dose rate average should not be controlled by the daily water intake, since this is generally unknown and can vary considerably with temperature, rainfall and dew.
e) The dose rate administered should preferably be related to the body-weight and milk production or growth rate and to the metabolic needs of the cow.
A. WATER INTAKE IN DAIRY CATTLE
A two year study by Phillips et al (1) at the Ruakura Agriculture Research Centre, on the water intake of pasture-fed dairy cows (both lactating and dry) showed that the intake was greater and much more uniform than was commonly supposed.
a) Relative Water Intake
The relative water intake was shown to be closely related to Dry Matter intake, and thus to body weight, growth rate and milk production.
Average water intakes were noted to be relatively stable, except for occasional “low” days when temperatures were low and probably feed intake was reduced.
On cold days cows tended to huddle together under shelter if available, and neglected to graze.
It was extremely rare however for water intakes to be low on several consecutive days.
b) Water Intake and Climate
In their study, it was found that daily water intakes generally followed the weather patterns, with occasional “low” days, usually preceded or followed by a day or days of reasonably high water intake.
Often water intake was more directly affected by the hours of sunshine than the amount of rain. The lack of sunshine was commonly more closely associated with a low intake than the amount of rain.
c) Diurnal Variation in Intake of Water
Water intake during the day and night periods is related to feed intake and the ambient temperature.
The average drinking patterns for day and night indicated that a peak, starting at about 9-10am, was fairly characteristic. In the day time this was often followed by a less pronounced peak in the afternoon. After the afternoon milking there was a pronounced peak of drinking, fading away as darkness came on. A late-night drink often occurred between 10pm and 12pm.
d) Daily Intakes
Much data is available on the average water intake of cattle [c.f. Winchester & Morris (2)] [Leitch & Thomson (3)1.
Water intake is directly proportional to the dry matter intake, therefore —
- Larger cows drink more
- Growing cattle drink more
- Lactating cows drink more.
For non-lactating cows, 1kg of dry matter (DM) required three to five litres of water. Water intake is a function of temperature thus —
- A rise from 10 °C – 20 °C represents a 30% increase in intake.
- A rise from 10 °C – 27 °C represents a 50% increase in intake.
In lactating cows, 1kg of milk at 4.5% milk fat increases estimated water intake by three litres.
e) Protein Level in Feed
A high protein diet of similar feed ingredients, increases water intake about 26% relative to that of a low-protein diet.
In the Ruakura study comparative water intakes for dairy cattle were calculated at —
For dairy cows at 380-400kg body weight.
Non-lactating cows dry matter intake of 6 to 13kg/day will require a water intake of 30 to 60 litres/day. Additional water requirement for milk production of 40 to 60 litres/day, total for milkers 70 to 120 litres/day.
Under full pasture feeding about 80% of this 120 litres per day would be provided by the water content of the pasture. This would vary according to the dry matter content of the pasture and supplementary feed, as well as temperature.
The large increase in water consumption with increasing temperature results from its use for cooling and to offset respiration loss in the animal.
B. WATER INTAKE OF BEEF CATTLE
The water intake of beef-cattle is the same as that of dairy cattle, relative to body-weight, except that the pronounced evening drinking pattern of milking cows is not so apparent.
In beef-cattle the treatment of drinking water is virtually the only method of bloat control and it has obvious advantages for supplementation with Magnesium, Sodium, Zinc and trace elements such as Cobalt, Copper and Selenium.
C. WATER INTAKE OF SHEEP
[c.f. Leitch & Thomson, (3) ]
The water requirement of sheep is similar to that of cattle in relation to body-weight, and it is proportional to dry-matter intake. The ratio of water-intake to dry matter in.take is in the range 2.0 to 3.5, compared with 3.0 to 4.0 for cattle. Water intake increases 30-50% in lactating ewes.
Under cool conditions, with fresh pasture, the water intake can be quite low, but under dry pasture conditions it can be 3.5 – 4.0 litres per day under cold conditions and 5.0 – 6.0 litres per day under summer conditions.
Mineral supplementation through the drinking water can be expected to be equally effective with sheep, particularly under dry summer conditions, given ready access to treated water supplies.
ADMINISTRATION OF MINERAL SUPPLEMENTS AND OTHER PROPHYLACTIC MATERIALS THROUGH THE DRINKING WATER
In the natural environment, animals acquire their mineral needs from a variety of sources including the drinking water. Animals are known to seek out water supplies containing essential minerals which are deficient in the grazing environment.
The treatment of farm drinking water supplies with appropriate supplements is a logical method, given the observed behaviour and the water intake characteristics of farm animals.
SINGLE-DOSE METHOD
The method of application most commonly used in the past has been to treat the drinking water trough with the required dose of sodium, magnesium or bloat material at the start of each drinking period.
The method has obvious disadvantages in that the concentration of active material changes with time as the trough continues filling through the ball-cock.
The decline in concentration is exponential with a rapid initial decline; when one trough-full has been removed, the concentration will have declined to 37% of the initial level. When two troughs-full have been removed, the concentration is reduced to 13.5% of the initial level.
Where taste is a factor (as with Magnesium and Zinc salts) some cows may delay drinking until late in the drinking period when concentration is reduced. This could seriously affect the uniformity of dose level!
PETA TROUGH DISPENSERS
A simple and effective way to treat farm drinking water was developed at the Ruakura Animal Research Centre by Dr D. Phillips. Using computer simulation it was found that a uniform concentration of additive could be maintained if the output characteristics of the dispensing system was matched to the average daily drinking pattern. This is illustrated in Fig. 1.
From this study were developed the PETA Floating Trough Dispenser units, which are now well established as a standard water treatment system for a variety of supplement materials in addition to medications such as bloat remedies and zinc sulphate for facial eczema control.
Once placed in the water trough, the solution of active material, either a dissolved salt or other prophylactic material, is dispersed from the outflow nozzle at a controlled rate, while water enters the container through the inlet hole to replace the more dense solution. This process continues in a controlled pattern over the drinking period, until 90-95% of the solution has been replaced by water in the dispenser.
The device was designed to dispense the active material into the water trough throughout a 12 to 24 hour drinking period.
Because the dispenser floats in the trough head-down, it continues to function normally, irrespective of the water level in the trough. Furthermore, the floating device is protected from damage by stock. A rigidly mounted device in contrast is unable to compensate easily for changes in water level and is very vulnerable to stock damage by rubbing and scratching etc.
a) Dose Rate
It is important to realise that everything put into the drinking trough eventually is ingested by the stock, so that the average intake over a period is known precisely.
b) Effect of Variations in Water Intake on Average Dose Rate
With the dispenser placed in the trough just before the start of high level drinking, the dispenser curve is a reasonable fit to the average drinking pattern. On high drinking days the drinking tends to start earlier, so that very little additive has run into the trough at that point. On low drinking days, the drinking starts later, and a portion of the additive will already lie on the bottom of the trough to be picked up readily as fresh water enters from the ball-cock, thus lifting the concentration quickly.
SOLID DISPENSER: Dispenser for Soluble Materials in Solid Form
A recent addition to the range of dispensers is a unit which can dispense crystalline soluble materials such as common salt, magnesium sulphate or zinc sulphate, etc., directly into the drinking water, without the need to prepare a concentrate solution.
The “Solid” Dispenser has these advantages:
- A greater weight of material can be dispensed from a relatively small container.
- The difficulty of dissolving a large mass of salt is eliminated.
The “Solid” Dispenser uses a 10 litre container and floats in the trough in the same way as the liquid dispensers. It can dispense up to 7.5kg over a period of 24 hours.
The amount to be dispensed depends on the number of cows to be treated. The output characteristics vary little with total dose as both density and viscosity of the solution vary together.
The shape of the output characteristics is modified to advantage by the distribution of grain size in the salt when using Grade 12 PACIFIC® Agricultural salt. The characteristics are similar for magnesium sulphate (Epsom salt) which can be dispensed directly from the crystalline form, in combination with salt if desired.
Where dry stock are to be treated, the dispenser can be used over a 24-hour period, as the water intake over the night period is quite low, in contrast to milking cows which have a high overnight water intake.
With milking cows, the 24 hour use still applies, but the dispenser can be lifted from the trough following the evening milking and shaken vigorously before replacing. This dissolves much of the remaining salt and starts a second rapid outflow period to meet the evening drinking peak.
1. SODIUM SUPPLEMENTATION
Several New Zealand researchers have demonstrated the positive benefits derived from sodium supplementation as follows —
i) Sodium supplementation of sheep and cattle fed lucerne [Joyce & Brunswick (4) ]
- In Sheep, average production increases in live weight gain were 65%, carcass weight-gain 90%, and wool growth 29% where supplementation as either a drench (twice weekly with 10.7g salt in 50ml water), herbage spray (11.2kg/ha salt) or lick (ad lib) were equally effective.
- Beef Cattle, group-fed green lucerne at ad lib levels gained liveweight and carcass weight 16-48% and 22-30% faster respectively when supplemented with sodium chloride (common salt) at 15.7g per day.
- Lactating Dairy Cows in a commercial herd, drenched with sodium chloride (14g sodium/day) produced 14% more milk (and consequently increased butter fat) than the un-drenched controls.
ii) Sodium supplementation of weaner Angus calves, and mature ewes grazing pasture [Towers et al (5) ].
- Weaner Calves, 25 Angus weaners grazing pastures with a history of sodium chloride (common salt) fertilisation, were drenched with 25g common salt twice weekly, and gained over a four week period 5kg more than a similar number of unsupplemented weaners grazing untreated control pastures, A further 25 weaners fed 25gm salt twice weekly and grazing untreated pasture, also showed increased growth rates.
- Ewes provided free access to salt lick for six weeks prior to mating, showed minor improvements in live weight gain at two higher pasture allowances, indicating that the sodium content of the pasture (at 0.7g/kg dry matter) was providing marginally inadequate sodium intake.
In both the above trials positive responses to sodium supplementation occurred despite the animals being offered pasture with sodium concentrations exceeding those calculated to be fully adequate. Current thinking varies between 30 and 40 ppm.
Substantial production gains and improved growth rates can be demonstrated in many areas from the use of common salt (sodium chloride) as a supplement.
The following data on sodium requirements of lactating cows provides a basis for supplementation.
Lactating Cows
| Dose Rate | ||||
| kg milk/day | 5 | 10 | 20 | 30 |
| sodium g/day | 12 | 15 | 21 | 27 |
| chloride g/day | 19 | 25 | 36 | 48 |
At a production average of 18kg of milk, the total requirement of sodium chloride would be about 50 g/day. It has been suggested that cows inevitably obtain some sodium from the feed, and that an added supplement of 50% of the total daily requirement should be adequate for most conditions.
Therefore If daily supplement of NaCI = 25 g/cow (2.5kg/100 cows/day) this provides 9.9 g sodium/day and 15.1 g chloride/day.
Salt – (Sodium Chloride) Administration Using Trough Dispenser
Calculations are based on the consumption of a herd of 100 cows with an average daily water intake of 20 litres per cow, using a trough of 750 litres capacity (200 gals) which is common on most dairy farms.
Assuming that the trough has previously been used on an “average drinking day” and that the 100 cows are treated at the rate of 25g of salt per day, the following would result:
| Trough volume | = 750 L |
| Assume average water intake | = 20 L/cow/day |
| Average concentration | = 1.25g/litre |
| Weight of salt in trough at start | = 937.5 g |
On a high drinking day, the average concentration rapidly adjusts to a lower level as water enters the trough, and on a low-drinking day the reverse takes place (Table 1).
Table 1:
| Mean water
intake/cow (L) |
Mean
concentration (g/L) |
% of daily
dose consumed |
| 40 | 0.72 | 115% |
| 20 | 1.25 | 100% |
| 10 | 1.96 | 78% |
| 5 | 2.75 | 45% |
It can be seen that wide variations in water intake do not result in the same degree of variation in mean concentration, or the daily intake of salt.
A reduction of the average water intake by four times will increase the mean concentration by a little over two times, so that abnormally low water intakes do not result in excessive increases in concentration.
On very cold wet days the treatment of the trough can be omitted if desired, as a regular intake is not necessary.
Grades 11 or 12 PACIFIC® Salt should be used with the PETA SOLID DISPENSER.
N.B.: Dosage requirements for sodium depend on sodium content of pasture, therefore consult your Veterinarian or MAF Farm Adviser for details, and have herbage analysed.
2. MAGNESIUM SUPPLEMENTATION
Research on magnesium supplementation for the prevention of Hypomagnesaemia (grass staggers) in beef cattle was reported in Ruakura Farmers Conference Proceedings by P. W. Young (6). Experimental studies involving the application of Epsom salts (magnesium sulphate) to the drinking water at the rate of approximately 60 g/cow per day, was sufficient to prevent clinical cases in beef cattle under severe deficiency conditions. Untreated cows in one trial showed a 25% incidence of clinical cases; of which only 20% recovered. Serum magnesium levels in treated cows were maintained well above critical levels.
Magnesium Content
60 grams magnesium sulphate (crystalline) provides 6.0 grams magnesium —
Hence dairy cow magnesium supplement:
high deficiency = 6.0 g/day
low deficiency = 3.0 g/day
Water Trough Treatment
Treatment of the sole source of drinking water with soluble magnesium salts, such as Epsom salts, at the rate of 60 g/cow/day (or 3-4 g/litre) can reduce the clinical incidence of grass staggers and generally increases mean serum magnesium levels in cattle by about 20-30%. This method is not one that can be adopted quickly and cows should be introduced to treated water at low concentrations over a 2-3 week period. With Trough Dispensers this takes place automatically during the first round of treatment under controlled grazing.
The treatment of hypomagnesaemia by the addition of magnesium sulphate to the drinking water is now a well established method. The amount of elemental magnesium in common commercially available salts is given in Table 2.
Water trough treatment can be applied very simply using the PETA Multi-Purpose Trough Dispenser.
The crystalline salt is placed in the dispenser directly, thus avoiding the need to dissolve it in water, which is quite difficult and requires a large water volume. The solution of the salt takes place gradually as the unit dispenses the resulting solution into the trough.
Other salt or trace element treatments can be applied along with the magnesium salt if desired.
The dispenser with the daily dose of dry crystalline salt is taken to the trough in the morning and after part filling with water at the trough is merely placed in the trough in an inverted position to dispense the content in a regulated pattern over the next 24 hours.
Unpalatability of Some Soluble Salts
When testing for unpalatability it is important to realise that it is the “change” in taste which is important and once accustomed to the new taste, cows accept it as “normal”.
The use of the trough dispenser system in a rotational grazing environment, has the advantage of gradually increasing the concentration over a period of 2-3 weeks. The first treatment of each trough will result in a low level of treatment as each trough starts with no additive. This has a useful consequence in that animals particularly influenced by the taste will drink early in the period, thus avoiding some of the additive. By the time the grazing rotation is complete, all troughs will carry a ‘”normal” concentration of additive, and all cows will have become adapted to the “new” taste of the water. With the dispenser system, troughs are left at “working concentration” at the end of the drinking period, and thus are already at the correct concentration when the next drinking period starts.
Combined Magnesium and Salt Treatment
There is no problem in using a combined Magnesium and Salt Dispenser at the same time as the Bloat-Control Dispenser. However, some care should be exercised in mixing the Bloat-Control and salt mixtures in the same dispenser, as some bloat control materials can form a gel which will not flow out of the nozzles. A few tests will decide if this will happen.
If the Magnesium and Sodium salts can be mixed with the Bloat-Control additive, the water treatment system has obvious advantages.
Trace element mixtures or combinations with common salt (such as SUMMIT® LIQUIMIN®) can also be dispensed with Magnesium supplements in the same dispenser.
The only requirement is that the total load of salt materials still allows the dispenser to float in the trough.
THE ADMINISTRATION OF TRACE ELEMENTS
Table 2:
| PERCENTAGE OF ESSENTIAL ELEMENTS IN COMMON COMPOUNDS AVAILABLE COMMERCIALLY | ||
| Compound | Element | Typical
Percentage |
| Copper Sulphate (5H20) | Copper | 25% |
| Zinc Sulphate (Hepta-hydiate) | Zinc | 22% |
| Zinc Sulphate (Mono-hydrate) | Zinc | 36% |
| Magnesium Oxide | Magnesium | 54% |
| Magnesium Sulphate (Epsom Salt — hepta-hydrate) | Magnesium | 9.5% |
| Magnesium Chloride | Magnesium | 25% |
| Sodium Chloride (Salt) | Sodium | 39% |
Supplementation with trace elements such as Cobalt, Selenium and Copper is now an important factor in the control of deficiency diseases in farm animals. Generally these elements are required in microscopic amounts. The daily requirements for cattle ranges from less than one milligram for Selenium to 300-400 milligrams for Copper. The actual dose rate per animal should be determined in consultation with the veterinarian or farm consultant, as these elements are generally highly toxic and required dose rates must not be exceeded.
Administering such small quantities, on a daily basis presents problems and drenching or injection at periods of weeks is currently the only available method. This also has problems, as the dose rate is then quite high and there is often irritation at point of injection. (9)
PETA SOLID DISPENSER (MULTI-PURPOSE DISPENSER)
A method which has great potential is to disperse the low volume trace element mix along with a bulk carrier (such as common salt, or preferably the combination SUMMIT® LIQUIMIN®) through the PETA MULTI-PURPOSE DISPENSER.
The trace element mix can be supplied by the veterinarian and added to a dose of 2-3kg of coarse salt or salt combination in the DISPENSER. Where a supplement such as Magnesium Sulphate or SUMMIT® LIQUIMIN® is being used, any additional trace element mix would be merely added to the normal daily dose in the dispenser.
The “Trace-element mix” based on specified dose rate per animal can thus be administered on a controlled basis along with the salt which acts as a carrier.
Trace element combinations are now available in preparations such as SUMMIT® LIQUIMIN® (licensed to and manufactured by Dominion Salt Ltd and distributed by Weddel Stockfoods Ltd).
These preparations can be readily measured out by the farmer at a specified rate per animal per day.
Overdose is virtually impossible, since this would require the intake of very large amounts of water and salt. The daily dose is controlled exactly by the amount of the “salt/trace element mix” placed in the dispenser, and individual water intake is determined by dry matter intake. Thus large animals are treated at a correspondingly higher rate than small animals.
Generally New Zealand soils and pastures are sodium deficient so that a small salt supplement is an advantage.
ZINC TREATMENT FOR FACIAL ECZEMA CONTROL
The use of zinc as a protection against liver damage from facial eczema is now a well established practice.
Zinc can be administered as a soluble salt in the drinking water system with excellent results. Usually Zinc Sulphate is used, either as common Zinc sulphate-hepta hydrate, or as the mono-hydrate (mono-zinc). These are equivalent but the dose rates differ due to the extra water molecules in the heptahydrate (see Table 2).
As the fine Zinc salts form a dense slurry, it is necessary to use a PETA Zinc Dispenser to provide the correct outflow rate.
The PETA ZINC DISPENSER is purposely designed to administer Zinc Sulphate.
Dose rates should be determined in association with a veterinarian or a qualified farm consultant, as zinc is toxic at high dose rates.
The PETA DISPENSER system is now widely used for Zinc treatment as it provides a carefully regulated daily dose to any desired group of stock. Treatment can be started readily when a facial eczema risk is apparent, and gradually increased over a few days if a rotation system of grazing is not in use. With rotation, the concentration in the trough builds up gradually.
BLOAT CONTROL THROUGH DRINKING WATER TREATMENT
BLOAT CONTROL MATERIALS
Bloat control materials such as Pluronics and other similar surface-active agents have been administered to cattle in drinking water since 1959 and are now in common usage.
Many important factors relating to their use have been identified over the past twenty or more years, and more effective methods of application have been developed.
Dr Phillips at Ruakura (7) carried out experiments with two groups of cows given separate access to the same paddock of red clover pasture. The experiment provided useful data on the relationship between Pluronic intake and bloat level where the Pluronic was administered in the drinking water.
Uniformity of control under normal grazing and drinking conditions
To maintain the average dose rate at a predetermined level, it is necessary to treat the water during each drinking period at a fixed rate per cow. This dose rate can be varied according to severity of bloat and weather conditions. With the dose rate fixed on a per cow basis, the mean daily intake is not controlled by the average water intake. In-line systems which treat the water on a per litre basis do not have this feature, and the mean dose rate is subject to wide variations in average daily water intake.
DRENCHING
Drenching with bloat control materials, while effective, has disadvantages. Firstly it is very labour intensive as it must be done at each milking. Generally the dose rate must be higher than with water treatment, as the concentrate does not mix well in the rumen.
A commonly ignored effect results from the fact that the concentrated detergent materials are quite caustic and cause severe irritation to the throat of the cow, reducing feed intake and hence production. The treatment is also disturbing to young stock and can cause milking problems.
In addition to this, a drenching programme eliminates all sign of bloat, so that the farmer cannot tell when bloat risk has ceased. Drenching can be stopped too soon with severe stock losses. Water treatment does not present this problem as it can be kept at a low level over long periods so that the onset of bloat is quite evident but not dangerous. If extra severe conditions are encountered, backup drenching can be applied at a somewhat reduced level.
WATER TREATMENT
The PETA TROUGH DISPENSER has major advantages over the much more costly in-line systems. With in-line systems, the water is treated on a “per litre” basis so that the average dose rate varies widely from day to day depending on the weather. This can be fatal unless very high dose rates are used to ensure protection on low water intake days.
In addition the detergent materials used for bloat control, can seriously damage the farm water supply system causing pipes to burst after a year or two of use.
The PETA TROUGH DISPENSER administers the bloat control material direct to the trough on a “per animal” per day basis, ensuring a fairly constant dose rate. Treatment is either on a 12 hour basis with control-grazed milking cows, or on a 24 hour basis with dry-stock or beef cattle. The system is self-checking, and equipment failure cannot put the herd at risk. It is more economical and very low cost.
ALTERNATIVE SYSTEMS OF WATER TREATMENT
In-Line Tank Dispenser
Several variations of this design have been developed to allow soluble materials to be dispensed directly into the water supply line feeding the farm water troughs.
The “in-line” tank unit has some of the advantages of the trough dispenser, in that it will dispense a specified daily dose to the cattle on the farm. The administration can follow the average drinking pattern, and thus maintain a relatively constant daily dose rate independent of the water intake.
With a dairy farm it would not be necessary to refill the in-line dispenser every 12 hours, as the low water intake of the dry stock in the evening period automatically provides extra additive for the milking cows who drink substantially after the afternoon milking. The dispenser can thus be filled with the required daily dose once in the morning. If the dispenser is located near the milking shed, no material need be transported to the drinking troughs. These systems however require an independent supply for stock use only, as well as being quite expensive.
Metering (Injector) System
In contrast, the “metering” type of in-line water treatment system which treats the water at a set rate per litre, gives a more widely varying dose rate depending on average water intake (Table 3). These figures represent the “worst case” situation for the “dispenser”, where all troughs were previously treated during the high water intake period. Under more average conditions the depressed intake of additive would take place only over periods of 2-3 days, and would then be made up by material left in the troughs from previous low intake periods.
When the floating trough dispenser is used, the daily intake of salt is maintained substantially constant by automatic changes in the concentration in the trough with changes in water intake On days of very low water intake (day 4 — Table 3) excessively high concentrations are avoided by storage in the trough water. This results in a reduced daily intake of salt, which is made up in later drinking periods.
The injector or in-line system on the other hand gives widely varying daily intakes.
Table 3:
Maintenance of dose rate by compensatory changes in concentration with water intake
| Dispenser System | Injector System | |||
| Day No. | Mean daytime water intake/cow (L) | Meal Salt concentration % of 12 hour (g/L) | % of 12 hour dose dose received | % of 12 hour dose using “Injector” |
| 1 | 32.1 | 0.39 | 102.0 | 136.2 |
| 2 | 17.8 | 0.60 | 87.5 | 75.6 |
| 3 | 24.5 | 0.51 | 100.8 | 103.8 |
| 4 | 7.7 | 1.0 | 63.5 | 32.6 |
| 5 | 40.5 | 0.31 | 102.7 | 171.9 |
Average water intake (Feb.-Mar.) = 47.2L/cow for 24 hours
(av-daytime = 28.0L)
Salt dose rate = 25 gram/cow/24 hrs (2,500g for 100 cows)
COMMENTS
Automatic dispensing systems connected to the water supply and delivering the additive on water-volume basis do not meet the requirements of efficiency and consistency of dose rate.With these systems, the daily dose rate is directly influenced by the water intake, thus on high drinking days cows are considerably over-dosed, while on low-drinking days, they are under-dosed.
Control of the average dose rate can only be set by observation of the additive usage, and cannot be controlled over short periods when ambient temperatures change the water intake substantially.
SUMMARY
Dr. Phillips summarises the administration techniques as follows —
Sodium and magnesium supplements to assist in the control of deficiencies in dairy cattle can be administered effectively through the drinking water. Measurements show that the average water intake of pasture-fed dairy cows both lactating and non-lactating are greater and much more uniform than commonly supposed. The levels of water intake are such that supplementation with sodium and magnesium salts can be achieved without problems arising from unduly high salt concentrations.
The few difficulties associated with the manual treatment of water troughs can be readily overcome by the use of the simple floating-bottle type of dispenser (illustrated). The dispenser unit, charged with the daily dose for the herd, can be dropped into the trough to carry out its function without further attention.
This method is ideally suited to the administration of trace element/salt mixtures such as SUMMIT® LIQUIMIN®, which can be accurately controlled on a daily intake basis.
The system ensures a precise control of the average dose rate throughout the treatment period without risk of over or under dosing; automatically adjusted to individual needs.
Supplementation with both sodium and magnesium using commercial grades of salt is relatively inexpensive. Both materials can be administered together using the trough dispenser system. The development of the system to allow it to use crystalline salts directly, avoids the need to make up a concentrate solution.
To a large extent the opposition to the administration of mineral supplements through the drinking water has been based on misconceptions and ignorance, and because there has not been simple and accurate equipment to meet the task.
The drinking water treatment system using simple dispensers now provides a method which is both cost and labour efficient which can be implemented throughout the dairy and beef industries.
SUMMARY OF MAIN POINTS
(1) Administration of mineral supplements to cattle through the drinking water can be effective.
(2) Floating-bottle or in-line tank dispensers ensure precise control of average dose.
(3) Supplementation with common salt (sodium chloride), magnesium, zinc and other minerals can be efficiently and inexpensively carried out.
(4) Trace element supplementation can be simply and safely administered with either low volume additions to a salt carrier, or by means of pre-mixed combinations such as SUMMIT LIQUIMIN.
(5) Commercial dispensers such as the PETA Dispensers trough units have made water treatment successful.
REFERENCES
(1) Phillips, D. S. M. Administration of Sodium and Magnesium supplements to Dairy Cattle via the drinking water. Ruakura Agricultural Research Centre, 1983.
(2) Winchester, C. F., and Morris, M. J. Water intake rates of cattle. Journal of Agricultural Science 15, 1956.
(3) Leiteh, I., and Thomson, J. S. The water economy of farm animals. Nutrition Abstracts and Reviews 14, 197.
(4) Joyce, J. P., and Brunswick L. C. F. Sodium supplementation of sheep and cattle fed lucerne. New Zealand Journal Exper. Agriculture 1975, 3 : 299-304.
(5) Towers, N. R., Young, P. W., and Smeaton, D. C. Sodium requirements of Grazing Stock, 1983.
(6) Young, P. W. Ruakura Farmers Conference Proceedings, 1975.
(7) Phillips, D. S. M. Important factors in the treatment of drinking water for bloat control. Ruakura, 1983.
(8) Phillips, D. S. M. Administration of Soluble Salts using the Dispenser System. Ruakura, 1983.
(9) Macky, Suzanne M. Selenium in dairy cattle: A practitioners approach. Processings 8th Seminar of N.Z. Dairy Cattle Society of N.Z. Veterinary Association 1991.
SUMMIT® LIQUIMIN® Registered Trademarks of Dominion Salt Ltd. Licensed under the Animal Remedies Act (1967) No. 6471.
DOMINION SALT accepts no responsibility for the incorrect use of information or for the incorrect use of salt for the purpose contained in this publication.
Published in the interest of greater productivity by
Dominion Salt Ltd,
P.O. Box 446, Blenheim, New Zealand