The livestock industry is looking for are liable means of regularly identifying individual animals for a variety of reasons, all of which stem from an economic requirement to reduce costs or improve efficiency.

With man, weight-for-age is taken as a useful guide to fitness. In the case of cattle, weight is used as an indicator of fitness or suitability for sale, for slaughter, for service and during pregnancy. Consequently machines for livestock weighing will become almost as common on the farm as personal scales are in the bathrooms of many homes. However animals do not read their own weights and seldom stand still during the exercise.

Because of the continuing increase in the number of cows in dairy herds, it is increasingly difficult for the herd manager to observe and control individual cows in his herd. Systems which can automatically watch over production and health in large dairy herds are required. Production control is a long-term process and for this purpose production data have to be collected in a suitable form. Health control can be realized by a system measuring and reporting deviations from the normal health status of each cow, so that preventative measures can be taken. Such a system would inevitably make use of those physiological variables which can be measured and recorded quickly and automatically at each milking.

The Milk Marketing Board (MMB) specification for milk yield recording defines the acceptable limits of error for any recording equipment whether manual or automatic. This is that at any milking 95 per cent of the measurements must not deviate more than ± 5 per cent or 0.25 kg (whichever is the greater) from the true weight. Hence an error of ± 0.25 kg is allowable for yields below 5 kg and 5 per cent of yield for quantities greater than 5 kg.

The milking machine has a unique place in the mechanization of dairy farming. It is, as yet, the only fully successful and almost universally accepted machine used directly with cattle and the rates of its acceptance and development have to a large extent governed the trends in other methods of milk production. The direct effects of machine milking on labour usage are very evident. One milker took an hour to hand-milk about 10 cows whereas he can now machine - milk 60 to 100 in the same time. The indirect effects are less obvious but at least as important. The progress of the mechanization of milking has required changes to be made in cattle housing, bedding methods, effluent handling, cattle feeding and made possible new systems of milk production. In a meeting on the mechanization of livestock production a brief review of the trends in milking machine development is useful. Although the development of mechanical milking has had major far-reaching effects on livestock husbandry the changes are not rapid and major innovations such as the development of milking parlours take many years to become assimilated into farming practice.

In the mechanization of milking least progress has been made in tasks involving direct contact with cows' teats and udders, namely fore-milk examination, udder and teat cleaning, application of teat cups and teat disinfection after milking. It is not surprising that this is so, since cows' udders and teats vary widely in size and shape and cows often object to mechanical interference with these organs. The tasks listed constitute the major manual labour of milking and thus limit milking performance. Applying the teat cups is inescapable but the other tasks are frequently omitted by milkers to reduce labour.

Many claims are made by suppliers of automatic teatcup cluster removal equipment and this paper considers these claims and attempts to describe and compare some of the different devices available to the dairy farmer.

Throughout the first 70 years of developments in machine milking systems (1889–1959) very little attempt was made towards either the mechanization or automation of cleaning. Aspects of mechanical efficiency were given much greater attention and, as long as the labour demands of cleaning the machine and the milking premises were acceptable in terms of cost and effort, no action was considered necessary. It is, therefore, not surprising that although four distinct phases of development in machine milking systems emerged over these years, cleaning of both the premises and equipment remained essentially a manual operation (Table 1).

Machine milking performance is measured in terms of cows milked per person per hour and is influenced by the duration of the routine work of the milker associated with each cow milked, the milk yield per cow at a milking, and the type and size of milking parlour installation (Clough and Dodd, 1959).

The purpose of cattle production is to convert crops and crop by-products which cannot be sold directly for human consumption into products which can be consumed. Cattle may also be used to increase the value of some crops which can be consumed directly, especially where the cattle enterprise is soundly based on crops which have no direct sale value; and where the cattle are highly productive (e.g. high-yielding dairy cows, calves, young growing and finishing cattle). Occasionally market circumstances may enable cattle to be fed entirely on crops which can be consumed by man, as in the all-concentrate beef system. Essentially, however, cattle production is a by-product enterprise, i.e. it is an adjunct to other farming enterprises or is undertaken in circumstances where there is no alternative method of utilizing land.

Automatic calf feeding systems are used to reduce the labour requirement of calf rearing. They can also be used to increase milk intake. Major points to consider when mechanizing calf rearing are first, control of voluntary milk intake and second, ensuring that each individual obtains sufficient. Level of feeding depends on the system selected. The greater milk intake the less solid food will be consumed and the latter can fall to a level where ingesta entering the rumen is insufficient to stimulate its development. Thus calves fed milk at high levels experience a check at weaning but once solid food is eaten rumen development is rapid so this effect is not usually prolonged. Ad libitum feeding initially gives faster growth but the post-weaning check reduces this effect. However, overall the outcome can be expected to be advantageous. For calves being reared as heifer replacements or for beef it is more economical to restrict milk powder intake and to early wean the calves. A major requirement of a mechanized calf rearing system for these purposes is therefore to restrict milk intake per calf but not run the risk of some calves not receiving sufficient. For veal calves the requirement is to ensure maximum milk intake per calf. Figure 1 schematically represents a range of possible calf rearing systems.

Engineers attempt to meet the requirements specified by biologists when designing machines. With mechanized feeding systems the engineer interacts with the biologist in two main areas:-

a) In attempting to minimize forage losses and in maintaining quality during storage.

b) By exercising control over the physical form, quantity and mixture of forages presented to the animal.

It is not possible in this short paper to cover in detail the large variety of fixed equipment available for rationing and dispensing forages to animals. Several reviews of this subject have been published in recent years (Nilsson, 1970; Nilsson, Lingvall and Wiktorsson 1977; Payne, 1971; Anon, 1973 and 1974; Turner and Filby, 1973 and 1974; Turner, 1975 (a)) which describe adequately most of the equipment available today. This paper concentrates on silage feeding and includes installation guidelines for improving reliability and performance.

When the subject of mobile equipment for dispensing forages is raised, bunker silage immediately springs to mind as the form of forage concerned. Current farming practice confirms this reaction to be generally correct but mobile equipment is also used for dispensing forage in the form of tower silage, green forage and occasionally dried grass, hay and straw. This paper will deal primarily with equipment for dispensing silage but will not entirely exclude consideration of other forms of forage.

Until recently nearly all dairy cows received their concentrate allocation whilst in the milking parlour. This followed on from the practice in cowsheds for many years and was a convenient way of giving each individual cow a rationed quantity of food. However, with many nutritionists advocating frequent feeding, and the development of more sophisticated equipment such as individual feeders with cow recognition systems and to a lesser extent conveyor systems and mixer-feeder wagons, some farmers are now feeding a lot of the concentrate ration outside the parlour. The variety of equipment available for feeding concentrates is now extensive, ranging from relatively simple mechanical dispensers to programmed feeders which will recognize animals and feed preset quantities to them. An outline of the possibilities open to farmers is shown in Figure 1.

The basic requirements of any automated system for collecting and processing data for a diary herd are that:-

- it must present the information required for day-to-day management in an easy and readily available form.

- it will be justified only if the system provides useful management data that would be more costly to produce in other ways or be impractical to obtain manually

- it should be built from a simple base with add-on units to a complete system, to allow for various sizes of herd, levels of technical development and cost. (Inputs could be either from manual records or automatic recorders)

- it should provide information on a visual display unit, with lists printed when required

- accurate identification is essential especially if automatic identification is used

- it should be developed to a fully computerized farm recording system.

Management control of a herd of animals is undertaken even at the most primitive level by recording data and subsequently recalling the information to effect decisions. This was true of the shepherd and goatherd of antiquity and the techniques used then were not much improved until the 1930's when an impetus for change came from setting up such bodies as the Milk Marketing Board. With dairy cattle, the major emphasis is now on herd control using methods equivalent to management control in industry. In management control, an aggregate of data, retrieved by suitable analysis, is used to effect a policy decision.

Domesticated livestock have always been an important part of agricultural production. They have been utilized as scavengers to consume the production which could not otherwise be marketed at a better return. Livestock systems were typically very small holdings and were cared for in the odd time that the farmer would have from tending crops. This has been referred to as chores. The chores were done in the morning before field work and in the evening after return from the field. There was slow change in this system or in the pattern of production until after World War II. Since that time because of the shifts in population and the desire for better living conditions that could be afforded in urban areas livestock production has been systemized. Dairy production was one of the first livestock operations to be mechanized. Perhaps this is due to the milking operation being one of the most odious chores which had to be performed in livestock production. The milking machine was a very welcome addition to the farm industry.

Not only in industry but also in agriculture there is an increased use of electronics for controlling routine work.

On large dairy farms where one man milks 50 to 60 cows per hour it is no longer possible to pay due attention to infected cows, cows on heat, individual production levels and the required amount of concentrates per animal.

The IMAG research aims at providing the dairy farmer with more information about his animals, so that he is better able to make his decisions.