The disposal of the surplus milk produced in the spring and early summer months is becoming a problem. Blaxter (1950) suggested that the conversion of milk protein into meat protein in the form of veal would be an ideal method of dealing with the surplus.

In March 1955, the Fatstock Marketing Corporation and the Milk Marketing Board jointly announced a scheme designed to divert surplus milk from the overloaded butter and cheese manufacturers to veal production at a time when home-killed meat is normally in short supply. From the beginning of April until the end of July, a minimum price of 3s. per lb. dressed carcass weight for Grade I calves in the weight range 60-100 lb. and 2s. 9d. per lb. between 101-125 lb. was offered by the Fatstock Marketing Corporation.

Before dealing with the marketing of livestock I will mention briefly the current arrangements for the disposal of our two main livestock products—milk and eggs. Milk is marketed through a Producers’ Marketing Board which operates on very much the same lines as the Milk Marketing Boards in Great Britain.

In the marketing of eggs we have a unique system for the control of egg quality. The eggs are collected in the normal way by packers, or collectors acting on their behalf, and are graded on a quality basis in the packer’s store. The producer is paid on the result of this grading, deductions being made for second quality eggs, cracked eggs, soiled eggs, etc. The grading and packing are supervised by officers of the Ministry of Agriculture who also carry out further checks on the standard of packing and quality of eggs being shipped to Great Britain. These further checks are carried out at the ports of shipment, random samples of eggs being subjected to further quality tests.

On hill farms where breeding cattle are kept there are advantages in retaining until the following spring at least a proportion of the surplus calves. The ability to winter them presents wider scope in choice of markets, while the sale of calves in spring, in addition to the dung produced, can provide a greater profit margin if wintering costs are minimised. Grass used efficiently in autumn offers an opportunity to reduce the requirement of the relatively expensive hay, silage, other crops and purchased feed. The value of extended grazing throughout autumn and winter months has been demonstrated by Smith (1953-4) for Blackface ewe hoggs, and for store stock and in-calf heifers by Hughes (1954) and Corbett (1954). In the case of calves, however, the period when late grass can be utilised depends on the continuance of moderate temperatures and availability of shelter from wind and rain, and therefore in most seasons will be relatively short. With these considerations in mind it was decided to compare the performance of two groups of weaned calves, one of which was housed and fed in courts immediately after weaning, while the other remained on grass for several weeks prior to court feeding.

The variations in the incidence of mastitis and infection with stage in lactation of dairy cattle have been the subject of a number of investigations (Oliver, 1955) but until recent years the udder health of dry cows has been given little attention. This is surprising, because many cows are dry for almost three months in each year and the dry period is immediately followed by a few weeks when the incidence of mastitis is high (Oliver et al .,1956a).

During the last ten years a study has been made at this Institute of the importance of the dry period to the control of mastitis in dairy cattle. The object of this article is to review the progress made.

In the Proceedings of this Society two years ago, A. T. G. Macarthur (1954) presented a method for the evaluation of dairy sires under farm conditions. Since that time, considerable use has been made of this technique in the Bureau of Records of the Milk Marketing Board and in this paper we propose to discuss the method critically, in the light of the results obtained on over 1,500 bulls.

As the experience we have gained has considerable bearing on the validity of this method, it would perhaps be valuable at the beginning to view the general problem of testing dairy bulls under British conditions. What evidence have we that the use of contemporary comparisons is the best tool that we have available for the assessment of dairy bulls? We must bear in mind here that we have two distinct problems. The first is the assessment of bulls used in A.I. whose daughters have been bred and milked in many herds. The second is the assessment of bulls used in natural service.

The growth of grass varies considerably from month to month. Where stock numbers are constant, as in a dairy herd, it is difficult to use grassland efficiently by grazing alone. But where grassland is used for meat production, livestock numbers may be subject to a considerable fluctuation, and with skilful adjustment of classes of stock this fluctuation can be made to approximate to the seasonal pattern of growth in the pasture.

The adjustment of stock numbers to the quantity of grass present is an art which is part of successful grazing management. Understocking will lead to an accumulation of pasture which will then have to be grazed at a more mature stage, while overstocking will result in a lower plane of nutrition for the animals. The efficiency of equating stocking intensity to the pasture available in a given period will be reflected in the progress of the individual animal (in terms of daily milk yield or live-weight gain) and in the output per acre of pasture.

It is generally recognised that spring grass does not provide a balanced ration for the grazing animal, since it contains excess of nitrogenous substances in relation to carbohydrate. Young lucerne similarly contains more nitrogen than is necessary to provide a balanced feed. When grazing these types of herbage, the animal wastes much of the ingested nitrogen. If the ration included carbohydrate rich foods in addition to the high quality herbage, the animal might be able to utilise more of the nitrogen it is consuming.

In this country little experimental evidence is available on the use of carbohydrate supplements for beef cattle, although several firms produce high carbohydrate cakes with low fibre content, for feeding in conjunction with young succulent grass.

The methods which we use in this country to calculate the rations for our livestock are based on studies made in Germany during the period 1890-1909, and in America at about the same time. These methods have been amended from time to time as the results of other studies have accrued, but, in the main, their basis lies in a few dozen experiments made by Kellner and Kuhn at Leipzig with steers and a very much smaller number made with milking cows. This basic information, expanded in many respects and certainly extrapolated well beyond its admittedly limited experimental foundation, is collected in two sets of tables in the books dealing with the feeding of livestock. One gives the requirements of different classes of stock in terms of energy values and the other gives the energy value of the common feeding stuffs.

The objects of this investigation were to discover the amount of current inbreeding, the extent of any genetic divergence between the beef and dairy types, and whether the breed was dominated by an élite group of herds as for example, in the British Friesian (Robertson, 1953). An extensive investigation by Sewall Wright (1923a), (1923b) and McPhee and Wright (1925), (1926) established that there was at that time little current inbreeding and that genetic divergence between Dairy and Beef Shorthorns was negligible. This work adds to and corroborates their findings and throws some light on breed structure.

The sampling technique in this investigation is based upon Wright (1925). If consisted of noting the number, parents, grandparents and great-grandparents of a randomly selected sample of 128 females registered in Coates’ Herd Book, Vol. 94, 1948. Simple random lines were traced back from each great-grandparent as far as 1900, a toss of a coin deciding whether to record a sire or a dam. The information contained in Coates’ Herd Book made it a simple matter to record in addition the mate of the randomly selected ancestor, thus providing 16 random lines behind the eight great-grandparents.

To wean calves early and then feed them dry meal, hay and water is thought to have a number of advantages over more conventional methods of calf rearing. These advantages include: a considerable saving of milk or milk substitutes, an early build-up of the microbial population of the rumen (thus permitting the use of simple inexpensive foods), and the saving of labour concomitant with early weaning.

Accordingly, a number of small experiments were set up to test the practicability of early weaning, the effect of different dry feeds and of a variety of types of flooring for calf pens.

A Number of authors (Bonsma and Neser, 1951; Bisschop, 1954; Wiener and Donald, 1955) have recently provided experimental evidence on the age at which the eruption of permanent incisors occurs in cattle and, in view of the wide ranges generally encountered, criticised the practice of estimating age from dental development. Though factors such as individuality, breed, plane of nutrition and type of grazing are frequently quoted as being responsible for deviations from the ‘accepted’ means (Miller and Robertson, 1952; Zorn, 1953), apparently little support is to be found in the scientific literature on the subject.

The ingenious biochemical system, which we generally call heredity, directs the body development and regulates the reaction of the individual in relation to the environmental conditions. It is this genetically determined adaptiveness of the individual which makes it possible for organic life to survive even when the climatic conditions and the supply of nutriment vary within wide limits in nature.

The interaction of heredity and environment involves several problems of vital importance for animal production. One such problem is the influence of level of nutrition during the rearing period on body development, fertility, milk production and longevity. When investigating the relative importance of heredity and various environmental factors on the production traits in dairy cattle, we have concentrated much of our effort on this special problem.

The herbage dry matter intake of grazing animals may be estimated by chemical marker and faecal analysis methods (Raymond, 1954) or by pasture sampling methods.

Pasture sampling methods generally involve two main difficulties. The first is the low precision resulting from the variability of pasture yields. When intake is estimated from the difference between the yields of herbage on a given area sampled before and after the grazing period, the estimate bears the error variances of both the sample means. The second difficulty lies in ensuring that the estimated difference in yields is the true difference due to consumption. The samples must be cut below the level to which the animal can graze, and the amount of herbage growth during the grazing period must be estimated and allowed for. Growth can be estimated from the difference between the yield of herbage before grazing and the yield of protected herbage at the end of the grazing period.

In the analysis of the causes of variation between cows of a given breed in milk production, differences between herds pose some difficult problems. The nature of this variation is of importance from several points of view in the discussion of breed improvement. The situation is complicated by the fact that the herds of any breed type do not form a uniform group but can be classified roughly into a sort of ‘social structure’ (Robertson and Asker, 1951). The discussion of variation between all herds of a given breed type can then be broken down into the variation between strata and that between herds in the same stratum. From the analysis of production data from herds using artificial insemination (Robertson and Rendel, 1954; Korkman, 1953) there is evidence that the genetic component is a small proportion of the total variance in these herds; and also that in Great Britain the genetic difference in yield between the dominant group of herds (which provide many of the bulls used in A.I.) and the herds using A.I. is small. This is in agreement with studies on breed structure. In this paper we shall discuss the genetic differences between members of the small group of important herds which dominate each breed. These usually supply a high proportion of the bulls used. If we have good estimates of the breeding values of such bulls from the production records of their progeny, we can then examine the different breeding herds according to the breeding value of the bulls bred in them. Evidence of this type has been presented for Jersey bulls in New Zealand (Castle, 1952) but without statistical analysis of the results, although inspection suggests that there are definite differences between studs.

The theme of ‘Animal Production from Grass’ proved a most successful choice for the fifth ‘study meeting’ of the European Association for Animal Production, which was held at Reading during July. Representatives of seventeen countries were present, and all stayed in two of the University's halls of residence; this contributed on the social side towards the success of the meeting.

As a preliminary to the meeting, most of the visiting European delegates took part in a tour beginning with a visit to the Royal Show at Nottingham, where the Council of the Royal Agricultural Society extended its hospitality to the visitors. Particular interest was shown in the display of British breeds of livestock. Afterwards, visits were made to the research farm at Thurgarton and the Veterinary Research Unit of Messrs. Boots, and to Mr. Maurice Passmore's farm at Wormleighton.

At Reading, the theme for discussion was introduced by two main papers, each being followed by shorter reports on current research in the various countries.

Recent work, mainly American, has indicated the possibility of using implanted synthetic oestrogens to induce faster and more economical weight gains in fattening lambs. Little has yet been done in this country to repeat or to extend these observations, and a possible reason for this may lie in the difference between the organisation of the fat lamb industries of the United Kingdom and the United States. Here, as in New Zealand and in other countries rearing sheep principally on pastures, many lambs are sold fat at light weights, while those not so well finished at weaning may either be fattened on grass or other green crops, or be overwintered and fattened as hoggets on grass in the following spring. In the U.K. fat lambs are thus seldom fed dry feeds as they are under U.S. ‘feed-lot’ conditions, and are slaughtered at rather lighter weights than their U.S. counterparts.

One of the advantages of keeping growing fattening pigs outside on pasture is that they are more healthy than those indoors (Fishwick, 1935), provided fresh ground, free from parasitic infections, is available. Reviewing American work, Morrison (1936) concluded that faster liveweight gains and improved efficiency of food utilisation are obtained from pigs full-fed on pasture compared with those full-fed in dry lot (also Fishwick, 1935; Smith et al., 1950). Pigs grazing outside in Great Britain usually receive enough sun on their skin to produce sufficient vitamin D to meet their requirements, except in adverse weather (Braude, 1954). Pigs at pasture have access to soil, which is a source of minerals (Davidson, 1930) and of vitamin B12 (Duckworth, 1955). Cunha et al. (1948) found that 5% of soil in a purified pig ration stimulated appetite and increased the haemoglobin value of the blood. Biggar (reported by Boden, 1952) obtained greater liveweight increases from pigs folded on pasture than from those folded on bare soil, showing that herbage is of value in addition to fresh air, sunlight and soil.