Progress and Problems in Artificial Breeding

New Zealand Journal of Agriculture, Volume 101, Issue 3, 15 September 1960, Page 251

Progress and Problems in Artificial Breeding

SINCE the first commercial artificial breeding groups started in 1949, when 1,600 cows were inseminated, growth has been very rapid and sustained, with 420,000 cows artificially bred last year and an annual increase in use of the service of about 80,000 cows. Dr J. P. James, who led the first experimental work in artificial breeding at the Ruakura Animal Research Station, later became Director of the New Zealand Dairy Board s Artificial Breeding Centre at Newstead, near Hamilton. Progress and problems in the service were discussed by him in a paper to the Ruakura Farmers' Conference in June, an adaptation of which follows.

ARTIFICIAL breeding has developed to a stage where the pattern of commercial service familiar to us for the past 10 years will shortly be showing some change. In a few important respects artificial breeding in New Zealand has differed from that in other dairying countries; firstly, our work has grown in a way to meet a highly seasonal demand from a single centre for the whole country, and, secondly, our methods of handling bulls have been different. To meet the continued rapid growth of artificial breeding, changes are inevitable, bringing in their train special problems. This is a suitable time, therefore, to give a short account of the present position in A.B. in this country and to discuss some of the problems facing future expansion and their remedies. Growth of A.B. During the past year 420,000 cows have been artificially bred. On the present dairy cow numbers in the Dominion this represents a coverage of about 20 per cent. Compared with the percentages in some other dairying countries this proportion may not appear high, but since the earliest commercial groups were started in 1949, when 1,600 cows were inseminated, the growth has been extremely rapid and sustained, the present rate being about 80,000 cows annually. As artificial breeding in New Zealand is regarded as solely a herd improvement scheme, users do not as a rule aim to settle more than 80 per cent of their herds, as this proportion has been found to be satisfactory if all herd replacements are to be obtained from the A.B. stud. Hence A.B. will be used in a higher proportion of the herds in the country than the percentage of cows would suggest. A.B. appears now to be used in nearly 30 per cent of the dairy herds of 10 cows or more. For similar reasons the A.B. service is just as attractive to the larger herds in the country, the average herd size in the scheme in this area being 71, of which on average

76 per cent, or 58 cows, are artificially bred. In the Auckland Herd Improvement Association’s area, and there probably would not be any difference in other areas, out of 172,525 cows bred artificially, 2,257, or 1.3 per cent, were registered pedigrees. Of the 2,257 pedigree cows inseminated, 526 were done under the nominated service scheme in which breeders may select any bull from the list of bulls in the Nominated Service Bull Catalogue. Of a total of 2,836 cows bred to the nominated service in this area, the pedigree use amounted to 18.5 per cent, a rather disappointing figure, in view of the fact that the list contained some of the better rated bulls as well as some from the best known and most fashionable studs in the country. It is encouraging therefore to know that arrangements are practically concluded between the Dairy Board’s Artificial Breeding Committee and the Council of the Jersey Breed Society to locate at the Dairy Board’s centres bulls selected by the breed society for the use of its members throughout New Zealand. I understand that service from this group of bulls will be available also to other A.B. users. Selection of bulls for this service will be entirely in the hands of the Jersey Society, so that the assertion that is often made by breeders . that the best bulls in the country are not found at the A.B. Centre can no longer be sustained. The importance of this arrangement is that the period of uneasy liaison between the largest breed society in the country and the A.B. organisation is ended and can be replaced by open cooperation, which, with good will on both sides, should encourage pedigree breeders to make much greater use of this service. This progress could have been achieved only with the assurance of cooperation from the various Herd Improvement Associations in the field side of the work. A start may be made in this new scheme in the coming breeding season, but it must be clearly understood that

it is a breed society scheme for which the A.B. Centre and the Herd Improvement Associations are servicing organisations. Other breed societies may wish later to make use of similar facilities for their members, but it must be emphasised that only breed societies as a whole will be given facilities for a similar service and not individuals or groups of individuals within a breed. To overcome distribution problems this type of service would largely have to be limited to what can be done through deep-freeze banks, and we must be prepared to face occasional disappointments when it is found that some promising bulls do not give good results with the deep-freeze method. Last season another dairy breed, the Milking Shorthorn, was added to the list of breeds at the centre. The team at present consists of two proven and five unproven bulls, with the expected addition of another proven bull before the coming season starts. Service is now available from four dairy breeds in the following order of popularity: Jersey 79.4 per cent, Friesian 12.4 per cent, Ayrshire 5.1 per cent, and Milking Shorthorn 0.9 per cent. The beef semen service is still available from the Polled Herefords, 2.2 per cent. New Facilities at Newstead To deal with the continued rapid expansion of artificial breeding, additional bull housing and collection facilities have had to be provided at Newstead. A departure has been made in our approach to handling bulls. This is a bull barn for 40 bulls designed to house them continuously for lengthy periods. On the success of this unit will depend the adoption of this system on a more extensive scale at Newstead or any other centres.

Development of Second Centre The most important addition to the service ability of the A.B. organisation in recent years is the purchase of a farm of about 200 acres at Awahuri, eight miles from Palmerston North, for developing into a second centre. It has been realised for several years now that Newstead could not go on expanding to meet the needs of the whole country, mainly because of distribution problems. These should be largely overcome when Awahuri comes into production, which will not be until next year. The coming season will be very difficult for distribution, especially as air services from Hamilton in the early morning are worse now than they were two years ago. The second centre will provide service for the southern part of the North Island and the South Island, and the area being developed should meet all requirements from these districts for several years even if expansion continues at the present rate. The advantages in distribution will be obvious, and another important feature of a second centre will be the division of the bull team against the possible, though we hope very remote, chance of some infectious disease closing down one centre. (In New Zealand this may seem a very slight risk, though last year [during the outbreaks of mucosal disease] we thought otherwise.) This same division of bulls will, however, create other problems, because relatively more bull power will be required for two centres, as wastage will be increased and the selection of bulls for each area will also be restricted. This will apply more to bulls of the Friesian, Ayrshire, and Milking Shorthorn breeds. Nominated service will be available from all suitable bulls at both centres to all users, and there will no doubt be some exchange of animals between the two centres. ' Conception Rates - For the past four years conception rates have been reasonably satisfactory, except in one area (WellingtonHawke’s Bay), which seems to contain some still unsolved problems, which were particularly evident during the past season, when the success, rate was lower than for the three years immediately before. A substantial part of this drop appears at present to have been due to distribution difficulties which should be resolved next year, when Awahuri comes into production. The conception rate is vital to the success of artificial breeding and the rate must be maintained at th? highest possible level, particularly in New Zealand, where so much dependence is placed on regular seasonal calving. When proven bull power is short a balance must be struck between the

ratio of proved and unproved bull semen. It is a question of giving the highest possible proportion of proven bull semen and at the same time maintaining a good conception rate. Most farmers would prefer a proved bull service of, say, 75 per cent with a conception rate of 60 per cent rather than 85 per cent proven service with conception rates below 60 per cent. This should be kept in mind during discussion of some of the problems facing the A.B. movement now. Experimental Semen We are at last in a strong position to carry out some experiments within the A.B. movement. The most urgent problem is finding an improved extender for chilled semen. Several variations of existing mixtures are now being tried out with very promising results. The keeping quality of diluted material from different bulls varies widely. If material from some of the poorer keepers could be improved, even for a few hours, it would raise the conception rates materially and

also ease the ever-present problem of proven bull power. Deep-frozen Semen Though this service is more expensive and the results in most areas rather lower than those from the use of chilled semen, the use of deepfrozen semen continues to expand. In 1959 a total of 9,258 cows were inseminated, of which 8,401 were classed as nominated services, 441 as “emergency” services (where frozen semen was used to overcome transport failures), and 416 as experimental deep-freeze, that is, testing out new bulls. Though the use of this material to meet transport failures was comparatively small, it was nevertheless extremely valuable in maintaining the service in the South Island. Results, though still behind the chilled semen figures (53 compared with 59.5 per cent), seem to be attractive enough for many grade farmers to be interested in it. Experimental deep-freeze semen is offered at chilled semen cost to encourage the use of new and unknown bulls. Last year, the first that this service was offered, the response was quite good. Production from A.B. Stock A.B. in New Zealand is a herd improvement scheme and its success must ultimately be measured on this basis. On the latest figures A.B. stock show an overall gain of 21 lb of fat, the figures being from 16,000 daughters of 61 bulls for which a comparison is available between their natural and their A.B. proofs. On the figures for the group the natural surveys showed a rating of 26. Only very few bulls have shown a disappointing drop from the natural survey rating to their A.B. rating, but the users of the scheme do not as a rule have many, daughters from any particular bull and would thus not be affected by the results from one or two bulls. The unproven bulls as a group show an overall improvement of 10 lb of fat. From present information it seems that we can expect about 40 per -cent of these carefully selected young bulls to qualify as merit sires at a sufficiently high rating to join the proven bull team at the board’s centres. But with the unavoidable losses occurring between the yearling or two-year-old stage until they can be proved, it seems that 25 per cent of an original intake of young bulls will eventually stand as merit sires. Dairy farmers in New Zealand will appreciate the high production standard which was set at the start of this work and the maintaining of

a very satisfactory rate of improvement in the face of extremely rapid expansion. Whether this can be continued in the light of present facts is discussed more fully below. Problems in A.B. in N.Z. Several problems face the various groups of workers concerned with providing this service throughout New Zealand. Some of these arise at the bull centres and others at distribution depots and in the Herd Improvement Department’s continuous search for suitable bulls. Not the least in this last group are the difficulties Herd Improvement Associations face in organising training groups in the winter and commercial groups in the busy spring. The hours of careful planning necessary to establish smooth working groups for a short period (seven to eight weeks) and overcoming the frustrating habitual alterations to public transport timetables are rather taken for granted. The solution is in these instances under the control of the workers concerned, and by altering schedules and increasing facilities and staff such problems can generally be overcome. Another class of problem the solution to which does not rest mainly on the technical or organisation aspects of the service, but on the users of it, is proven bull power in the future. The fact that A.B. in New Zealand is solely a herd improvement measure means that the best bulls (judged on production) must be located and bought for the A.B. bull studs. That the efforts so far have been successful, more successful than in any other major dairying country, has been shown in the production figures quoted earlier. This success has been built on the sire survey scheme introduced as part of the Herd Improvement Plan of the Herd Recording Council in the late 19305. In its turn sire survey work is built up on herd testing. Those who have supported herd testing regularly have been the only source of the proven bull which has been used so successfully in our A.B. work. It was stated earlier that 40 per cent of testing members were now using the A.B. service; hence these herds are lost to the organisation as far as naturally proved bulls are concerned. The fact has also to be faced that the percentage of A.B. users testing is dropping each year. This means that the potential for proving A.B. stock is falling. These trends have been known for some time, and measures to counteract their effects have been tried, unsuccessfully it seems. It has been realised that as the A.B. service grew, more and more of the testing members would join, and the naturally proven bull would become scarcer. Each year therefore a group of yearlings was

bought to be proved out within our own scheme. Need to Test Young Bulls The arithmetic of the business is as follows: If it takes 100 proven bulls to provide a certain population of cows with an 80 per cent proven bull service, each year 100 young bulls must be brought in for proving. This is because we find that about 25 bulls out of a stud of 100 proven ones are lost each year through deaths, infertility, or accident, and it was estimated earlier that of each 100 bulls taken in for proving at the yearling stage only 25 were left to join the bull team if production standards were to be maintained. The Herd Recording Department requires 50 heifers tested to give a satisfactory proof on each young bull, but very largely because of the fact that there is wastage at many points, 1,000 cows must be inseminated to each young bull to ensure 50 tested daughters. Owing to the very high wastage of this class of material in the field, we are faced with the ridiculous situation of having to collect and process 2,500 doses of semen from each year-

ling bull if we expect to have a proof on 50 tested daughters in three years. Anyone who has had experience in the handling of bulls of about 14 months of age will realise that to achieve this target in the early part of the season needs the persistence of Hercules and the patience of Job. In spite of a display . of these virtues it was extremely disheartening last season for the yearling collecting, team to find that wastage in the field in most areas was extremely high, and that their best efforts had not resulted in as many young bulls reaching the target as was expected. The cause for this very serious situation is simply that A.B. users will not take their share of the material from the young bulls; and because there is such a low percentage of users testing their herds, they are thus accepting the benefits derived from herd testing but are themselves failing to test. Realising that this situation. was developing, the Dairy Board three years ago offered a bonus of £5 for each heifer identified and tested from each of the young bulls being proved. It seems that this has not increased

the use of the young bulls and has not made any difference to numbers testing. What we must face also is the fact that if a young bull is not given enough cows for proving him out in the first year he is used, he has to come back again the following year to complete them. Therefore not using them one year means only that they are going to make a backlog for the next year, thus mounting up the numbers to be proved. This has now happened. There will be on hand next season 165 bulls (100 new ones and 65 as a backlog from previous years) to complete their quotas; this number, if everyone had used their share in past years, could have been reduced to 110. To catch up this season A.B. users will have to accept one service in four from unproved bulls. This means that there will still be a 75 per cent service from the proved team. New Zealand now enjoys an A.B. service with a higher percentage of service from proved bulls than any other country. Unless the usage of young bulls can be raised to the level of 25 per cent, we must face a falling rate of improvement from artificial breeding in the future.

Unless we can get 25 per cent of the young bulls used this coming season, the value of A.B. will surely diminish. If a special effort could be made to use these young bulls for this season at any rate, it would make the lot of the field technicians much easier. It is not easy for relatively young technicians to insist that the “big shots” in the farming world on their rounds take their fair share. The position will be closely watched this spring. If the daughters from these young bulls are not identified, and later tested, the scheme falls down again. It costs Is. to have a heifer calf identified and there is £5 for it when it is tested. A few heifers qualifying for the £5 rebate would help quite materially in meeting testing fees. Use of Milk Metering- Devices Strenuous efforts are being made to replace one of the major obstacles to more extensive testing (that is, the testing buckets in the sheds) with milk metering devices. If these devices are successful, I hope herd testing will show a very substantial increase so that we can put the genetic resources of a much larger sample of our dairying animals to work through A.B. for

the advantage of all dairy farmers in New Zealand. There is no shortage of bull power in New Zealand, but obviously we are trying to sort out the few at the top to make them available to any dairyman in New Zealand who wants them. Whether we use the top 1 or 2 per cent or whether we have to dip more deeply and take the top 5 per cent depends on the quality and numbersof proven bulls available, which, as the bull team in the future must depend very largely on the numbers proved within the A.B. organisation, must in turn depend on the number of young bulls used today and proved tomorrow. Unless greater use is made of the young bulls at our A.B. studs, users must expect a lowering of the present production gains. To avoid this a usage of 25 per cent of the unproven bulls is necessary, but with a bonus for identified tested daughters, which is at present £5, this should not be a very serious burden. If proven bulls of high standard become scarce, it may be necessary to increase the proportion of unproven bulls to safeguard the conception rate. This is one of our most important problems in A.B. and one which users alone can solve.

Beef Cows Also Susceptible to Contagious Abortion

BEEF cows are just as susceptible to contagious abortion as dairy herds, and many farmers have been able to increase the calving percentage of their beef cows by vaccinating heifers before mating.

Vaccination has reduced the New Zealand average rate of abortion in dairy cows from about .5 per cent to 1 per cent. Too many dairy farmers, however, still do not vaccinate their calves. Past freedom from abortion is no excuse for not vaccinating, as infection may be introduced into a herd at any time. ■

Though vaccination does not begin until early next year, applications should be made several months before to a Department of Agriculture officer or club veterinarian, as heavy itineraries have to be arranged.

Ruakura Research Station Given Valuable Collection of Books

MR J. M. RANSTEAD, of Matangi, a Waikato farmer with a wide knowledge of animal genetics, has given his library of 3,000 books to the Department of Agriculture’s Ruakura Animal Research Station. The collection includes a comprehensive and valuable section on animal genetics, some of the books being the earliest publications on this subject. Mr Ranstead, who was born in England and received his early education there, holds a diploma from Canterbury Agricultural College. A prominent breeder of Milking Shorthorns, Mr Ranstead is a former president and an honorary life member of the New Zealand Milking Shorthorn Association, and author of a history of the breed, which appeared in the “Journal” in 1950. He was the first president of the New Zealand Society of Animal Production and is an honorary life member. He served on the Council of Scientific and Industrial Research from 1936 to 1954, on the management committee of the Dairy Research Institute from 1947 to 1956, and on the Ruakura Animal Research Station farm advisory committee from 1945 to 1950. In 1931 Mr Ranstead was awarded the Bledisloe Medal, which is presented annually to an old student of Canter-

bury Agricultural College for outstanding service to agriculture. There have been few more familiar figures than Mr Ranstead’s at Ruakura Farmers’ Conferences, where he is received with the respect and esteem which are rightly his for his long association with and assistance to the work and objects of the Station. The generous gift of his library, which will be known as the Ranstead Collection, will be a fitting memorial in a fitting place to one who has been generous also with his time and energy in the promotion of better animal husbandry.

Care Needed in Injecting Pigs with Antibiotics ABSCESSES deep in the muscle tissue have been found in legs of pork and in hams. The Department of Agriculture considers that these blemishes have probably been caused by injections of penicillin cerate or other antibiotic substances which have either been outdated and inert at the time of use or been contaminated in some way. It is considered likely that the use of dirty needles or failure to sterilise the skin at the site of injection has caused much of the trouble, and pathogenic organisms planted deeply in the tissues have produced abscesses which are not usually found until the joint is carved at the table. The Department advises farmers using antibiotic injections for treating pigs to take the following precautions: Don’t use tubes of antibiotics after their expiry date. Use a needle sterilised by boiling,. Clean the skin at the injection site with methylated spirit or a reliable disinfectant. Inject into the area at the base of the ear; just behind the ear there is ample tissue into which the cerate can be squeezed. Do not inject into the muscle tissue of the hams.