DAIRY-HERD IMPROVEMENT.*

New Zealand Journal of Agriculture, Volume XXVII, Issue 1, 20 July 1923, Page 21

DAIRY-HERD IMPROVEMENT.*

SOME LEADING FACTORS.

W. M. SINGLETON,

Director of the Dairy Division.

HERD-TESTING.

“ By their fruits ye shall know them ” is a saying not more true of human beings than of dairy cattle, and there is conclusive evidence that during the past two seasons our dairy-farmers have been more inclined to obtain an accurate idea of what amount of butterfat the individual dairy cow is delivering. Until more recent years comparatively little testing was done — partly because many dairymen were making a comfortable living without going to that trouble, and partly because man thought the Babcock machine could not tell them very much about their cows ; in other cases, again, the releaser system of machine milking did not facilitate the taking of individual samples and milkweights. In some instances it is possible that owners were rather afraid that some of their favourite cows might not make good, and as a consequence did not test. However, more dairymen are now facing facts, and in the past season some eighty-four thousand cows were tested for yield under the association system.

The influence of herd-testing is frequently very manifest during the second testing season for the herd. For example, among the herdtesting associations whose computations were made at the headquarters of the Dairy Division, during T 920-21 and 1921-22 were some 218 herds which were tested in both these seasons. The yield of the average cow in these herds increased from 213 lb. to 253 lb. of butterfat, or about 19 per cent. Even granting that some portion of this increase may have been due to the fact that 1921-22 was a better season for grass, much of the improvement is undoubtedly due to knowledge gained as . the result of the previous season’s testing. In these herds the number of cows tested each season was very similar. Our figures show that often dairy-farmers reduce their herds as the result of testing, and still maintain the total yield of the herd. We also have data which show that in certain cases during a second testing season with only two-thirds of the previous season’s herd the total butterfat produced underwent no reduction, while one dairy-farmer during his first testing-year milked twenty-three cows to produce as much butterfat as did sixteen which he milked two seasons later. Instances which bear out the same principle could be multiplied. The first testing season’s returns were prejudiced by overstocking and therefore underfeeding. ■

MANAGEMENT.

Like children, dairy cows are perhaps more often “ sinned against than sinning.” The yield of the average dairy cow in New Zealand

would be very materially increased with better feeding and attention, for there are many cows in our herds which if given all the feed they can consume and convert into milk would produce much larger credits for butterfat. Not all crossbred cows would respond as well as purebred, but our experience in testing purebreds goes to indicate that frequently it is the owner and not the cow who is the cause of poor production. One breeder in the early days of the certificate-of-record system entered over thirty purebred cows for test in one season. With so large a team it was found impossible to give the individual attention requisite for the production of good records, and the result was that only two of the cows produced as high as 400 lb. of butterfat —the season’s work, so far as C.O.R. testing was concerned, being undoubtedly a failure. However, a number of the cows were retested during a later season and under better conditions, with the result that the butterfat records were increased as follows : Lot 1 : j First record, 351 lb. ; second record, 581 lb. Lot 2 : First record, 319 lb. ; second record, 528 lb. Lot 3 : First record, 304 lb. ; second record, 566 lb. Lot 4 : First record, 286 lb. ; second record, 630 lb.

THE CULL-COW PROBLEM.

It is necessary that known low producers which have been culled should as far as possible be prevented from entering other dairy herds if the greatest improvement in the production, of our average cow is to be safeguarded. Many methods of solving the cull-cow problem have been put forward, but so far no really successful way out of the difficulty has been found. Branding has frequently been urged, but is, or would be, difficult to enforce ; and spaying has. been practised by some with satisfactory results. The best solution in the end, however, may be found to be better breeding, which will lessen the proportion of low producers as results become more generally extended throughout our dairy herds.

INFLUENCE OF THE PUREBRED SIRE.

The influence of the purebred sire has been often stressed, and not without reason. In a herd of registered purebred dairy cattle it may be assumed that a purebred sire is at least " one-half the herd.” This will, of course, depend on the breeding. In many purebred herds, and also in grade or crossbred dairy herds, a registered purebred sire of good breeding is more than half the herd. It is more prepotent for good or evil, as ' the case may be. The Dairy Division possesses tabulated records of ninety dairy cows and of daughters of these cows sired by purebred dairy bulls. The records were made at various ages, but correcting them to a basis of records at mature age it has been found that the records of the daughters are 28 per cent, higher than those of the dams. Possibly some of the daughters had better testing-conditions than their dams, as the owners may have' profited by experience obtained while the 'dams were under test or after they were tested ; but even if the percentage of improvement is reduced from 28 to, say, 10 there still remains a potent recommendation for better breeding.

■ It is becoming more generally recognized that the earning-power of purebred stock is considerably above' that of scrub stock, even if

sales of progeny be eliminated from consideration.. That this principle holds good with dairy stock in an exceptional degree will,- I believe, be admitted. The fact is becoming evidenced in the increase in the proportion of purebred dairy bulls in . use in dairy herds. During the 1917-18 season some 8-5 per cent, of the total, bulls in such use were purebred Jersey, Friesian, Ayrshire, or Guernsey. During the 1921-22 season the percentage was 14-5, and a marked increase may be expected during the next decade. This extension of better breeding practice is one of the most encouraging factors among those affecting herd - improvement, largely because it is possibly the most potent factor operating in that direction. Given a reasonably good environment, including suitable feed, high-grade or purebred cows may be relied upon to produce from 25 to 50 per cent, more than scrubs. In one of our best herd-testing associations the lowest-yielding herd was headed by a grade Shorthorn sire,, whereas all herds averaging 300 lb. of'butterfat or over were headed by purebred dairy sires.

BREEDING METHODS.

The most popular system of breeding, and one which can be strongly recommended, is that known as line-breeding. This may be indicated as mating a grandson to granddaughters or great-granddaughters of the same animal by a different line. This class of breeding fixes type more slowly than inbreeding, but by means of the .bringing-in of the,outcrosses it enables the correction of defects in the strain whose blood lines are being concentrated. Line-breeding is a safe system, and does not require the consummate skill which inbreeding demands of the breeder so far as selection and culling are concerned. Inbreeding, which implies the mating of such near relatives as sire and daughter, son and mother, or brother and sister, accentuates inferior factors just as readily as good ones, and may be responsible for sterility, lack of constitution, or defective type, if such exist in the animal whose blood lines are being concentrated in the progeny. The Duchess family of Shorthorns developed sterility because .the original Duchess was a “ shy breeder.” . •

HEREDITY AND ENVIRONMENT.

There has for years been a difference of opinion between scientists regarding the extent of the respective influence of,heredity and environment. But so far as these affect the evolution of a good dairy herd there should be no difficulty. The best breeders believe in endowing the calf at conception with all the factors, pertaining to heavy production which heredity can give it through good breeding. This, however, must be followed by suitable environment, such as will enable that calf, both before and after birth, to so develop that those hereditary factors may not be handicapped in any way, but may get free play to' carry out that for which they were preordained by Nature. Thus heifer dairy calves in the hands of the best owners will not only be well bred, but grown on foods which will promote excellent growth, constitution, and capacity. If the young animal be. underfed and small the heredity factors for high production cannot possibly produce the large yields of which they would be capable if housed in a welldeveloped body maintained by a strong constitution.

NEW ZEALAND AND DENMARK.

Denmark began cow-testing much earlier than New Zealand ; in fact, I believe that some Danish dairymen were weighing the milk of individual cows before Wellington was founded in 1840. The first cow-testing associations in Denmark were started in 1895, and in 1921-22 there were tested through milk-recording societies some 230,000 out of a total of 1,184,000 dairy cows, some 20 per cent, thus being under test.

In the past 1922-23 season New Zealand has tested some 84,000 out of a total of 1,137,000,. or about 7’35 per cent. We have a considerable distance to go yet along this line, but. judging by the two last seasons’ progress we are catching up very well indeed. The butterfat yield of the average Danish cow on test for the 1921 season was 261 lb. The yield in New Zealand for the 1921-22 season was some 245 lb. for cows on association test. This difference between the Danish and New Zealand average cow on test is not so large but that we may hope to overtake it, but personally I do not consider the overtaking of it a vital matter in the meantime. I consider it better to overtake the proportion of cows being tested, even although this might bring under test animals which would lower the average yield of cows on test.

We estimated the butterfat yield of the average cow in New Zealand during the 1921-22 season, taking those in milk and dry, as 168 lb. If one animal in -ten be .non-productive this gives the yield of the average cow in milk as 187 lb. The average butterfat yield of 660,000 cows supplying Danish co-operative creameries during 1920-21 was 198 lb., as nearly as can be calculated. It should therefore not be impossible for us to overtake the Danes. In the meantime- dairying in New Zealand is in the evolutionary stage. In a young country such as this, where the dairy industry is extending each year, we cannot expect to attain to the production of the average cow of, say, Denmark until our cow population stabilizes in greater degree. The Dominion’s carrying - capacity for dairy cows is increasing rapidly. New land is being steadily brought into grass, and top-dressing is improving older pastures. Our dairy-cow population has increased by over 50 per cent, in the last five years, the 1923 statistics showing another gain of 100,000 head.

When the dairy [land in this country, is all brought in as in Denmark, and when the number of our dairy cows shows little or no increase, we may reasonably expect greater improvement in their average yield. We can then cull the herds more severely, and the influence of better breeding and culling will be more generally demonstrated. I believe it to be only a matter of time until the New Zealand dairyman has the -yielding average dairy cow in the world.

■ Importation of Sheep into Argentina. — Under a recently issued Argentine decree sheep for breeding purposes may be imported into Argentina from New Zealand and Australia even if they have been transhipped at Cape Town, provided that their sanitary condition is satisfactory and that they arrive with the regulation certificates. . .: " . C.....’. .

* Substance of a paper read at the annual conference of the New Zealand Council of Agriculture, Wellington, July, 1923.