THE AGE OF FIRST CALVING .sx At what age should a heifer calve ?sx This point is raised by a critic in the Irish Times , who , after remarking that opinion varies among farmers , adds :sx Something depends on breed , of course ; for Jersey and Guernsey cows usually have their first calf at around two years , which is much earlier than with most other breeds .sx Obviously , the earlier a cow calves the less is her cost up to the time of coming to profit .sx On the other hand , too early calving retards the growth of the dam , though it appears that stunted development is due not so much to carrying the calf as to the lactation which follows it .sx In actual farm practice , the time when heifers are first mated depends rather on their size than their age .sx Many farmers like their heifers to calve early in order " to get the milking habit into them , " as they put it .sx If first calving is postponed , they argue , the animals do not yield so well in later life .sx The problem is a complicated one , as is emphasised by studies lately made at Cambridge of records collected from a large number of herds .sx Exactly comparative experiments are not possible , of course ; for , as the investigators point out , " once a heifer has calved at two years old , it cannot be determined what she would have done if she had been left till another year .sx " The Cambridge results so far got are based on the outputs of 84 Shorthorn heifers of the ordinary farm type .sx When the animals were divided into five groups , according to age at first calving , the following figures were obtained :sx - With slight irregularities the rise in yield with age works out at an average increase of 80 lb .sx of milk in the lactation for every month of age .sx Now , since the older a heifer is , the larger she is , there is also a relationship between size and yield .sx Comparative measurements of all heifers were made :sx shoulder height being taken as the best single measure of size .sx The outcome is expressed in the statement that the lactation yield rose by 67 lb .sx for every centimetre ( 2 centimetres - 1 inch ) in shoulder height .sx Both age and size have influence in the milk yield , " part of the rise with age being due to size increase , and part of the rise with size being due to increase in age .sx " This sounds rather bewildering ; but , fortunately , the investigators have been able to disentangle the two effects of age and size to their own satisfaction .sx They express the final result by saying that a heifer's first lactation is put up by 66 lb .sx for every month's delay in calving , and by 51 lb .sx for every additional centimetre in shoulder height .sx At present all that can be deduced from the figures is that the longer the first calving is delayed the higher will be the yield in the first lactation .sx Time must elapse before the comparative yields of the different groups in later life is known , which is the all-important question .sx The average age of the first calving of all the 84 heifers was about 35 months , which is fairly close to the time at which Shorthorns in England and Ireland do calve first .sx As a result of the work the suggestion is made that it might be a good plan if heifers were calved for the first time at a rather earlier age to get them into milk , but not served again for some time , so as to give them a chance to make up growth during the first lactation .sx CHEESE AND BUTTER GRADING IN CANADA .sx Points connected with the grading and export of Canadian dairy produce were discussed by Dr. J. A. Ruddick , of the Canadian Department of Agriculture , when addressing the London Provision Exchange Ltd. , recently .sx Dr. Ruddick said that the outlook for Canadian butter and cheese at the present time was difficult to sum up .sx He did not look for a great increase in cheese production .sx The figures this year showed a small decrease as compared with last year .sx The prices of butter remained high , and the wholesale figure was from 31 to 33 cents per pound .sx So far as butter was concerned , there was a very substantial increase in production , and especially as regards the increase for home consumption .sx The increase of consumption from 1921 to 1929 was equivalent to 154,000,000 lb .sx of butter fat .sx In 1921 the consumption of butter was 25.79 lb .sx per head , and in 1929 30.56 lb .sx , an increase of 18.4 per cent .sx Cheese consumed in 1921 was 2.51 1b .sx , and in 1929 3.54 1b .sx , an increase of 41 per cent .sx About the time Canada ceased exporting butter to this country new regulations came into force .sx It was laid down that all butter should be branded and that there should be date marking .sx In the years previous to 1926 there had been considerable speculation on the part of those who were not connected in any way with the dairying industry .sx It was their practice to buy up considerable quantities of stocks and hold them , in some case for quite a long period , until the market prices rose at above the figure which was originally paid for the stocks .sx That was the reason why the Date Marking Order came into force ; the object , of course , being to ensure the freshness of the butter .sx He had an open mind on the subject , but if it could be shown that a Date Marking Order would be detrimental to the butter and dairying trade , it could easily be altered , but they all hoped that it would work out to everyone's advantage .sx Under the grading system existing to-day they were enabled to pass on to the chief officials statements showing the registered number of factories and those who were sending out inferior cheeses .sx That information had put all the managers on their toes , and several associations had been formed .sx Great interest was being taken in the matter , and it was the object of everyone nowadays in Canada to produce the highest grade cheese .sx Grading became compulsory in the spring of 1923 , and nothing had had such a marked effect on the cheese industry .sx In the first year the first class graded cheese in some factories was 78 per cent .sx , and last year it was 93 per cent .sx , and in some cases 98 per cent .sx Some factories had last year produced cheeses throughout the season which were 100 per cent .sx first class .sx Practically all the cheese made in Canada was now graded and the Canadians felt that they had also made very substantial progress in bettering the quality of butter during the past five or six years .sx There had been some suggestion made to adopt a national brand , but so far that was only a suggestion .sx DEPRECIATION IN DAIRY COWS .sx In recent years several investigations have been made into the length of the life of the dairy cow .sx One of the latest inquiries on the subject has been that made by the Agricultural Organiser of Kent .sx Though limited to that county is was fairly extensive in scope , for it covered 32 herds in 1930 and 50 in 1929 , all on milk-selling farms .sx The significance of the results turn largely on the interpretation of the term " wastage .sx " Cows are eliminated from the dairy herd while still fairly young for other reasons than disease or failure to breed .sx Thus in the Kent inquiry it was found that apart from disease , cows were discarded because their milk sometimes failed to reach the standard , to make room for incoming heifers of promise , or - it was presumed - simply because their owners happened to be short of cash .sx One may add , too , that since so large a proportion of our dairy herds consists of dual-purpose stock , the fate of many animals of barely average milking capacity will be decided by their value for beef purposes at any given time .sx The heavy cost of feeding and general upkeep will encourage a tendency to fatten off many cows whilst they are yet young enough to command a reasonable monetary return on the beef market .sx Animals eliminated for any of these various reasons cannot be classed as " wastage " in the ordinary sense of the term .sx Of the 596 cows which died or were discarded from the Kentish herds investigated during the two years , 99 were sold for one or other of the above reasons , leaving a net wastage of 497 .sx This works out as representing 21.8 per cent .sx of the total head , which gives 4 years and 7 months as the average milking life of cows .sx Sterility ( 131 ) , Johne's disease ( 47 ) , mastitis , or loss of quarter ( 46 ) , and tuberculosis ( 29 ) are mentioned as the chief causes of loss , and no doubt these troubles were often accelerated by malnutrition .sx Depreciation is certainly a serious item in connection with the value of the cow .sx A Dairy Shorthorn at the time she drops her third calf is worth approximately 35 .sx After milking for five more years , she should be worth about 15 as cow beef when ten years old , so that depreciation in such a case amounts to 4 per annum .sx This is certainly not excessive , but usually it represents a charge of over a penny a gallon on the milk produced .sx When the length of life is much shorter , depreciation may be so high as twopence a gallon .sx The Council of the British Friesian Society declares that the average milking life of the cows of their breed is as high as seven years .sx The cows investigated for the purpose were some 300 Friesians producing around 2,000 gallons a year each .sx PLEA FOR FIXED BACTERIOLOGICAL STANDARD .sx A number of local bodies have decided to support the following resolution passed by the Gloucester City Council :sx " That in view of the great danger of dirty milk to consumers , and particularly children , the Minister of Health by urged to take the necessary steps to enable a definite bacteriological standard for milk to be fixed , and to make it an offence for producers and retailers to sell milk not of fixed standard .sx " When the resolution was considered by the Walsall Town Council Alderman Leckie opposed it on grounds that the health committee already had ample powers to deal with the question of milk quality .sx " This resolution comes from Gloucester , " said the Alderman .sx " Well , I can confidently say that there is no danger of dirty milk in Walsall .sx If there is any dirty milk , it is because the sanitary authorities are not doing their duty .sx They have ample powers to see that milk is clean and pure .sx " He would remind the Council of the very stringent regulations buyers had already to observe .sx If they went on passing resolutions of that kind they would make production at a reasonable price impossible .sx Alderman Hucker , replying , said that it was the producer who was to blame for dirty milk .sx They could not provide enough milk for Walsall from the borough alone ; much of it had come from the county .sx The Council finally decided by a large majority to support the resolution .sx Bristol and Bath public health committees both gave their support .sx Dr. H. R. Parry , medical officer of health for Bristol , said :sx " I feel that we are not doing nearly enough for the sake of clean milk .sx I think there is a great deal to be said in favour of this examination for bacteria in addition to the examination for fat .sx We make some examinations for bacteria , but there should be more of them .sx " At the Bath Public Health Committee Dr. Blackett said that the difficulty was not so much adulteration , but cleanliness in the working of a farm dairy department .sx A bacteriological standard , if practicable , was certainly desirable ; it was not possible to have bacteriologically pure milk without pure methods preceding it .sx The Chairman ( Major Timmins ) agreed that it was the method of milking rather than the magnificence or otherwise of the building which really mattered .sx He said he had known beautiful buildings and filthy methods , and old buildings where much cleaner methods prevailed .sx