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13. Total Butterfat Production : The level of total butterfat production for the Dominion is a direct result of total number of cows and average per-cow production. It has been noted that, with but minor exceptions, the movement in cow numbers and in their average production has been consistently upwards, and the combination of the two factors showing cumulative increases has resulted in a rapid advancement of the season's output from year to year. This is shown in Table lof the Statistical Appendix, where total butterfat produced is given to the nearest million pounds from 1901-2 onwards. In fourteen seasons, ending in 1920, production was doubled. In the fourteen succeeding seasons ending in 1934 production exceeded the 1919-20 level by more than three times. The highest annual increase was registered in the season 1932-33, when the previous season's output was exceeded to the extent of 57,000,000 lb. of butterfat, or an amount approximately equal to the total increase recorded between the seasons 1908-9 and 1919-20. Total butterfat production on an index basis is also shown in Table 1 of the Statistical Appendix. 14. Replacement Stock : Movements in total butterfat production are influenced to a greater extent by the movement in cow numbers than by per-cow production. In view of possible restrictive marketing measures to be faced in the future, the present stock-replacement position is of great importance. The total number of cows carried during the current milking season will not be enumerated till January, 1935, but is determined by the number of dairy cows carried last season, plus replacement stock, less deaths and killings of mature cows. The position should therefore be approximately as follows :— Total cows, January, 1934 .. .. .. .. .. 1,932,000 Add replacement heifers .. .. .. .. .. .. 372,000 2,304,000 Subtract deaths, say, 70,000, plus killings, say, 250,000 .. .. 320,000 1,984,000 The accuracy of this estimate of 1,984,000 depends upon the number of dairy cows slaughtered for the year ending 31st January, 1935. Although such killings have increased of recent years, the highest number yet reached is approximately 200,000. This would have to be increased to 300,000 for the current year to keep the Dominion's total herd at the 1933-34 level. It is not anticipated that the suggested figure of 250,000 will be exceeded, in which case at least 50,000 more dairy cows will be carried than last year. Even if killings of dairy cows reach 250,000, it is more than probable that additional killings will be of dry cows, in which case the effective milking herd for the present season may be more than 50,000 in excess of last season. The position of heifer calves shows very little variation from last year, the figures being 381,000, compared with 380,000 in 1933. Thus the foundation stock is available to ensure that the 1935-36 herd is maintained and increased unless a policy of heavier killing is adopted. 15. Factors affecting Increased Production : As previously stated, the number of cows carried and the average per-cow production determine the volume output of butterfat. These two basic factors are the resultants of (a) the amount and quality of feed made available to dairy cows ; and (b) the inherent production capacity of dairy stock carried. (a) The fundamental determinants of quantity and quality of grass-growth are the incidence and spread of rainfall, temperature, soil fertility, and topography of the land used. As the dairyfarmers of New Zealand depend almost entirely on pasture in its green or cured state to provide stock food, the factors mentioned are of supreme importance, and have been increasingly exploited during recent years. Intensification of pasture management has taken the form of improved pasture associations and the use of proved strains of grasses and clovers, closer subdivision of farms, greater attention to pasture cultivation, rationalized rotational grazing, and conservation of surplus pasturegrowth. These management features, combined with the discriminate use of artificial fertilizers, have enabled farmers to bring their good pasture-land to a higher state of efficiency, and to bring portions or the whole of previously undeveloped areas of their farms into a state of improved productivity. The area devoted to, and consequently the feed available for, dairy cows has been expanded during the past four years through a partial change-over from sheep-farming to dairying, where sheep-farmers had suitable land available. This movement has been brought about by the extremely low prices ruling for meat and wool in the early years of the depression, and by reason of the fact that dairy cows offered a means of increasing sheep-farmers' incomes without the necessity of incurring much capital expenditure. The utilization of fertilizers on dairy farms is not scheduled separately from that used on sheep farms, but the following figures, showing the total area top-dressed, indicate the trend during recent years : — „ Area Top-dressed, Season. . \ r- wrmmm m Acres. 1926-27 .. .. .. .. .. .. .. 1,414,264 1927-28 .. .. .. .. .. .. .. 1,834,366 1928-29 .. .. .. .. .. .. .. 2,534,496 1929-30 .. .. .. .. .. .. .. 2,650,748 1930-31 .. .. .. .. .. .. .. 2,432,438 1931-32 .. .. .. .. .. .. .. 2,454,321 1932-33 .. .. .. .. .. .. .. 2,4-38,114 1933-34 .. .. .. .. .. .. .. 2,249,170

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