POULTRY NOTES

Bay of Plenty Beacon, Volume 1, Issue 55, 28 August 1939, Page 7

POULTRY NOTES

CORRECT ARTIFICIAL BROODING Most poultry-keepers now realise thnt unless a sufficient number of good pullets can be reared each year to replace from one-third to onehalf of their flocks the venture not likely to prove the greatest sue. cess. The question is of ten asked: ''What is the average or normal lo:"S that may be expected during the rearing stage?" Tiie following remarks concerning this matter are taken from W . A. Lippinott'.s "Poultry Production." ''Losses by death are commonly accepted as a necessary part of the cost of raising chickens but there has been no agreement as to what might be looked upon as standard nor mal mortality. Indeed, there has been little available evidence on which to base such calculations uiHil \ery recently. The mounting death losses in many sections of the country led eventually to the outlining and carrying out of rather rigid sani tation programmes, and the results of their adoption have shown clearly that death losses can be greatly ie» duced from what they would be without the application of such prac tices. "In a technical sense, it is important to distinguish between the normal or expected mortal ity ? such as might properly be used for the construction of a life table, and the specific death loss resulting from infectious diseases, parasitic infestation and the like, though the practical poultryman is chiefly concerned with the total death loss and its monetary significance. DAILY MORTALITY. "Voorliies and Read (1931) have made the only extensive study of daily mortality in young chicks and their data over the first 1-t days of the brooding period, and which included (5,000,000 chicks in 6313 broods in the years 1927, 1928 and 1929. The total loss, or crude death rate, in each of the three years was (585 739 and 843 respectively per 10000 chicks. On the basis of daily mortality their data shows a rapi'l rise to a sharply-defined peak on. the fifth day, with a rapid falling off alter the fifth day until the 14tb, when the rate is slightly below that of the first day. They concluded that there are indications of a typical curve depicting the chances of life for a baby chick during the first 14 days of the brooding period, and that baby chicks have approximately 920 chances out of 1000 of reaching the 15th day of the brooding period. "Landauer and Landauer (1931) made a study of mortality in relation to the sex ratio. Thev found that the combined figures for all observations of various workers, of the sex of chicks "t hatching, amount to a total 'I <57,903 chicks, with 33,1(52 or 18.77 per cent, males. V. cannot be doubted, therefore, in gen era! there is a deficiency of male chicks at hatching time. They found that the mortality during the first two months after hatching was greater among males than among females. FIRST EIGHT WEEKS. "Barrett (1929) studied the causes and distribution of mortality among -180(5 chicks in seven different hatches during the first eight weeks. The total loss amounted to slightly more than 11 per cent. He concluded that the crude mortality' curve, plotted on a time basis is characteristically bimodal when both pullorum disease and coccidiosis are factors in the death loss, and monomodal in the absence of coccidiosis. He found a relatively high initial mortality unassociated with disease, that was greatest during the first week and much reduced during the second and third weeks. This is in accord with the findings of Voorhies and Read. "Judging from the results of sanitation plans that have been carried out in a number of States during the past few years it is entirely possible t 0 reduce the total mortality, from hatching time to maturity, to something less than 10 per cent. It is probable that it will become increasingly necessary for a commercial poultryman who expects to remain in business to adopt a management plan thnt will keep his gross rearing mortality at or below this figure."