Observations on the occasional depressing influence of fish meal on the hatchability of hens' eggs

Abstract

The failure of a high proportion of fertile eggs to hatch still remains a major cause of financial loss to the poultry industry. Payne (1919) pointed out the consistent manner in which embryonic mortality manifested peak periods at the fourth day and the nineteenth day of incubation, and he drew attention to the fact that the latter period of susoeptibility showed an increased level of mortality with artificial incubation compared with natural methods. Romanoff (1949) summarized the explanations put forward to account for these two peaks of embryonic mortality. Riddle (1930) suggested that the first period was caused by respiratory maladjustments, and he, and others, considered that the failure of the developing embryo to make the fine adjustments at this time and to deal effectively with the excretion of various toxic substances may be a major cause of death. The second peak period of mortality occurs at the transition from allantoic to pulmonary respiration. Failure to achieve this change, with the consequent death of the chick in the last stages of development, may be greatly influenced by the cumulative effect of all the unfavourable conditions to which the hatching egg has been subjected. Not the least of these will be environmental conditions in the incubator and the incubator house adversely affecting the oxygen supply and the relative humidity.

Inorganic Iodine is not the Factor in Fish Meal which Depresses Hatchability

“…Since this substance has been incorporated in rations for many years it was rather surprising when Black (1953) and Black et al (1954) reported that fish meal depresses the hatchability of fertile eggs. This result has, however, been confirmed by Shaw (1955) and Coles (1956), and has been repeated on several occasions at Reading. Black et al, opened all eggs which failed to hatch and found the decrease in hatchability to be accounted for by increased embryo mortality during the last 3 days of incubation.…”

The effect of white fish meal on the hatchability of hens’ eggs

“…The results reported here, together with those of Shaw (1955) and Coles (1956Coles ( , 1957a, make it possible to extend meal, the magnitude of the response in different circumstances and with different levels of fish'meal, and the possibility that samples of fish meal differ in their effect on hatchability. No attempt will be made in this paper to review all the possible causes of the fish meal effect.…”

“…However, work carried out at Reading over a number of years has shown that its use in certain types of breeding rations results in lowered hatchability (Black, Jenning, Morris and Palgrave, 1954;Black, Morris and Palgrave, 1957;Marsden, Jennings and Martin, 1957). Shaw (1955) and Coles (1956Coles ( , 1957a have also reported that fish meal lowers hatchability. The basal ration used both at Reading and by Shaw was a simple mixture of ground cereals, cereal by-products, salt, manganese sulphate and vitamins.…”

“…The possibility that the depression is due to a higher intake of protein, rather than a specific effect of fish meal, has been eliminated by other experiments in which earthnut meal and meat-and-bone meal have been used as alternative protein supplements (Fox and Martin,i960). Coles (1956) suggested that lowered hatchability might be caused by bacterial contamination of the fish meal sample, but abandoned this explanation after a further year's work (Coles, 1957a). From a comparison of four samples offish meal, he then suggested that depressed hatchability might be due to heat-damage of the proteins in certain samples offish meal (Coles, 1957a).…”

“…The original work on the subject of fish meal and hatchability (Black etal, 1954) and more recent papers by Coles (1956Coles ( , 1957a suggest that the depressant effect of fish meal is only found in certain samples.…”