Death Of Chickens Research Articles

EFFECT OF DIETARY EDTA ON THE ABILITY OF CHICKS TO TOLERATE SODIUM CHLORIDE IN THE WATER

Broiler chicks, allocated in a randomized block design, were fed four diets containing ethylene diamine tetraacetic acid (EDTA) at 0, 0.1, 0.2 and 0.4% of the diet and drinking water with a high salt concentration (6000 ppm). A control group received tap water and the EDTA-free diet. The addition of 6000 ppm NaCl in the drinking water had no effect on weight gain or feed conversion. Similarly, the inclusion of up to 0.4% EDTA in the feed had no adverse effect on weight gain. Analyses of packed-cell volume (PCV) and plasma sodium, chloride and calcium concentrations showed no changes as a result of treatment. Water consumption almost doubled for the chicks subjected to high salt water regimens compared with the control. Two groups of chicks received the EDTA-free diet, and significantly (P < 0.10) higher mortality was found for the group on the salt water compared with the tap water controls. The mortality in the former was also significantly (P < 0.10) higher than for the group receiving 0.2% EDTA in the diet and salt water. The chicks on the 0.4% EDTA diet had significantly (P < 0.05) higher mortality than control chicks on tap water and those chicks receiving salt water and diets containing 0.1% and 0.2% EDTA. Postmortem examination indicated that ascites and widespread edema were the causes of death in chicks that drank salt water and consumed diets containing no EDTA or 0.4% EDTA. The death of chicks on treatments that resulted in low mortality rates was not attributable to ascites. The reason for the apparent beneficial effect of feeding 0.2% EDTA in the diet in conjunction with the salt water remains open to conjecture.

ASPECTS OF McCORMICK SKUA BREEDING BIOLOGY

SUMMARYThe breeding behaviour of the McCormick Skua was studied at Cape Royds, Antarctica, for three summers. These observations followed the work of Young (1963a, b).Records of banded birds suggest that at the age of five to six years birds return to breed in the area where they were reared. Breeding pairs retain the same territory and mate over consecutive summers. The male will retain a territory and remate if the female does not return, while there is some evidence to suggest that if the male is absent the female will leave the territory and remate elsewhere.Unfavourable weather frequently forced incubating birds to desert their eggs and as a result some pairs laid three clutches (at the most two clutches of two eggs and a clutch of one).The death of sibling chicks from fighting was examined by comparing the early growth of 11 successful pairs of chicks with that of 12 pairs in which one of the siblings died as a result of fighting. From a comparison of weights at hatching and the interval between the hatching of members of chick pairs, it appears that the difference in weight between twins and the gain in weight by one chick in the first few days is critical for the survival of the twins.The breeding success, calculated from the total eggs laid and the total number of chicks fledging, was 40%, 42% and 17% for the three respective summers. Storms (periods of wind with snow) were the main factor influencing breeding success.

Deaths of guinea-fowl chicks associated with forage mite infestation.

Deaths of guinea-fowl chicks associated with forage mite infestation.

Non-parasitic Mites causing Death of Guinea-fowl Chicks

IN Britain, hay is often infested with mites, especially the species Tyrophagus longior (Gervais) and Kleemania plumosus (Oud.), and Hughes1 gives other species which occur in hay. Near Aberdeen recently, substantial losses of guinea-fowl chicks occurred where birds were housed directly beneath a loft containing baled hay. The hay was found to be heavily infested with the following species of mites: T. longior, K. plumosus, K. plumigera (Oud.), Glycyphagus destructor (Schrank) and Acarus farris (Oud.)—mainly hypopi. Veterinary examination did not indicate any specific disease to be responsible for the death of birds, which amounted to about seven hundred out of a total of two thousand chickens. All deaths occurred when the chicks were about 14 days old, and over a period of 2–3 days. It was found that the mites were “raining down” on to the chicks from the loft. Although guinea-fowl are hardy and easy to rear they are very nervous, and the number of mites present was considered to be responsible for affecting the behaviour of the chicks. Excessive overcrowding, with birds three to four deep, caused suffocation under the brooders, where the birds congregated as a result of the mites constantly present without brooder cover.

COMPARATIVE BIOLOGY OF THE WHITE BOOBY AND THE BROWN BOOBY SULA SPP. ATASCENSION

SUMMARYThe breeding cycles and related biology of the White Boorby Sula dactylatra and the Brown Booby S. leucogaster at Ascension were investigated between November 1957 and April 1959.In both species there were marked peaks of laying, with intervening periods of very few new clutches. In the White Booby, although only one full season was studied, an annual cycle was deduced; in the Brown Booby (two full seasons) the cycle appeared to be eight‐monthly. The breeding season (laying of eggs to fledging of chicks) was however roughly the same length in both species, namely six to seven months. Individuals of both species for the most part conformed to the breeding seasons of the population as a whole, i.e. if out of phase for some reason, had a longer or shorter “rest” period as necessary to bring them into phase again for the next season. These discoveries indicate that external factors are controlling the times of breeding. The proximate factors are not known; at Ascension there is no appreciable seasonal variation in day‐length or climate, and possible cycles in the surrounding sea could not be investigated.The two species' periodicity was such that, if maintained, every two years they would lay at almost the same time of year, July–August. The possible relation of these observations to a single underlying factor, perhaps annual variation in oceanic conditions with their origin in the seasonal melting of the Antarctic ice and consequent effect on the food cycles, is discussed.Details of incubation, desertion, feeding, care and growth of the chick are given. The regular death of the second chick as a result of asynchronous hatching, and experiments with twins are described. A low breeding‐success, and deaths of chicks from starvation, indicated that both species suffered a shortage of food over an ill‐defined period around August‐September 1958. Regurgitations of food examined throughout the study, and a few observations on feeding, indicated a big overlap in the two species' diets, mainly flying‐fish, but some differences did appear.Details of moult, mainly in the White Booby, are given. Shedding and re‐growth of the juvenile primaries began at about seven months of age, proceeding from the innermost outwards in three spaced concurrent cycles, this remarkable pattern continuing throughout adult life. A period of pause in the primary moult was correlated with the time when most birds had chicks, but some birds were known to be moulting their primaries while breeding. A prolonged moult with a pause during breeding was indicated by examination of some other Ascension species; the relevance of this to the availability of food and breeding seasons in tropical sea‐birds is discussed.

A Consideration of Galactose Toxicity in Male and Female Chicks

A CONSIDERATION of galactose toxicity and metabolism in the chick is significant in that milk products are often fed to poultry. As problems arise in some animals and humans when galactose is ingested, it is important to understand the basis of galactose toxicity. The chick is particularly sensitive to ingested galactose and exhibits some striking and characteristic symptoms. In so far as results with he chicks may be generalized, such studies are also of some theoretical significance.Although Dam (1944) reported that a diet containing 55 percent galactose caused convulsions and death of young chicks, it was subsequently found (Rutter et al., 1953) that galactose is not tolerated by chicks when fed at levels exceeding 10 percent of the diet. A typical quivering syndrome develops after several days of feeding galactose and in more severe cases epileptiform seizures and sometimes death result. Traces of lactose and high concentrations of galactose …

The Influence of Egg-Shell Porosity on the Number of Chickens Hatched from Incubating Eggs

INTRODUCTIONTODAY a great number of hereditary factors are known which may cause death of chicks in the course of embryonic development. Lethal factors influence decisively the number of chicks hatched from incubating eggs. In addition to these hereditary defects there are many others which influence the hatching results. The knowledge of all facts relevant to this matter is, of course, of great practical importance; for, the profitableness of incubation—under optimum conditions of temperature and moisture—depends above all, aside from fertilization, on the hatching power of the eggs. In this connection attention is directed to the excellent, concise treatises by Axelsson (1932), Hutt (1949) and Jull (1947), as well as those by Landauer (1948), Romanoff (1949) and Taylor (1949). Tests were made in order to establish the relation between the hatching result and the following factors: the age of the hen, the time of the day and the .

The Effects of Various Degrees of Chilling on Mortality and Growth of Baby Chicks

The chick embryo during its early development reacts as a poikilothermic or “cold-blooded” animal (Romanoff, 1941), but as the incubation period progresses, the embryo acts more like a homeothermic or “warm-blooded” animal until about the 20th or 21st day when there is no marked response to changes in external temperature (Pembrey, Gordon, and Warren, 1895). Lamoreux and Hutt (1939) reported a pronounced rise in the body temperature of the chick during the first week after hatching. Randall (1942) found that the temperature of the Barred Plymouth Rock chick increases from a temperature identical to that of its environment (incubator at 38° to 39° C.) to about 41° C. (105.8° F.) ten days after hatching, after which time it approaches and remains within the limits of the diurnal variation of the adult. The same worker reported further that hypothermic death in chicks is primarily caused by anoxic paralysis of the respiratory .