Studies on the Resistance of the Chicken to the Nematode Ascaridia Perspicillum*

Age Resistance of Chickens to the Nematode Ascaridia lineata (Schneider)

“…In the same year, while studying the effects of the intestinal nematode, Ascaridia lineata, in chickens, Ackert and Herrick (I928) found that the birds four months of age were much more resistant to the nematodes than were the chicks one month old. Subsequent confirmations of these findings led to the studies of Herrick (1926) who found a gradual increase in the resistance of chickens to the growth of the nematode during periods of 10 days of parasitism. Beginning with chicks five days of age his results indicated that the resistance increased with age up to 103 days after which no further increase was detected.…”

Experimental Studies on the Biology of Capillaria obsignata Madsen, 1945, a Nematode Parasite of the Domestic Fowl

“…Age resistance is known in many nematode infections and has been demonstrated in the fowl against A.galli and H. gallinarum (Herrick, 1928;Ackert, Porter and Beach, 1935;Deo and Srivastava, 1962a, b). The present report appears to be the first record of such resistance to C. obsignata.…”

The Nature of Helminth Infestations in Chickens in East Tennessee

“…Concerning these seven species, it can be noted that the adult birds had the higher percentages of infection in 5 instances; adult birds had a higher average number of worms present in 5 instances; and the range of specimens present reached higher levels in adults in 6 instances. Despite the fact that older chickens have been demonstrated to develop an increasing resistance to infection with Ascaridia galli in the absence of previous infections (Herrick, 1926), age resistance apparently does not prevent infection at any age. Adult chickens examined in Tennessee during 1945 carried, on a given helminth stimulates the development of an acquired immunity, a second assumption to be considered is that the larger the initial infection, the fewer will be the number of helminths able to develop in a second infection.…”