Variation in resistance to Pasteurella multocida among turkey lines

Abstract

Previous research has shown that a line (F) of turkeys selected long-term for increased 16-wk body weight was more susceptible to challenge with washed Pasteurella multocida than a randombred control line (RBC2), the base population of F. A previous study also indicated that the mortality of the F line following challenge with P. multocida was similar to that of sire lines from two of the three major primary breeders. The purpose of the present study was to compare the resistance of the sire line from the third major primary turkey breeder (C) not previously studied with that of the F and RBC2 lines to determine whether there is variation in resistance among the sire lines from three major primary breeders. The sire lines from all three primary breeders were used in the production of commercial turkeys. Body weights of the F line were greater than those of the C line at the time of challenge with P. multocida. Both the C and F lines were heavier than the RBC2 line. The birds were challenged at 6 wk of age with a field isolate of washed P. multocida (1.2 x 10(7) organism per bird of capsular serogroup A and somatic serotype 3,4). Mortality was recorded daily for 14 d. Mortality following challenge with P. multocida was higher in the F line than in the C line, and both large-bodied lines had higher mortality than the RBC2 line. Based on the present results and those published in the literature, there may be variation in resistance among commercial sire lines from the three major primary breeders.

Multivariate evaluation of 1-dimensional sarcoplasmic protein profile patterns of turkey breast muscle during early post-hatch development

“…The developmental pattern obtained by the PCA methodology can aid in the planning of more efficient experimental designs so the developmental stage of individuals can be more accurately assessed. the last 30 yr comparing the RBC2 and F line turkeys for various aspects of growth, reproductive fitness, and disease resistance (Nestor et al, 1999a;Nestor et al, 1999b). The F-line turkeys weigh approximately twice as much as the RBC2 at selection age (16 wk), but there are no correlated increases in the proportional weight of the breast muscles.…”

Comparison of heterophil functions of modern commercial and wild-type Rio Grande turkeys

“…Observations in chickens and turkeys have revealed the host immune response has been negatively effected by selection for larger, heavier bodied, faster growing birds with highly improved feed efficiencies (Quereshi & Havenstein, 1994;Nestor et al ., 1999;Li et al ., 1999a,b). The traits of the modern commercial chicken and turkey allow producers to harvest larger, market-ready birds in less time than could be done previously.…”

“…These differences included decreased non-specific phagocytic capabilities, as well as increased populations of CD4 ' /CD8 ( T cells, and an increase in mortality from bacterial infections as compared with random-bred turkeys from the same lines (Li et al ., 1999a(Li et al ., ,b, 2000a(Li et al ., ,b, 2001). Nestor and others have shown through the use of lines of turkeys selected for higher body weights that these turkeys have reduced disease resistance and are more susceptible to infections with Pasteurella and Newcastle disease virus (Tsai et al ., 1992;Nestor et al ., 1999). These studies indicated that the acquired immune response was in large part unaffected by selection for large-bodied turkeys, although some differences were noted (Sacco et al ., 1994;Li et al ., 2001).…”