The dietary supplementation of canthaxanthin in combination with 25OHD3 results in reproductive, performance, and progeny quality gains in broiler breeders.

The objective of this study was to evaluate the effects of the dietary supplementation of canthaxanthin and cholecalciferol (25OHD3) to broiler breeders and their progenies on their performance. Eighty 25-wk-old Cobb 500 broiler breeders were distributed according to a completely randomized design in 2 experimental treatments, with 10 replicates of 4 birds each. The treatments consisted of the supplementation or not of a corn-soybean meal diet with canthaxanthin + 25OHD3 to broiler breeders fed from 25 to 62 wk of age. Egg production, fertility, hatchability, hatchability of fertile eggs, embryonic mortality, and egg specific gravity were evaluated. Breeders were inseminated at 35, 45, and 62 wk of age, the eggs were incubated, and the performance of the progenies was evaluated. From the progeny of each breeder age, 300 male chicks were distributed according to a completely randomized design in a 2 × 2 factorial arrangement (chicks from breeders supplemented or not with canthaxanthin + 25OHD3 and chicks supplemented or not with canthaxanthin + 25OHD3), totaling 4 treatments with 5 replicates of 15 birds each. Canthaxanthin + 25OHD3 were supplied to the chicks until 21 D of age. The combination of canthaxanthin and 25OHD3, containing 69 mg of 25OHD3 and 6 g of canthaxanthin, was supplemented at 1 kg/t of feed. Breeders supplemented with canthaxanthin + 25OHD3 showed higher egg production, total hatchability, hatchability of fertile eggs, and lower early embryo mortality compared with those fed the control diet. Broilers from breeders fed canthaxanthin + 25OHD3 and supplemented with this additive up to 21 D of age presented a better feed conversion ratio and higher carcass and breast yields than those derived from nonsupplemented breeders.

Pleural eosinophil infiltration induced by PAF-acether is not a desensitizable phenomenon.

This study investigated the effect of successive daily intrathoracic (it) injections of PAF-acether upon its demonstrated ability to generate eosinochemotaxin(s). Repeated administration of PAF-acether led to a selective state of desensitization, characterized by a gradual reduction of its ability to induce exudation. Concomitantly, however, there was a progressive pleural accumulation of eosinophils leading to a 7-fold increase in the eosinophil counts after the 4th restimulation. The generation of eosinochemotaxin(s) elicited by PAF-acether was not modified by desensitization, as detected by transferring the cell-free pleural fluid from donor to recipient animals. We conclude that, in contrast to exudation, eosinophil tissue infiltration induced by PAF-acether is not a desensitizable phenomenon.

Pleural eosinophil infiltration induced by PAF-acether is not a desensitizable phenomenon

This study investigated the effect of successive daily intrathoracic (it) injections of PAF-acether upon its demonstrated ability to generate eosinochemotaxin(s). Repeated administration of PAF-acether led to a selective state of desensitization, characterized by a gradual reduction of its ability to induce exudation. Concomitantly, however, there was a progressive pleural accumulation of eosinophilis leading to a 7-fold increase in the eosinophil counts after the 4th restimulation. The generation of eosinochemotaxin(s) elicited by PAF-acether was not modified by desensitization, as detected by transferring the cell-free pleural fluid from donor to recipient animals. We conclude that, in contrast to exudation, eosinophil tissue infiltration induced by PAF-acether is not a desensitizable phenomenon