@article{brake_hamilton_kittrell_2002, title={Effects of the tricothecene mycotoxin diacetoxyscirpenol on egg production of broiler breeders}, volume={81}, ISSN={["0032-5791"]}, DOI={10.1093/ps/81.12.1807}, abstractNote={Three experiments were conducted to determine the effects of 4,15-diacetoxyscirpenol (DAS) on egg quality and egg production of broiler breeders. In Experiment 1, feed containing 0, 1.25, 2.5, or 5.0 mg DAS/ kg was fed from 67 to 69 wk of age followed by a 3-wk recovery period on a slat-litter floor. In Experiment 2, individually caged broiler breeder females were studied from 23 to 31 wk of age. The basal diet containing 0, 5, 10, or 20 mg DAS/kg was fed from 25 to 27 wk of age. In Experiment 3, individually caged broiler breeder hens were studied from 23 to 32 wk of age. DAS was fed at levels of 0 (basal), 5, 10, and 20 mg DAS/kg for 2 wk beginning at Week 24, followed by the basal breeder diet for 7 wk. Egg production was not affected by levels of up to 5 mg DAS/kg in the older hens of Experiment 1. When fed from 25 to 27 wk of age in Experiment 2, DAS decreased egg production at the 20 mg/kg level only. When fed from 24 to 25 wk of age in Experiment 3, DAS had no significant effect on egg production or egg quality. Short-term consumption of DAS at levels that might naturally occur appears to have little effect on broiler breeder egg production.}, number={12}, journal={POULTRY SCIENCE}, author={Brake, J and Hamilton, PB and Kittrell, RS}, year={2002}, month={Dec}, pages={1807–1810} }
 @article{brake_hamilton_kittrell_2000, title={Effects of the trichothecene mycotoxin diacetoxyscirpenol on feed consumption, body weight, and oral lesions of broiler breeders}, volume={79}, ISSN={["0032-5791"]}, DOI={10.1093/ps/79.6.856}, abstractNote={Three experiments were conducted to determine the effects of 4,15-diacetoxyscirpenol (DAS) on BW, feed consumption, and oral lesions of broiler breeders. In Experiment 1, caged broiler breeder hens were fed 0, 5, 10, or 20 mg DAS/kg diet from 24 to 25 wk of age. There were dose-related decreases in BW and feed consumption indicating feed refusal, as well as dose-related increases in the extent of mouth lesions. The areas of the mouth most sensitive to DAS were associated with the salivary glands and the tip of the tongue. In Experiment 2, individually caged male and female broiler breeders were fed a basal diet containing 0, 5, 10, or 20 mg DAS/kg from 25 to 27 wk of age. There were dose-related decreases in BW and feed consumption for the female broiler breeders, whereas there was a decrease in feed consumption for the male broiler breeders at the 10 and 20 mg DAS/kg levels. In Experiment 3, male broiler breeders were fed 0 or 10 mg DAS/kg diet from 23 to 25 wk of age on a litter floor. For this experiment the daily intake of feed was restricted, and the feed consumption rate was measured. There was an increased amount of unconsumed feed at 23 wk of age due to the presence of DAS. In summary, the experiments provided evidence that DAS caused decreased BW and feed consumption as well as cytotoxic injury including oral lesions in broiler breeders.}, number={6}, journal={POULTRY SCIENCE}, author={Brake, J and Hamilton, PB and Kittrell, RS}, year={2000}, month={Jun}, pages={856–863} }
 @article{brake_hamilton_kittrell_1999, title={Effects of the tricothecene mycotoxin diacetoxyscirpenol on fertility and hatchability of broiler breeders}, volume={78}, DOI={10.1093/ps/78.12.1690}, abstractNote={Two experiments were conducted to determine the effects of 4,15-diacetoxyscirpenol (DAS) on fertility and hatchability of broiler breeders. In Experiment 1, naturally mated broiler breeders were studied. A limited daily allocation of feed containing 0 (basal), 1.25, 2.5, or 5.0 mg DAS/kg diet was provided from 67 to 69 wk of age in slat-litter floor pens. Fertility was consistently improved by the 5.0 mg/kg level of DAS and intermittently by the 1.25 and 2.50 mg/kg levels. The effect disappeared upon removal of DAS. In Experiment 2, individually caged broiler breeder males and females were fed a basal diet containing 0, 5, 10, or 20 mg DAS/kg diet from 25 to 27 wk of age. Semen was pooled from males within each treatment and used to inseminate females from each treatment in a 4 x 4 factorial design. Female-related fertility was increased at the 5 and 10 mg DAS/kg levels and male-related fertility was decreased by the 10 and 20 mg DAS/kg levels. Small, fluid-filled cysts were observed on the testes of many DAS-treated males upon necropsy. In summary, low levels of DAS (< or =10 mg DAS/kg) appeared to improve female-related fertility, presumably because of enhanced spermatozoal storage within the oviduct. Conversely, DAS (> or =10 mg DAS/kg) decreased male-related fertility, presumably by direct toxic effects on the testes. Overall, it appeared that levels of DAS below 5 mg DAS/kg feed would not be detrimental to fertility and hatchability.}, number={12}, journal={Poultry Science}, author={Brake, J. and Hamilton, P. B. and Kittrell, R. S.}, year={1999}, pages={1690–1694} }
 @article{qureshi_brundage_hamilton_1998, title={4 beta, 15-diacetoxyscirpenol induces cytotoxicity and alterations in phagocytic and Fc-receptor expression functions in chicken macrophages in vitro}, volume={20}, ISSN={["0892-3973"]}, DOI={10.3109/08923979809031515}, abstractNote={4 beta, 15 Diacetoxyscirpenol (DAS) mycotoxin produced by Fusarium species was tested for detrimental effects on macrophage viability, phagocytosis, and Fc-receptor expression. Sephadex-elicited chicken abdominal cells were harvested to establish adherent macrophage monolayers on glass coverslips. Coverslips were then assigned randomly to treatment groups (0, 12.5 and 25 micrograms/mL DAS). Macrophage monolayers were exposed to treatments for 1 h, washed, and tested for various functional endpoints. Treatment with DAS resulted in decreased viability of macrophages (90.8% vs 81.5% vs 70.4% viable in the 0, 12.5 and 25 micrograms treatments, respectively) and decreased the percentage of macrophages phagocytizing sheep erythrocytes (81.6% vs 53.1% vs 46.0%. DAS also caused a decrease in the mean number of opsonized cells engulfed per phagocytic macrophage (5.7 vs 3.7 vs 2.9). A similar trend was observed using unopsonized sheep erythrocytes (15.4% vs 7.6% vs 5.5% phagocytic macrophages and 0.29 vs 0.11 vs 0.08 erythrocytes engulfed per macrophage). The incidence of Fc-receptor positive macrophages determined by sheep erythrocyte rosetting was also decreased in DAS-treated macrophages as compared to the control (49.2% vs 32.7% vs 24.2%). The findings of this study demonstrate that DAS exposure causes a suppression in macrophage phagocytic function and therefore may alter the first line of immunological defense in chickens.}, number={4}, journal={IMMUNOPHARMACOLOGY AND IMMUNOTOXICOLOGY}, author={Qureshi, MA and Brundage, MA and Hamilton, PB}, year={1998}, pages={541–553} }
 @article{qureshi_brake_hamilton_hagler_nesheim_1998, title={Dietary exposure of broiler breeders to aflatoxin results in immune dysfunction in progeny chicks}, volume={77}, ISSN={["1525-3171"]}, DOI={10.1093/ps/77.6.812}, abstractNote={Broiler breeder hens were fed diets amended with 0 and 10 mg/kg (Trial 1) or 0, 0.2, 1, or 5 mg/kg (Trial 2) of aflatoxin (AF). Fertile eggs collected during 14 d of AF feeding were examined for AF residues. Various immunological endpoints were examined in chicks hatched from these eggs. Eggs collected at 7 d of AF feeding (Trial 1) had 0.15 to 0.48 ng/g of AFB1 and 0.22 to 0.51 ng/g of aflatoxicol, whereas eggs collected at 14 d of AF feeding had 0.05 to 0.60 ng of AFB1/g and 0.19 to 1.20 ng of aflatoxicol/g. In both trials, AF dietary exposure resulted in embryonic mortality and reduction in hatchability compared to controls. The AF progeny chicks in Trial 2 had total anti-SRBC antibodies similar to the controls during the primary antibody response. However, at 5 and 7 d after secondary SRBC injection, the antibody levels in the 1 and 5 mg/kg AF groups were lower than those of controls. Depression in anti-Brucella abortus antibodies occurred only in chicks from the 5 mg/kg AF group. Furthermore, phagocytosis of SRBC and reactive oxygen intermediate production by macrophages from AF progeny chicks were reduced as compared with the control chicks. The findings of this study imply that the progeny chicks from hens consuming a AF-amended diet may be increasingly susceptible to disease owing to suppression of humoral and cellular immunity.}, number={6}, journal={POULTRY SCIENCE}, author={Qureshi, MA and Brake, J and Hamilton, PB and Hagler, WM and Nesheim, S}, year={1998}, month={Jun}, pages={812–819} }
 @article{hamilton_1992, title={THE USE OF HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY FOR STUDYING PIGMENTATION}, volume={71}, ISSN={["0032-5791"]}, DOI={10.3382/ps.0710718}, abstractNote={The use of HPLC has established that chickens possess unexpected metabolic abilities to acylate, deacylate, reduce, and oxidize carotenoids. The use of HPLC permits more consistent and more economic pigmentation of carcasses and of egg yolks. Hopefully, the use of HPLC will raise pigmentation from an art to a science. Apparently, HPLC will be an essential tool in terms of future efforts to understand and master the process of poultry pigmentation.}, number={4}, journal={POULTRY SCIENCE}, author={HAMILTON, PB}, year={1992}, month={Apr}, pages={718-&} }
 @article{hamilton_tirado_garciahernandez_1990, title={DEPOSITION IN EGG-YOLKS OF THE CAROTENOIDS FROM SAPONIFIED AND UNSAPONIFIED OLEORESIN OF RED PEPPER (CAPSICUM-ANNUUM) FED TO LAYING HENS}, volume={69}, ISSN={["0032-5791"]}, DOI={10.3382/ps.0690462}, abstractNote={Abstract The influence of saponification on the deposition in egg yolks of the carotenoids from oleoresin of red pepper (Capsicum annuum) was investigated. Four replicates of 10 hens depleted of carotenoid stores were fed for 3 wk with a basal diet of white corn and soybean meal, amended with saponified (Diet A) or unsaponified (Diet B) oleoresin. The yolks from the eggs collected on Days 0, 7, 14, and 21 were analyzed by reflectance colorimetry and by HPLC. With both diets, the ah (redness), in particular, and the bh (yellowness) increased significantly (P}, number={3}, journal={POULTRY SCIENCE}, author={HAMILTON, PB and TIRADO, FJ and GARCIAHERNANDEZ, F}, year={1990}, month={Mar}, pages={462–470} }
 @article{hamilton_parkhurst_1990, title={IMPROVED DEPOSITION OF OXYCAROTENOIDS IN EGG-YOLKS BY DIETARY COTTONSEED OIL}, volume={69}, ISSN={["0032-5791"]}, DOI={10.3382/ps.0690354}, abstractNote={Abstract The effect of added dietary fat on the pigmentation of egg yolks was investigated by substituting cottonseed oil (0, 2, 4, and 6%) isocalorically for corn starch in a basal diet of white corn, soybean meal, and starch amended with a stabilized, saponified extract of marigold (Tagetes erecta) to provide 70 μg of trans- lutein per g of 0% added fat diet. Two groups of 30 hens per treatment were depleted of carotenoid stores prior to the experiment by feeding the unamended basal diet for 3 wk. After the hens had been fed the experimental diets for 21 days, five replicates of 4 eggs per pen were collected and were analyzed by HPLC for oxycarotenoid content. The diets with 0, 2, 4, and 6% fat yielded egg yolks with 45.42, 68.56, 75.57, and 80.89 μg of total oxycarotenoids per g yolk of which trans-lutein was 75, 76, 76, and 77% of the total, respectively. The minor oxycarotenoids detected were trans-lutein monoesters, trans-3′-oxolutein, trans-zeaxanthin, and cis-luteins. The yolks from hens fed the diets with 0, 2, 4, and 6% fat had scores of 10.3, 12.8, 13.2, and 13.3, respectively, according to the Roche Yolk Colour fan. Most earlier reports of positive, negative, and no effects for added dietary fat on yolk pigmentation can now be reconciled.}, number={2}, journal={POULTRY SCIENCE}, author={HAMILTON, PB and PARKHURST, CR}, year={1990}, month={Feb}, pages={354–359} }