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This study investigated the effects of supplementing diets consisting of two dent corn hybrids (soft- and hard-type) with different amounts of rapeseed oil (2, 3, and 4%) and with (0.05%) or without emulsifier (Lysoforte Extended, Kemin) on the content and deposition of carotenoids in egg yolk. The feeding trial was conducted with 216 Lohmann Brown laying hens which were by 3 located in 72 cages. The cages were randomly assigned to 12 dietary treatments (2 hybrids × 3 rapeseed oil levels × 2 emulsifier levels), resulting in 6 cages (replicates) per each dietary treatment. After depletion, hens were fed treatment diets without added pigment for 7 wk. After stabilization of the carotenoid profile (lutein, zeaxanthin, α- and β-cryptoxanthin and β-carotene and total carotenoids), eggs were collected once a week until the end of the experiment and deposition efficiency was calculated based on carotenoid content in yolk and diets, yolk weight, egg production and diet intake. Corn hybrid and rapeseed oil affected (P < 0.05) the yolk content and deposition efficiency of most carotenoids. Moreover, a significant (P < 0.05) hybrid × rapeseed oil level interaction for all carotenoids indicated hybrid-specific responses to rapeseed oil supplementation. In the soft-type hybrid, the addition of 3% rapeseed oil enhanced the carotenoid content compared to 2% of rapeseed oil, whereas for the hard-type hybrid, 2 and 3% of rapeseed oil resulted in similar contents. Supplementation of 4% rapeseed oil reduced the content regardless of the hybrid. Emulsifier addition positively affected (P < 0.05) the deposition efficiency of all carotenoids except β-carotene. In conclusion, supplementing corn diets with rapeseed oil and emulsifier affected carotenoid utilization and these responses varied in hybrids differing in grain hardness, which should be considered when using corn as the sole source of carotenoids in hen diets., Competing Interests: DISCLOSURES The authors declare no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Yolk carotenoid profile reflects the hen diet when corn grain is the only source of carotenoids, but corn origin and processing may affect carotenoid utilization. In the present study, 2 commercial dent corn hybrids differing in grain hardness (soft- and hard-type) were dried at low (40°C) and high (85°C) temperature and ground through a 5- and 9-mm sieve to investigate their effects on carotenoid bioavailability in laying hens. With 3 hens per cage, 168 Lohmann Brown laying hens were allocated to 8 dietary treatments (2 hybrids × 2 drying temperatures × 2 grinding sieves) in a completely randomized design (8 treatments × 7 cages). The trial lasted 8 wk, during which eggs were collected for analysis every 3 d until carotenoid content stabilized, and then once a week until the end of the experiment. The carotenoid profile of the experimental diets and yolks was analyzed using an HPLC method and deposition efficiency was calculated based on carotenoid contents, yolk weight, egg production and diet intake. The deposition efficiency for lutein, zeaxanthin, α- and β-cryptoxanthin, and β-carotene averaged 27.37, 18.67, 6.29, 3,32, and 0.94%, respectively. As expected, the tested hybrids highly affected the carotenoid content in egg yolk due to their differences in carotenoid profile. Interestingly, hard- and soft-type hybrids differed in the deposition efficiency for all individual carotenoids but not for the total carotenoids. High grain drying temperature tended to increase the bioavailability of lutein and zeaxanthin in both hybrids. For the hard-type hybrid, the content of β-carotene in egg yolk was higher when grains were dried at a high temperature, while the opposite response was found in the soft-type hybrid. The effect of grinding sieve size was important for the zeaxanthin bioavailability in the soft-type hybrid only. In conclusion, our findings showed that corn hybrid had a primary influence on the carotenoid content in the yolks of laying hens, but grain processing may change the bioavailability of carotenoids., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The objective of study was to investigate the relationships between maize kernel properties and carotenoid release during simulated gastrointestinal digestion of 103 hybrids of dent type. Commercial maize hybrids significantly differed in kernel hardness, chemical composition and carotenoid profile. Across all hybrids, the amount of digestible individual carotenoids increased as follows: β-carotene < α-cryptoxanthin < β-cryptoxanthin < lutein < zeaxanthin. The amount of digested carotenoids correlated negatively with amylose content and amylose-to-amylopectin ratio, while it correlated positively with the content of neutral detergent fibres and amylopectin as well as the Stenvert index. However, the content of endosperm lipids could not be related to carotenoid digestibility. Findings clearly indicate that the carotenoid release from the kernel during digestion is related to specific physical and chemical properties, leading to a better understanding of the effects of kernel matrix structure on carotenoid digestibility in dent-type maize hybrids., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Carotenoids in maize grain degrade during storage, but the relationship between their stability and the physicochemical properties of the grain is unclear. Therefore, the carotenoid degradation rate in milled grain of three dent hybrids differing in grain hardness was evaluated at various temperatures (-20, 4 and 22 °C). The carotenoid degradation rate was calculated using first-order kinetics based on the content in the samples after 7, 14, 21, 28, 42, 56, 70 and 90 days of storage and related to the physicochemical properties of the grain. The highest grain hardness was found in the hybrid with the highest zein and endosperm lipid concentration, while the lowest grain hardness was found in the hybrid with the highest amylose content and the specific surface area of starch granule (SSA). As expected, carotenoids in milled maize grain were most stable at -20 °C, followed by storage at 4 and 22 °C. Tested hybrids differed in the degradation rate of zeaxanthin, α-cryptoxanthin and β-carotene, and these responses were also temperature-dependent. In contrast, all hybrids showed similar degradation rate for lutein and β-cryptoxanthin regardless of the storage temperature. Averaged over the hybrids, the degradation rate for individual carotenoids ranked as follows: lutein < zeaxanthin < α-cryptoxanthin < β-cryptoxanthin < β-carotene. The lower degradation rate for most carotenoids was mainly associated with a higher content of zein and specific endosperm lipids, with the exception of zeaxanthin, which showed an opposite pattern of response. Degradation rate for lutein and zeaxanthin negatively correlated with SSA, but interestingly, small starch granules were positively associated with higher degradation rate for mostcarotenoids. Dent-type hybrids may differ significantly in carotenoid degradation rate, which was associated with specific physicochemical properties of the maize grain., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Alopecurus myosuroides Huds. is an important pinoxaden-resistant grass weed in many countries of Europe. Recently, the low efficacy of pinoxaden was reported in winter cereals in Croatia, but a preliminary dose-response trial showed no herbicide resistance for the investigated weed population. Therefore, a two-year experiment was conducted under greenhouse conditions to determine the efficacy of various pinoxaden doses (20, 40 and 80 g a.i. ha -1 ) on weed visual injuries and biomass reduction after herbicide application at different growth stages. As expected, the maximum weed biomass reduction (97.3%) was achieved by applying the highest dose (80 g a.i. ha -1 ) at the earliest growth stage (ZCK 12-14). A pinoxaden dose of 20 g a.i. ha -1 resulted in satisfactory weed biomass reduction (88.9%) only when applied at ZCK 12-14. The recommended dose (40 g a.i. ha -1 ) also provided sufficient weed control up to the growth stage ZCK 21-25. Slightly delayed (ZCK 31-32) application of the recommended dose brought about a low weed biomass reduction (60.1%). Double than the recommended dose also failed to provide satisfactory weed control at the advanced weed growth stages (ZCK 31-32 and ZCK 37-39). Thus, reported low efficacy of pinoxaden is most likely because of delayed herbicide application when A. myosuroides is overgrown.