&nbsp;A 2 &times; 3 factorial design experiment was conducted to evaluate the effect of adding lycopene <br />(0 and 75 mg/kg) and vitamin E (0.50 and 100 mg/kg) to the diet of chickens. Moreover, the study investigated growth traits, oxidative stability and chemical composition of leg meat and the vitamin content of meat and liver. The study was conducted using five hundred and forty Ross 308 male broilers that were assigned to one of the six dietary treatments. Significant interactions between lycopene and vitamin E additions affected the body weight of 21-days-old chickens (P = 0.005), the malondialdehyde content in fresh leg meat (P &lt; 0.001) and leg meat stored for 3 days at temperatures of 2.5 to 4&deg;C (P = 0.032), the cholesterol content in leg meat (P &lt; 0.001) and the lycopene content in liver (P = 0.006). The chickens with the highest body weight were fed 75 mg/kg of lycopene and 50 mg/kg of vitamin E. The vitamin E supplement increased the oxidative stability of fresh and stored leg muscle (P &lt; 0.001). The lowest mean cholesterol value (3.49 g/kg of dry matter) was found out in the meat from broilers that were fed 75 mg/kg of lycopene in contrast to broilers fed the control treatment without lycopene (3.93 g/kg of dry matter). Dietary vitamin E significantly reduced the fat content (P = 0.033) and increased the ash content of&nbsp;leg meat. The highest lycopene concentration in liver (2.82 mg/kg of dry matter) was in chickens that were fed the highest levels of vitamin E and lycopene in contrast with the control group (0.28 mg/kg of dry matter). &nbsp;

The effect of hempseed in the diet of laying hens was evaluated at 0, 30, 60 and 90 g/kg concentrations. The aim of the study was to determine the effect of dietary treatment on the performance of hens, the physical characteristics of egg quality, the concentrations of α- and γ-tocopherol and the carotenoid and cholesterol contents of egg yolks, together with the breaking strength of tibial measurements. In light of the obtained results, our study aimed to address the optimal dietary level of hempseed in laying hen diets. Lohmann Brown hens (n = 240) were divided into 4 dietary treatment groups (6 cages per treatment) with 10 hens per cage. The experiment lasted for 12 weeks. The level of nutrients in all diets (wheat-corn) was well balanced. The dietary metabolisable energy was adjusted using rapeseed oil. The addition of 30 g/kg of hempseed to the diet significantly increased (P˂0.001) egg production and egg mass. Alpha-tocopherol increased significantly (P = 0.002) only in the case of the 60 g/kg hempseed level (101 mg/kg dry matter (DM) versus 83 mg/ kg DM in the control group). In contrast, the level of γ-tocopherol increased gradually from 11 mg/kg DM in the control to 29, 39 and 43 mg/kg DM at the 30, 60 and 90 g/kg levels of dietary hempseed, respectively. The concentrations of beta carotene, zeaxanthin and lutein in egg yolks were not influenced by the dietary treatment. Hempseed at 90 g/kg (P = 0.036) decreased egg shell thickness without affecting its strength. The addition of hempseed decreased (P˂0.001) the cholesterol concentration in the egg yolks in all experimental groups. The addition of 30, 60 and 90 g hempseed increased (P˂0.001) the breaking strength of the tibia to 354, 352 and 350 N, respectively, compared to 297 N in the control group. The highest level of hempseed in the diet positively influenced the Ca concentration in the tibia (P = 0.021). The concentration of P in the tibia was negatively affected in the 60 to 90 g/kg hempseed treatments (P˂0.001). Eggs are a significant source of α-tocopherol. Based on our results, there is a possibility for enrichment of egg yolks with γ-tocopherol, with all of its associated health benefits, by the addition of hempseed to the diet of laying hens. Another significant benefit of hempseed is its effect on the breaking strength of the tibia, which can help with crucial problems in the commercial breeding of laying hens.

ABSTRACT:Two experiments conducted on laying hens, aged 50 and 52 weeks, were carried out to evaluate the effect of dietary Mg and its relationship to the Ca : NPP (non-phytate phosphorus) ratio using a various grain-size of limestone. The Ca : NPP ratio in each experiment was 12.8 and 18, respectively. Two Mg levels were evalued in the first (1.56 and 4.0 g/kg) and the second experiment (1.52 and 4.0 g/kg). A fine-grained limestone (< 0.5 mm; FL) or a coarse-grained limestone (0.8-2 mm; CL) was used in the first experiment. In the second experiment, a mixture of both the aforementioned limestone forms (FCL) was used as the third alternative. The main parameters estimated in this study were egg production and egg shell breaking strength. In the first experiment, CL significantly increased hen-day egg production (P = 0.043) and Mg (in dietary concentration up to 4 g/kg) increased egg weight (P < 0.001). The addition of Mg to the mixed feed, together with CL, decreased yolk percentage (P = 0.008), increased egg shell percentage (P = 0.044), increased egg shell thickness (P = 0.014), and egg shell breaking strength (P = 0.003). Higher dietary Mg, together with a wider Ca : NPP ratio in the second experiment, increased egg production and egg weight (P < 0.001), but it did not influence egg shell breaking strength. CL increased egg shell breaking strength compared to the addition of FL, as well as FCL (P < 0.05), regardless of the Mg levels. Lower level of Mg with FL decreased ash content of shells (P = 0.004).

The purpose of the experiment was to determine how the addition of dehydrated alfalfa (DA) and ascorbic acid (AA) into the diet of hens influences the performance characteristics and egg quality characterised by physical parameters, yolk carotenoid content, and the oxidative stability of yolks. Two hundred and forty Hisex Brown hens were divided into 6 treatment groups according to the level of DA (0 and 40 g/kg) and concentration of AA (0, 100, and 200 mg/kg) in the diet. Hen-day egg production and egg mass production were reduced by the supplement of DA (P &lt; 0.001) and AA (P = 0.017). The addition of DA itself increased the feed intake per egg (P &lt; 0.001) and the feed conversion ratio (P &lt; 0.001). The heaviest eggs (P &lt; 0.001) were laid by hens fed a diet with 100 mg/kg of AA (67.6 g). The AA supplement improved egg content quality, i.e., Haugh units (P &lt; 0.001), albumen index (P &lt; 0.001), and yolk index (P &lt; 0.001), whereas the addition of DA increased values of yolk colour (P &lt; 0.001) and had a negative effect on shell quality. The interaction of DA and AA was detected in the zeaxanthin concentration in the yolks (P = 0.002). The highest concentration was found in eggs from hens fed a diet with a DA supplement and 100 or 200 mg/kg of AA (17.33 or 17.25 mg/kg dry matter of yolk). In addition, 40 g/kg of DA significantly increased the concentration of other carotenoids, lutein (P &lt; 0.001) and β-carotene (P &lt; 0.001) in the yolks and increased the oxidative stability of fresh eggs (P &lt; 0.001). The results suggest that adding DA in the amount of 40 g/kg to the hen diet provides a good source of carotenoids and, in combination with AA, a better deposition of carotenoids in egg yolks. On the other hand, DA deteriorates performance and shell quality.