Productive, Qualitative, and Physiological Aspects of Layer Hens Fed with Propolis

The effect of propolis addition to the laying-hen diet on performance, serum lipid profile and liver fat rate

The aim of this study was to evaluate the effect of propolis (P) on performance, egg quality parameters, serum lipid profile, some liver enzymes and liver fat ratio. One-hundred-and-twenty Lohmann (LSL) laying hens were divided into five groups, and each group consisted of six subgroups. The control group was fed basal diet. The other groups were fed high-energy (HE) diets to induce fatty liver syndrome, and 0, 100, 200 and 300 mg kg- 1 of propolis were supplemented with high-energy feeds. During the 8-week trial, feed and water were given ad libitum. It was determined that egg production and feed conversion ratio were decreased in the high-energy feed group without the addition of propolis. The highest egg production was found in HE +  100 and HE +  200 mg kg- 1 of P groups. It was found that liver fat ratios were higher in the group fed with HE +  0 mg kg- 1 of P feed (P < 0.01 ) than other groups. But the addition of P decreased the liver fat rate significantly. The highest very low density lipoprotein (VLDL), triglyceride (TG) and low-density lipoprotein (LDL) values were found for the HE +  0 mg kg- 1 of P group. The addition of 200 mg kg- 1 of P to high-energy feed increased glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) values. In conclusion, high-energy feed adversely affected egg production and liver fat ratio, but the addition of 100 or 200 mg kg- 1 of propolis improved egg production and decreased liver fat ratio.

Royal Jelly Improves the Morphology of the Reproductive Tract, Internal Egg Quality, and Blood Biochemical Parameters in Laying Hens at the Late Stage of Production

The purpose of this study was to evaluate the effects of royal jelly (RJ) on the morphology of the reproductive tract, egg production, and blood biochemical indices of aged laying hens. In total, 120 Lohman Brown laying hens at week 58 of age were randomly assigned into three equal groups. Pure RJ was dissolved in distilled water and injected subcutaneously as follows: the first treatment (R₁; 100 mg RJ kg^-1); the second treatment (R₂; 200 mg RJ kg^-1); the control treatment (CON; 1 mL distilled water). Both RJ-treated groups exhibited a significantly higher number of large yellow follicles (LYFs), small yellow follicles (SYFs), and large white follicles (LWFs) (p ˂ 0.05). Furthermore, RJ treatment significantly increased the diameter and weight of the F1 follicles. However, only the R2 group exhibited significantly greater ovary and uterus weights. RJ treatment did not affect the percentage of oviduct and weight of ovarian stroma. In addition, RJ increased the hen-day egg production rate compared with the CON group; however, only the R₂ group showed greater egg weight (p = 0.032). RJ treatment also improved the albumen height, Haugh units, and yolk index. The administration of RJ significantly decreased the serum glucose, but increased the levels of serum albumen and cholesterol. In conclusion, RJ treatment may improve the morphology of the reproductive tract (including follicular growth and oviduct morphology), egg production rate, and internal egg quality traits of aged laying hens.

Chemical Composition of Volatile Compounds in Apis mellifera Propolis from the Northeast Region of Pará State, Brazil

Propolis is a balsamic product obtained from vegetable resins by exotic Africanized bees Apis mellifera L., transported and processed by them, originating from the activity that explores and maintains these individuals. Because of its vegetable and natural origins, propolis is a complex mixture of different compound classes; among them are the volatile compounds present in the aroma. In this sense, in the present study we evaluated the volatile fraction of propolis present in the aroma obtained by distillation and simultaneous extraction, and its chemical composition was determined using coupled gas chromatography, mass spectrometry, and flame ionization detection. The majority of compounds were sesquiterpene and hydrocarbons, comprising 8.2-22.19% α-copaene and 6.2-21.7% β-caryophyllene, with additional compounds identified in greater concentrations. Multivariate analysis showed that samples collected from one region may have different chemical compositions, which may be related to the location of the resin's production. This may be related to other bee products.

Reporting of thermography parameters in biology: a systematic review of thermal imaging literature

Infrared (IR) thermography, where temperature measurements are made with IR cameras, has proven to be a very useful and widely used tool in biological science. Several thermography parameters are critical to the proper operation of thermal cameras and the accuracy of measurements, and these must usually be provided to the camera. Failure to account for these parameters may lead to less accurate measurements. Furthermore, the failure to provide information of parameter choices in reports may compromise appraisal of accuracy and replicate studies. In this review, we investigate how well biologists report thermography parameters. This is done through a systematic review of biological thermography literature that included articles published between years 2007 and 2017. We found that in primary biological thermography papers, which make some kind of quantitative temperature measurement, 48% fail to report values used for emissivity (an object's capacity to emit thermal radiation relative to a black body radiator), which is the minimum level of reporting that should take place. This finding highlights the need for life scientists to take into account and report key parameter information when carrying out thermography, in the future.