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.

Improved biological value of eggs due to the addition of pomegranate seed oil to laying-hen diets.

In this study, the effects of the addition of pomegranate seed oil (PSO) at different levels (0, 0.5, 1, and 1.5  mL kg - 1 ) to laying-hen rations on performance values, egg quality criteria, egg shelf life, some enzyme activity, and the fatty acid composition of yolks were investigated. In the study, 96 Lohman LSL laying hens at 64 weeks of age were used. The trial consisted of four groups, each containing 24 hens. Chickens were given feed and water ad libitum during the 8-week experiment. The first group was the control group and was fed with a basal diet, while the other groups were fed with feeds with 0.5, 1.0, and 1.5  mL kg - 1 PSO added to the basal feed, respectively. The lowest feed consumption and the highest egg weight were determined in the 1  mL kg - 1 PSO group. The highest feed conversion ratio, the lowest eggshell weight, and the shell-breaking strength were determined in the 0.5  mL kg - 1 PSO group. It was determined that the egg yolk malondialdehyde (MDA) value in the groups to which pomegranate seed oil was added was significantly lower than the control group on the 28th day of storage. The lowest glutation (GSH) and catalase values were found in the control group, and the highest total antioxidant capacity (TAC) was found in the 1  mL kg - 1 PSO group. It was determined that the addition of PSO to the diet significantly increased the rate of saturated fatty acids (SEFA), conjugated linoleic acid (CLA), and conjugated linolenic acids (CLnA) in yolk. The results showed that the addition of 1  mL kg - 1 pomegranate seed oil to the feeds decreased feed consumption, increased egg weight, and positively affected the shelf life of the egg. In short, the addition of PSO had a positive effect on shelf life, and it increased punicic acid and CLA levels without reducing egg quality.