Effects of dietary fat source on lutein, zeaxanthin and total carotenoids content of the egg yolk in laying hens during the early laying period.

1. The study was conducted to investigate the effects of different dietary levels of an unsaturated or saturated fat source and the effects of different dietary energy levels in laying hen diets on the carotenoid content of the egg yolk. 2. Seventy-two ISA Brown laying hens aged 22 weeks old were allocated, for a 10 week period, to three treatments: control diet (HE group) with a 3.4% supplemented fat containing 2.1% soybean and 1.3% palm oil as fat sources and a ratio of unsaturated to saturated fatty acid (u/s) of 3.33; a lowered energy diet with 2.4% supplemented fat containing 1.4% soybean and 1.0% palm oil and u/s of 3.41 (LE+high u/s); a lowered energy diet with 2.4% supplemented fat containing 0.5% soybean and 1.9% palm oil and a u/s of 2.39 (LE+low u/s). A marigold plant extract supplement was used as a source of lutein. 3. Performance parameters (feed consumption, feed conversion, body weight), egg production rate and egg quality parameters were similar between treatments. Dietary fat digestibility at the middle of the study period was not different. Egg yolk total fat content was similar in all treatments at the middle and at the end of the study period. 4. Lutein, zeaxanthin, cis-lutein and total carotenoids content were significantly lower in eggs produced from the LE+low u/s group compared to those from the HE and the LE+high u/s groups (P < 0.01 for all parameters). 5. It was concluded that feeding laying hens with a diet containing 1% less supplemented fat and a lower u/s ratio compared to a control diet and to a diet with 1% less supplemented fat with a higher u/s ratio resulted in a significant reduction of carotenoid expression in the egg yolk at the end of experimental period. Performance and egg quality parameters were not affected by treatments.

Effects of lysolecithin supplementation in low-energy diets on growth performance, nutrient digestibility, viscosity and intestinal morphology of broilers.

1. The study aimed to investigate the effect of lysolecithin supplementation in low-energy diets on growth, nutrient digestibility and intestinal mucosa characteristics of broilers. 2. A total of 800 one-d-old Ross 308 broiler chickens were assigned to 4 dietary treatments consisting of 10 replicates of 20 broilers each. Broilers were fed with 4 different diets: (i) HE: positive control group broilers received a diet with unaltered energy; (ii) LE: negative control group broilers received a diet with lower energy of about 0.27 MJ/kg; (iii) LElys500: broilers received a diet similar to LE supplemented with 500 g/tn lysolecithin product (Lysoforte Booster DryTM); and (iv) LElys300: broilers received a diet similar to LE supplemented with 300 g/tn lysolecithin product. The experimental period was 42 d. 3. Body weight gain in treatments HE was higher than LE during the overall experimental period, while LElys500 and LElys300 had intermediate values. Feed conversion ratio was lower in HE and LElys500 than LE group, while the LElys300 had intermediate values. Fat digestibility was improved in both LElys 500 and LElys300 compared to the HE group. Apparent metabolisable energy (AMEn) was higher in HE, LElys500 and LElys300 than LE. Ileum viscosity at 42 d was also affected, being higher in LE group compared to HE. At 28 d mucosal thickness was lower both in LElys500 and LElys300 compared to HE and LE, while no difference occurred between treatment proliferation patterns of duodenal epithelial cells. 4. These findings indicated that lysolecithin supplementation at 500 g/tn of feed in low-energy diets maintained broiler performance. Supplementation of reformulated low-energy diets induced an increase in digesta viscosity. Lysolecithin supplementation resulted in variable alterations in the duodenum mucosal morphology.

Dietary supplementation with the clay mineral palygorskite affects performance and beneficially modulates caecal microbiota in laying pullets.

AIMS: The objective of this study was twofold: (i) to examine the effect of early-posthatch dietary inclusion of the clay mineral palygorskite on laying pullets' growth and (ii) to determine the potential effects of the latter diet on caecal microbial communities. METHODS AND RESULTS: Four hundred and thirty-two female, 1-day-old Hyline Brown chickens were equally and randomly allocated to two dietary treatment groups; control and palygorskite (0 and 0·5% palygorskite respectively). They were reared in floor pens for 18 weeks. Feed intake, feed conversion ratio, body weight gain and uniformity were assessed. At the end of the rearing period, 53 birds per group were transferred to laying cages without any changes in their respective dietary treatments. At onset of lay, eight birds from each group were euthanized and their caeca were obtained for analysis. Culture-independent and sequencing-based methods were used to analyse caecal microbial composition. CONCLUSIONS: Palygorskite dietary supplementation increased the uniformity of the relative group at the end of the rearing period. Pullets that received palygorskite had different and more homogeneous caecal microbial profiles at onset of lay when compared to controls. Moreover, in the caeca of the former pullets a more favourable microbiota was evident; it comprised largely of bacteria that are major degraders of resistant polysaccharides and efficient in butyrate production. SIGNIFICANCE AND IMPACT OF THE STUDY: The novelty of this study lies to the beneficial effect of palygorskite (a clay mineral) to pullets growth and health, likely through modulation of the gut microbiota.