ABSTRACT:We investigated the effects of lupin (Lupinus angustifolius L.) seed supplementation on egg production performance and egg quality in laying hens. A total of 120 Hy-Line Brown laying hens (29-week old) were used in a nine week trial. Laying hens were sorted into pens with six birds per pen and five pens per treatment. Treatments were (1) control, corn-soybean meal-based control diets, (2) 11% lupin (control + 11% lupin), (3) 16.5% lupin (control + 16.5% lupin), and (4) 22% lupin (control + 22% lupin). The average daily feed intake of laying hens fed with lupin diets was increased compared with control at Week 6 (P < 0.05). The egg production rate was higher in lupin diets than in the control diet at Week 3, 4, and 5 (P < 0.05). Supplementation with lupin improved the egg production rate linearly at Week 3, 4, 5, and 9, as dietary lupin increased from 11 to 22%. Laying hens fed with 11% and 16.5% lupin diets had higher rates of extra-large-sized egg production at Week 1 (quadratic, P = 0.04). Yolk colour was higher in hens fed lupin diets than in those fed with the control at Week 9 (P < 0.05). Supplementation of lupin in laying hen diets linearly improved the yolk colour (P < 0.05) at Week 5. In conclusion, supplementation of the diet with lupin can improve egg production and yolk colour with no apparent effect on average daily feed intake and eggshell quality in laying hens.

Hy-line brown commercial layers (32 weeks old) were used to investigate the effects of GABA (gamma-aminobutyric acid) derived from E. coli strains on productivity, egg quality, and blood profile. In total, 288 birds (1946 ± 0.5 g) were fed four different levels of GABA (0, 25, 50, and 100 ppm), in a basal diet based on corn-soybean meal, for five weeks. Egg production, egg weight, and egg mass during weeks 32 to 36 showed significant improvement, as dietary GABA was increased from 0 to 100 ppm (linear, P < 0.05). Additionally, GABA supplementation was associated with increased eggshell breaking strength and albumen height (quadratic and linear, P < 0.05). Blood variables, such as white blood cells, red blood cells, lymphocyte, cortisol, epinephrine, and norepinephrine concentrations, were not influenced by addition of GABA to the diet; however, the haptoglobin concentration decreased significantly (linearly) and the IgG concentration increased (quadratically) in the GABAfed groups (P < 0.05). These results suggest that diets containing GABA may beneficially affect productivity, egg quality, serum haptoglobin, and IgG concentrations in layers.