Dietary interaction of 1,4-diaminobutane (putrescine) and calcium on eggshell quality and performance in laying hens.

An experiment was conducted to evaluate the potential dietary interaction between 1,4-diaminobutane (putrescine) and calcium on eggshell quality and overall laying performance. One hundred ninety-two 30-wk-old White Leghorn hens were fed a corn-and soybean-meal-based diet supplemented with 0.00, 0.05, 0.10, or 0.15% putrescine and 2.5, 3.0, 3.5, or 4.0% calcium in a factorial design (12 birds per diet) for 4 wk. The percentage of egg production increased linearly (P < 0.05) with increasing levels of dietary calcium. Significant interactions (P < 0.05) were observed between dietary putrescine and calcium for eggshell thickness, eggshell deformation, percentage of eggshell, calcium intake, total calcium retention, total eggshell calcium, and percentage of eggshell calcium. Interactions were due to quadratic effects of putrescine or calcium on these parameters. Eggshell thickness and percent eggshell increased when hens were fed 3.5% calcium in combination with 0.1% putrescine; however, calcium intake and calcium retention were significantly lower (P < 0.05). Eggshell quality improved with increasing dietary levels of calcium due to increased calcium retention and calcium balance. Increasing levels of dietary putrescine did not have a negative effect on eggshell quality; however, calcium intake was lower at higher-supplemented levels of putrescine. It was observed that dietary calcium in excess of requirements resulted in increased egg production and eggshell quality. Eggshell quality improved when hens were fed 3.5% calcium diet in combination with 0.10% putrescine. It was concluded that small supplements of dietary putrescine may improve eggshell quality, depending on dietary calcium concentration.