Impact of grape (Vitis vinifera) seed extract on egg production traits, nutrients digestability, lipid peroxidation and fertility of golden laying hens (Gallus gallus) during early stage of production

Grape by-products represent outstanding alternatives to replace conventional and unsustainable feed sources, given the substantial quantities generated annually by the winery industry. Regrettably, the majority of these by-products are wasted, resulting in significant environmental and economic repercussions. This study was conducted to assess the growth performance, feed efficiency, egg production and quality, lipid peroxidation, fertility and hatchability of reproductive laying hens during their early production stage. A total of 720 golden laying hens, all approximately 25 weeks old and with similar body weights, were randomly assigned to four experimental treatments (six replicates) as follows: control group receiving only the standard diet, (2) a group receiving the standard diet supplemented with grape seed extract at a rate of 250 g/kg (GSE1), (3) a group receiving the standarddiet supplemented with grape seed extract at a rate of 500 g/kg (GSE2), and (4) a group receiving the standarddiet supplemented with grape seed extract at a rate of 750 g/kg (GSE3). There were no significant change (p > 0.05) in feed intak, body weight gain and feed conversion ratio between the control and the experimental groups. Egg weight, egg shell thickness and egg shell weight were significantly (p